ignore already published

Fixes a bug in the kernel memory allocator where the space used by the
`MemoryRoot` wasn't being considered

---------

Co-authored-by: Benjamin Eckel <bhelx@users.noreply.github.com>

.github/workflows/release-rust.yaml

@@ -19,17 +19,21 @@ jobs:
           override: true
           target: ${{ matrix.target }}
 
-      - name: Release Rust Host SDK
+      - name: Release Rust Manifest Crate
         env:
           CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_API_TOKEN }}
         run: |
           # order of crate publication matter: manifest, runtime, rust
-
           cargo publish --manifest-path manifest/Cargo.toml
           # allow for crates.io to update so dependant crates can locate extism-manifest
           sleep 5 
 
-          cargo publish --manifest-path runtime/Cargo.toml --no-verify
+      - name: Release Rust Host SDK
+        if: always()
+        env:
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_API_TOKEN }}
+        run: |
+          #cargo publish --manifest-path runtime/Cargo.toml --no-verify
           cargo publish --manifest-path rust/Cargo.toml
       
   

.gitignore

@@ -30,6 +30,7 @@ rust/test.log
 duniverse
 _build
 php/Extism.php
+python/docs
 dist-newstyle
 .stack-work
 vendor

Cargo.toml

@@ -4,5 +4,5 @@ members = [
   "runtime",
   "rust",
   "libextism",
-  "elixir/native/extism_nif"
 ]
+exclude = ["kernel"]

Makefile

@@ -21,6 +21,10 @@ endif
 build:
 	cargo build --release $(FEATURE_FLAGS) --manifest-path libextism/Cargo.toml
 
+.PHONY: kernel
+kernel:
+	cd kernel && bash build.sh
+
 lint:
 	cargo clippy --release --no-deps --manifest-path runtime/Cargo.toml
 

browser/index.html

@@ -103,7 +103,11 @@
         }
 
         async loadFunctions(url) {
-            let plugin = await this.extismContext.newPlugin({ "wasm": [ { "path": url } ] }) 
+            let helloWorld = function(index){
+              console.log("Hello, " + this.allocator.getString(index));
+              return index;
+            };
+            let plugin = await this.extismContext.newPlugin({ "wasm": [ { "path": url } ] }, {"hello_world": helloWorld});
             let functions = Object.keys(await plugin.getExports())
             console.log("funcs ", functions)
             this.setState({functions})
@@ -135,7 +139,13 @@
 
         async handleOnRun(e) {
           e && e.preventDefault && e.preventDefault();
-          let plugin = await this.extismContext.newPlugin({ "wasm": [ { "path": this.state.url } ] }) 
+          let helloWorld = function(index){
+            console.log("Hello, " + this.allocator.getString(index));
+            return index;
+          };
+          let plugin = await this.extismContext.newPlugin({ "wasm": [ { "path": this.state.url } ] }, {
+              "hello_world": helloWorld
+          });
           let result = await plugin.call(this.state.func_name, this.state.input)
           let output = result
           this.setState({output})

browser/package-lock.json

@@ -1,15 +1,15 @@
 {
   "name": "@extism/runtime-browser",
-  "version": "0.2.2",
+  "version": "0.3.0",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@extism/runtime-browser",
-      "version": "0.2.2",
+      "version": "0.3.0",
       "license": "BSD-3-Clause",
       "dependencies": {
-        "@bjorn3/browser_wasi_shim": "^0.2.1"
+        "@bjorn3/browser_wasi_shim": "^0.2.7"
       },
       "devDependencies": {
         "@types/jest": "^29.2.2",
@@ -568,9 +568,9 @@
       "dev": true
     },
     "node_modules/@bjorn3/browser_wasi_shim": {
-      "version": "0.2.1",
-      "resolved": "https://registry.npmjs.org/@bjorn3/browser_wasi_shim/-/browser_wasi_shim-0.2.1.tgz",
-      "integrity": "sha512-QBI2VPoCksV+bN47v1edbFC0td1nXvEhK3i1oTrByKOnLG39RoxZR2KmLByR/6S+8ivAf2E4pWhqRRZsBWItyQ=="
+      "version": "0.2.7",
+      "resolved": "https://registry.npmjs.org/@bjorn3/browser_wasi_shim/-/browser_wasi_shim-0.2.7.tgz",
+      "integrity": "sha512-ONBGleCpaH5HC4MLLkUmLz69xA28HQIbvwsdA1WTMXvjyhOWXR7jVrC0DkYr/iRqmkNMBZtEVVZWm1L6ZAnJvw=="
     },
     "node_modules/@cnakazawa/watch": {
       "version": "1.0.4",
@@ -7618,9 +7618,9 @@
       }
     },
     "node_modules/tough-cookie": {
-      "version": "4.1.2",
-      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.1.2.tgz",
-      "integrity": "sha512-G9fqXWoYFZgTc2z8Q5zaHy/vJMjm+WV0AkAeHxVCQiEB1b+dGvWzFW6QV07cY5jQ5gRkeid2qIkzkxUnmoQZUQ==",
+      "version": "4.1.3",
+      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.1.3.tgz",
+      "integrity": "sha512-aX/y5pVRkfRnfmuX+OdbSdXvPe6ieKX/G2s7e98f4poJHnqH3281gDPm/metm6E/WRamfx7WC4HUqkWHfQHprw==",
       "dev": true,
       "dependencies": {
         "psl": "^1.1.33",
@@ -8108,9 +8108,9 @@
       }
     },
     "node_modules/word-wrap": {
-      "version": "1.2.3",
-      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.3.tgz",
-      "integrity": "sha512-Hz/mrNwitNRh/HUAtM/VT/5VH+ygD6DV7mYKZAtHOrbs8U7lvPS6xf7EJKMF0uW1KJCl0H701g3ZGus+muE5vQ==",
+      "version": "1.2.4",
+      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.4.tgz",
+      "integrity": "sha512-2V81OA4ugVo5pRo46hAoD2ivUJx8jXmWXfUkY4KFNw0hEptvN0QfH3K4nHiwzGeKl5rFKedV48QVoqYavy4YpA==",
       "dev": true,
       "engines": {
         "node": ">=0.10.0"
@@ -8681,9 +8681,9 @@
       "dev": true
     },
     "@bjorn3/browser_wasi_shim": {
-      "version": "0.2.1",
-      "resolved": "https://registry.npmjs.org/@bjorn3/browser_wasi_shim/-/browser_wasi_shim-0.2.1.tgz",
-      "integrity": "sha512-QBI2VPoCksV+bN47v1edbFC0td1nXvEhK3i1oTrByKOnLG39RoxZR2KmLByR/6S+8ivAf2E4pWhqRRZsBWItyQ=="
+      "version": "0.2.7",
+      "resolved": "https://registry.npmjs.org/@bjorn3/browser_wasi_shim/-/browser_wasi_shim-0.2.7.tgz",
+      "integrity": "sha512-ONBGleCpaH5HC4MLLkUmLz69xA28HQIbvwsdA1WTMXvjyhOWXR7jVrC0DkYr/iRqmkNMBZtEVVZWm1L6ZAnJvw=="
     },
     "@cnakazawa/watch": {
       "version": "1.0.4",
@@ -13986,9 +13986,9 @@
       }
     },
     "tough-cookie": {
-      "version": "4.1.2",
-      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.1.2.tgz",
-      "integrity": "sha512-G9fqXWoYFZgTc2z8Q5zaHy/vJMjm+WV0AkAeHxVCQiEB1b+dGvWzFW6QV07cY5jQ5gRkeid2qIkzkxUnmoQZUQ==",
+      "version": "4.1.3",
+      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.1.3.tgz",
+      "integrity": "sha512-aX/y5pVRkfRnfmuX+OdbSdXvPe6ieKX/G2s7e98f4poJHnqH3281gDPm/metm6E/WRamfx7WC4HUqkWHfQHprw==",
       "dev": true,
       "requires": {
         "psl": "^1.1.33",
@@ -14334,9 +14334,9 @@
       }
     },
     "word-wrap": {
-      "version": "1.2.3",
-      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.3.tgz",
-      "integrity": "sha512-Hz/mrNwitNRh/HUAtM/VT/5VH+ygD6DV7mYKZAtHOrbs8U7lvPS6xf7EJKMF0uW1KJCl0H701g3ZGus+muE5vQ==",
+      "version": "1.2.4",
+      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.4.tgz",
+      "integrity": "sha512-2V81OA4ugVo5pRo46hAoD2ivUJx8jXmWXfUkY4KFNw0hEptvN0QfH3K4nHiwzGeKl5rFKedV48QVoqYavy4YpA==",
       "dev": true
     },
     "wrap-ansi": {

browser/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@extism/runtime-browser",
-  "version": "0.2.2",
+  "version": "0.3.0",
   "description": "Extism runtime in the browser",
   "scripts": {
     "build": "node build.js && tsc --emitDeclarationOnly --outDir dist",
@@ -34,6 +34,6 @@
     "typescript": "^4.8.4"
   },
   "dependencies": {
-    "@bjorn3/browser_wasi_shim": "^0.2.1"
+    "@bjorn3/browser_wasi_shim": "^0.2.7"
   }
 }

browser/src/context.ts

@@ -1,5 +1,5 @@
 import { Manifest, PluginConfig, ManifestWasmFile, ManifestWasmData } from './manifest';
-import ExtismPlugin from './plugin';
+import { ExtismPlugin } from './plugin';
 
 /**
  * Can be a {@link Manifest} or just the raw bytes of the WASM module as an ArrayBuffer.
@@ -20,7 +20,7 @@ export default class ExtismContext {
    * @param config - Config details for the plugin
    * @returns A new Plugin scoped to this Context
    */
-  async newPlugin(manifest: ManifestData, config?: PluginConfig) {
+  async newPlugin(manifest: ManifestData, functions: Record<string, any> = {}, config?: PluginConfig) {
     let moduleData: ArrayBuffer | null = null;
     if (manifest instanceof ArrayBuffer) {
       moduleData = manifest;
@@ -40,6 +40,6 @@ export default class ExtismContext {
       throw Error(`Unsure how to interpret manifest ${manifest}`);
     }
 
-    return new ExtismPlugin(moduleData, config);
+    return new ExtismPlugin(moduleData, functions, config);
   }
 }

browser/src/index.test.ts

@@ -19,6 +19,6 @@ describe('', () => {
     // expect(parse(output)).toEqual({ count: 7 });
     // output = await plugin.call('count_vowels', 'this is a test thrice');
     // expect(parse(output)).toEqual({ count: 6 });
-    expect(true).toEqual(true)
+    expect(true).toEqual(true);
   });
 });

browser/src/index.ts

@@ -1,3 +1,4 @@
 import ExtismContext from './context';
+import { ExtismFunction, ExtismPlugin } from './plugin';
 
-export { ExtismContext };
+export { ExtismContext, ExtismFunction, ExtismPlugin };

browser/src/plugin.ts

@@ -1,9 +1,10 @@
 import Allocator from './allocator';
 import { PluginConfig } from './manifest';
-//@ts-ignore TODO add types to this library
-import { WASI, File } from "@bjorn3/browser_wasi_shim";
+import { WASI, Fd } from '@bjorn3/browser_wasi_shim';
 
-export default class ExtismPlugin {
+export type ExtismFunction = any;
+
+export class ExtismPlugin {
   moduleData: ArrayBuffer;
   allocator: Allocator;
   config?: PluginConfig;
@@ -11,14 +12,16 @@ export default class ExtismPlugin {
   input: Uint8Array;
   output: Uint8Array;
   module?: WebAssembly.WebAssemblyInstantiatedSource;
+  functions: Record<string, ExtismFunction>;
 
-  constructor(moduleData: ArrayBuffer, config?: PluginConfig) {
+  constructor(moduleData: ArrayBuffer, functions: Record<string, ExtismFunction> = {}, config?: PluginConfig) {
     this.moduleData = moduleData;
     this.allocator = new Allocator(1024 * 1024);
     this.config = config;
     this.vars = {};
     this.input = new Uint8Array();
     this.output = new Uint8Array();
+    this.functions = functions;
   }
 
   async getExports(): Promise<WebAssembly.Exports> {
@@ -65,26 +68,31 @@ export default class ExtismPlugin {
     const environment = this.makeEnv();
     const args: Array<string> = [];
     const envVars: Array<string> = [];
-    let fds = [
-        new File([]), // stdin
-        new File([]), // stdout
-        new File([]), // stderr
+    let fds: Fd[] = [
+      // new XtermStdio(term), // stdin
+      // new XtermStdio(term), // stdout
+      // new XtermStdio(term), // stderr
     ];
     let wasi = new WASI(args, envVars, fds);
     let env = {
       wasi_snapshot_preview1: wasi.wasiImport,
-      env: environment
+      env: environment,
     };
     this.module = await WebAssembly.instantiate(this.moduleData, env);
+    // normally we would call wasi.start here but it doesn't respect when there is
+    // no _start function
+    //@ts-ignore
+    wasi.inst = this.module.instance;
     if (this.module.instance.exports._start) {
-      wasi.start(this.module.instance);
+      //@ts-ignore
+      this.module.instance.exports._start();
     }
     return this.module;
   }
 
   makeEnv(): any {
     const plugin = this;
-    return {
+    var env: any = {
       extism_alloc(n: bigint): bigint {
         return plugin.allocator.alloc(n);
       },
@@ -183,5 +191,13 @@ export default class ExtismPlugin {
         console.error(s);
       },
     };
+
+    for (const [name, func] of Object.entries(this.functions)) {
+      env[name] = function () {
+        return func.apply(plugin, arguments);
+      };
+    }
+
+    return env;
   }
 }

cpp/example.cpp

@@ -15,7 +15,6 @@ std::vector<uint8_t> read(const char *filename) {
 
 int main(int argc, char *argv[]) {
   auto wasm = read("../wasm/code-functions.wasm");
-  Context context = Context();
   std::string tmp = "Testing";
 
   // A lambda can be used as a host function
@@ -34,7 +33,7 @@ int main(int argc, char *argv[]) {
                [](void *x) { std::cout << "Free user data" << std::endl; }),
   };
 
-  Plugin plugin = context.plugin(wasm, true, functions);
+  Plugin plugin(wasm, true, functions);
 
   const char *input = argc > 1 ? argv[1] : "this is a test";
   ExtismSize length = strlen(input);

cpp/extism.hpp

@@ -342,9 +342,10 @@ class Plugin {
 
 public:
   // Create a new plugin
-  Plugin(std::shared_ptr<ExtismContext> ctx, const uint8_t *wasm,
-         ExtismSize length, bool with_wasi = false,
-         std::vector<Function> functions = std::vector<Function>())
+  Plugin(const uint8_t *wasm, ExtismSize length, bool with_wasi = false,
+         std::vector<Function> functions = std::vector<Function>(),
+         std::shared_ptr<ExtismContext> ctx = std::shared_ptr<ExtismContext>(
+             extism_context_new(), extism_context_free))
       : functions(functions) {
     std::vector<const ExtismFunction *> ptrs;
     for (auto i : this->functions) {
@@ -359,6 +360,19 @@ public:
     this->context = ctx;
   }
 
+  Plugin(const std::string &str, bool with_wasi = false,
+         std::vector<Function> functions = {},
+         std::shared_ptr<ExtismContext> ctx = std::shared_ptr<ExtismContext>(
+             extism_context_new(), extism_context_free))
+      : Plugin((const uint8_t *)str.c_str(), str.size(), with_wasi, functions,
+               ctx) {}
+
+  Plugin(const std::vector<uint8_t> &data, bool with_wasi = false,
+         std::vector<Function> functions = {},
+         std::shared_ptr<ExtismContext> ctx = std::shared_ptr<ExtismContext>(
+             extism_context_new(), extism_context_free))
+      : Plugin(data.data(), data.size(), with_wasi, functions, ctx) {}
+
   CancelHandle cancel_handle() {
     return CancelHandle(
         extism_plugin_cancel_handle(this->context.get(), this->id()));
@@ -366,8 +380,10 @@ public:
 
 #ifndef EXTISM_NO_JSON
   // Create a new plugin from Manifest
-  Plugin(std::shared_ptr<ExtismContext> ctx, const Manifest &manifest,
-         bool with_wasi = false, std::vector<Function> functions = {}) {
+  Plugin(const Manifest &manifest, bool with_wasi = false,
+         std::vector<Function> functions = {},
+         std::shared_ptr<ExtismContext> ctx = std::shared_ptr<ExtismContext>(
+             extism_context_new(), extism_context_free)) {
     std::vector<const ExtismFunction *> ptrs;
     for (auto i : this->functions) {
       ptrs.push_back(i.get());
@@ -506,28 +522,28 @@ public:
   // Create plugin from uint8_t*
   Plugin plugin(const uint8_t *wasm, size_t length, bool with_wasi = false,
                 std::vector<Function> functions = {}) const {
-    return Plugin(this->pointer, wasm, length, with_wasi, functions);
+    return Plugin(wasm, length, with_wasi, functions, this->pointer);
   }
 
   // Create plugin from std::string
   Plugin plugin(const std::string &str, bool with_wasi = false,
                 std::vector<Function> functions = {}) const {
-    return Plugin(this->pointer, (const uint8_t *)str.c_str(), str.size(),
-                  with_wasi, functions);
+    return Plugin((const uint8_t *)str.c_str(), str.size(), with_wasi,
+                  functions, this->pointer);
   }
 
   // Create plugin from uint8_t vector
   Plugin plugin(const std::vector<uint8_t> &data, bool with_wasi = false,
                 std::vector<Function> functions = {}) const {
-    return Plugin(this->pointer, data.data(), data.size(), with_wasi,
-                  functions);
+    return Plugin(data.data(), data.size(), with_wasi, functions,
+                  this->pointer);
   }
 
 #ifndef EXTISM_NO_JSON
   // Create plugin from Manifest
   Plugin plugin(const Manifest &manifest, bool with_wasi = false,
                 std::vector<Function> functions = {}) const {
-    return Plugin(this->pointer, manifest, with_wasi, functions);
+    return Plugin(manifest, with_wasi, functions, this->pointer);
   }
 #endif
 

cpp/test/test.cpp

@@ -21,21 +21,19 @@ TEST(Context, Basic) {
 }
 
 TEST(Plugin, Manifest) {
-  Context context;
   Manifest manifest = Manifest::path(code);
   manifest.set_config("a", "1");
 
-  ASSERT_NO_THROW(Plugin plugin = context.plugin(manifest));
-  Plugin plugin = context.plugin(manifest);
+  ASSERT_NO_THROW(Plugin plugin(manifest));
+  Plugin plugin(manifest);
 
   Buffer buf = plugin.call("count_vowels", "this is a test");
   ASSERT_EQ((std::string)buf, "{\"count\": 4}");
 }
 
 TEST(Plugin, BadManifest) {
-  Context context;
   Manifest manifest;
-  ASSERT_THROW(Plugin plugin = context.plugin(manifest), Error);
+  ASSERT_THROW(Plugin plugin(manifest), Error);
 }
 
 TEST(Plugin, Bytes) {
@@ -68,7 +66,6 @@ TEST(Plugin, FunctionExists) {
 }
 
 TEST(Plugin, HostFunction) {
-  Context context;
   auto wasm = read("../../wasm/code-functions.wasm");
   auto t = std::vector<ValType>{ValType::I64};
   Function hello_world =
@@ -82,7 +79,7 @@ TEST(Plugin, HostFunction) {
   auto functions = std::vector<Function>{
       hello_world,
   };
-  Plugin plugin = context.plugin(wasm, true, functions);
+  Plugin plugin(wasm, true, functions);
   auto buf = plugin.call("count_vowels", "aaa");
   ASSERT_EQ(buf.length, 4);
   ASSERT_EQ((std::string)buf, "test");

dotnet/nuget/Extism.runtime.win.csproj

@@ -1,24 +1,24 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-    <PropertyGroup>
-        <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
-        <NoBuild>true</NoBuild>
-        <IncludeBuildOutput>false</IncludeBuildOutput>
-    </PropertyGroup>
+  <PropertyGroup>
+    <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
+    <NoBuild>true</NoBuild>
+    <IncludeBuildOutput>false</IncludeBuildOutput>
+  </PropertyGroup>
 
-    <PropertyGroup>
-        <PackageId>Extism.runtime.win-x64</PackageId>
-        <Version>0.4.0</Version>
-        <Authors>Extism Contributors</Authors>
-        <Description>Internal implementation package for Extism to work on Windows x64</Description>
-        <Tags>extism, wasm, plugin</Tags>
-        <PackageLicenseExpression>BSD-3-Clause</PackageLicenseExpression>
-    </PropertyGroup>
+  <PropertyGroup>
+    <PackageId>Extism.runtime.win-x64</PackageId>
+    <Version>0.7.0</Version>
+    <Authors>Extism Contributors</Authors>
+    <Description>Internal implementation package for Extism to work on Windows x64</Description>
+    <Tags>extism, wasm, plugin</Tags>
+    <PackageLicenseExpression>BSD-3-Clause</PackageLicenseExpression>
+  </PropertyGroup>
 
-    <ItemGroup>
-        <Content Include="runtimes/win-x64.dll"
-            CopyToOutputDirectory="Always"
-            Pack="true"
-            PackagePath="runtimes\win-x64\native\extism.dll" />
-    </ItemGroup>
+  <ItemGroup>
+    <Content Include="runtimes/win-x64.dll"
+      CopyToOutputDirectory="Always"
+      Pack="true"
+      PackagePath="runtimes\win-x64\native\extism.dll" />
+  </ItemGroup>
 </Project>

dotnet/samples/Extism.Sdk.Sample/Extism.Sdk.Sample.csproj

@@ -1,21 +1,29 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
-    <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>enable</Nullable>
-  </PropertyGroup>
+	<PropertyGroup>
+		<OutputType>Exe</OutputType>
+		<TargetFramework>net7.0</TargetFramework>
+		<ImplicitUsings>enable</ImplicitUsings>
+		<Nullable>enable</Nullable>
+		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+	</PropertyGroup>
 
-  <ItemGroup>
-    <None Include="..\..\..\wasm\code.wasm" Link="code.wasm">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </None>
-  </ItemGroup>
+	<ItemGroup>
+		<None Include="..\..\..\wasm\code.wasm" Link="code.wasm">
+			<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+		</None>
+		<None Include="..\..\..\wasm\code-functions.wasm" Link="code-functions.wasm">
+			<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+		</None>
+	</ItemGroup>
 
-  <ItemGroup>
-    <ProjectReference Include="..\..\src\Extism.Sdk\Extism.Sdk.csproj" />
-  </ItemGroup>
+	<ItemGroup>
+		<PackageReference Include="Extism.runtime.win-x64" Version="0.4.0" />
+	</ItemGroup>
+
+	<ItemGroup>
+		<ProjectReference Include="..\..\src\Extism.Sdk\Extism.Sdk.csproj" />
+	</ItemGroup>
 
 
-</Project>
+</Project>

dotnet/samples/Extism.Sdk.Sample/Program.cs

@@ -1,11 +1,40 @@
+using Extism.Sdk;
 using Extism.Sdk.Native;
+
+using System.Runtime.InteropServices;
 using System.Text;
 
 var context = new Context();
-var wasm = await File.ReadAllBytesAsync("./code.wasm");
-using var plugin = context.CreatePlugin(wasm, withWasi: true);
+
+var userData = Marshal.StringToHGlobalAnsi("Hello again!");
+
+using var helloWorld = new HostFunction(
+    "hello_world",
+    "env",
+    new[] { ExtismValType.I64 },
+    new[] { ExtismValType.I64 },
+    userData,
+    HelloWorld);
+
+void HelloWorld(CurrentPlugin plugin, Span<ExtismVal> inputs, Span<ExtismVal> outputs, nint data)
+{
+    Console.WriteLine("Hello from .NET!");
+
+    var text = Marshal.PtrToStringAnsi(data);
+    Console.WriteLine(text);
+
+    var input = plugin.ReadString(new nint(inputs[0].v.i64));
+    Console.WriteLine($"Input: {input}");
+
+    outputs[0].v.i64 = plugin.WriteString(input);
+}
+
+var wasm = File.ReadAllBytes("./code-functions.wasm");
+using var plugin = context.CreatePlugin(wasm, new[] { helloWorld }, withWasi: true);
 
 var output = Encoding.UTF8.GetString(
     plugin.CallFunction("count_vowels", Encoding.UTF8.GetBytes("Hello World!"))
 );
-Console.WriteLine(output); // prints {"count": 3}
+
+Console.WriteLine($"Output: {output}");
+

dotnet/src/Extism.Sdk/Context.cs

@@ -1,3 +1,4 @@
+using System.Collections.Concurrent;
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.InteropServices;
 
@@ -6,8 +7,10 @@ namespace Extism.Sdk.Native;
 /// <summary>
 /// Represents an Extism context through which you can load <see cref="Plugin"/>s.
 /// </summary>
-public class Context : IDisposable
+public unsafe class Context : IDisposable
 {
+    private readonly ConcurrentDictionary<int, Plugin> _plugins = new ConcurrentDictionary<int, Plugin>();
+
     private const int DisposedMarker = 1;
 
     private int _disposed;
@@ -17,33 +20,63 @@ public class Context : IDisposable
     /// </summary>
     public Context()
     {
-        NativeHandle = LibExtism.extism_context_new();
+        unsafe
+        {
+            NativeHandle = LibExtism.extism_context_new();
+        }
     }
 
     /// <summary>
     /// Native pointer to the Extism Context.
     /// </summary>
-    internal IntPtr NativeHandle { get; }
+    internal LibExtism.ExtismContext* NativeHandle { get; }
 
     /// <summary>
     /// Loads an Extism <see cref="Plugin"/>.
     /// </summary>
     /// <param name="wasm">A WASM module (wat or wasm) or a JSON encoded manifest.</param>
+    /// <param name="functions">List of host functions expected by the plugin.</param>
     /// <param name="withWasi">Enable/Disable WASI.</param>
-    public Plugin CreatePlugin(ReadOnlySpan<byte> wasm, bool withWasi)
+    public Plugin CreatePlugin(ReadOnlySpan<byte> wasm, HostFunction[] functions, bool withWasi)
     {
         CheckNotDisposed();
 
+        var functionHandles = functions.Select(f => f.NativeHandle).ToArray();
+
         unsafe
         {
             fixed (byte* wasmPtr = wasm)
+            fixed (IntPtr* functionsPtr = functionHandles)
             {
-                var plugin = LibExtism.extism_plugin_new(NativeHandle, wasmPtr, wasm.Length, null, 0, withWasi);
-                return new Plugin(this, plugin);
+                var index = LibExtism.extism_plugin_new(NativeHandle, wasmPtr, wasm.Length, functionsPtr, functions.Length, withWasi);
+                if (index == -1)
+                {
+                    var errorMsg = GetError();
+                    if (errorMsg != null)
+                    {
+                        throw new ExtismException(errorMsg);
+                    }
+                    else
+                    {
+                        throw new ExtismException("Failed to create plugin.");
+                    }
+                }
+
+                return _plugins[index] = new Plugin(this, functions, index);
             }
         }
     }
 
+    /// <summary>
+    /// Get a plugin by index.
+    /// </summary>
+    /// <param name="index">Index of plugin.</param>
+    /// <returns></returns>
+    public Plugin GetPlugin(int index)
+    {
+        return _plugins[index];
+    }
+
     /// <summary>
     /// Remove all plugins from this <see cref="Context"/>'s registry.
     /// </summary>
@@ -110,6 +143,11 @@ public class Context : IDisposable
             // Free up any managed resources here
         }
 
+        foreach (var plugin in _plugins.Values)
+        {
+            plugin.Dispose();
+        }
+
         // Free up unmanaged resources
         LibExtism.extism_context_free(NativeHandle);
     }
@@ -151,34 +189,3 @@ public class Context : IDisposable
         return LibExtism.extism_log_file(logPath, logLevel);
     }
 }
-
-/// <summary>
-/// Extism Log Levels
-/// </summary>
-public enum LogLevel
-{
-    /// <summary>
-    /// Designates very serious errors.
-    /// </summary>
-    Error,
-
-    /// <summary>
-    /// Designates hazardous situations.
-    /// </summary>
-    Warning,
-
-    /// <summary>
-    /// Designates useful information.
-    /// </summary>
-    Info,
-
-    /// <summary>
-    /// Designates lower priority information.
-    /// </summary>
-    Debug,
-
-    /// <summary>
-    /// Designates very low priority, often extremely verbose, information.
-    /// </summary>
-    Trace
-}

dotnet/src/Extism.Sdk/CurrentPlugin.cs

@@ -0,0 +1,138 @@
+using Extism.Sdk.Native;
+
+using System.Text;
+
+namespace Extism.Sdk
+{
+    /// <summary>
+    /// Represents the current plugin. Can only be used within <see cref="HostFunction"/>s.
+    /// </summary>
+    public class CurrentPlugin
+    {
+        internal CurrentPlugin(nint nativeHandle)
+        {
+            NativeHandle = nativeHandle;
+        }
+
+        internal nint NativeHandle { get; }
+
+        /// <summary>
+        /// Returns a pointer to the memory of the currently running plugin.
+        /// NOTE: this should only be called from host functions.
+        /// </summary>
+        /// <returns></returns>
+        public nint GetMemory()
+        {
+            return LibExtism.extism_current_plugin_memory(NativeHandle);
+        }
+
+        /// <summary>
+        /// Reads a string from a memory block using UTF8.
+        /// </summary>
+        /// <param name="pointer"></param>
+        /// <returns></returns>
+        public string ReadString(nint pointer)
+        {
+            return ReadString(pointer, Encoding.UTF8);
+        }
+
+        /// <summary>
+        /// Reads a string form a memory block.
+        /// </summary>
+        /// <param name="pointer"></param>
+        /// <param name="encoding"></param>
+        /// <returns></returns>
+        public string ReadString(nint pointer, Encoding encoding)
+        {
+            var buffer = ReadBytes(pointer);
+
+            return encoding.GetString(buffer);
+        }
+
+        /// <summary>
+        /// Returns a span of bytes for a given block.
+        /// </summary>
+        /// <param name="pointer"></param>
+        /// <returns></returns>
+        public unsafe Span<byte> ReadBytes(nint pointer)
+        {
+            var mem = GetMemory();
+            var length = (int)BlockLength(pointer);
+            var ptr = (byte*)mem + pointer;
+
+            return new Span<byte>(ptr, length);
+        }
+
+        /// <summary>
+        /// Writes a string into the current plugin memory using UTF-8 encoding and returns the pointer of the block.
+        /// </summary>
+        /// <param name="value"></param>
+        public nint WriteString(string value)
+            => WriteString(value, Encoding.UTF8);
+
+        /// <summary>
+        /// Writes a string into the current plugin memory and returns the pointer of the block.
+        /// </summary>
+        /// <param name="value"></param>
+        /// <param name="encoding"></param>
+        public nint WriteString(string value, Encoding encoding)
+        {
+            var bytes = encoding.GetBytes(value);
+            var pointer = AllocateBlock(bytes.Length);
+            WriteBytes(pointer, bytes);
+
+            return pointer;
+        }
+
+        /// <summary>
+        /// Writes a byte array into a block of memory.
+        /// </summary>
+        /// <param name="pointer"></param>
+        /// <param name="bytes"></param>
+        public unsafe void WriteBytes(nint pointer, Span<byte> bytes)
+        {
+            var length = BlockLength(pointer);
+            if (length < bytes.Length)
+            {
+                throw new InvalidOperationException("Destination block length is less than source block length.");
+            }
+
+            var mem = GetMemory();
+            var ptr = (void*)(mem + pointer);
+            var destination = new Span<byte>(ptr, bytes.Length);
+
+            bytes.CopyTo(destination);
+        }
+
+        /// <summary>
+        /// Frees a block of memory belonging to the current plugin.
+        /// </summary>
+        /// <param name="pointer"></param>
+        public void FreeBlock(nint pointer)
+        {
+            LibExtism.extism_current_plugin_memory_free(NativeHandle, pointer);
+        }
+
+        /// <summary>
+        /// Allocate a memory block in the currently running plugin.
+        /// 
+        /// </summary>
+        /// <param name="length"></param>
+        /// <returns></returns>
+        public nint AllocateBlock(long length)
+        {
+            return LibExtism.extism_current_plugin_memory_alloc(NativeHandle, length);
+        }
+
+        /// <summary>
+        /// Get the length of an allocated block.
+        /// NOTE: this should only be called from host functions.
+        /// </summary>
+        /// <param name="pointer"></param>
+        /// <returns></returns>
+        public long BlockLength(nint pointer)
+        {
+            return LibExtism.extism_current_plugin_memory_length(NativeHandle, pointer);
+        }
+    }
+}

dotnet/src/Extism.Sdk/Extism.Sdk.csproj

@@ -1,28 +1,28 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-	<PropertyGroup>
-		<TargetFramework>netstandard2.1</TargetFramework>
-		<ImplicitUsings>enable</ImplicitUsings>
-		<Nullable>enable</Nullable>
-		<AllowUnsafeBlocks>True</AllowUnsafeBlocks>
-		<LangVersion>10</LangVersion>
-	</PropertyGroup>
+  <PropertyGroup>
+    <TargetFramework>netstandard2.1</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+    <LangVersion>10</LangVersion>
+  </PropertyGroup>
 
-	<PropertyGroup>
-		<PackageId>Extism.Sdk</PackageId>
-		<Version>0.3.0</Version>
-		<Authors>Extism Contributors</Authors>
-		<Description>Extism SDK that allows hosting Extism plugins in .NET apps.</Description>
-		<Tags>extism, wasm, plugin</Tags>
-		<PackageLicenseExpression>BSD-3-Clause</PackageLicenseExpression>
-		<PackageReadmeFile>README.md</PackageReadmeFile>
-	</PropertyGroup>
+  <PropertyGroup>
+    <PackageId>Extism.Sdk</PackageId>
+    <Version>0.7.0</Version>
+    <Authors>Extism Contributors</Authors>
+    <Description>Extism SDK that allows hosting Extism plugins in .NET apps.</Description>
+    <Tags>extism, wasm, plugin</Tags>
+    <PackageLicenseExpression>BSD-3-Clause</PackageLicenseExpression>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+  </PropertyGroup>
 
-	<ItemGroup>
-		<None Include="README.md" Pack="true" PackagePath="\"/>
-	</ItemGroup>
+  <ItemGroup>
+    <None Include="README.md" Pack="true" PackagePath="\" />
+  </ItemGroup>
 
-	<ItemGroup>
-		<PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="6.0.0" />
-	</ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="6.0.0" />
+  </ItemGroup>
 </Project>

dotnet/src/Extism.Sdk/ExtismException.cs

@@ -28,7 +28,7 @@ public class ExtismException : Exception
     /// with a specified error message and a reference to the inner exception
     /// that is the cause of this exception.
     /// </summary>
-    /// <param name="message">The message that describes the error .</param>
+    /// <param name="message">The message that describes the error.</param>
     /// <param name="innerException">
     ///  The exception that is the cause of the current exception, or a null reference
     ///  (Nothing in Visual Basic) if no inner exception is specified.

dotnet/src/Extism.Sdk/HostFunction.cs

@@ -0,0 +1,146 @@
+using Extism.Sdk.Native;
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace Extism.Sdk
+{
+    /// <summary>
+    /// A host function signature.
+    /// </summary>
+    /// <param name="plugin">Plugin Index</param>
+    /// <param name="inputs">Input parameters</param>
+    /// <param name="outputs">Output parameters, the host function can change this.</param>
+    /// <param name="userData">A data passed in during Host Function creation.</param>
+    public delegate void ExtismFunction(CurrentPlugin plugin, Span<ExtismVal> inputs, Span<ExtismVal> outputs, IntPtr userData);
+
+    /// <summary>
+    /// A function provided by the host that plugins can call.
+    /// </summary>
+    public class HostFunction : IDisposable
+    {
+        private const int DisposedMarker = 1;
+        private int _disposed;
+
+        /// <summary>
+        /// Registers a Host Function.
+        /// </summary>
+        /// <param name="functionName">The literal name of the function, how it would be called from a <see cref="Plugin"/>.</param>
+        /// <param name="inputTypes">The types of the input arguments/parameters the <see cref="Plugin"/> caller will provide.</param>
+        /// <param name="outputTypes">The types of the output returned from the host function to the <see cref="Plugin"/>.</param>
+        /// <param name="userData">An opaque pointer to an object from the host, accessible to the <see cref="Plugin"/>.
+        /// NOTE: it is the shared responsibility of the host and <see cref="Plugin"/> to cast/dereference this value properly.</param>
+        /// <param name="hostFunction"></param>
+        public HostFunction(
+            string functionName,
+            Span<ExtismValType> inputTypes,
+            Span<ExtismValType> outputTypes,
+            IntPtr userData,
+            ExtismFunction hostFunction) :
+            this(functionName, "", inputTypes, outputTypes, userData, hostFunction)
+        {
+
+        }
+
+        /// <summary>
+        /// Registers a Host Function.
+        /// </summary>
+        /// <param name="functionName">The literal name of the function, how it would be called from a <see cref="Plugin"/>.</param>
+        /// <param name="namespace">Function namespace.</param>
+        /// <param name="inputTypes">The types of the input arguments/parameters the <see cref="Plugin"/> caller will provide.</param>
+        /// <param name="outputTypes">The types of the output returned from the host function to the <see cref="Plugin"/>.</param>
+        /// <param name="userData">An opaque pointer to an object from the host, accessible to the <see cref="Plugin"/>.
+        /// NOTE: it is the shared responsibility of the host and <see cref="Plugin"/> to cast/dereference this value properly.</param>
+        /// <param name="hostFunction"></param>
+        unsafe public HostFunction(
+            string functionName,
+            string @namespace,
+            Span<ExtismValType> inputTypes,
+            Span<ExtismValType> outputTypes,
+            IntPtr userData,
+            ExtismFunction hostFunction)
+        {
+            fixed (ExtismValType* inputs = inputTypes)
+            fixed (ExtismValType* outputs = outputTypes)
+            {
+                NativeHandle = LibExtism.extism_function_new(functionName, inputs, inputTypes.Length, outputs, outputTypes.Length, CallbackImpl, userData, IntPtr.Zero);
+            }
+
+            if (!string.IsNullOrEmpty(@namespace))
+            {
+                LibExtism.extism_function_set_namespace(NativeHandle, @namespace);
+            }
+
+            void CallbackImpl(
+                nint plugin,
+                ExtismVal* inputsPtr,
+                uint n_inputs,
+                ExtismVal* outputsPtr,
+                uint n_outputs,
+                IntPtr data)
+            {
+                var outputs = new Span<ExtismVal>(outputsPtr, (int)n_outputs);
+                var inputs = new Span<ExtismVal>(inputsPtr, (int)n_inputs);
+
+                hostFunction(new CurrentPlugin(plugin), inputs, outputs, data);
+            }
+        }
+
+        internal IntPtr NativeHandle { get; }
+
+        /// <summary>
+        /// Frees all resources held by this Host Function.
+        /// </summary>
+        public void Dispose()
+        {
+            if (Interlocked.Exchange(ref _disposed, DisposedMarker) == DisposedMarker)
+            {
+                // Already disposed.
+                return;
+            }
+
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        /// <summary>
+        /// Throw an appropriate exception if the Host Function has been disposed.
+        /// </summary>
+        /// <exception cref="ObjectDisposedException"></exception>
+        protected void CheckNotDisposed()
+        {
+            Interlocked.MemoryBarrier();
+            if (_disposed == DisposedMarker)
+            {
+                ThrowDisposedException();
+            }
+        }
+
+        [DoesNotReturn]
+        private static void ThrowDisposedException()
+        {
+            throw new ObjectDisposedException(nameof(HostFunction));
+        }
+
+        /// <summary>
+        /// Frees all resources held by this Host Function.
+        /// </summary>
+        unsafe protected virtual void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                // Free up any managed resources here
+            }
+
+            // Free up unmanaged resources
+            LibExtism.extism_function_free(NativeHandle);
+        }
+
+        /// <summary>
+        /// Destructs the current Host Function and frees all resources used by it.
+        /// </summary>
+        ~HostFunction()
+        {
+            Dispose(false);
+        }
+    }
+}

dotnet/src/Extism.Sdk/LibExtism.cs

@@ -2,24 +2,197 @@ using System.Runtime.InteropServices;
 
 namespace Extism.Sdk.Native;
 
+/// <summary>
+/// A union type for host function argument/return values.
+/// </summary>
+[StructLayout(LayoutKind.Explicit)]
+public struct ExtismValUnion
+{
+    /// <summary>
+    /// Set this for 32 bit integers
+    /// </summary>
+    [FieldOffset(0)]
+    public int i32;
+
+    /// <summary>
+    /// Set this for 64 bit integers
+    /// </summary>
+    [FieldOffset(0)]
+    public long i64;
+
+    /// <summary>
+    /// Set this for 32 bit floats
+    /// </summary>
+    [FieldOffset(0)]
+    public float f32;
+
+    /// <summary>
+    /// Set this for 64 bit floats
+    /// </summary>
+    [FieldOffset(0)]
+    public double f64;
+}
+
+/// <summary>
+/// Represents Wasm data types that Extism can understand
+/// </summary>
+public enum ExtismValType : byte
+{
+    /// <summary>
+    /// Signed 32 bit integer. Equivalent of <see cref="int"/> or <see cref="uint"/>
+    /// </summary>
+    I32,
+
+    /// <summary>
+    /// Signed 64 bit integer. Equivalent of <see cref="long"/> or <see cref="ulong"/>
+    /// </summary>
+    I64,
+
+    /// <summary>
+    /// Floating point 32 bit integer. Equivalent of <see cref="float"/>
+    /// </summary>
+    F32,
+
+    /// <summary>
+    /// Floating point 64 bit integer. Equivalent of <see cref="double"/>
+    /// </summary>
+    F64,
+
+    /// <summary>
+    /// A 128 bit number.
+    /// </summary>
+    V128,
+
+    /// <summary>
+    /// A reference to opaque data in the Wasm instance.
+    /// </summary>
+    FuncRef,
+
+    /// <summary>
+    /// A reference to opaque data in the Wasm instance.
+    /// </summary>
+    ExternRef
+}
+
+/// <summary>
+/// `ExtismVal` holds the type and value of a function argument/return
+/// </summary>
+[StructLayout(LayoutKind.Sequential)]
+public struct ExtismVal
+{
+    /// <summary>
+    /// The type for the argument
+    /// </summary>
+    public ExtismValType t;
+
+    /// <summary>
+    /// The value for the argument
+    /// </summary>
+    public ExtismValUnion v;
+}
+
 /// <summary>
 /// Functions exposed by the native Extism library.
 /// </summary>
 internal static class LibExtism
 {
+    /// <summary>
+    /// A `Context` is used to store and manage plugins.
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct ExtismContext { }
+
+    /// <summary>
+    /// Host function signature
+    /// </summary>
+    /// <param name="plugin"></param>
+    /// <param name="inputs"></param>
+    /// <param name="n_inputs"></param>
+    /// <param name="outputs"></param>
+    /// <param name="n_outputs"></param>
+    /// <param name="data"></param>
+    unsafe internal delegate void InternalExtismFunction(nint plugin, ExtismVal* inputs, uint n_inputs, ExtismVal* outputs, uint n_outputs, IntPtr data);
+
+    /// <summary>
+    /// Returns a pointer to the memory of the currently running plugin.
+    /// NOTE: this should only be called from host functions.
+    /// </summary>
+    /// <param name="plugin"></param>
+    /// <returns></returns>
+    [DllImport("extism", EntryPoint = "extism_current_plugin_memory")]
+    internal static extern IntPtr extism_current_plugin_memory(nint plugin);
+
+    /// <summary>
+    /// Allocate a memory block in the currently running plugin
+    /// </summary>
+    /// <param name="plugin"></param>
+    /// <param name="n"></param>
+    /// <returns></returns>
+    [DllImport("extism", EntryPoint = "extism_current_plugin_memory_alloc")]
+    internal static extern IntPtr extism_current_plugin_memory_alloc(nint plugin, long n);
+
+    /// <summary>
+    /// Get the length of an allocated block.
+    /// NOTE: this should only be called from host functions.
+    /// </summary>
+    /// <param name="plugin"></param>
+    /// <param name="n"></param>
+    /// <returns></returns>
+    [DllImport("extism", EntryPoint = "extism_current_plugin_memory_length")]
+    internal static extern long extism_current_plugin_memory_length(nint plugin, long n);
+
+    /// <summary>
+    /// Get the length of an allocated block.
+    /// NOTE: this should only be called from host functions.
+    /// </summary>
+    /// <param name="plugin"></param>
+    /// <param name="ptr"></param>
+    [DllImport("extism", EntryPoint = "extism_current_plugin_memory_free")]
+    internal static extern void extism_current_plugin_memory_free(nint plugin, IntPtr ptr);
+
+    /// <summary>
+    /// Create a new host function.
+    /// </summary>
+    /// <param name="name">function name, this should be valid UTF-8</param>
+    /// <param name="inputs">argument types</param>
+    /// <param name="nInputs">number of argument types</param>
+    /// <param name="outputs">return types</param>
+    /// <param name="nOutputs">number of return types</param>
+    /// <param name="func">the function to call</param>
+    /// <param name="userData">a pointer that will be passed to the function when it's called this value should live as long as the function exists</param>
+    /// <param name="freeUserData">a callback to release the `user_data` value when the resulting `ExtismFunction` is freed.</param>
+    /// <returns></returns>
+    [DllImport("extism", EntryPoint = "extism_function_new")]
+    unsafe internal static extern IntPtr extism_function_new(string name, ExtismValType* inputs, long nInputs, ExtismValType* outputs, long nOutputs, InternalExtismFunction func, IntPtr userData, IntPtr freeUserData);
+
+    /// <summary>
+    /// Set the namespace of an <see cref="ExtismFunction"/>
+    /// </summary>
+    /// <param name="ptr"></param>
+    /// <param name="namespace"></param>
+    [DllImport("extism", EntryPoint = "extism_function_set_namespace")]
+    internal static extern void extism_function_set_namespace(IntPtr ptr, string @namespace);
+
+    /// <summary>
+    /// Free an <see cref="ExtismFunction"/>
+    /// </summary>
+    /// <param name="ptr"></param>
+    [DllImport("extism", EntryPoint = "extism_function_free")]
+    internal static extern void extism_function_free(IntPtr ptr);
+
     /// <summary>
     /// Create a new context.
     /// </summary>
     /// <returns>A pointer to the newly created context.</returns>
     [DllImport("extism")]
-    public static extern IntPtr extism_context_new();
+    unsafe internal static extern ExtismContext* extism_context_new();
 
     /// <summary>
     /// Remove a context from the registry and free associated memory.
     /// </summary>
     /// <param name="context"></param>
     [DllImport("extism")]
-    public static extern void extism_context_free(IntPtr context);
+    unsafe internal static extern void extism_context_free(ExtismContext* context);
 
     /// <summary>
     /// Load a WASM plugin.
@@ -32,7 +205,7 @@ internal static class LibExtism
     /// <param name="withWasi">Enables/disables WASI.</param>
     /// <returns></returns>
     [DllImport("extism")]
-    unsafe public static extern IntPtr extism_plugin_new(IntPtr context, byte* wasm, int wasmSize, IntPtr *functions, int nFunctions, bool withWasi);
+    unsafe internal static extern int extism_plugin_new(ExtismContext* context, byte* wasm, int wasmSize, IntPtr* functions, int nFunctions, bool withWasi);
 
     /// <summary>
     /// Update a plugin, keeping the existing ID.
@@ -42,13 +215,13 @@ internal static class LibExtism
     /// <param name="context">Pointer to the context the plugin is associated with.</param>
     /// <param name="plugin">Pointer to the plugin you want to update.</param>
     /// <param name="wasm">A WASM module (wat or wasm) or a JSON encoded manifest.</param>
-    /// <param name="wasmLength">The length of the `wasm` parameter.</param>
+    /// <param name="wasmSize">The length of the `wasm` parameter.</param>
     /// <param name="functions">Array of host function pointers.</param>
     /// <param name="nFunctions">Number of host functions.</param>
     /// <param name="withWasi">Enables/disables WASI.</param>
     /// <returns></returns>
     [DllImport("extism")]
-    unsafe public static extern bool extism_plugin_update(IntPtr context, IntPtr plugin, byte* wasm, int wasmLength, IntPtr *functions, int nFunctions, bool withWasi);
+    unsafe internal static extern bool extism_plugin_update(ExtismContext* context, int plugin, byte* wasm, long wasmSize, Span<IntPtr> functions, long nFunctions, bool withWasi);
 
     /// <summary>
     /// Remove a plugin from the registry and free associated memory.
@@ -56,14 +229,14 @@ internal static class LibExtism
     /// <param name="context">Pointer to the context the plugin is associated with.</param>
     /// <param name="plugin">Pointer to the plugin you want to free.</param>
     [DllImport("extism")]
-    public static extern void extism_plugin_free(IntPtr context, IntPtr plugin);
+    unsafe internal static extern void extism_plugin_free(ExtismContext* context, int plugin);
 
     /// <summary>
     /// Remove all plugins from the registry.
     /// </summary>
     /// <param name="context"></param>
     [DllImport("extism")]
-    public static extern void extism_context_reset(IntPtr context);
+    unsafe internal static extern void extism_context_reset(ExtismContext* context);
 
     /// <summary>
     /// Update plugin config values, this will merge with the existing values.
@@ -74,7 +247,7 @@ internal static class LibExtism
     /// <param name="jsonLength">The length of the `json` parameter.</param>
     /// <returns></returns>
     [DllImport("extism")]
-    unsafe public static extern bool extism_plugin_config(IntPtr context, IntPtr plugin, byte* json, int jsonLength);
+    unsafe internal static extern bool extism_plugin_config(ExtismContext* context, int plugin, byte* json, int jsonLength);
 
     /// <summary>
     /// Returns true if funcName exists.
@@ -84,7 +257,7 @@ internal static class LibExtism
     /// <param name="funcName"></param>
     /// <returns></returns>
     [DllImport("extism")]
-    public static extern bool extism_plugin_function_exists(IntPtr context, IntPtr plugin, string funcName);
+    unsafe internal static extern bool extism_plugin_function_exists(ExtismContext* context, int plugin, string funcName);
 
     /// <summary>
     /// Call a function.
@@ -96,7 +269,7 @@ internal static class LibExtism
     /// <param name="dataLen">The length of the `data` parameter.</param>
     /// <returns></returns>
     [DllImport("extism")]
-    unsafe public static extern int extism_plugin_call(IntPtr context, IntPtr plugin, string funcName, byte* data, int dataLen);
+    unsafe internal static extern int extism_plugin_call(ExtismContext* context, int plugin, string funcName, byte* data, int dataLen);
 
     /// <summary>
     /// Get the error associated with a Context or Plugin, if plugin is -1 then the context error will be returned.
@@ -105,7 +278,7 @@ internal static class LibExtism
     /// <param name="plugin">A plugin pointer, or -1 for the context error.</param>
     /// <returns></returns>
     [DllImport("extism")]
-    public static extern IntPtr extism_error(IntPtr context, nint plugin);
+    unsafe internal static extern IntPtr extism_error(ExtismContext* context, nint plugin);
 
     /// <summary>
     /// Get the length of a plugin's output data.
@@ -114,7 +287,7 @@ internal static class LibExtism
     /// <param name="plugin"></param>
     /// <returns></returns>
     [DllImport("extism")]
-    public static extern long extism_plugin_output_length(IntPtr context, IntPtr plugin);
+    unsafe internal static extern long extism_plugin_output_length(ExtismContext* context, int plugin);
 
     /// <summary>
     /// Get the plugin's output data.
@@ -123,7 +296,7 @@ internal static class LibExtism
     /// <param name="plugin"></param>
     /// <returns></returns>
     [DllImport("extism")]
-    public static extern IntPtr extism_plugin_output_data(IntPtr context, IntPtr plugin);
+    unsafe internal static extern IntPtr extism_plugin_output_data(ExtismContext* context, int plugin);
 
     /// <summary>
     /// Set log file and level.
@@ -132,43 +305,43 @@ internal static class LibExtism
     /// <param name="logLevel"></param>
     /// <returns></returns>
     [DllImport("extism")]
-    public static extern bool extism_log_file(string filename, string logLevel);
+    internal static extern bool extism_log_file(string filename, string logLevel);
 
     /// <summary>
     /// Get the Extism version string.
     /// </summary>
     /// <returns></returns>
     [DllImport("extism", EntryPoint = "extism_version")]
-    public static extern IntPtr extism_version();
+    internal static extern IntPtr extism_version();
 
     /// <summary>
     /// Extism Log Levels
     /// </summary>
-    public static class LogLevels
+    internal static class LogLevels
     {
         /// <summary>
         /// Designates very serious errors.
         /// </summary>
-        public const string Error = "Error";
+        internal const string Error = "Error";
 
         /// <summary>
         /// Designates hazardous situations.
         /// </summary>
-        public const string Warn = "Warn";
+        internal const string Warn = "Warn";
 
         /// <summary>
         /// Designates useful information.
         /// </summary>
-        public const string Info = "Info";
+        internal const string Info = "Info";
 
         /// <summary>
         /// Designates lower priority information.
         /// </summary>
-        public const string Debug = "Debug";
+        internal const string Debug = "Debug";
 
         /// <summary>
         /// Designates very low priority, often extremely verbose, information.
         /// </summary>
-        public const string Trace = "Trace";
+        internal const string Trace = "Trace";
     }
-}
+}

dotnet/src/Extism.Sdk/LogLevel.cs

@@ -0,0 +1,32 @@
+namespace Extism.Sdk.Native;
+
+/// <summary>
+/// Extism Log Levels
+/// </summary>
+public enum LogLevel
+{
+    /// <summary>
+    /// Designates very serious errors.
+    /// </summary>
+    Error,
+
+    /// <summary>
+    /// Designates hazardous situations.
+    /// </summary>
+    Warning,
+
+    /// <summary>
+    /// Designates useful information.
+    /// </summary>
+    Info,
+
+    /// <summary>
+    /// Designates lower priority information.
+    /// </summary>
+    Debug,
+
+    /// <summary>
+    /// Designates very low priority, often extremely verbose, information.
+    /// </summary>
+    Trace
+}

dotnet/src/Extism.Sdk/Plugin.cs

@@ -11,18 +11,32 @@ public class Plugin : IDisposable
     private const int DisposedMarker = 1;
 
     private readonly Context _context;
+    private readonly HostFunction[] _functions;
     private int _disposed;
 
-    internal Plugin(Context context, IntPtr handle)
+    /// <summary>
+    /// Create a and load a plug-in
+    /// Using this constructor will give the plug-in it's own internal Context
+    /// </summary>
+    /// <param name="wasm">A WASM module (wat or wasm) or a JSON encoded manifest.</param>
+    /// <param name="functions">List of host functions expected by the plugin.</param>
+    /// <param name="withWasi">Enable/Disable WASI.</param>
+    public static Plugin Create(ReadOnlySpan<byte> wasm, HostFunction[] functions, bool withWasi) {
+        var context = new Context();
+        return context.CreatePlugin(wasm, functions, withWasi);
+    }
+
+    internal Plugin(Context context, HostFunction[] functions, int index)
     {
         _context = context;
-        NativeHandle = handle;
+        _functions = functions;
+        Index = index;
     }
 
     /// <summary>
     /// A pointer to the native Plugin struct.
     /// </summary>
-    internal IntPtr NativeHandle { get; }
+    internal int Index { get; }
 
     /// <summary>
     /// Update a plugin, keeping the existing ID.
@@ -33,9 +47,10 @@ public class Plugin : IDisposable
     {
         CheckNotDisposed();
 
+        var functions = _functions.Select(f => f.NativeHandle).ToArray();
         fixed (byte* wasmPtr = wasm)
         {
-            return LibExtism.extism_plugin_update(_context.NativeHandle, NativeHandle, wasmPtr, wasm.Length, null, 0, withWasi);
+            return LibExtism.extism_plugin_update(_context.NativeHandle, Index, wasmPtr, wasm.Length, functions, 0, withWasi);
         }
     }
 
@@ -49,18 +64,18 @@ public class Plugin : IDisposable
 
         fixed (byte* jsonPtr = json)
         {
-            return LibExtism.extism_plugin_config(_context.NativeHandle, NativeHandle, jsonPtr, json.Length);
+            return LibExtism.extism_plugin_config(_context.NativeHandle, Index, jsonPtr, json.Length);
         }
     }
 
     /// <summary>
     /// Checks if a specific function exists in the current plugin.
     /// </summary>
-    public bool FunctionExists(string name)
+    unsafe public bool FunctionExists(string name)
     {
         CheckNotDisposed();
 
-        return LibExtism.extism_plugin_function_exists(_context.NativeHandle, NativeHandle, name);
+        return LibExtism.extism_plugin_function_exists(_context.NativeHandle, Index, name);
     }
 
     /// <summary>
@@ -78,14 +93,20 @@ public class Plugin : IDisposable
 
         fixed (byte* dataPtr = data)
         {
-            int response = LibExtism.extism_plugin_call(_context.NativeHandle, NativeHandle, functionName, dataPtr, data.Length);
-            if (response == 0) {
+            int response = LibExtism.extism_plugin_call(_context.NativeHandle, Index, functionName, dataPtr, data.Length);
+            if (response == 0)
+            {
                 return OutputData();
-            } else {
+            }
+            else
+            {
                 var errorMsg = GetError();
-                if (errorMsg != null) {
+                if (errorMsg != null)
+                {
                     throw new ExtismException(errorMsg);
-                } else {
+                }
+                else
+                {
                     throw new ExtismException("Call to Extism failed");
                 }
             }
@@ -96,11 +117,11 @@ public class Plugin : IDisposable
     /// Get the length of a plugin's output data.
     /// </summary>
     /// <returns></returns>
-    internal int OutputLength()
+    unsafe internal int OutputLength()
     {
         CheckNotDisposed();
 
-        return (int)LibExtism.extism_plugin_output_length(_context.NativeHandle, NativeHandle);
+        return (int)LibExtism.extism_plugin_output_length(_context.NativeHandle, Index);
     }
 
     /// <summary>
@@ -114,7 +135,7 @@ public class Plugin : IDisposable
 
         unsafe
         {
-            var ptr = LibExtism.extism_plugin_output_data(_context.NativeHandle, NativeHandle).ToPointer();
+            var ptr = LibExtism.extism_plugin_output_data(_context.NativeHandle, Index).ToPointer();
             return new Span<byte>(ptr, length);
         }
     }
@@ -123,11 +144,11 @@ public class Plugin : IDisposable
     /// Get the error associated with the current plugin.
     /// </summary>
     /// <returns></returns>
-    internal string? GetError()
+    unsafe internal string? GetError()
     {
         CheckNotDisposed();
 
-        var result = LibExtism.extism_error(_context.NativeHandle, NativeHandle);
+        var result = LibExtism.extism_error(_context.NativeHandle, Index);
         return Marshal.PtrToStringUTF8(result);
     }
 
@@ -168,7 +189,7 @@ public class Plugin : IDisposable
     /// <summary>
     /// Frees all resources held by this Plugin.
     /// </summary>
-    protected virtual void Dispose(bool disposing)
+    unsafe protected virtual void Dispose(bool disposing)
     {
         if (disposing)
         {
@@ -176,7 +197,7 @@ public class Plugin : IDisposable
         }
 
         // Free up unmanaged resources
-        LibExtism.extism_plugin_free(_context.NativeHandle, NativeHandle);
+        LibExtism.extism_plugin_free(_context.NativeHandle, Index);
     }
 
     /// <summary>
@@ -186,4 +207,4 @@ public class Plugin : IDisposable
     {
         Dispose(false);
     }
-}
+}

dotnet/test/Extism.Sdk/BasicTests.cs

@@ -1,6 +1,7 @@
 using Extism.Sdk.Native;
 
 using System.Reflection;
+using System.Runtime.InteropServices;
 using System.Text;
 
 using Xunit;
@@ -9,6 +10,17 @@ namespace Extism.Sdk.Tests;
 
 public class BasicTests
 {
+    [Fact]
+    public void CountHelloWorldVowelsWithoutContext()
+    {
+        var binDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!;
+        var wasm = File.ReadAllBytes(Path.Combine(binDirectory, "code.wasm"));
+        using var plugin = Plugin.Create(wasm, Array.Empty<HostFunction>(), withWasi: true);
+
+        var response = plugin.CallFunction("count_vowels", Encoding.UTF8.GetBytes("Hello World"));
+        Assert.Equal("{\"count\": 3}", Encoding.UTF8.GetString(response));
+    }
+
     [Fact]
     public void CountHelloWorldVowels()
     {
@@ -16,9 +28,46 @@ public class BasicTests
 
         var binDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!;
         var wasm = File.ReadAllBytes(Path.Combine(binDirectory, "code.wasm"));
-        using var plugin = context.CreatePlugin(wasm, withWasi: true);
+        using var plugin = context.CreatePlugin(wasm, Array.Empty<HostFunction>(), withWasi: true);
 
         var response = plugin.CallFunction("count_vowels", Encoding.UTF8.GetBytes("Hello World"));
         Assert.Equal("{\"count\": 3}", Encoding.UTF8.GetString(response));
     }
-}
+
+    [Fact]
+    public void CountVowelsHostFunctions()
+    {
+        using var context = new Context();
+
+        var userData = Marshal.StringToHGlobalAnsi("Hello again!");
+
+        using var helloWorld = new HostFunction(
+            "hello_world",
+            "env",
+            new[] { ExtismValType.I64 },
+            new[] { ExtismValType.I64 },
+            userData,
+            HelloWorld);
+
+        var binDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!;
+        var wasm = File.ReadAllBytes(Path.Combine(binDirectory, "code-functions.wasm"));
+        using var plugin = context.CreatePlugin(wasm, new[] { helloWorld }, withWasi: true);
+
+        var response = plugin.CallFunction("count_vowels", Encoding.UTF8.GetBytes("Hello World"));
+        Assert.Equal("{\"count\": 3}", Encoding.UTF8.GetString(response));
+
+        void HelloWorld(CurrentPlugin plugin, Span<ExtismVal> inputs, Span<ExtismVal> outputs, nint data)
+        {
+            Console.WriteLine("Hello from .NET!");
+
+            var text = Marshal.PtrToStringAnsi(data);
+            Console.WriteLine(text);
+
+            var input = plugin.ReadString(new nint(inputs[0].v.i64));
+            Console.WriteLine($"Input: {input}");
+
+            var output = new string(input); // clone the string
+            outputs[0].v.i64 = plugin.WriteString(output);
+        }
+    }
+}

dotnet/test/Extism.Sdk/Extism.Sdk.Tests.csproj

@@ -25,6 +25,9 @@
 		<None Include="..\..\..\wasm\code.wasm" Link="code.wasm">
 			<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
 		</None>
+		<None Include="..\..\..\wasm\code-functions.wasm" Link="code-functions.wasm">
+			<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+		</None>
 	</ItemGroup>
 
 
@@ -32,4 +35,8 @@
 		<ProjectReference Include="..\..\src\Extism.Sdk\Extism.Sdk.csproj" />
 	</ItemGroup>
 
+	<ItemGroup>
+		<PackageReference Include="Extism.runtime.win-x64" Version="0.4.0" />
+	</ItemGroup>
+
 </Project>

dune-project

@@ -26,7 +26,7 @@
   (ctypes-foreign (>= 0.18.0))
   (bigstringaf (>= 0.9.0))
   (ppx_yojson_conv (>= v0.15.0))
-  extism-manifest
+  (extism-manifest (= :version))
   (ppx_inline_test (>= v0.15.0))
   (cmdliner (>= 1.1.1))
  )

elixir/lib/extism/cancel_handle.ex

@@ -5,7 +5,7 @@ defmodule Extism.CancelHandle do
   """
   defstruct [
     # The actual NIF Resource. PluginIndex and the context
-    handle: nil,
+    handle: nil
   ]
 
   def wrap_resource(handle) do

elixir/lib/extism/plugin.ex

@@ -15,12 +15,25 @@ defmodule Extism.Plugin do
     }
   end
 
+  @doc """
+  Creates a new plugin
+  """
+  def new(manifest, wasi \\ false, context \\ nil) do
+    ctx = context || Extism.Context.new()
+    {:ok, manifest_payload} = JSON.encode(manifest)
+
+    case Extism.Native.plugin_new_with_manifest(ctx.ptr, manifest_payload, wasi) do
+      {:error, err} -> {:error, err}
+      res -> {:ok, Extism.Plugin.wrap_resource(ctx, res)}
+    end
+  end
+
   @doc """
   Call a plugin's function by name
 
   ## Examples
 
-      iex> {:ok, plugin} = Extism.Context.new_plugin(ctx, manifest, false)
+      iex> {:ok, plugin} = Extism.Plugin.new(manifest, false)
       iex> {:ok, output} = Extism.Plugin.call(plugin, "count_vowels", "this is a test")
          # {:ok, "{\"count\": 4}"}
 

elixir/mix.exs

@@ -4,7 +4,7 @@ defmodule Extism.MixProject do
   def project do
     [
       app: :extism,
-      version: "0.3.0",
+      version: "0.5.0",
       elixir: "~> 1.12",
       start_permanent: Mix.env() == :prod,
       deps: deps(),
@@ -23,7 +23,7 @@ defmodule Extism.MixProject do
 
   defp deps do
     [
-      {:rustler, "~> 0.27.0"},
+      {:rustler, "~> 0.29.1"},
       {:json, "~> 1.4"},
       {:ex_doc, "~> 0.21", only: :dev, runtime: false}
     ]

elixir/mix.lock

@@ -1,12 +1,12 @@
 %{
-  "earmark_parser": {:hex, :earmark_parser, "1.4.31", "a93921cdc6b9b869f519213d5bc79d9e218ba768d7270d46fdcf1c01bacff9e2", [:mix], [], "hexpm", "317d367ee0335ef037a87e46c91a2269fef6306413f731e8ec11fc45a7efd059"},
-  "ex_doc": {:hex, :ex_doc, "0.29.2", "dfa97532ba66910b2a3016a4bbd796f41a86fc71dd5227e96f4c8581fdf0fdf0", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "6b5d7139eda18a753e3250e27e4a929f8d2c880dd0d460cb9986305dea3e03af"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.33", "3c3fd9673bb5dcc9edc28dd90f50c87ce506d1f71b70e3de69aa8154bc695d44", [:mix], [], "hexpm", "2d526833729b59b9fdb85785078697c72ac5e5066350663e5be6a1182da61b8f"},
+  "ex_doc": {:hex, :ex_doc, "0.30.5", "aa6da96a5c23389d7dc7c381eba862710e108cee9cfdc629b7ec021313900e9e", [:mix], [{:earmark_parser, "~> 1.4.31", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "88a1e115dcb91cefeef7e22df4a6ebbe4634fbf98b38adcbc25c9607d6d9d8e6"},
   "jason": {:hex, :jason, "1.4.0", "e855647bc964a44e2f67df589ccf49105ae039d4179db7f6271dfd3843dc27e6", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "79a3791085b2a0f743ca04cec0f7be26443738779d09302e01318f97bdb82121"},
   "json": {:hex, :json, "1.4.1", "8648f04a9439765ad449bc56a3ff7d8b11dd44ff08ffcdefc4329f7c93843dfa", [:mix], [], "hexpm", "9abf218dbe4ea4fcb875e087d5f904ef263d012ee5ed21d46e9dbca63f053d16"},
   "makeup": {:hex, :makeup, "1.1.0", "6b67c8bc2882a6b6a445859952a602afc1a41c2e08379ca057c0f525366fc3ca", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "0a45ed501f4a8897f580eabf99a2e5234ea3e75a4373c8a52824f6e873be57a6"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.16.0", "f8c570a0d33f8039513fbccaf7108c5d750f47d8defd44088371191b76492b0b", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "28b2cbdc13960a46ae9a8858c4bebdec3c9a6d7b4b9e7f4ed1502f8159f338e7"},
-  "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
-  "nimble_parsec": {:hex, :nimble_parsec, "1.2.3", "244836e6e3f1200c7f30cb56733fd808744eca61fd182f731eac4af635cc6d0b", [:mix], [], "hexpm", "c8d789e39b9131acf7b99291e93dae60ab48ef14a7ee9d58c6964f59efb570b0"},
-  "rustler": {:hex, :rustler, "0.27.0", "53ffe86586fd1a2ea60ad07f1506962914eb669dba26c23010cf672662ec8d64", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:toml, "~> 0.6", [hex: :toml, repo: "hexpm", optional: false]}], "hexpm", "d7f5ccaec6e7a96f700330898ff2e9d48818e40789fd2951ba41ecf457986e92"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.16.1", "cc9e3ca312f1cfeccc572b37a09980287e243648108384b97ff2b76e505c3555", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "e127a341ad1b209bd80f7bd1620a15693a9908ed780c3b763bccf7d200c767c6"},
+  "makeup_erlang": {:hex, :makeup_erlang, "0.1.2", "ad87296a092a46e03b7e9b0be7631ddcf64c790fa68a9ef5323b6cbb36affc72", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "f3f5a1ca93ce6e092d92b6d9c049bcda58a3b617a8d888f8e7231c85630e8108"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.3.1", "2c54013ecf170e249e9291ed0a62e5832f70a476c61da16f6aac6dca0189f2af", [:mix], [], "hexpm", "2682e3c0b2eb58d90c6375fc0cc30bc7be06f365bf72608804fb9cffa5e1b167"},
+  "rustler": {:hex, :rustler, "0.29.1", "880f20ae3027bd7945def6cea767f5257bc926f33ff50c0d5d5a5315883c084d", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:toml, "~> 0.6", [hex: :toml, repo: "hexpm", optional: false]}], "hexpm", "109497d701861bfcd26eb8f5801fe327a8eef304f56a5b63ef61151ff44ac9b6"},
   "toml": {:hex, :toml, "0.7.0", "fbcd773caa937d0c7a02c301a1feea25612720ac3fa1ccb8bfd9d30d822911de", [:mix], [], "hexpm", "0690246a2478c1defd100b0c9b89b4ea280a22be9a7b313a8a058a2408a2fa70"},
 }

elixir/native/extism_nif/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "extism_nif"
-version = "0.2.0"
+version = "0.3.0"
 edition = "2021"
 authors = ["Benjamin Eckel <bhelx@simst.im>"]
 
@@ -9,7 +9,10 @@ name = "extism_nif"
 path = "src/lib.rs"
 crate-type = ["cdylib"]
 
+# need this to be here and be empty
+[workspace]
+
 [dependencies]
-rustler = "0.27.0"
-extism = { version = "0.3.0", path = "../../../rust", package = "extism" }
+rustler = "0.28.0"
+extism = "0.5.0"
 log = "0.4"

elixir/native/extism_nif/src/lib.rs

@@ -62,8 +62,8 @@ fn plugin_new_with_manifest(
     manifest_payload: String,
     wasi: bool,
 ) -> Result<i32, rustler::Error> {
-    let context = &ctx.ctx.write().unwrap();
-    let result = match Plugin::new(context, manifest_payload, [], wasi) {
+    let context = ctx.ctx.write().unwrap();
+    let result = match Plugin::new(&context, manifest_payload, [], wasi) {
         Err(e) => Err(to_rustler_error(e)),
         Ok(plugin) => {
             let plugin_id = plugin.as_i32();

extism.go

@@ -173,8 +173,9 @@ func (ctx *Context) Free() {
 
 // Plugin is used to call WASM functions
 type Plugin struct {
-	ctx *Context
-	id  int32
+	ctx       *Context
+	id        int32
+	functions []Function
 }
 
 type WasmData struct {
@@ -272,7 +273,7 @@ func register(ctx *Context, data []byte, functions []Function, wasi bool) (Plugi
 		)
 	}
 
-	return Plugin{id: int32(plugin), ctx: ctx}, nil
+	return Plugin{id: int32(plugin), ctx: ctx, functions: functions}, nil
 }
 
 func update(ctx *Context, plugin int32, data []byte, functions []Function, wasi bool) error {
@@ -323,6 +324,18 @@ func update(ctx *Context, plugin int32, data []byte, functions []Function, wasi
 	)
 }
 
+// NewPlugin creates a plugin in its own context
+func NewPlugin(module io.Reader, functions []Function, wasi bool) (Plugin, error) {
+	ctx := NewContext()
+	return ctx.Plugin(module, functions, wasi)
+}
+
+// NewPlugin creates a plugin in its own context from a manifest
+func NewPluginFromManifest(manifest Manifest, functions []Function, wasi bool) (Plugin, error) {
+	ctx := NewContext()
+	return ctx.PluginFromManifest(manifest, functions, wasi)
+}
+
 // PluginFromManifest creates a plugin from a `Manifest`
 func (ctx *Context) PluginFromManifest(manifest Manifest, functions []Function, wasi bool) (Plugin, error) {
 	data, err := json.Marshal(manifest)
@@ -349,7 +362,7 @@ func (p *Plugin) Update(module io.Reader, functions []Function, wasi bool) error
 	if err != nil {
 		return err
 	}
-
+	p.functions = functions
 	return update(p.ctx, p.id, wasm, functions, wasi)
 }
 
@@ -360,6 +373,7 @@ func (p *Plugin) UpdateManifest(manifest Manifest, functions []Function, wasi bo
 		return err
 	}
 
+	p.functions = functions
 	return update(p.ctx, p.id, data, functions, wasi)
 }
 

extism.opam

@@ -16,7 +16,7 @@ depends: [
   "ctypes-foreign" {>= "0.18.0"}
   "bigstringaf" {>= "0.9.0"}
   "ppx_yojson_conv" {>= "v0.15.0"}
-  "extism-manifest"
+  "extism-manifest" {= version}
   "ppx_inline_test" {>= "v0.15.0"}
   "cmdliner" {>= "1.1.1"}
   "odoc" {with-doc}

go/main.go

@@ -36,9 +36,6 @@ func main() {
 	version := extism.ExtismVersion()
 	fmt.Println("Extism Version: ", version)
 
-	ctx := extism.NewContext()
-	defer ctx.Free() // this will free the context and all associated plugins
-
 	// set some input data to provide to the plugin module
 	var data []byte
 	if len(os.Args) > 1 {
@@ -49,7 +46,7 @@ func main() {
 	manifest := extism.Manifest{Wasm: []extism.Wasm{extism.WasmFile{Path: "../wasm/code-functions.wasm"}}}
 	f := extism.NewFunction("hello_world", []extism.ValType{extism.I64}, []extism.ValType{extism.I64}, C.hello_world, "Hello again!")
 	defer f.Free()
-	plugin, err := ctx.PluginFromManifest(manifest, []extism.Function{f}, true)
+	plugin, err := extism.NewPluginFromManifest(manifest, []extism.Function{f}, true)
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)

haskell/Example.hs

@@ -1,16 +1,24 @@
 module Main where
 
 import Extism
+import Extism.CurrentPlugin
 import Extism.Manifest(manifest, wasmFile)
 
 unwrap (Right x) = x
 unwrap (Left (ExtismError msg)) = do
   error msg
 
+hello plugin params msg = do
+  putStrLn "Hello from Haskell!"
+  putStrLn msg
+  offs <- allocBytes plugin (toByteString "{\"count\": 999}")
+  return [toI64 offs]
+
 main = do
-  let m = manifest [wasmFile "../wasm/code.wasm"]
-  context <- Extism.newContext
-  plugin <- unwrap <$> Extism.pluginFromManifest context m False
-  res <- unwrap <$> Extism.call plugin "count_vowels" (Extism.toByteString "this is a test")
-  putStrLn (Extism.fromByteString res)
-  Extism.free plugin
+  setLogFile "stdout" Error
+  let m = manifest [wasmFile "../wasm/code-functions.wasm"]
+  f <- hostFunction "hello_world" [I64] [I64] hello "Hello, again"
+  plugin <- unwrap <$> createPluginFromManifest m [f] True
+  res <- unwrap <$> call plugin "count_vowels" (toByteString "this is a test")
+  putStrLn (fromByteString res)
+  free plugin

haskell/extism.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               extism
-version:            0.2.0
+version:            0.5.0
 license:            BSD-3-Clause
 maintainer:         oss@extism.org
 author:             Extism authors
@@ -8,10 +8,10 @@ bug-reports:        https://github.com/extism/extism
 synopsis:           Extism bindings
 description:        Bindings to Extism, the universal plugin system
 category:           Plugins, WebAssembly
-extra-source-files: CHANGELOG.md
+extra-doc-files: CHANGELOG.md
 
 library
-    exposed-modules:    Extism
+    exposed-modules:    Extism Extism.CurrentPlugin
     reexported-modules: Extism.Manifest
     hs-source-dirs:     src
     other-modules:      Extism.Bindings
@@ -19,10 +19,10 @@ library
     extra-libraries:    extism
     extra-lib-dirs:     /usr/local/lib
     build-depends:
-        base              >= 4.16.1 && < 4.19.0,
-        bytestring        >= 0.11.3 && < 0.12,
-        json              >= 0.10 && < 0.11,
-        extism-manifest   >= 0.0.0 && < 0.3.0
+        base              >= 4.16.1 && < 5,
+        bytestring        >= 0.11.3 && <= 0.12,
+        json              >= 0.10 && <= 0.11,
+        extism-manifest   >= 0.0.0 && < 0.4.0
 
 test-suite extism-example
     type:             exitcode-stdio-1.0

haskell/manifest/Extism/JSON.hs

@@ -16,8 +16,8 @@ isNull JSNull = True
 isNull _ = False
 filterNulls obj = [(a, b) | (a, b) <- obj, not (isNull b)]
 object x = makeObj $ filterNulls x
-objectWithNulls x = makeObj x
-nonNull x = NotNull x
+objectWithNulls = makeObj
+nonNull = NotNull
 null' = Null
 (.=) a b = (a, showJSON b)
 toNullable (Just x) = NotNull x
@@ -40,7 +40,7 @@ find :: JSON a => String -> JSValue -> Nullable a
 find k obj = obj .? k
 
 update :: JSON a => String -> a -> JSValue -> JSValue
-update k v (JSObject obj) = object $ (fromJSObject obj) ++ [k .= v]
+update k v (JSObject obj) = object $ fromJSObject obj ++ [k .= v]
 
 instance JSON a => JSON (Nullable a) where
   showJSON (NotNull x) = showJSON x

haskell/manifest/extism-manifest.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               extism-manifest
-version:            0.2.0
+version:            0.3.0
 license:            BSD-3-Clause
 maintainer:         oss@extism.org
 author:             Extism authors
@@ -8,14 +8,14 @@ bug-reports:        https://github.com/extism/extism
 synopsis:           Extism manifest bindings
 description:        Bindings to Extism WebAssembly manifest
 category:           Plugins, WebAssembly
-extra-source-files: CHANGELOG.md
+extra-doc-files: CHANGELOG.md
 
 library
     exposed-modules:    Extism.Manifest Extism.JSON
     hs-source-dirs:     .
     default-language:   Haskell2010
     build-depends:
-        base              >= 4.16.1 && < 4.19.0,
-        bytestring        >= 0.11.3 && < 0.12,
-        json              >= 0.10 && < 0.11,
+        base              >= 4.16.1 && < 5,
+        bytestring        >= 0.11.3 && <= 0.12,
+        json              >= 0.10 && <= 0.11,
         base64-bytestring >= 1.2.1 && < 1.3,

haskell/src/Extism.hs

@@ -1,10 +1,21 @@
-module Extism (module Extism, module Extism.Manifest) where
+module Extism (
+  module Extism,
+  module Extism.Manifest,
+  ValType(..),
+  Val(..)
+) where
+
 import Data.Int
 import Data.Word
 import Control.Monad (void)
 import Foreign.ForeignPtr
 import Foreign.C.String
 import Foreign.Ptr
+import Foreign.Marshal.Array
+import Foreign.Storable
+import Foreign.StablePtr
+import Foreign.Concurrent
+import Foreign.Marshal.Utils (copyBytes, moveBytes)
 import Data.ByteString as B
 import Data.ByteString.Internal (c2w, w2c)
 import Data.ByteString.Unsafe (unsafeUseAsCString)
@@ -16,10 +27,17 @@ import Extism.Bindings
 -- | Context for managing plugins
 newtype Context = Context (ForeignPtr ExtismContext)
 
--- | Plugins can be used to call WASM function
-data Plugin = Plugin Context Int32
+-- | Host function
+data Function = Function (ForeignPtr ExtismFunction) (StablePtr ())
 
-data CancelHandle = CancelHandle (Ptr ExtismCancelHandle)
+-- | Plugins can be used to call WASM function
+data Plugin = Plugin Context Int32 [Function]
+
+-- | Cancellation handle for Plugins
+newtype CancelHandle = CancelHandle (Ptr ExtismCancelHandle)
+
+-- | Access the plugin that is currently executing from inside a host function
+type CurrentPlugin = Ptr ExtismCurrentPlugin
 
 -- | Log level
 data LogLevel = Error | Warn | Info | Debug | Trace deriving (Show)
@@ -53,68 +71,94 @@ reset (Context ctx) =
 newContext :: IO Context
 newContext = do
   ptr <- extism_context_new
-  fptr <- newForeignPtr extism_context_free ptr
+  fptr <- Foreign.ForeignPtr.newForeignPtr extism_context_free ptr
   return (Context fptr)
- 
+
 -- | Execute a function with a new 'Context' that is destroyed when it returns
 withContext :: (Context -> IO a) -> IO a
 withContext f = do
   ctx <- newContext
   f ctx
 
+-- | Execute a function with the provided 'Plugin' as a parameter, then frees the 'Plugin'
+-- | before returning the result.
+withPlugin :: (Plugin -> IO a) -> Plugin -> IO a
+withPlugin f plugin = do
+  res <- f plugin
+  free plugin
+  return res
+
 -- | Create a 'Plugin' from a WASM module, `useWasi` determines if WASI should
 -- | be linked
-plugin :: Context -> B.ByteString -> Bool -> IO (Result Plugin)
-plugin c wasm useWasi =
+plugin :: Context -> B.ByteString -> [Function] -> Bool -> IO (Result Plugin)
+plugin c wasm functions useWasi =
+  let nfunctions = fromIntegral (Prelude.length functions) in
   let length = fromIntegral (B.length wasm) in
   let wasi = fromInteger (if useWasi then 1 else 0) in
   let Context ctx = c in
   do
+    funcs <- Prelude.mapM (\(Function ptr _) -> withForeignPtr ptr (\x -> do return x)) functions
     withForeignPtr ctx (\ctx -> do
       p <- unsafeUseAsCString wasm (\s ->
-        extism_plugin_new ctx (castPtr s) length nullPtr 0 wasi )
+        withArray funcs (\funcs ->
+          extism_plugin_new ctx (castPtr s) length funcs nfunctions wasi ))
       if p < 0 then do
         err <- extism_error ctx (-1)
         e <- peekCString err
         return $ Left (ExtismError e)
       else
-        return $ Right (Plugin c p))
+        return $ Right (Plugin c p functions))
+
+-- | Create a 'Plugin' with its own 'Context'
+createPlugin :: B.ByteString -> [Function] -> Bool -> IO (Result Plugin)
+createPlugin c functions useWasi = do
+  ctx <- newContext
+  plugin ctx c functions useWasi
 
 -- | Create a 'Plugin' from a 'Manifest'
-pluginFromManifest :: Context -> Manifest -> Bool -> IO (Result Plugin)
-pluginFromManifest ctx manifest useWasi =
+pluginFromManifest :: Context -> Manifest -> [Function] -> Bool -> IO (Result Plugin)
+pluginFromManifest ctx manifest functions useWasi =
   let wasm = toByteString $ toString manifest in
-  plugin ctx wasm useWasi
+  plugin ctx wasm functions useWasi
+
+-- | Create a 'Plugin' with its own 'Context' from a 'Manifest'
+createPluginFromManifest :: Manifest -> [Function] -> Bool -> IO (Result Plugin)
+createPluginFromManifest manifest functions useWasi = do
+  ctx <- newContext
+  pluginFromManifest ctx manifest functions useWasi
 
 -- | Update a 'Plugin' with a new WASM module
-update :: Plugin -> B.ByteString -> Bool -> IO (Result ())
-update (Plugin (Context ctx) id) wasm useWasi =
+update :: Plugin -> B.ByteString -> [Function] -> Bool -> IO (Result Plugin)
+update (Plugin (Context ctx) id _) wasm functions useWasi =
+  let nfunctions = fromIntegral (Prelude.length functions) in
   let length = fromIntegral (B.length wasm) in
   let wasi = fromInteger (if useWasi then 1 else 0) in
   do
-    withForeignPtr ctx (\ctx -> do
+    funcs <- Prelude.mapM (\(Function ptr _ ) -> withForeignPtr ptr (\x -> do return x)) functions
+    withForeignPtr ctx (\ctx' -> do
       b <- unsafeUseAsCString wasm (\s ->
-        extism_plugin_update ctx id (castPtr s) length nullPtr 0 wasi)
+        withArray funcs (\funcs ->
+          extism_plugin_update ctx' id (castPtr s) length funcs nfunctions wasi))
       if b <= 0 then do
-        err <- extism_error ctx (-1)
+        err <- extism_error ctx' (-1)
         e <- peekCString err
         return $ Left (ExtismError e)
       else
-        return (Right ()))
+        return (Right (Plugin (Context ctx) id functions)))
 
 -- | Update a 'Plugin' with a new 'Manifest'
-updateManifest :: Plugin -> Manifest -> Bool -> IO (Result ())
-updateManifest plugin manifest useWasi =
+updateManifest :: Plugin -> Manifest -> [Function] -> Bool -> IO (Result Plugin)
+updateManifest plugin manifest functions useWasi =
   let wasm = toByteString $ toString manifest in
-  update plugin wasm useWasi
+  update plugin wasm functions useWasi
 
 -- | Check if a 'Plugin' is valid
 isValid :: Plugin -> Bool
-isValid (Plugin _ p) = p >= 0
+isValid (Plugin _ p _) = p >= 0
 
 -- | Set configuration values for a plugin
 setConfig :: Plugin -> [(String, Maybe String)] -> IO Bool
-setConfig (Plugin (Context ctx) plugin) x =
+setConfig (Plugin (Context ctx) plugin _) x =
   if plugin < 0
     then return False
   else
@@ -143,14 +187,14 @@ setLogFile filename level =
 
 -- | Check if a function exists in the given plugin
 functionExists :: Plugin -> String -> IO Bool
-functionExists (Plugin (Context ctx) plugin) name = do
+functionExists (Plugin (Context ctx) plugin _) name = do
   withForeignPtr ctx (\ctx -> do
     b <- withCString name (extism_plugin_function_exists ctx plugin)
     if b == 1 then return True else return False)
 
 --- | Call a function provided by the given plugin
 call :: Plugin -> String -> B.ByteString -> IO (Result B.ByteString)
-call (Plugin (Context ctx) plugin) name input =
+call (Plugin (Context ctx) plugin _) name input =
   let length = fromIntegral (B.length input) in
   do
     withForeignPtr ctx (\ctx -> do
@@ -172,15 +216,73 @@ call (Plugin (Context ctx) plugin) name input =
 -- | Free a 'Plugin', this will automatically be called for every plugin
 -- | associated with a 'Context' when that 'Context' is freed
 free :: Plugin -> IO ()
-free (Plugin (Context ctx) plugin) =
+free (Plugin (Context ctx) plugin _) =
   withForeignPtr ctx (`extism_plugin_free` plugin)
 
+-- | Create a new 'CancelHandle' that can be used to cancel a running plugin
+-- | from another thread.
 cancelHandle :: Plugin -> IO CancelHandle
-cancelHandle (Plugin (Context ctx) plugin) = do
-  handle <- withForeignPtr ctx (\ctx -> extism_plugin_cancel_handle ctx plugin)
+cancelHandle (Plugin (Context ctx) plugin _) = do
+  handle <- withForeignPtr ctx (`extism_plugin_cancel_handle` plugin)
   return (CancelHandle handle)
 
+-- | Cancel a running plugin using a 'CancelHandle'
 cancel :: CancelHandle -> IO Bool
-cancel (CancelHandle handle) = 
+cancel (CancelHandle handle) =
   extism_plugin_cancel handle
 
+
+-- | Create a new 'Function' that can be called from a 'Plugin'
+hostFunction :: String -> [ValType] -> [ValType] -> (CurrentPlugin -> [Val] -> a -> IO [Val]) -> a -> IO Function
+hostFunction name params results f v =
+  let nparams = fromIntegral $ Prelude.length params in
+  let nresults = fromIntegral $ Prelude.length results in
+  do
+    cb <- callbackWrap (callback f :: CCallback)
+    free <- freePtrWrap freePtr
+    userData <- newStablePtr (v, free, cb)
+    let userDataPtr = castStablePtrToPtr userData
+    x <- withCString name (\name ->  do
+      withArray params (\params ->
+        withArray results (\results -> do
+          extism_function_new name params nparams results nresults cb userDataPtr free)))
+    let freeFn = extism_function_free x
+    fptr <- Foreign.Concurrent.newForeignPtr x freeFn
+    return $ Function fptr (castPtrToStablePtr userDataPtr)
+
+
+-- | Create a new I32 'Val'
+toI32 :: Integral a => a -> Val
+toI32 x = ValI32 (fromIntegral x)
+
+-- | Create a new I64 'Val'
+toI64 :: Integral a => a -> Val
+toI64 x = ValI64 (fromIntegral x)
+
+-- | Create a new F32 'Val'
+toF32 :: Float -> Val
+toF32 = ValF32
+
+-- | Create a new F64 'Val'
+toF64 :: Double -> Val
+toF64 = ValF64
+
+-- | Get I32 'Val'
+fromI32 :: Integral a => Val -> Maybe a
+fromI32 (ValI32 x) = Just (fromIntegral x)
+fromI32 _ = Nothing
+
+-- | Get I64 'Val'
+fromI64 :: Integral a => Val -> Maybe a
+fromI64 (ValI64 x) = Just (fromIntegral x)
+fromI64 _ = Nothing
+
+-- | Get F32 'Val'
+fromF32 :: Val -> Maybe Float
+fromF32 (ValF32 x) = Just x
+fromF32 _ = Nothing
+
+-- | Get F64 'Val'
+fromF64 :: Val -> Maybe Double
+fromF64 (ValF64 x) = Just x
+fromF64 _ = Nothing

haskell/src/Extism/Bindings.hs

@@ -7,10 +7,77 @@ import Foreign.Ptr
 import Foreign.C.String
 import Data.Int
 import Data.Word
+import Foreign.Storable
+import Foreign.Marshal.Array
+import Foreign.StablePtr
+
+type FreeCallback = Ptr () -> IO ()
 
 newtype ExtismContext = ExtismContext () deriving Show
 newtype ExtismFunction = ExtismFunction () deriving Show
 newtype ExtismCancelHandle = ExtismCancelHandle () deriving Show
+newtype ExtismCurrentPlugin = ExtismCurrentPlugin () deriving Show
+data ValType = I32 | I64 | F32 | F64 | V128 | FuncRef | ExternRef deriving (Show, Eq)
+data Val = ValI32 Int32 | ValI64 Int64 | ValF32 Float | ValF64 Double deriving (Show, Eq)
+
+typeOfVal (ValI32 _) = I32
+typeOfVal (ValI64 _) = I64
+typeOfVal (ValF32 _) = F32
+typeOfVal (ValF64 _) = F64
+
+type CCallback = Ptr ExtismCurrentPlugin -> Ptr Val -> Word64 -> Ptr Val -> Word64 -> Ptr () -> IO ()
+
+_32Bit = sizeOf (undefined :: Int) == 4
+
+instance Storable Val where
+  sizeOf _ =
+    if _32Bit then 12 else 16
+  alignment _ = 1
+  peek ptr = do
+    let offs = if _32Bit then 4 else 8
+    t <- valTypeOfInt <$> peekByteOff ptr 0
+    case t of
+      I32 -> ValI32 <$> peekByteOff ptr offs
+      I64 -> ValI64 <$> peekByteOff ptr offs
+      F32 -> ValF32 <$> peekByteOff ptr offs
+      F64 -> ValF64 <$> peekByteOff ptr offs
+  poke ptr x = do
+    let offs = if _32Bit then 4 else 8
+    pokeByteOff ptr 0 (typeOfVal x)
+    case x of
+      ValI32 x -> pokeByteOff ptr offs x
+      ValI64 x -> pokeByteOff ptr offs x
+      ValF32 x -> pokeByteOff ptr offs x
+      ValF64 x -> pokeByteOff ptr offs x
+
+
+intOfValType :: ValType -> CInt
+intOfValType I32 = 0
+intOfValType I64 = 1
+intOfValType F32 = 2
+intOfValType F64 = 3
+intOfValType V128 = 4
+intOfValType FuncRef = 5
+intOfValType ExternRef = 6
+
+valTypeOfInt :: CInt -> ValType
+valTypeOfInt 0 = I32
+valTypeOfInt 1 = I64
+valTypeOfInt 2 = F32
+valTypeOfInt 3 = F64
+valTypeOfInt 4 = V128
+valTypeOfInt 5 = FuncRef
+valTypeOfInt 6 = ExternRef
+valTypeOfInt _ = error "Invalid ValType"
+
+instance Storable ValType where
+  sizeOf _ = 4
+  alignment _ = 1
+  peek ptr = do
+    x <- peekByteOff ptr 0
+    return $ valTypeOfInt (x :: CInt)
+  poke ptr x = do
+    pokeByteOff ptr 0 (intOfValType x)
 
 foreign import ccall safe "extism.h extism_context_new" extism_context_new :: IO (Ptr ExtismContext)
 foreign import ccall safe "extism.h &extism_context_free" extism_context_free :: FunPtr (Ptr ExtismContext -> IO ())
@@ -28,3 +95,28 @@ foreign import ccall safe "extism.h extism_context_reset" extism_context_reset :
 foreign import ccall safe "extism.h extism_version" extism_version :: IO CString
 foreign import ccall safe "extism.h extism_plugin_cancel_handle" extism_plugin_cancel_handle :: Ptr ExtismContext -> Int32 -> IO (Ptr ExtismCancelHandle)
 foreign import ccall safe "extism.h extism_plugin_cancel" extism_plugin_cancel :: Ptr ExtismCancelHandle -> IO Bool
+
+foreign import ccall safe "extism.h extism_function_new" extism_function_new :: CString -> Ptr ValType -> Word64 -> Ptr ValType -> Word64 -> FunPtr CCallback -> Ptr () -> FunPtr FreeCallback -> IO (Ptr ExtismFunction)
+foreign import ccall safe "extism.h extism_function_free" extism_function_free :: Ptr ExtismFunction -> IO ()
+foreign import ccall safe "extism.h extism_current_plugin_memory" extism_current_plugin_memory :: Ptr ExtismCurrentPlugin -> IO (Ptr Word8)
+foreign import ccall safe "extism.h extism_current_plugin_memory_alloc" extism_current_plugin_memory_alloc :: Ptr ExtismCurrentPlugin -> Word64 -> IO Word64
+foreign import ccall safe "extism.h extism_current_plugin_memory_length" extism_current_plugin_memory_length :: Ptr ExtismCurrentPlugin -> Word64 -> IO Word64
+foreign import ccall safe "extism.h extism_current_plugin_memory_free" extism_current_plugin_memory_free :: Ptr ExtismCurrentPlugin -> Word64 -> IO ()
+
+freePtr ptr = do
+  let s = castPtrToStablePtr ptr
+  (a, b, c) <- deRefStablePtr s
+  freeHaskellFunPtr b
+  freeHaskellFunPtr c
+  freeStablePtr s
+
+foreign import ccall "wrapper" freePtrWrap :: FreeCallback -> IO (FunPtr FreeCallback)
+
+foreign import ccall "wrapper" callbackWrap :: CCallback -> IO (FunPtr CCallback)
+
+callback :: (Ptr ExtismCurrentPlugin -> [Val] -> a -> IO [Val]) -> (Ptr ExtismCurrentPlugin -> Ptr Val -> Word64 -> Ptr Val -> Word64 -> Ptr () -> IO ())
+callback f plugin params nparams results nresults ptr = do
+    p <- peekArray (fromIntegral nparams) params
+    (userData, _, _)  <- deRefStablePtr (castPtrToStablePtr ptr)
+    res <- f plugin p userData
+    pokeArray results res

haskell/src/Extism/CurrentPlugin.hs

@@ -0,0 +1,48 @@
+module Extism.CurrentPlugin where
+
+import Extism
+import Extism.Bindings
+import Data.Word
+import Data.ByteString as B
+import Foreign.Ptr
+import Foreign.Marshal.Array
+
+-- | Allocate a new handle of the given size
+memoryAlloc :: CurrentPlugin -> Word64 -> IO Word64
+memoryAlloc = extism_current_plugin_memory_alloc
+
+-- | Get the length of a handle, returns 0 if the handle is invalid
+memoryLength :: CurrentPlugin -> Word64 -> IO Word64
+memoryLength = extism_current_plugin_memory_length
+
+-- | Free allocated memory
+memoryFree :: CurrentPlugin -> Word64 -> IO ()
+memoryFree = extism_current_plugin_memory_free
+
+-- | Access a pointer to the entire memory region
+memory :: CurrentPlugin -> IO (Ptr Word8)
+memory = extism_current_plugin_memory
+
+-- | Access a pointer the a specific offset in memory
+memoryOffset :: CurrentPlugin -> Word64 -> IO (Ptr Word8)
+memoryOffset plugin offs = do
+  x <- extism_current_plugin_memory plugin
+  return $ plusPtr x (fromIntegral offs)
+
+-- | Access the data associated with a handle as a 'ByteString'
+memoryBytes :: CurrentPlugin -> Word64 ->  IO B.ByteString
+memoryBytes plugin offs = do
+  ptr <- memoryOffset plugin offs
+  len <- memoryLength plugin offs
+  arr <- peekArray (fromIntegral len) ptr
+  return $ B.pack arr
+
+-- | Allocate memory and copy an existing 'ByteString' into it
+allocBytes :: CurrentPlugin -> B.ByteString -> IO Word64
+allocBytes plugin s = do
+  let length = B.length s
+  offs <- memoryAlloc plugin (fromIntegral length)
+  ptr <- memoryOffset plugin offs
+  pokeArray ptr (B.unpack s)
+  return offs
+

haskell/test/Test.hs

@@ -1,6 +1,7 @@
 import Test.HUnit
 import Extism
 import Extism.Manifest
+import Extism.CurrentPlugin
 
 
 unwrap (Right x) = return x
@@ -8,46 +9,58 @@ unwrap (Left (ExtismError msg)) =
   assertFailure msg
 
 defaultManifest = manifest [wasmFile "../../wasm/code.wasm"]
+hostFunctionManifest = manifest [wasmFile "../../wasm/code-functions.wasm"]
 
-initPlugin :: Context -> IO Plugin
-initPlugin context =
-  Extism.pluginFromManifest context defaultManifest False >>= unwrap
+initPlugin :: Maybe Context -> IO Plugin
+initPlugin Nothing =
+  Extism.createPluginFromManifest defaultManifest [] False >>= unwrap
+initPlugin (Just ctx) =
+  Extism.pluginFromManifest ctx defaultManifest [] False >>= unwrap
 
 pluginFunctionExists = do
-  withContext (\ctx -> do
-    p <- initPlugin ctx
-    exists <- functionExists p "count_vowels"
-    assertBool "function exists" exists
-    exists' <- functionExists p "function_doesnt_exist"
-    assertBool "function doesn't exist" (not exists'))
+  p <- initPlugin Nothing
+  exists <- functionExists p "count_vowels"
+  assertBool "function exists" exists
+  exists' <- functionExists p "function_doesnt_exist"
+  assertBool "function doesn't exist" (not exists')
 
 checkCallResult p = do
-    res <- call p "count_vowels" (toByteString "this is a test") >>= unwrap
-    assertEqual "count vowels output" "{\"count\": 4}" (fromByteString res)
+  res <- call p "count_vowels" (toByteString "this is a test") >>= unwrap
+  assertEqual "count vowels output" "{\"count\": 4}" (fromByteString res)
 
 pluginCall = do
-  withContext (\ctx -> do
-    p <- initPlugin ctx
-    checkCallResult p)
+  p <- initPlugin Nothing
+  checkCallResult p
+
+
+hello plugin params () = do
+  putStrLn "Hello from Haskell!"
+  offs <- allocBytes plugin (toByteString "{\"count\": 999}")
+  return [toI64 offs]
+
+pluginCallHostFunction = do
+  p <- Extism.createPluginFromManifest hostFunctionManifest [] False >>= unwrap
+  res <- call p "count_vowels" (toByteString "this is a test") >>= unwrap
+  assertEqual "count vowels output" "{\"count\": 999}" (fromByteString res)
 
 pluginMultiple = do
-  withContext (\ctx -> do
-    p <- initPlugin ctx
+  withContext(\ctx -> do
+    p <- initPlugin (Just ctx)
     checkCallResult p
-    q <- initPlugin ctx
-    r <- initPlugin ctx
+    q <- initPlugin (Just ctx)
+    r <- initPlugin (Just ctx)
     checkCallResult q
     checkCallResult r)
 
 pluginUpdate = do
   withContext (\ctx -> do
-    p <- initPlugin ctx
-    updateManifest p defaultManifest True >>= unwrap
+    p <- initPlugin (Just ctx)
+    updateManifest p defaultManifest [] True >>= unwrap
     checkCallResult p)
 
 pluginConfig = do
   withContext (\ctx -> do
-    p <- initPlugin ctx
+    p <- initPlugin (Just ctx)
     b <- setConfig p [("a", Just "1"), ("b", Just "2"), ("c", Just "3"), ("d", Nothing)]
     assertBool "set config" b)
 
@@ -62,6 +75,7 @@ main = do
     [
       t "Plugin.FunctionExists" pluginFunctionExists
       , t "Plugin.Call" pluginCall
+      , t "Plugin.CallHostFunction" pluginCallHostFunction
       , t "Plugin.Multiple" pluginMultiple
       , t "Plugin.Update" pluginUpdate
       , t "Plugin.Config" pluginConfig

java/pom.xml

@@ -1,193 +1,194 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <groupId>org.extism.sdk</groupId>
-    <artifactId>extism</artifactId>
-    <packaging>jar</packaging>
-    <version>0.3.0</version>
-    <name>extism</name>
-    <url>https://github.com/extism/extism</url>
-    <description>Java-SDK for Extism to use webassembly from Java</description>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.extism.sdk</groupId>
+  <artifactId>extism</artifactId>
+  <packaging>jar</packaging>
+  <version>0.5.0</version>
+  <name>extism</name>
+  <url>https://github.com/extism/extism</url>
+  <description>Java-SDK for Extism to use webassembly from Java</description>
 
-    <licenses>
-        <license>
-            <name>BSD 3-Clause</name>
-            <url>https://opensource.org/licenses/BSD-3-Clause</url>
-        </license>
-    </licenses>
+  <licenses>
+    <license>
+      <name>BSD 3-Clause</name>
+      <url>https://opensource.org/licenses/BSD-3-Clause</url>
+    </license>
+  </licenses>
 
-    <organization>
-        <name>Dylibso, Inc.</name>
-        <url>https://dylib.so</url>
-    </organization>
+  <organization>
+    <name>Dylibso, Inc.</name>
+    <url>https://dylib.so</url>
+  </organization>
 
-    <developers>
-        <developer>
-            <name>The Extism Authors</name>
-            <email>oss@extism.org</email>
-            <roles>
-                <role>Maintainer</role>
-            </roles>
-            <organization>Dylibso, Inc.</organization>
-            <organizationUrl>https://dylib.so</organizationUrl>
-        </developer>
-    </developers>
+  <developers>
+    <developer>
+      <name>The Extism Authors</name>
+      <email>oss@extism.org</email>
+      <roles>
+        <role>Maintainer</role>
+      </roles>
+      <organization>Dylibso, Inc.</organization>
+      <organizationUrl>https://dylib.so</organizationUrl>
+    </developer>
+  </developers>
 
-    <scm>
-        <connection>scm:git:git://github.com/extism/extism.git</connection>
-        <developerConnection>scm:git:ssh://git@github.com/extism/extism.git</developerConnection>
-        <url>https://github.com/extism/extism/tree/main/java</url>
-        <tag>main</tag>
-    </scm>
+  <scm>
+    <connection>scm:git:git://github.com/extism/extism.git</connection>
+    <developerConnection>scm:git:ssh://git@github.com/extism/extism.git</developerConnection>
+    <url>https://github.com/extism/extism/tree/main/java</url>
+    <tag>main</tag>
+  </scm>
 
-    <issueManagement>
-        <system>Github</system>
-        <url>https://github.com/extism/extism/issues</url>
-    </issueManagement>
+  <issueManagement>
+    <system>Github</system>
+    <url>https://github.com/extism/extism/issues</url>
+  </issueManagement>
 
-    <properties>
-        <java.version>11</java.version>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  <properties>
+    <java.version>11</java.version>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 
-        <!-- dependencies -->
-        <jna.version>5.12.1</jna.version>
-        <gson.version>2.10</gson.version>
+    <!-- dependencies -->
+    <jna.version>5.12.1</jna.version>
+    <gson.version>2.10</gson.version>
 
-        <!-- testing -->
-        <junit-jupiter-engine.version>5.9.1</junit-jupiter-engine.version>
-        <assertj-core.version>3.23.1</assertj-core.version>
+    <!-- testing -->
+    <junit-jupiter-engine.version>5.9.1</junit-jupiter-engine.version>
+    <assertj-core.version>3.23.1</assertj-core.version>
 
-        <!-- maven plugins -->
-        <maven-compiler-plugin.version>3.10.1</maven-compiler-plugin.version>
-        <maven-surefire-plugin.version>2.22.2</maven-surefire-plugin.version>
+    <!-- maven plugins -->
+    <maven-compiler-plugin.version>3.10.1</maven-compiler-plugin.version>
+    <maven-surefire-plugin.version>2.22.2</maven-surefire-plugin.version>
 
-        <!-- jreleaser -->
-        <jreleaser.git.root.search>true</jreleaser.git.root.search>
-    </properties>
+    <!-- jreleaser -->
+    <jreleaser.git.root.search>true</jreleaser.git.root.search>
+  </properties>
 
-    <profiles>
-      <profile>
-        <id>release</id>
-        <build>
-          <plugins>
-            <plugin>
-              <groupId>org.apache.maven.plugins</groupId>
-              <artifactId>maven-javadoc-plugin</artifactId>
-              <version>3.4.1</version>
-              <configuration>
-               <additionalJOption>-Xdoclint:none</additionalJOption>
-              </configuration>
-              <executions>
-                <execution>
-                  <id>attach-javadoc</id>
-                  <goals>
-                    <goal>jar</goal>
-                  </goals>
-                </execution>
-              </executions>
-            </plugin>
-            <plugin>
-              <groupId>org.apache.maven.plugins</groupId>
-              <artifactId>maven-source-plugin</artifactId>
-              <version>3.2.1</version>
-              <executions>
-                <execution>
-                  <id>attach-source</id>
-                  <goals>
-                    <goal>jar</goal>
-                  </goals>
-                </execution>
-              </executions>
-            </plugin>
-            <plugin>
-              <groupId>org.jreleaser</groupId>
-              <artifactId>jreleaser-maven-plugin</artifactId>
-              <version>1.3.1</version>
-              <configuration>
-                <jreleaser>
-                  <release>
-                    <github>
-                      <skipRelease>true</skipRelease>
-                    </github>
-                  </release>
-                  <signing>
-                    <active>ALWAYS</active>
-                    <armored>true</armored>
-                  </signing>
-                  <deploy>
-                    <maven>
-                      <nexus2>
-                        <maven-central>
-                          <active>ALWAYS</active>
-                          <url>https://s01.oss.sonatype.org/service/local</url>
-                          <!--
+  <profiles>
+    <profile>
+      <id>release</id>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-javadoc-plugin</artifactId>
+            <version>3.4.1</version>
+            <configuration>
+              <additionalJOption>-Xdoclint:none</additionalJOption>
+            </configuration>
+            <executions>
+              <execution>
+                <id>attach-javadoc</id>
+                <goals>
+                  <goal>jar</goal>
+                </goals>
+              </execution>
+            </executions>
+          </plugin>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-source-plugin</artifactId>
+            <version>3.2.1</version>
+            <executions>
+              <execution>
+                <id>attach-source</id>
+                <goals>
+                  <goal>jar</goal>
+                </goals>
+              </execution>
+            </executions>
+          </plugin>
+          <plugin>
+            <groupId>org.jreleaser</groupId>
+            <artifactId>jreleaser-maven-plugin</artifactId>
+            <version>1.3.1</version>
+            <configuration>
+              <jreleaser>
+                <release>
+                  <github>
+                    <skipRelease>true</skipRelease>
+                  </github>
+                </release>
+                <signing>
+                  <active>ALWAYS</active>
+                  <armored>true</armored>
+                </signing>
+                <deploy>
+                  <maven>
+                    <nexus2>
+                      <maven-central>
+                        <active>ALWAYS</active>
+                        <url>https://s01.oss.sonatype.org/service/local</url>
+                        <!--
                           <closeRepository>false</closeRepository>
                           <releaseRepository>false</releaseRepository>
                           -->
-                          <stagingRepositories>target/staging-deploy</stagingRepositories>
-                        </maven-central>
-                      </nexus2>
-                    </maven>
-                  </deploy>
-                </jreleaser>
-              </configuration>
-            </plugin>
-          </plugins>
-        </build>
-      </profile>
-    </profiles>
-
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven-compiler-plugin.version}</version>
-                <configuration>
-                    <release>${java.version}</release>
-                </configuration>
-            </plugin>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-surefire-plugin</artifactId>
-                <version>${maven-surefire-plugin.version}</version>
-                <configuration>
-                    <systemPropertyVariables>
-                        <jna.library.path>../target/release</jna.library.path>
-                    </systemPropertyVariables>
-                </configuration>
-            </plugin>
+                        <stagingRepositories>target/staging-deploy</stagingRepositories>
+                      </maven-central>
+                    </nexus2>
+                  </maven>
+                </deploy>
+              </jreleaser>
+            </configuration>
+          </plugin>
         </plugins>
-    </build>
-    <dependencies>
-        <dependency>
-            <groupId>net.java.dev.jna</groupId>
-            <artifactId>jna</artifactId>
-            <version>${jna.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.google.code.gson</groupId>
-            <artifactId>gson</artifactId>
-            <version>${gson.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <version>${junit-jupiter-engine.version}</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.assertj</groupId>
-            <artifactId>assertj-core</artifactId>
-            <version>${assertj-core.version}</version>
-            <scope>test</scope>
-        </dependency>
+      </build>
+    </profile>
+  </profiles>
 
-        <dependency>
-            <groupId>uk.org.webcompere</groupId>
-            <artifactId>model-assert</artifactId>
-            <version>1.0.0</version>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>${maven-compiler-plugin.version}</version>
+        <configuration>
+          <release>${java.version}</release>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>${maven-surefire-plugin.version}</version>
+        <configuration>
+          <systemPropertyVariables>
+            <jna.library.path>../target/release</jna.library.path>
+          </systemPropertyVariables>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+  <dependencies>
+    <dependency>
+      <groupId>net.java.dev.jna</groupId>
+      <artifactId>jna</artifactId>
+      <version>${jna.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.google.code.gson</groupId>
+      <artifactId>gson</artifactId>
+      <version>${gson.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <version>${junit-jupiter-engine.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.assertj</groupId>
+      <artifactId>assertj-core</artifactId>
+      <version>${assertj-core.version}</version>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>uk.org.webcompere</groupId>
+      <artifactId>model-assert</artifactId>
+      <version>1.0.0</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
 </project>

java/src/main/java/org/extism/sdk/Plugin.java

@@ -62,6 +62,16 @@ public class Plugin implements AutoCloseable {
         this(context, serialize(manifest), withWASI, functions);
     }
 
+
+    public Plugin(byte[] manifestBytes, boolean withWASI, HostFunction[] functions) {
+        this(new Context(), manifestBytes, withWASI, functions);
+    }
+
+    
+    public Plugin(Manifest manifest, boolean withWASI, HostFunction[] functions) {
+        this(new Context(), serialize(manifest), withWASI, functions);
+    }
+
     private static byte[] serialize(Manifest manifest) {
         Objects.requireNonNull(manifest, "manifest");
         return JsonSerde.toJson(manifest).getBytes(StandardCharsets.UTF_8);

java/src/test/java/org/extism/sdk/PluginTests.java

@@ -20,10 +20,10 @@ public class PluginTests {
 
     @Test
     public void shouldInvokeFunctionWithMemoryOptions() {
-        //FIXME check whether memory options are effective
         var manifest = new Manifest(List.of(CODE.pathWasmSource()), new MemoryOptions(0));
-        var output = Extism.invokeFunction(manifest, "count_vowels", "Hello World");
-        assertThat(output).isEqualTo("{\"count\": 3}");
+        assertThrows(ExtismException.class, () -> {
+            Extism.invokeFunction(manifest, "count_vowels", "Hello World");
+        });
     }
 
     @Test

kernel/.cargo/config

@@ -0,0 +1,2 @@
+[build]
+target = "wasm32-unknown-unknown"

kernel/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "extism-runtime-kernel"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+[workspace]
+members = [
+  "."
+]

kernel/README.md

@@ -0,0 +1,20 @@
+# Extism kernel
+
+The Extism kernel implements core parts of the Extism runtime in Rust compiled to WebAssembly. This code is a conceptual
+re-write of [memory.rs][] with the goal of making core parts of the Extism implementation more portable across WebAssembly
+runtimes.
+
+See [lib.rs][] for more details about the implementation itself.
+
+## Building
+
+Because this crate is built using the `wasm32-unknown-unknown` target, it is a separate build process from the `extism-runtime` crate. 
+
+To build `extism-runtime.wasm`, strip it and copy it to the proper location in the `extism-runtime` tree you can run:
+
+```shell
+$ sh build.sh
+```
+
+[memory.rs]: https://github.com/extism/extism/blob/f4aa139eced4a74eb4a103f78222ba503e146109/runtime/src/memory.rs
+[lib.rs]: ./src/lib.rs

kernel/build.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+cargo build --release --target wasm32-unknown-unknown --package extism-runtime-kernel --bin extism-runtime
+cp target/wasm32-unknown-unknown/release/extism-runtime.wasm .
+wasm-strip extism-runtime.wasm
+mv extism-runtime.wasm ../runtime/src/extism-runtime.wasm
+

kernel/src/bin/extism-runtime.rs

@@ -0,0 +1,10 @@
+#![no_main]
+#![no_std]
+
+pub use extism_runtime_kernel::*;
+
+#[cfg(target_arch = "wasm32")]
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    core::arch::wasm32::unreachable()
+}

kernel/src/lib.rs

@@ -0,0 +1,450 @@
+//! # Extism kernel
+//!
+//! - Isolated memory from both host and plugin
+//! - An allocator for managing that memory
+//! - Input/output handling
+//! - Error message handling
+//! - Backward compatible `extism_*` functions
+//!
+//! ## Allocator
+//!
+//! The Extism allocator is a bump allocator that tracks the `length` of the total number of bytes
+//! available to the allocator and `position` to track how much of the data has been used. Things like memory
+//! have not really been optimized at all. When a new allocation that is larger than the remaning size is made,
+//! the allocator attempts to call `memory.grow` if that fails a `0` offset is returned, which should be interpreted
+//! as a failed allocation.
+//!
+//! ## Input/Output
+//!
+//! Input and output are just allocated blocks of memory that are marked as either input or output using
+//! the `extism_input_set` or `extism_output_set` functions. The global variables `INPUT_OFFSET` contains
+//! the offset in memory to the input data and `INPUT_LENGTH` contains the size of the input data. `OUTPUT_OFFSET`
+//! and `OUTPUT_LENGTH` are used for the output data.
+//!
+//! ## Error handling
+//!
+//! The `ERROR` global is used to track the current error message. If it is set to `0` then there is no error.
+//! The length of the error message can be retreived using `extism_length`.
+//!
+//! ## Memory offsets
+//! An offset of `0` is similar to a `NULL` pointer in C - it implies an allocation failure or memory error
+//! of some kind
+//!
+//! ## Extism functions
+//!
+//! These functions are backward compatible with the pre-kernel runtime, but a few new functions are added to
+//! give runtimes more access to the internals necesarry to load data in and out of a plugin.
+#![no_std]
+#![allow(clippy::missing_safety_doc)]
+
+use core::sync::atomic::*;
+
+pub type Pointer = u64;
+pub type Length = u64;
+
+/// WebAssembly page size
+const PAGE_SIZE: usize = 65536;
+
+/// Determines the amount of bytes that can be wasted by re-using a block. If more than this number is wasted by re-using
+/// a block then it will be split into two smaller blocks.
+const BLOCK_SPLIT_SIZE: usize = 128;
+
+/// Offset to the input data
+static mut INPUT_OFFSET: Pointer = 0;
+
+/// Length of the input data
+static mut INPUT_LENGTH: Length = 0;
+
+/// Offset to the output data
+static mut OUTPUT_OFFSET: Pointer = 0;
+
+/// Offset to the input data
+static mut OUTPUT_LENGTH: Length = 0;
+
+/// Current error message
+static mut ERROR: AtomicU64 = AtomicU64::new(0);
+
+/// Determines if the kernel has been initialized already
+static mut INITIALIZED: AtomicBool = AtomicBool::new(false);
+
+/// A pointer to the first page that will be managed by Extism, this is set during initialization
+static mut START_PAGE: usize = 0;
+
+/// Provides information about the usage status of a `MemoryBlock`
+#[repr(u8)]
+#[derive(PartialEq)]
+pub enum MemoryStatus {
+    /// Unused memory that is available b
+    Unused = 0,
+    /// In-use memory
+    Active = 1,
+    /// Free memory that is available for re-use
+    Free = 2,
+}
+
+/// A single `MemoryRoot` exists at the start of the memory to track information about the total
+/// size of the allocated memory and the position of the bump allocator.
+///
+/// The overall layout of the Extism-manged memory is organized like this:
+
+/// |------|-------|---------|-------|--------------|
+/// | Root | Block |  Data   | Block |     Data     | ...
+/// |------|-------|---------|-------|--------------|
+///
+/// Where `Root` and `Block` are fixed to the size of the `MemoryRoot` and `MemoryBlock` structs. But
+/// the size of `Data` is dependent on the allocation size.
+#[repr(C)]
+pub struct MemoryRoot {
+    /// Position of the bump allocator, relative to `START_PAGE`
+    pub position: AtomicU64,
+    /// The total size of all data allocated using this allocator
+    pub length: AtomicU64,
+    /// A pointer to where the blocks begin
+    pub blocks: [MemoryBlock; 0],
+}
+
+/// A `MemoryBlock` contains some metadata about a single allocation
+#[repr(C)]
+pub struct MemoryBlock {
+    /// The usage status of the block, `Unused` or `Free` blocks can be re-used.
+    pub status: AtomicU8,
+    /// The total size of the allocation
+    pub size: usize,
+    /// The number of bytes currently being used. If this block is a fresh allocation then `size` and `used` will
+    /// always be the same. If a block is re-used then these numbers may differ.
+    pub used: usize,
+    /// A pointer to the block data
+    pub data: [u8; 0],
+}
+
+/// Returns the number of pages needed for the given number of bytes
+pub fn num_pages(nbytes: u64) -> usize {
+    let npages = nbytes / PAGE_SIZE as u64;
+    let remainder = nbytes % PAGE_SIZE as u64;
+    if remainder != 0 {
+        (npages + 1) as usize
+    } else {
+        npages as usize
+    }
+}
+
+// Get the `MemoryRoot` at the correct offset in memory
+#[inline]
+unsafe fn memory_root() -> &'static mut MemoryRoot {
+    &mut *((START_PAGE * PAGE_SIZE) as *mut MemoryRoot)
+}
+
+impl MemoryRoot {
+    /// Initialize or load the `MemoryRoot` from the correct position in memory
+    pub unsafe fn new() -> &'static mut MemoryRoot {
+        // If this fails then `INITIALIZED` is already `true` and we can just return the
+        // already initialized `MemoryRoot`
+        if INITIALIZED
+            .compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed)
+            .is_err()
+        {
+            return memory_root();
+        }
+
+        // Ensure that at least one page is allocated to store the `MemoryRoot` data
+        START_PAGE = core::arch::wasm32::memory_grow(0, 1);
+        if START_PAGE == usize::MAX {
+            panic!("Out of memory");
+        }
+
+        // Initialize the `MemoryRoot` length, position and data
+        let root = memory_root();
+        root.length.store(
+            PAGE_SIZE as u64 - core::mem::size_of::<MemoryRoot>() as u64,
+            Ordering::Release,
+        );
+        root.position.store(0, Ordering::Release);
+
+        // Ensure the first block is marked as `Unused`
+        #[allow(clippy::size_of_in_element_count)]
+        core::ptr::write_bytes(
+            root.blocks.as_mut_ptr() as *mut _,
+            MemoryStatus::Unused as u8,
+            core::mem::size_of::<MemoryBlock>(),
+        );
+        root
+    }
+
+    /// Resets the position of the allocator and zeroes out all allocations
+    pub unsafe fn reset(&mut self) {
+        core::ptr::write_bytes(
+            self.blocks.as_mut_ptr() as *mut u8,
+            0,
+            self.length.load(Ordering::Acquire) as usize,
+        );
+        self.position.store(0, Ordering::Release);
+    }
+
+    // Find a block that is free to use, this can be a new block or an existing freed block. The `self_position` argument
+    // is used to avoid loading the allocators position more than once when performing an allocation.
+    unsafe fn find_free_block(
+        &mut self,
+        length: Length,
+        self_position: u64,
+    ) -> Option<&'static mut MemoryBlock> {
+        // Get the first block
+        let mut block = self.blocks.as_mut_ptr();
+
+        // Only loop while the block pointer is less then the current position
+        while (block as u64) < self.blocks.as_ptr() as u64 + self_position {
+            let b = &mut *block;
+
+            let status = b.status.load(Ordering::Acquire);
+
+            // An unused block is safe to use
+            if status == MemoryStatus::Unused as u8 {
+                return Some(b);
+            }
+
+            // Re-use freed blocks when they're large enough
+            if status == MemoryStatus::Free as u8 && b.size >= length as usize {
+                // Split block if there is too much excess
+                if b.size - length as usize >= BLOCK_SPLIT_SIZE {
+                    b.size -= length as usize;
+                    b.used = 0;
+
+                    let block1 = b.data.as_mut_ptr().add(b.size) as *mut MemoryBlock;
+                    let b1 = &mut *block1;
+                    b1.size = length as usize;
+                    b1.used = 0;
+                    b1.status.store(MemoryStatus::Free as u8, Ordering::Release);
+                    return Some(b1);
+                }
+
+                // Otherwise return the whole block
+                return Some(b);
+            }
+
+            // Get the next block
+            block = b.next_ptr();
+        }
+
+        None
+    }
+
+    /// Create a new `MemoryBlock`, when `Some(block)` is returned, `block` will contain at least enough room for `length` bytes
+    /// but may be as large as `length` + `BLOCK_SPLIT_SIZE` bytes. When `None` is returned the allocation has failed.
+    pub unsafe fn alloc(&mut self, length: Length) -> Option<&'static mut MemoryBlock> {
+        let self_position = self.position.load(Ordering::Acquire);
+        let self_length = self.length.load(Ordering::Acquire);
+        let b = self.find_free_block(length, self_position);
+
+        // If there's a free block then re-use it
+        if let Some(b) = b {
+            b.used = length as usize;
+            b.status
+                .store(MemoryStatus::Active as u8, Ordering::Release);
+            return Some(b);
+        }
+
+        // Get the current index for a new block
+        let curr = self.blocks.as_ptr() as u64 + self_position;
+
+        // Get the number of bytes available
+        let mem_left = self_length - self_position - core::mem::size_of::<MemoryRoot>() as u64;
+
+        // When the allocation is larger than the number of bytes available
+        // we will need to try to grow the memory
+        if length >= mem_left {
+            // Calculate the number of pages needed to cover the remaining bytes
+            let npages = num_pages(length - mem_left);
+            let x = core::arch::wasm32::memory_grow(0, npages);
+            if x == usize::MAX {
+                return None;
+            }
+            self.length
+                .fetch_add(npages as u64 * PAGE_SIZE as u64, Ordering::SeqCst);
+        }
+
+        // Bump the position by the size of the actual data + the size of the MemoryBlock structure
+        self.position.fetch_add(
+            length + core::mem::size_of::<MemoryBlock>() as u64,
+            Ordering::SeqCst,
+        );
+
+        // Initialize a new block at the current position
+        let ptr = curr as *mut MemoryBlock;
+        let block = &mut *ptr;
+        block
+            .status
+            .store(MemoryStatus::Active as u8, Ordering::Release);
+        block.size = length as usize;
+        block.used = length as usize;
+        Some(block)
+    }
+
+    /// Finds the block at an offset in memory
+    pub unsafe fn find_block(&mut self, offs: Pointer) -> Option<&mut MemoryBlock> {
+        if offs >= self.blocks.as_ptr() as Pointer + self.length.load(Ordering::Acquire) as Pointer
+        {
+            return None;
+        }
+        let ptr = offs - core::mem::size_of::<MemoryBlock>() as u64;
+        let ptr = ptr as *mut MemoryBlock;
+        Some(&mut *ptr)
+    }
+}
+
+impl MemoryBlock {
+    /// Get a pointer to the next block
+    ///
+    /// NOTE: This does no checking to ensure the resulting pointer is valid, the offset
+    /// is calculated based on metadata provided by the current block
+    #[inline]
+    pub unsafe fn next_ptr(&mut self) -> *mut MemoryBlock {
+        self.data
+            .as_mut_ptr()
+            .add(self.size + core::mem::size_of::<MemoryBlock>()) as *mut MemoryBlock
+    }
+
+    /// Mark a block as free
+    pub fn free(&mut self) {
+        self.status
+            .store(MemoryStatus::Free as u8, Ordering::Release);
+    }
+}
+
+// Extism functions - these functions should be
+
+/// Allocate a block of memory and return the offset
+#[no_mangle]
+pub unsafe fn extism_alloc(n: Length) -> Pointer {
+    let region = MemoryRoot::new();
+    let block = region.alloc(n);
+    match block {
+        Some(block) => block.data.as_mut_ptr() as Pointer,
+        None => 0,
+    }
+}
+
+/// Free allocated memory
+#[no_mangle]
+pub unsafe fn extism_free(p: Pointer) {
+    let block = MemoryRoot::new().find_block(p);
+    if let Some(block) = block {
+        block.free();
+    }
+}
+
+/// Get the length of an allocated memory block
+#[no_mangle]
+pub unsafe fn extism_length(p: Pointer) -> Length {
+    if p == 0 {
+        return 0;
+    }
+    if let Some(block) = MemoryRoot::new().find_block(p) {
+        block.used as Length
+    } else {
+        0
+    }
+}
+
+/// Load a byte from Extism-managed memory
+#[no_mangle]
+pub unsafe fn extism_load_u8(p: Pointer) -> u8 {
+    *(p as *mut u8)
+}
+
+/// Load a u64 from Extism-managed memory
+#[no_mangle]
+pub unsafe fn extism_load_u64(p: Pointer) -> u64 {
+    *(p as *mut u64)
+}
+
+/// Load a byte from the input data
+#[no_mangle]
+pub unsafe fn extism_input_load_u8(p: Pointer) -> u8 {
+    *((INPUT_OFFSET + p) as *mut u8)
+}
+
+/// Load a u64 from the input data
+#[no_mangle]
+pub unsafe fn extism_input_load_u64(p: Pointer) -> u64 {
+    *((INPUT_OFFSET + p) as *mut u64)
+}
+
+/// Write a byte in Extism-managed memory
+#[no_mangle]
+pub unsafe fn extism_store_u8(p: Pointer, x: u8) {
+    *(p as *mut u8) = x;
+}
+
+/// Write a u64 in Extism-managed memory
+#[no_mangle]
+pub unsafe fn extism_store_u64(p: Pointer, x: u64) {
+    unsafe {
+        *(p as *mut u64) = x;
+    }
+}
+
+/// Set the range of the input data in memory
+#[no_mangle]
+pub fn extism_input_set(p: Pointer, len: Length) {
+    unsafe {
+        INPUT_OFFSET = p;
+        INPUT_LENGTH = len;
+    }
+}
+
+/// Set the range of the output data in memory
+#[no_mangle]
+pub fn extism_output_set(p: Pointer, len: Length) {
+    unsafe {
+        OUTPUT_OFFSET = p;
+        OUTPUT_LENGTH = len;
+    }
+}
+
+/// Get the input length
+#[no_mangle]
+pub fn extism_input_length() -> Length {
+    unsafe { INPUT_LENGTH }
+}
+
+/// Get the input offset in Exitsm-managed memory
+#[no_mangle]
+pub fn extism_input_offset() -> Length {
+    unsafe { INPUT_OFFSET }
+}
+
+/// Get the output length
+#[no_mangle]
+pub fn extism_output_length() -> Length {
+    unsafe { OUTPUT_LENGTH }
+}
+
+/// Get the output offset in Extism-managed memory
+#[no_mangle]
+pub fn extism_output_offset() -> Length {
+    unsafe { OUTPUT_OFFSET }
+}
+
+/// Reset the allocator
+#[no_mangle]
+pub unsafe fn extism_reset() {
+    ERROR.store(0, Ordering::SeqCst);
+    MemoryRoot::new().reset()
+}
+
+/// Set the error message offset
+#[no_mangle]
+pub unsafe fn extism_error_set(ptr: Pointer) {
+    ERROR.store(ptr, Ordering::SeqCst);
+}
+
+/// Get the error message offset, if it's `0` then no error has been set
+#[no_mangle]
+pub unsafe fn extism_error_get() -> Pointer {
+    ERROR.load(Ordering::SeqCst)
+}
+
+/// Get the position of the allocator, this can be used as an indication of how many bytes are currently in-use
+#[no_mangle]
+pub unsafe fn extism_memory_bytes() -> Length {
+    MemoryRoot::new().position.load(Ordering::Acquire)
+}

libextism/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libextism"
-version = "0.3.0"
+version = "0.5.2"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"

manifest/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "extism-manifest"
-version = "0.3.0"
+version = "0.5.0"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"

manifest/src/lib.rs

@@ -4,7 +4,7 @@ use std::path::{Path, PathBuf};
 #[deprecated]
 pub type ManifestMemory = MemoryOptions;
 
-#[derive(Default, serde::Serialize, serde::Deserialize)]
+#[derive(Default, Clone, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 #[serde(deny_unknown_fields)]
 pub struct MemoryOptions {
@@ -12,7 +12,7 @@ pub struct MemoryOptions {
     pub max_pages: Option<u32>,
 }
 
-#[derive(serde::Serialize, serde::Deserialize)]
+#[derive(Clone, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 #[serde(deny_unknown_fields)]
 pub struct HttpRequest {
@@ -43,7 +43,7 @@ impl HttpRequest {
     }
 }
 
-#[derive(Default, serde::Serialize, serde::Deserialize)]
+#[derive(Default, Clone, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 #[serde(deny_unknown_fields)]
 pub struct WasmMetadata {
@@ -81,7 +81,7 @@ impl From<Vec<u8>> for Wasm {
 #[deprecated]
 pub type ManifestWasm = Wasm;
 
-#[derive(serde::Serialize, serde::Deserialize)]
+#[derive(Clone, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 #[serde(untagged)]
 #[serde(deny_unknown_fields)]
@@ -153,7 +153,7 @@ fn base64_schema(gen: &mut schemars::gen::SchemaGenerator) -> schemars::schema::
     schema.into()
 }
 
-#[derive(Default, serde::Serialize, serde::Deserialize)]
+#[derive(Default, Clone, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 #[serde(deny_unknown_fields)]
 pub struct Manifest {

node/example.js

@@ -1,6 +1,5 @@
 const {
-  withContext,
-  Context,
+  Plugin,
   HostFunction,
   ValType,
 } = require("./dist/index.js");
@@ -13,29 +12,31 @@ function f(currentPlugin, inputs, outputs, userData) {
   outputs[0] = inputs[0];
 }
 
-let hello_world = new HostFunction(
+const hello_world = new HostFunction(
   "hello_world",
   [ValType.I64],
   [ValType.I64],
   f,
-  "Hello again!"
+  "Hello again!",
 );
 
-let functions = [hello_world];
+async function main() {
+  const functions = [hello_world];
 
-withContext(async function (context) {
-  let wasm = readFileSync("../wasm/code-functions.wasm");
-  let p = context.plugin(wasm, true, functions);
+  const wasm = readFileSync("../wasm/code-functions.wasm");
+  const p = new Plugin(wasm, true, functions);
 
   if (!p.functionExists("count_vowels")) {
     console.log("no function 'count_vowels' in wasm");
     process.exit(1);
   }
 
-  let buf = await p.call("count_vowels", process.argv[2] || "this is a test");
+  const buf = await p.call("count_vowels", process.argv[2] || "this is a test");
   console.log(JSON.parse(buf.toString())["count"]);
   p.free();
-});
+}
+
+main();
 
 // or, use a context like this:
 // let ctx = new Context();

node/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@extism/extism",
-  "version": "0.3.0",
+  "version": "0.5.0",
   "description": "Extism Host SDK for Node",
   "keywords": [
     "extism",
@@ -39,12 +39,12 @@
   "devDependencies": {
     "@types/ffi-napi": "^4.0.6",
     "@types/jest": "^29.2.0",
-    "@types/node": "^18.11.4",
+    "@types/node": "^20.1.0",
     "jest": "^29.2.2",
-    "prettier": "2.8.4",
+    "prettier": "3.0.2",
     "ts-jest": "^29.0.3",
     "ts-node": "^10.9.1",
-    "typedoc": "^0.23.18",
-    "typescript": "^4.8.4"
+    "typedoc": "^0.24.1",
+    "typescript": "^5.0.4"
   }
 }

node/src/index.ts

@@ -104,7 +104,7 @@ interface LibExtism {
     data_len: number,
     functions: Buffer,
     nfunctions: number,
-    wasi: boolean
+    wasi: boolean,
   ) => number;
   extism_plugin_update: (
     ctx: Buffer,
@@ -113,7 +113,7 @@ interface LibExtism {
     data_len: number,
     functions: Buffer,
     nfunctions: number,
-    wasi: boolean
+    wasi: boolean,
   ) => boolean;
   extism_error: (ctx: Buffer, plugin_id: number) => string;
   extism_plugin_call: (
@@ -121,7 +121,7 @@ interface LibExtism {
     plugin_id: number,
     func: string,
     input: string,
-    input_len: number
+    input_len: number,
   ) => number;
   extism_plugin_output_length: (ctx: Buffer, plugin_id: number) => number;
   extism_plugin_output_data: (ctx: Buffer, plugin_id: number) => Uint8Array;
@@ -129,13 +129,13 @@ interface LibExtism {
   extism_plugin_function_exists: (
     ctx: Buffer,
     plugin_id: number,
-    func: string
+    func: string,
   ) => boolean;
   extism_plugin_config: (
     ctx: Buffer,
     plugin_id: number,
     data: string | Buffer,
-    data_len: number
+    data_len: number,
   ) => void;
   extism_plugin_free: (ctx: Buffer, plugin_id: number) => void;
   extism_context_reset: (ctx: Buffer) => void;
@@ -148,7 +148,7 @@ interface LibExtism {
     nOutputs: number,
     f: Buffer,
     user_data: Buffer | null,
-    free: Buffer | null
+    free: Buffer | null,
   ) => Buffer;
   extism_function_set_namespace: (f: Buffer, s: string) => void;
   extism_function_free: (f: Buffer) => void;
@@ -321,9 +321,9 @@ export class Context {
     manifest: ManifestData,
     wasi: boolean = false,
     functions: HostFunction[] = [],
-    config?: PluginConfig
+    config?: PluginConfig,
   ) {
-    return new Plugin(this, manifest, wasi, functions, config);
+    return new Plugin(manifest, wasi, functions, config, this);
   }
 
   /**
@@ -385,7 +385,7 @@ export class CurrentPlugin {
     return Buffer.from(
       lib.extism_current_plugin_memory(this.pointer).buffer,
       offset,
-      length
+      length,
     );
   }
 
@@ -442,7 +442,7 @@ export class CurrentPlugin {
    * @param input - The input to read
    */
   inputBytes(input: typeof Val): Buffer {
-    return this.memory(input.v.i64)
+    return this.memory(input.v.i64);
   }
 
   /**
@@ -450,7 +450,7 @@ export class CurrentPlugin {
    * @param input - The input to read
    */
   inputString(input: typeof Val): string {
-    return this.memory(input.v.i64).toString()
+    return this.memory(input.v.i64).toString();
   }
 }
 
@@ -489,7 +489,7 @@ export class HostFunction {
         nInputs: number,
         outputs: Buffer,
         nOutputs: number,
-        user_data
+        user_data,
       ) => {
         let inputArr = [];
         let outputArr = [];
@@ -506,13 +506,13 @@ export class HostFunction {
           new CurrentPlugin(currentPlugin),
           inputArr,
           outputArr,
-          ...this.userData
+          ...this.userData,
         );
 
         for (var i = 0; i < nOutputs; i++) {
           Val.set(outputs, i, outputArr[i]);
         }
-      }
+      },
     );
     this.name = name;
     this.inputs = new ValTypeArray(inputs);
@@ -525,23 +525,23 @@ export class HostFunction {
       this.outputs.length,
       this.callback,
       null,
-      null
+      null,
     );
     this.userData = userData;
     functionRegistry.register(this, this.pointer, this.pointer);
   }
 
-  /** 
+  /**
    * Set function namespace
    */
   setNamespace(name: string) {
     if (this.pointer !== null) {
-      lib.extism_function_set_namespace(this.pointer, name)
+      lib.extism_function_set_namespace(this.pointer, name);
     }
   }
 
-  withNamespace(name: string) : HostFunction {
-    this.setNamespace(name)
+  withNamespace(name: string): HostFunction {
+    this.setNamespace(name);
     return this;
   }
 
@@ -560,18 +560,18 @@ export class HostFunction {
 }
 
 /**
-  * CancelHandle is used to cancel a running Plugin
-  */
+ * CancelHandle is used to cancel a running Plugin
+ */
 export class CancelHandle {
-  handle: Buffer
+  handle: Buffer;
 
   constructor(handle: Buffer) {
     this.handle = handle;
   }
 
   /**
-    * Cancel execution of the Plugin associated with the CancelHandle 
-    */
+   * Cancel execution of the Plugin associated with the CancelHandle
+   */
   cancel(): boolean {
     return lib.extism_plugin_cancel(this.handle);
   }
@@ -589,19 +589,22 @@ export class Plugin {
   /**
    * Constructor for a plugin. @see {@link Context#plugin}.
    *
-   * @param ctx - The context to manage this plugin
    * @param manifest - The {@link Manifest}
    * @param wasi - Set to true to enable WASI support
    * @param functions - An array of {@link HostFunction}
    * @param config - The plugin config
+   * @param ctx - The context to manage this plugin, or null to use a new context
    */
   constructor(
-    ctx: Context,
     manifest: ManifestData,
     wasi: boolean = false,
     functions: HostFunction[] = [],
-    config?: PluginConfig
+    config?: PluginConfig,
+    ctx: Context | null = null,
   ) {
+    if (ctx == null) {
+      ctx = new Context();
+    }
     let dataRaw: string | Buffer;
     if (Buffer.isBuffer(manifest) || typeof manifest === "string") {
       dataRaw = manifest;
@@ -621,7 +624,7 @@ export class Plugin {
       Buffer.byteLength(dataRaw, "utf-8"),
       this.functions,
       functions.length,
-      wasi
+      wasi,
     );
     if (plugin < 0) {
       var err = lib.extism_error(ctx.pointer, -1);
@@ -640,7 +643,7 @@ export class Plugin {
         ctx.pointer,
         this.id,
         s,
-        Buffer.byteLength(s, "utf-8")
+        Buffer.byteLength(s, "utf-8"),
       );
     }
   }
@@ -666,7 +669,7 @@ export class Plugin {
     manifest: ManifestData,
     wasi: boolean = false,
     functions: HostFunction[] = [],
-    config?: PluginConfig
+    config?: PluginConfig,
   ) {
     let dataRaw: string | Buffer;
     if (Buffer.isBuffer(manifest) || typeof manifest === "string") {
@@ -688,7 +691,7 @@ export class Plugin {
       Buffer.byteLength(dataRaw, "utf-8"),
       this.functions,
       functions.length,
-      wasi
+      wasi,
     );
     if (!ok) {
       var err = lib.extism_error(this.ctx.pointer, -1);
@@ -704,7 +707,7 @@ export class Plugin {
         this.ctx.pointer,
         this.id,
         s,
-        Buffer.byteLength(s, "utf-8")
+        Buffer.byteLength(s, "utf-8"),
       );
     }
   }
@@ -721,7 +724,7 @@ export class Plugin {
     return lib.extism_plugin_function_exists(
       this.ctx.pointer,
       this.id,
-      functionName
+      functionName,
     );
   }
 
@@ -739,7 +742,7 @@ export class Plugin {
    *
    * @param functionName - The name of the function
    * @param input - The input data
-   *@returns A Buffer repreesentation of the output
+   * @returns A Buffer repreesentation of the output
    */
   async call(functionName: string, input: string | Buffer): Promise<Buffer> {
     return new Promise<Buffer>((resolve, reject) => {
@@ -749,7 +752,7 @@ export class Plugin {
         this.id,
         functionName,
         input.toString(),
-        Buffer.byteLength(input, "utf-8")
+        Buffer.byteLength(input, "utf-8"),
       );
       if (rc !== 0) {
         var err = lib.extism_error(this.ctx.pointer, this.id);
@@ -763,7 +766,7 @@ export class Plugin {
       var buf = Buffer.from(
         lib.extism_plugin_output_data(this.ctx.pointer, this.id).buffer,
         0,
-        out_len
+        out_len,
       );
       resolve(buf);
     });

ocaml/Makefile

@@ -1,4 +1,5 @@
-VERSION?=0.2.0
+VERSION?=0.4.0
+TAG?=0.5.0
 
 build:
 	dune build
@@ -12,4 +13,4 @@ prepare:
 	opam install .. --deps-only
 
 publish:
-	opam publish -v $(VERSION) -t $(VERSION) ..
+	opam publish -v $(VERSION) https://github.com/extism/extism/archive/refs/tags/v$(TAG).tar.gz ..

ocaml/bin/main.ml

@@ -4,10 +4,9 @@ open Cmdliner
 let read_stdin () = In_channel.input_all stdin
 
 let main file func_name input =
-  with_context @@ fun ctx ->
   let input = if String.equal input "-" then read_stdin () else input in
   let file = In_channel.with_open_bin file In_channel.input_all in
-  let plugin = Plugin.create ctx file ~wasi:true |> Result.get_ok in
+  let plugin = Plugin.create file ~wasi:true |> Result.get_ok in
   let res = Plugin.call plugin ~name:func_name input |> Result.get_ok in
   print_endline res
 

ocaml/lib/extism.mli

@@ -208,7 +208,7 @@ module Plugin : sig
     ?config:Manifest.config ->
     ?wasi:bool ->
     ?functions:Function.t list ->
-    Context.t ->
+    ?context:Context.t ->
     string ->
     (t, Error.t) result
   (** Make a new plugin from raw WebAssembly or JSON encoded manifest *)
@@ -216,7 +216,7 @@ module Plugin : sig
   val of_manifest :
     ?wasi:bool ->
     ?functions:Function.t list ->
-    Context.t ->
+    ?context:Context.t ->
     Manifest.t ->
     (t, Error.t) result
   (** Make a new plugin from a [Manifest] *)

ocaml/lib/plugin.ml

@@ -26,7 +26,8 @@ let free t =
   if not (Ctypes.is_null t.ctx.pointer) then
     Bindings.extism_plugin_free t.ctx.pointer t.id
 
-let create ?config ?(wasi = false) ?(functions = []) ctx wasm =
+let create ?config ?(wasi = false) ?(functions = []) ?context wasm =
+  let ctx = match context with Some c -> c | None -> Context.create () in
   let func_ptrs = List.map (fun x -> x.Function.pointer) functions in
   let arr = Ctypes.CArray.of_list Ctypes.(ptr void) func_ptrs in
   let n_funcs = Ctypes.CArray.length arr in
@@ -48,16 +49,15 @@ let create ?config ?(wasi = false) ?(functions = []) ctx wasm =
       let () = Gc.finalise free t in
       Ok t
 
-let of_manifest ?wasi ?functions ctx manifest =
+let of_manifest ?wasi ?functions ?context manifest =
   let data = Manifest.to_json manifest in
-  create ctx ?wasi ?functions data
+  create ?wasi ?functions ?context data
 
 let%test "free plugin" =
   let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
-  with_context (fun ctx ->
-      let plugin = of_manifest ctx manifest |> Error.unwrap in
-      free plugin;
-      true)
+  let plugin = of_manifest manifest |> Error.unwrap in
+  free plugin;
+  true
 
 let update plugin ?config ?(wasi = false) ?(functions = []) wasm =
   let { id; ctx; _ } = plugin in
@@ -77,7 +77,9 @@ let update plugin ?config ?(wasi = false) ?(functions = []) wasm =
     | Some msg -> Error (`Msg msg)
   else if not (set_config plugin config) then
     Error (`Msg "call to set_config failed")
-  else Ok ()
+  else
+    let () = plugin.functions <- functions in
+    Ok ()
 
 let update_manifest plugin ?wasi manifest =
   let data = Manifest.to_json manifest in
@@ -85,11 +87,10 @@ let update_manifest plugin ?wasi manifest =
 
 let%test "update plugin manifest and config" =
   let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
-  with_context (fun ctx ->
-      let config = [ ("a", Some "1") ] in
-      let plugin = of_manifest ctx manifest |> Error.unwrap in
-      let manifest = Manifest.with_config manifest config in
-      update_manifest plugin manifest |> Result.is_ok)
+  let config = [ ("a", Some "1") ] in
+  let plugin = of_manifest manifest |> Error.unwrap in
+  let manifest = Manifest.with_config manifest config in
+  update_manifest plugin manifest |> Result.is_ok
 
 let call' f { id; ctx; _ } ~name input len =
   let rc = f ctx.pointer id name input len in
@@ -114,11 +115,10 @@ let call_bigstring (t : t) ~name input =
 
 let%test "call_bigstring" =
   let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
-  with_context (fun ctx ->
-      let plugin = of_manifest ctx manifest |> Error.unwrap in
-      call_bigstring plugin ~name:"count_vowels"
-        (Bigstringaf.of_string ~off:0 ~len:14 "this is a test")
-      |> Error.unwrap |> Bigstringaf.to_string = "{\"count\": 4}")
+  let plugin = of_manifest manifest |> Error.unwrap in
+  call_bigstring plugin ~name:"count_vowels"
+    (Bigstringaf.of_string ~off:0 ~len:14 "this is a test")
+  |> Error.unwrap |> Bigstringaf.to_string = "{\"count\": 4}"
 
 let call (t : t) ~name input =
   let len = String.length input in
@@ -127,10 +127,9 @@ let call (t : t) ~name input =
 
 let%test "call" =
   let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
-  with_context (fun ctx ->
-      let plugin = of_manifest ctx manifest |> Error.unwrap in
-      call plugin ~name:"count_vowels" "this is a test"
-      |> Error.unwrap = "{\"count\": 4}")
+  let plugin = of_manifest manifest |> Error.unwrap in
+  call plugin ~name:"count_vowels" "this is a test"
+  |> Error.unwrap = "{\"count\": 4}"
 
 let%test "call_functions" =
   let open Types.Val_type in
@@ -147,22 +146,18 @@ let%test "call_functions" =
   in
   let functions = [ hello_world ] in
   let manifest = Manifest.(create [ Wasm.file "test/code-functions.wasm" ]) in
-  with_context (fun ctx ->
-      let plugin =
-        of_manifest ctx manifest ~functions ~wasi:true |> Error.unwrap
-      in
-      call plugin ~name:"count_vowels" "this is a test"
-      |> Error.unwrap = "{\"count\": 4}")
+  let plugin = of_manifest manifest ~functions ~wasi:true |> Error.unwrap in
+  call plugin ~name:"count_vowels" "this is a test"
+  |> Error.unwrap = "{\"count\": 4}"
 
 let function_exists { id; ctx; _ } name =
   Bindings.extism_plugin_function_exists ctx.pointer id name
 
 let%test "function exists" =
   let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
-  with_context (fun ctx ->
-      let plugin = of_manifest ctx manifest |> Error.unwrap in
-      function_exists plugin "count_vowels"
-      && not (function_exists plugin "function_does_not_exist"))
+  let plugin = of_manifest manifest |> Error.unwrap in
+  function_exists plugin "count_vowels"
+  && not (function_exists plugin "function_does_not_exist")
 
 module Cancel_handle = struct
   type t = { inner : unit Ctypes.ptr }

ocaml/manifest/extism_manifest.ml

@@ -1,3 +1,5 @@
+open Ppx_yojson_conv_lib.Yojson_conv
+
 type base64 = string
 
 let yojson_of_base64 x = `String (Base64.encode_exn x)

php/example/index.php

@@ -2,9 +2,8 @@
 
 require_once __DIR__ . '/vendor/autoload.php';
 
-$ctx = new \Extism\Context();
 $wasm = file_get_contents("../../wasm/code.wasm");
-$plugin = new \Extism\Plugin($ctx, $wasm);
+$plugin = new \Extism\Plugin($wasm);
 
 $output = $plugin->call("count_vowels", "this is an example");
 $json = json_decode(pack('C*', ...$output));

php/src/Plugin.php

@@ -31,8 +31,12 @@ class Plugin
 
     private $id;
 
-    public function __construct($ctx, $data, $wasi = false, $config = null) 
+    public function __construct($data, $wasi = false, $config = null, $ctx = null) 
     {
+        if ($ctx == null) {
+          $ctx = new Context();
+        }
+
         $this->lib = $ctx->lib;
 
         $this->wasi = $wasi;
@@ -49,7 +53,7 @@ class Plugin
         $id = $this->lib->extism_plugin_new($ctx->pointer, $data, count($data), null, 0, (int)$wasi);
         if ($id < 0) {
             $err = $this->lib->extism_error($ctx->pointer, -1);
-            throw new \Exception("Extism: unable to load plugin: " . $err);
+            throw new \Exception("Extism: unable to load plugin: " . $err->toString());
         }
         $this->id = $id;
         $this->context = $ctx;
@@ -91,7 +95,7 @@ class Plugin
             $msg = "code = " . $rc;
             $err = $this->lib->extism_error($this->context->pointer, $this->id);
             if ($err) {
-                $msg = $msg . ", error = " . $err;
+                $msg = $msg . ", error = " . $err->toString();
             }
             throw new \Exception("Extism: call to '".$name."' failed with " . $msg);
         }
@@ -121,7 +125,7 @@ class Plugin
         $ok = $this->lib->extism_plugin_update($this->context->pointer, $this->id, $data, count($data), null, 0, (int)$wasi);
         if (!$ok) {
             $err = $this->lib->extism_error($this->context->pointer, -1);
-            throw new \Exception("Extism: unable to update plugin: " . $err);
+            throw new \Exception("Extism: unable to update plugin: " . $err->toString());
         }
 
         if ($config != null) {
@@ -138,4 +142,4 @@ function string_to_bytes($string) {
     }
 
     return $bytes;
-}
+}

python/Makefile

@@ -20,7 +20,7 @@ lint:
 	poetry run black --check extism/ tests/ example.py
 
 docs:
-	poetry run pdoc --force --html extism
+	poetry run pycco extism/*.py
 
 show-docs: docs
-	open html/extism/index.html
+	open docs/extism.html

python/example.py

@@ -5,11 +5,13 @@ import hashlib
 import pathlib
 
 sys.path.append(".")
-from extism import Context, Function, host_fn, ValType
+from extism import Function, host_fn, ValType, Plugin, set_log_file
+
+set_log_file("stderr", "trace")
 
 
 @host_fn
-def hello_world(plugin, input_, output, context, a_string):
+def hello_world(plugin, input_, output, a_string):
     print("Hello from Python!")
     print(a_string)
     print(input_)
@@ -26,35 +28,33 @@ def main(args):
     if len(args) > 1:
         data = args[1].encode()
     else:
-        data = b"some data from python!"
+        data = b"a" * 1024
 
     wasm_file_path = (
         pathlib.Path(__file__).parent.parent / "wasm" / "code-functions.wasm"
     )
     wasm = wasm_file_path.read_bytes()
     hash = hashlib.sha256(wasm).hexdigest()
-    config = {"wasm": [{"data": wasm, "hash": hash}], "memory": {"max": 5}}
+    manifest = {"wasm": [{"data": wasm, "hash": hash}]}
 
-    # a Context provides a scope for plugins to be managed within. creating multiple contexts
-    # is expected and groups plugins based on source/tenant/lifetime etc.
-    with Context() as context:
-        functions = [
-            Function(
-                "hello_world",
-                [ValType.I64],
-                [ValType.I64],
-                hello_world,
-                context,
-                "Hello again!",
-            )
-        ]
-        plugin = context.plugin(config, wasi=True, functions=functions)
-        # Call `count_vowels`
-        wasm_vowel_count = json.loads(plugin.call("count_vowels", data))
+    functions = [
+        Function(
+            "hello_world",
+            [ValType.I64],
+            [ValType.I64],
+            hello_world,
+            "Hello again!",
+        )
+    ]
+    plugin = Plugin(manifest, wasi=True, functions=functions)
+    # Call `count_vowels`
+    wasm_vowel_count = plugin.call("count_vowels", data)
+    print(wasm_vowel_count)
+    j = json.loads(wasm_vowel_count)
 
-    print("Number of vowels:", wasm_vowel_count["count"])
+    print("Number of vowels:", j["count"])
 
-    assert wasm_vowel_count["count"] == count_vowels(data)
+    assert j["count"] == count_vowels(data)
 
 
 if __name__ == "__main__":

python/extism/extism.py

@@ -193,7 +193,9 @@ class Context:
         Plugin
             The created plugin
         """
-        return Plugin(self, manifest, wasi, config, functions)
+        return Plugin(
+            manifest, context=self, wasi=wasi, config=config, functions=functions
+        )
 
 
 class Function:
@@ -247,17 +249,21 @@ class Plugin:
 
     def __init__(
         self,
-        context: Context,
         plugin: Union[str, bytes, dict],
+        context=None,
         wasi=False,
         config=None,
         functions=None,
     ):
         """
-        Construct a Plugin. Please use Context#plugin instead.
+        Construct a Plugin
         """
 
+        if context is None:
+            context = Context()
+
         wasm = _wasm(plugin)
+        self.functions = functions
 
         # Register plugin
         if functions is not None:
@@ -305,6 +311,7 @@ class Plugin:
         """
         wasm = _wasm(manifest)
         if functions is not None:
+            self.functions = functions
             functions = [f.pointer for f in functions]
             ptr = _ffi.new("ExtismFunction*[]", functions)
             ok = _lib.extism_plugin_update(

python/pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "extism"
-version = "0.3.0"
+version = "0.5.0"
 description = "Extism Host SDK for python"
 authors = ["The Extism Authors <oss@extism.org>"]
 license = "BSD-3-Clause"
@@ -12,7 +12,7 @@ cffi = "^1.10.0"
 
 [tool.poetry.dev-dependencies]
 black = "^23.1.0"
-pdoc3 = "^0.10.0"
+pycco = "^0.6.0"
 
 [build-system]
 requires = ["poetry-core>=1.0.0"]

python/tests/test_extism.py

@@ -104,23 +104,24 @@ class TestExtism(unittest.TestCase):
         with extism.Context() as ctx:
             plugin = ctx.plugin(self._loop_manifest())
             cancel_handle = plugin.cancel_handle()
+
             def cancel(handle):
                 time.sleep(0.5)
                 handle.cancel()
+
             Thread(target=cancel, args=[cancel_handle]).run()
             self.assertRaises(extism.Error, lambda: plugin.call("infinite_loop", b""))
 
     def _manifest(self, functions=False):
         wasm = self._count_vowels_wasm(functions)
         hash = hashlib.sha256(wasm).hexdigest()
-        return {"wasm": [{"data": wasm, "hash": hash}], "memory": {"max_pages": 5}}
+        return {"wasm": [{"data": wasm, "hash": hash}]}
 
     def _loop_manifest(self):
         wasm = self._infinite_loop_wasm()
         hash = hashlib.sha256(wasm).hexdigest()
         return {
             "wasm": [{"data": wasm, "hash": hash}],
-            "memory": {"max_pages": 5},
             "timeout_ms": 1000,
         }
 

ruby/Gemfile

@@ -11,5 +11,5 @@ gem "ffi", "~> 1.15.5"
 group :development do
   gem "yard", "~> 0.9.28"
   gem "rufo", "~> 0.13.0"
-  gem "minitest", "~> 5.18.0"
+  gem "minitest", "~> 5.19.0"
 end

ruby/example.rb

@@ -1,17 +1,11 @@
 require "./lib/extism"
 require "json"
 
-# a Context provides a scope for plugins to be managed within. creating multiple contexts
-# is expected and groups plugins based on source/tenant/lifetime etc.
-# We recommend you use `Extism.with_context` unless you have a reason to keep your context around.
-# If you do you can create a context with `Extism#new`, example: `ctx = Extism.new`
-Extism.with_context do |ctx|
-  manifest = {
-    :wasm => [{ :path => "../wasm/code.wasm" }],
-  }
+manifest = {
+  :wasm => [{ :path => "../wasm/code.wasm" }],
+}
 
-  plugin = ctx.plugin(manifest)
-  res = JSON.parse(plugin.call("count_vowels", ARGV[0] || "this is a test"))
+plugin = Extism::Plugin.new(manifest)
+res = JSON.parse(plugin.call("count_vowels", ARGV[0] || "this is a test"))
 
-  puts res["count"]
-end
+puts res["count"]

ruby/lib/extism.rb

@@ -86,12 +86,13 @@ module Extism
 
     # Create a new plugin from a WASM module or JSON encoded manifest
     #
+    # @see Plugin#new
     # @param wasm [Hash, String] The manifest for the plugin. See https://extism.org/docs/concepts/manifest/.
     # @param wasi [Boolean] Enable WASI support
     # @param config [Hash] The plugin config
     # @return [Plugin]
     def plugin(wasm, wasi = false, config = nil)
-      Plugin.new(self, wasm, wasi, config)
+      Plugin.new(wasm, wasi, config, self)
     end
   end
 
@@ -131,12 +132,14 @@ module Extism
   class Plugin
     # Intialize a plugin
     #
-    # @see Extism::Context#plugin
-    # @param context [Context] The context to manager this plugin
     # @param wasm [Hash, String] The manifest or WASM binary. See https://extism.org/docs/concepts/manifest/.
     # @param wasi [Boolean] Enable WASI support
     # @param config [Hash] The plugin config
-    def initialize(context, wasm, wasi = false, config = nil)
+    # @param context [Context] The context to manager this plugin
+    def initialize(wasm, wasi = false, config = nil, context = nil)
+      if context.nil? then
+        context = Context.new
+      end
       @context = context
       if wasm.class == Hash
         wasm = JSON.generate(wasm)

ruby/lib/extism/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Extism
-  VERSION = "0.3.0"
+  VERSION = '0.5.0'
 end

runtime/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "extism-runtime"
-version = "0.3.0"
+version = "0.5.2"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"
@@ -9,9 +9,9 @@ repository = "https://github.com/extism/extism"
 description = "Extism runtime component"
 
 [dependencies]
-wasmtime = "6.0.1"
-wasmtime-wasi = "6.0.1"
-wasmtime-wasi-nn = {version = "6.0.1", optional=true}
+wasmtime = ">= 10.0.0, < 12.0.0"
+wasmtime-wasi = ">= 10.0.0, < 12.0.0"
+wasmtime-wasi-nn = {version = ">= 10.0.0, < 12.0.0", optional=true}
 anyhow = "1"
 serde = {version = "1", features = ["derive"]}
 serde_json = "1"
@@ -22,8 +22,7 @@ log4rs = "1.1"
 url = "2"
 glob = "0.3"
 ureq = {version = "2.5", optional=true}
-extism-manifest = { version = "0.3.0", path = "../manifest" }
-pretty-hex = { version = "0.3" }
+extism-manifest = { version = "0.5.0", path = "../manifest" }
 uuid = { version = "1", features = ["v4"] }
 libc = "0.2"
 

runtime/build.rs

@@ -1,4 +1,6 @@
 fn main() {
+    println!("cargo:rerun-if-changed=src/extism-runtime.wasm");
+
     let fn_macro = "
 #define EXTISM_FUNCTION(N) extern void N(ExtismCurrentPlugin*, const ExtismVal*, ExtismSize, ExtismVal*, ExtismSize, void*)
 #define EXTISM_GO_FUNCTION(N) extern void N(void*, ExtismVal*, ExtismSize, ExtismVal*, ExtismSize, uintptr_t)
@@ -16,7 +18,7 @@ fn main() {
         .rename_item("Context", "ExtismContext")
         .rename_item("ValType", "ExtismValType")
         .rename_item("ValUnion", "ExtismValUnion")
-        .rename_item("Plugin", "ExtismCurrentPlugin")
+        .rename_item("Internal", "ExtismCurrentPlugin")
         .with_style(cbindgen::Style::Type)
         .generate()
     {

runtime/extism.h

@@ -54,7 +54,7 @@ typedef struct ExtismCancelHandle ExtismCancelHandle;
 typedef struct ExtismFunction ExtismFunction;
 
 /**
- * Plugin contains everything needed to execute a WASM function
+ * Internal stores data that is available to the caller in PDK functions
  */
 typedef struct ExtismCurrentPlugin ExtismCurrentPlugin;
 
@@ -81,7 +81,12 @@ typedef struct {
 /**
  * Host function signature
  */
-typedef void (*ExtismFunctionType)(ExtismCurrentPlugin *plugin, const ExtismVal *inputs, ExtismSize n_inputs, ExtismVal *outputs, ExtismSize n_outputs, void *data);
+typedef void (*ExtismFunctionType)(ExtismCurrentPlugin *plugin,
+                                   const ExtismVal *inputs,
+                                   ExtismSize n_inputs,
+                                   ExtismVal *outputs,
+                                   ExtismSize n_outputs,
+                                   void *data);
 
 typedef int32_t ExtismPlugin;
 
@@ -245,7 +250,7 @@ const char *extism_error(ExtismContext *ctx, ExtismPlugin plugin);
 ExtismSize extism_plugin_output_length(ExtismContext *ctx, ExtismPlugin plugin);
 
 /**
- * Get the length of a plugin's output data
+ * Get a pointer to the output data
  */
 const uint8_t *extism_plugin_output_data(ExtismContext *ctx, ExtismPlugin plugin);
 

runtime/src/context.rs

@@ -1,4 +1,3 @@
-use std::cell::UnsafeCell;
 use std::collections::{BTreeMap, VecDeque};
 
 use crate::*;
@@ -8,7 +7,7 @@ static mut TIMER: std::sync::Mutex<Option<Timer>> = std::sync::Mutex::new(None);
 /// A `Context` is used to store and manage plugins
 pub struct Context {
     /// Plugin registry
-    pub plugins: BTreeMap<PluginIndex, UnsafeCell<Plugin>>,
+    pub plugins: BTreeMap<PluginIndex, Plugin>,
 
     /// Error message
     pub error: Option<std::ffi::CString>,
@@ -91,7 +90,7 @@ impl Context {
                 return -1;
             }
         };
-        self.plugins.insert(id, UnsafeCell::new(plugin));
+        self.plugins.insert(id, plugin);
         id
     }
 
@@ -127,7 +126,7 @@ impl Context {
     /// Get a plugin from the context
     pub fn plugin(&mut self, id: PluginIndex) -> Option<*mut Plugin> {
         match self.plugins.get_mut(&id) {
-            Some(x) => Some(x.get_mut()),
+            Some(x) => Some(x),
             None => None,
         }
     }

runtime/src/function.rs

@@ -169,12 +169,12 @@ impl Function {
     ) -> Function
     where
         F: 'static
-            + Fn(&mut crate::Plugin, &[Val], &mut [Val], UserData) -> Result<(), Error>
+            + Fn(&mut Internal, &[Val], &mut [Val], UserData) -> Result<(), Error>
             + Sync
             + Send,
     {
         let user_data = user_data.unwrap_or_default();
-        let data = UserData::new_pointer(user_data.ptr, None);
+        let data = user_data.make_copy();
         Function {
             name: name.into(),
             ty: wasmtime::FuncType::new(
@@ -182,7 +182,7 @@ impl Function {
                 returns.into_iter().map(wasmtime::ValType::from),
             ),
             f: std::sync::Arc::new(move |mut caller, inp, outp| {
-                f(caller.data_mut().plugin_mut(), inp, outp, data.make_copy())
+                f(caller.data_mut(), inp, outp, data.make_copy())
             }),
             namespace: None,
             _user_data: std::sync::Arc::new(user_data),

runtime/src/internal.rs

@@ -0,0 +1,345 @@
+use std::collections::BTreeMap;
+
+use crate::*;
+
+/// WASI context
+pub struct Wasi {
+    /// wasi
+    pub ctx: wasmtime_wasi::WasiCtx,
+
+    /// wasi-nn
+    #[cfg(feature = "nn")]
+    pub nn: wasmtime_wasi_nn::WasiNnCtx,
+}
+
+/// Internal stores data that is available to the caller in PDK functions
+pub struct Internal {
+    /// Store
+    pub store: *mut Store<Internal>,
+
+    /// Linker
+    pub linker: *mut wasmtime::Linker<Internal>,
+
+    /// WASI context
+    pub wasi: Option<Wasi>,
+
+    /// Keep track of the status from the last HTTP request
+    pub http_status: u16,
+
+    /// Plugin variables
+    pub vars: BTreeMap<String, Vec<u8>>,
+
+    pub manifest: Manifest,
+
+    pub available_pages: Option<u32>,
+
+    pub(crate) memory_limiter: Option<MemoryLimiter>,
+}
+
+/// InternalExt provides a unified way of acessing `memory`, `store` and `internal` values
+pub trait InternalExt {
+    fn store(&self) -> &Store<Internal>;
+
+    fn store_mut(&mut self) -> &mut Store<Internal>;
+
+    fn linker(&self) -> &Linker<Internal>;
+
+    fn linker_mut(&mut self) -> &mut Linker<Internal>;
+
+    fn linker_and_store(&mut self) -> (&mut Linker<Internal>, &mut Store<Internal>);
+
+    fn internal(&self) -> &Internal {
+        self.store().data()
+    }
+
+    fn internal_mut(&mut self) -> &mut Internal {
+        self.store_mut().data_mut()
+    }
+
+    fn memory_ptr(&mut self) -> *mut u8 {
+        let (linker, mut store) = self.linker_and_store();
+        if let Some(mem) = linker.get(&mut store, "env", "memory") {
+            if let Some(mem) = mem.into_memory() {
+                return mem.data_ptr(&mut store);
+            }
+        }
+
+        std::ptr::null_mut()
+    }
+
+    fn memory(&mut self) -> &mut [u8] {
+        let (linker, mut store) = self.linker_and_store();
+        let mem = linker
+            .get(&mut store, "env", "memory")
+            .unwrap()
+            .into_memory()
+            .unwrap();
+        let ptr = mem.data_ptr(&store);
+        if ptr.is_null() {
+            return &mut [];
+        }
+        let size = mem.data_size(&store);
+        unsafe { std::slice::from_raw_parts_mut(ptr, size) }
+    }
+
+    fn memory_read(&mut self, offs: u64, len: Size) -> &[u8] {
+        trace!("memory_read: {}, {}", offs, len);
+        let offs = offs as usize;
+        let len = len as usize;
+        let mem = self.memory();
+        &mem[offs..offs + len]
+    }
+
+    fn memory_read_str(&mut self, offs: u64) -> Result<&str, std::str::Utf8Error> {
+        let len = self.memory_length(offs);
+        std::str::from_utf8(self.memory_read(offs, len))
+    }
+
+    fn memory_write(&mut self, offs: u64, bytes: impl AsRef<[u8]>) {
+        trace!("memory_write: {}", offs);
+        let b = bytes.as_ref();
+        let offs = offs as usize;
+        let len = b.len();
+        self.memory()[offs..offs + len].copy_from_slice(bytes.as_ref());
+    }
+
+    fn memory_alloc(&mut self, n: Size) -> Result<u64, Error> {
+        let (linker, mut store) = self.linker_and_store();
+        let output = &mut [Val::I64(0)];
+        linker
+            .get(&mut store, "env", "extism_alloc")
+            .unwrap()
+            .into_func()
+            .unwrap()
+            .call(&mut store, &[Val::I64(n as i64)], output)?;
+        let offs = output[0].unwrap_i64() as u64;
+        if offs == 0 {
+            anyhow::bail!("out of memory")
+        }
+        trace!("memory_alloc: {}, {}", offs, n);
+        Ok(offs)
+    }
+
+    fn memory_alloc_bytes(&mut self, bytes: impl AsRef<[u8]>) -> Result<u64, Error> {
+        let b = bytes.as_ref();
+        let offs = self.memory_alloc(b.len() as Size)?;
+        self.memory_write(offs, b);
+        Ok(offs)
+    }
+
+    fn memory_free(&mut self, offs: u64) {
+        let (linker, mut store) = self.linker_and_store();
+        linker
+            .get(&mut store, "env", "extism_free")
+            .unwrap()
+            .into_func()
+            .unwrap()
+            .call(&mut store, &[Val::I64(offs as i64)], &mut [])
+            .unwrap();
+    }
+
+    fn memory_length(&mut self, offs: u64) -> u64 {
+        let (linker, mut store) = self.linker_and_store();
+        let output = &mut [Val::I64(0)];
+        linker
+            .get(&mut store, "env", "extism_length")
+            .unwrap()
+            .into_func()
+            .unwrap()
+            .call(&mut store, &[Val::I64(offs as i64)], output)
+            .unwrap();
+        let len = output[0].unwrap_i64() as u64;
+        trace!("memory_length: {}, {}", offs, len);
+        len
+    }
+
+    // A convenience method to set the plugin error and return a value
+    fn error<E>(&mut self, e: impl std::fmt::Debug, x: E) -> E {
+        let s = format!("{e:?}");
+        debug!("Set error: {:?}", s);
+        if let Ok(offs) = self.memory_alloc_bytes(&s) {
+            let (linker, mut store) = self.linker_and_store();
+            if let Some(f) = linker.get(&mut store, "env", "extism_error_set") {
+                f.into_func()
+                    .unwrap()
+                    .call(&mut store, &[Val::I64(offs as i64)], &mut [])
+                    .unwrap();
+            }
+        }
+        x
+    }
+
+    fn clear_error(&mut self) {
+        let (linker, mut store) = self.linker_and_store();
+        if let Some(f) = linker.get(&mut store, "env", "extism_error_set") {
+            f.into_func()
+                .unwrap()
+                .call(&mut store, &[Val::I64(0)], &mut [])
+                .unwrap();
+        }
+    }
+
+    fn has_error(&mut self) -> bool {
+        let (linker, mut store) = self.linker_and_store();
+        let output = &mut [Val::I64(0)];
+        linker
+            .get(&mut store, "env", "extism_error_get")
+            .unwrap()
+            .into_func()
+            .unwrap()
+            .call(&mut store, &[], output)
+            .unwrap();
+        output[0].unwrap_i64() != 0
+    }
+
+    fn get_error(&mut self) -> Option<&str> {
+        let (linker, mut store) = self.linker_and_store();
+        let output = &mut [Val::I64(0)];
+        linker
+            .get(&mut store, "env", "extism_error_get")
+            .unwrap()
+            .into_func()
+            .unwrap()
+            .call(&mut store, &[], output)
+            .unwrap();
+        let offs = output[0].unwrap_i64() as u64;
+        if offs == 0 {
+            return None;
+        }
+
+        let length = self.memory_length(offs);
+        let data = self.memory_read(offs, length);
+        let s = std::str::from_utf8(data);
+        match s {
+            Ok(s) => Some(s),
+            Err(_) => None,
+        }
+    }
+}
+
+impl Internal {
+    pub(crate) fn new(
+        manifest: Manifest,
+        wasi: bool,
+        available_pages: Option<u32>,
+    ) -> Result<Self, Error> {
+        let wasi = if wasi {
+            let auth = wasmtime_wasi::ambient_authority();
+            let mut ctx = wasmtime_wasi::WasiCtxBuilder::new();
+            for (k, v) in manifest.as_ref().config.iter() {
+                ctx = ctx.env(k, v)?;
+            }
+
+            if let Some(a) = &manifest.as_ref().allowed_paths {
+                for (k, v) in a.iter() {
+                    let d = wasmtime_wasi::Dir::open_ambient_dir(k, auth)?;
+                    ctx = ctx.preopened_dir(d, v)?;
+                }
+            }
+
+            #[cfg(feature = "nn")]
+            let nn = wasmtime_wasi_nn::WasiNnCtx::new()?;
+
+            Some(Wasi {
+                ctx: ctx.build(),
+                #[cfg(feature = "nn")]
+                nn,
+            })
+        } else {
+            None
+        };
+
+        let memory_limiter = if let Some(pgs) = available_pages {
+            let n = pgs as usize * 65536;
+            Some(MemoryLimiter {
+                max_bytes: n,
+                bytes_left: n,
+            })
+        } else {
+            None
+        };
+
+        Ok(Internal {
+            wasi,
+            manifest,
+            http_status: 0,
+            vars: BTreeMap::new(),
+            linker: std::ptr::null_mut(),
+            store: std::ptr::null_mut(),
+            available_pages,
+            memory_limiter,
+        })
+    }
+
+    pub fn linker(&self) -> &wasmtime::Linker<Internal> {
+        unsafe { &*self.linker }
+    }
+
+    pub fn linker_mut(&mut self) -> &mut wasmtime::Linker<Internal> {
+        unsafe { &mut *self.linker }
+    }
+}
+
+impl InternalExt for Internal {
+    fn store(&self) -> &Store<Internal> {
+        unsafe { &*self.store }
+    }
+
+    fn store_mut(&mut self) -> &mut Store<Internal> {
+        unsafe { &mut *self.store }
+    }
+
+    fn linker(&self) -> &Linker<Internal> {
+        unsafe { &*self.linker }
+    }
+
+    fn linker_mut(&mut self) -> &mut Linker<Internal> {
+        unsafe { &mut *self.linker }
+    }
+
+    fn linker_and_store(&mut self) -> (&mut Linker<Internal>, &mut Store<Internal>) {
+        unsafe { (&mut *self.linker, &mut *self.store) }
+    }
+}
+
+pub(crate) struct MemoryLimiter {
+    bytes_left: usize,
+    max_bytes: usize,
+}
+
+impl MemoryLimiter {
+    pub(crate) fn reset(&mut self) {
+        self.bytes_left = self.max_bytes;
+    }
+}
+
+impl wasmtime::ResourceLimiter for MemoryLimiter {
+    fn memory_growing(
+        &mut self,
+        current: usize,
+        desired: usize,
+        maximum: Option<usize>,
+    ) -> Result<bool> {
+        if let Some(max) = maximum {
+            if desired > max {
+                return Ok(false);
+            }
+        }
+
+        let d = desired - current;
+        if d > self.bytes_left {
+            return Ok(false);
+        }
+
+        self.bytes_left -= d;
+        Ok(true)
+    }
+
+    fn table_growing(&mut self, _current: u32, desired: u32, maximum: Option<u32>) -> Result<bool> {
+        if let Some(max) = maximum {
+            return Ok(desired <= max);
+        }
+
+        Ok(true)
+    }
+}

runtime/src/lib.rs

@@ -3,8 +3,8 @@ pub(crate) use wasmtime::*;
 
 mod context;
 mod function;
+mod internal;
 pub mod manifest;
-mod memory;
 pub(crate) mod pdk;
 mod plugin;
 mod plugin_ref;
@@ -13,9 +13,9 @@ mod timer;
 
 pub use context::Context;
 pub use function::{Function, UserData, Val, ValType};
+pub use internal::{Internal, InternalExt, Wasi};
 pub use manifest::Manifest;
-pub use memory::{MemoryBlock, PluginMemory, ToMemoryBlock};
-pub use plugin::{Internal, Plugin, Wasi};
+pub use plugin::Plugin;
 pub use plugin_ref::PluginRef;
 pub(crate) use timer::{Timer, TimerAction};
 

runtime/src/manifest.rs

@@ -7,7 +7,7 @@ use sha2::Digest;
 use crate::*;
 
 /// Manifest wraps the manifest exported by `extism_manifest`
-#[derive(Default, serde::Serialize, serde::Deserialize)]
+#[derive(Default, Clone, serde::Serialize, serde::Deserialize)]
 #[serde(transparent)]
 pub struct Manifest(extism_manifest::Manifest);
 
@@ -60,6 +60,8 @@ fn check_hash(hash: &Option<String>, data: &[u8]) -> Result<(), Error> {
     }
 }
 
+const WASM: &[u8] = include_bytes!("extism-runtime.wasm");
+
 /// Convert from manifest to a wasmtime Module
 fn to_module(engine: &Engine, wasm: &extism_manifest::Wasm) -> Result<(String, Module), Error> {
     match wasm {
@@ -167,6 +169,7 @@ const WASM_MAGIC: [u8; 4] = [0x00, 0x61, 0x73, 0x6d];
 impl Manifest {
     /// Create a new Manifest, returns the manifest and a map of modules
     pub fn new(engine: &Engine, data: &[u8]) -> Result<(Self, BTreeMap<String, Module>), Error> {
+        let extism_module = Module::new(engine, WASM)?;
         let has_magic = data.len() >= 4 && data[0..4] == WASM_MAGIC;
         let is_wast = data.starts_with(b"(module") || data.starts_with(b";;");
         if !has_magic && !is_wast {
@@ -178,12 +181,14 @@ impl Manifest {
             }
 
             let t = serde_json::from_slice::<Self>(data)?;
-            let m = t.modules(engine)?;
+            let mut m = t.modules(engine)?;
+            m.insert("env".to_string(), extism_module);
             return Ok((t, m));
         }
 
         let m = Module::new(engine, data)?;
         let mut modules = BTreeMap::new();
+        modules.insert("env".to_string(), extism_module);
         modules.insert("main".to_string(), m);
         Ok((Manifest::default(), modules))
     }

runtime/src/memory.rs

@@ -1,331 +0,0 @@
-use std::collections::BTreeMap;
-
-use crate::*;
-
-use pretty_hex::PrettyHex;
-
-/// Handles memory for plugins
-pub struct PluginMemory {
-    pub store: Store<Internal>,
-    pub memory: Memory,
-    pub live_blocks: BTreeMap<usize, usize>,
-    pub free: Vec<MemoryBlock>,
-    pub position: usize,
-}
-
-pub trait ToMemoryBlock {
-    fn to_memory_block(&self, mem: &PluginMemory) -> Result<MemoryBlock, Error>;
-}
-
-impl ToMemoryBlock for MemoryBlock {
-    fn to_memory_block(&self, _mem: &PluginMemory) -> Result<MemoryBlock, Error> {
-        Ok(*self)
-    }
-}
-
-impl ToMemoryBlock for (usize, usize) {
-    fn to_memory_block(&self, _mem: &PluginMemory) -> Result<MemoryBlock, Error> {
-        Ok(MemoryBlock {
-            offset: self.0,
-            length: self.1,
-        })
-    }
-}
-
-impl ToMemoryBlock for usize {
-    fn to_memory_block(&self, mem: &PluginMemory) -> Result<MemoryBlock, Error> {
-        match mem.at_offset(*self) {
-            Some(x) => Ok(x),
-            None => Err(Error::msg(format!("Invalid memory offset: {}", self))),
-        }
-    }
-}
-
-const PAGE_SIZE: u32 = 65536;
-
-// BLOCK_SIZE_THRESHOLD exists to ensure that free blocks are never split up any
-// smaller than this value
-const BLOCK_SIZE_THRESHOLD: usize = 32;
-
-impl PluginMemory {
-    /// Create memory for a plugin
-    pub fn new(store: Store<Internal>, memory: Memory) -> Self {
-        PluginMemory {
-            free: Vec::new(),
-            live_blocks: BTreeMap::new(),
-            store,
-            memory,
-            position: 1,
-        }
-    }
-
-    /// Write byte to memory
-    pub(crate) fn store_u8(&mut self, offs: usize, data: u8) -> Result<(), MemoryAccessError> {
-        trace!("store_u8: offset={offs} data={data:#04x}");
-        if offs >= self.size() {
-            // This should raise MemoryAccessError
-            let buf = &mut [0];
-            self.memory.read(&self.store, offs, buf)?;
-            return Ok(());
-        }
-        self.memory.data_mut(&mut self.store)[offs] = data;
-        Ok(())
-    }
-
-    /// Read byte from memory
-    pub(crate) fn load_u8(&self, offs: usize) -> Result<u8, MemoryAccessError> {
-        trace!("load_u8: offset={offs}");
-        if offs >= self.size() {
-            // This should raise MemoryAccessError
-            let buf = &mut [0];
-            self.memory.read(&self.store, offs, buf)?;
-            return Ok(0);
-        }
-        Ok(self.memory.data(&self.store)[offs])
-    }
-
-    /// Write u64 to memory
-    pub(crate) fn store_u64(&mut self, offs: usize, data: u64) -> Result<(), Error> {
-        trace!("store_u64: offset={offs} data={data:#18x}");
-        let handle = MemoryBlock {
-            offset: offs,
-            length: 8,
-        };
-        self.write(handle, data.to_ne_bytes())?;
-        Ok(())
-    }
-
-    /// Read u64 from memory
-    pub(crate) fn load_u64(&self, offs: usize) -> Result<u64, Error> {
-        trace!("load_u64: offset={offs}");
-        let mut buf = [0; 8];
-        let handle = MemoryBlock {
-            offset: offs,
-            length: 8,
-        };
-        self.read(handle, &mut buf)?;
-        Ok(u64::from_ne_bytes(buf))
-    }
-
-    /// Write slice to memory
-    pub fn write(&mut self, pos: impl ToMemoryBlock, data: impl AsRef<[u8]>) -> Result<(), Error> {
-        let pos = pos.to_memory_block(self)?;
-        assert!(data.as_ref().len() <= pos.length);
-        self.memory
-            .write(&mut self.store, pos.offset, data.as_ref())?;
-        Ok(())
-    }
-
-    /// Read slice from memory
-    pub fn read(&self, pos: impl ToMemoryBlock, mut data: impl AsMut<[u8]>) -> Result<(), Error> {
-        let pos = pos.to_memory_block(self)?;
-        assert!(data.as_mut().len() <= pos.length);
-        self.memory.read(&self.store, pos.offset, data.as_mut())?;
-        Ok(())
-    }
-
-    /// Size of memory in bytes
-    pub fn size(&self) -> usize {
-        self.memory.data_size(&self.store)
-    }
-
-    /// Size of memory in pages
-    pub fn pages(&self) -> u32 {
-        self.memory.size(&self.store) as u32
-    }
-
-    /// Reserve `n` bytes of memory
-    pub fn alloc(&mut self, n: usize) -> Result<MemoryBlock, Error> {
-        debug!("Allocating {n} bytes");
-
-        for (i, block) in self.free.iter_mut().enumerate() {
-            if block.length == n {
-                let block = self.free.swap_remove(i);
-                self.live_blocks.insert(block.offset, block.length);
-                debug!("Found block with exact size at offset {}", block.offset);
-                return Ok(block);
-            } else if block.length.saturating_sub(n) >= BLOCK_SIZE_THRESHOLD {
-                let handle = MemoryBlock {
-                    offset: block.offset,
-                    length: n,
-                };
-                debug!(
-                    "Using block with size {} at offset {}",
-                    block.length, block.offset
-                );
-
-                block.offset += n;
-                block.length -= n;
-                self.live_blocks.insert(handle.offset, handle.length);
-                return Ok(handle);
-            }
-        }
-
-        let new_offset = self.position.saturating_add(n);
-
-        // If there aren't enough bytes, try to grow the memory size
-        if new_offset >= self.size() {
-            debug!("Need more memory");
-
-            let bytes_needed = (new_offset as f64 - self.size() as f64) / PAGE_SIZE as f64;
-            let mut pages_needed = bytes_needed.ceil() as u64;
-            if pages_needed == 0 {
-                pages_needed = 1
-            }
-
-            debug!("Requesting {pages_needed} more pages");
-            // This will fail if we've already allocated the maximum amount of memory allowed
-            self.memory.grow(&mut self.store, pages_needed)?;
-        }
-
-        let mem = MemoryBlock {
-            offset: self.position,
-            length: n,
-        };
-
-        debug!(
-            "Allocated new block: {} bytes at offset {}",
-            mem.length, mem.offset
-        );
-
-        self.live_blocks.insert(mem.offset, mem.length);
-        self.position += n;
-        Ok(mem)
-    }
-
-    /// Allocate and copy `data` into the wasm memory
-    pub fn alloc_bytes(&mut self, data: impl AsRef<[u8]>) -> Result<MemoryBlock, Error> {
-        let handle = self.alloc(data.as_ref().len())?;
-        self.write(handle, data)?;
-        Ok(handle)
-    }
-
-    /// Free the block allocated at `offset`
-    pub fn free(&mut self, offset: usize) {
-        debug!("Freeing block at {offset}");
-        if let Some(length) = self.live_blocks.remove(&offset) {
-            self.free.push(MemoryBlock { offset, length });
-        } else {
-            return;
-        }
-
-        let free_size: usize = self.free.iter().map(|x| x.length).sum();
-
-        // Perform compaction if there is at least 1kb of free memory available
-        if free_size >= 1024 {
-            let mut last: Option<MemoryBlock> = None;
-            let mut free = Vec::new();
-            for block in self.free.iter() {
-                match last {
-                    None => {
-                        free.push(*block);
-                    }
-                    Some(last) => {
-                        if last.offset + last.length == block.offset {
-                            free.push(MemoryBlock {
-                                offset: last.offset,
-                                length: last.length + block.length,
-                            });
-                        }
-                    }
-                }
-                last = Some(*block);
-            }
-            self.free = free;
-        }
-    }
-
-    /// Log entire memory as hexdump using the `trace` log level
-    pub fn dump(&self) {
-        let data = self.memory.data(&self.store);
-
-        trace!("{:?}", data[..self.position].hex_dump());
-    }
-
-    /// Reset memory - clears free-list and live blocks and resets position
-    pub fn reset(&mut self) {
-        self.free.clear();
-        self.live_blocks.clear();
-        self.position = 1;
-    }
-
-    /// Get memory as a slice of bytes
-    pub fn data(&self) -> &[u8] {
-        self.memory.data(&self.store)
-    }
-
-    /// Get memory as a mutable slice of bytes
-    pub fn data_mut(&mut self) -> &mut [u8] {
-        self.memory.data_mut(&mut self.store)
-    }
-
-    /// Get bytes occupied by the provided memory handle
-    pub fn get(&self, handle: impl ToMemoryBlock) -> Result<&[u8], Error> {
-        let handle = handle.to_memory_block(self)?;
-        Ok(&self.memory.data(&self.store)[handle.offset..handle.offset + handle.length])
-    }
-
-    /// Get mutable bytes occupied by the provided memory handle
-    pub fn get_mut(&mut self, handle: impl ToMemoryBlock) -> Result<&mut [u8], Error> {
-        let handle = handle.to_memory_block(self)?;
-        Ok(
-            &mut self.memory.data_mut(&mut self.store)
-                [handle.offset..handle.offset + handle.length],
-        )
-    }
-
-    /// Get str occupied by the provided memory handle
-    pub fn get_str(&self, handle: impl ToMemoryBlock) -> Result<&str, Error> {
-        let handle = handle.to_memory_block(self)?;
-        Ok(std::str::from_utf8(
-            &self.memory.data(&self.store)[handle.offset..handle.offset + handle.length],
-        )?)
-    }
-
-    /// Get mutable str occupied by the provided memory handle
-    pub fn get_mut_str(&mut self, handle: impl ToMemoryBlock) -> Result<&mut str, Error> {
-        let handle = handle.to_memory_block(self)?;
-        Ok(std::str::from_utf8_mut(
-            &mut self.memory.data_mut(&mut self.store)
-                [handle.offset..handle.offset + handle.length],
-        )?)
-    }
-
-    /// Pointer to the provided memory handle
-    pub fn ptr(&self, handle: impl ToMemoryBlock) -> Result<*mut u8, Error> {
-        let handle = handle.to_memory_block(self)?;
-        Ok(unsafe { self.memory.data_ptr(&self.store).add(handle.offset) })
-    }
-
-    /// Get the length of the block starting at `offs`
-    pub fn block_length(&self, offs: usize) -> Option<usize> {
-        self.live_blocks.get(&offs).cloned()
-    }
-
-    /// Get the block at the specified offset
-    pub fn at_offset(&self, offset: usize) -> Option<MemoryBlock> {
-        let block_length = self.block_length(offset);
-        block_length.map(|length| MemoryBlock { offset, length })
-    }
-}
-
-#[derive(Clone, Copy)]
-pub struct MemoryBlock {
-    pub offset: usize,
-    pub length: usize,
-}
-
-impl From<(usize, usize)> for MemoryBlock {
-    fn from(x: (usize, usize)) -> Self {
-        MemoryBlock {
-            offset: x.0,
-            length: x.1,
-        }
-    }
-}
-
-impl MemoryBlock {
-    pub fn new(offset: usize, length: usize) -> Self {
-        MemoryBlock { offset, length }
-    }
-}

runtime/src/pdk.rs

@@ -18,178 +18,6 @@ macro_rules! args {
     };
 }
 
-/// Get the input length
-/// Params: none
-/// Returns: i64 (length)
-pub(crate) fn input_length(
-    caller: Caller<Internal>,
-    _input: &[Val],
-    output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &Internal = caller.data();
-    output[0] = Val::I64(data.input_length as i64);
-    Ok(())
-}
-
-/// Load a byte from input
-/// Params: i64 (offset)
-/// Returns: i32 (byte)
-pub(crate) fn input_load_u8(
-    caller: Caller<Internal>,
-    input: &[Val],
-    output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &Internal = caller.data();
-    if data.input.is_null() {
-        return Ok(());
-    }
-    output[0] = unsafe { Val::I32(*data.input.add(input[0].unwrap_i64() as usize) as i32) };
-    Ok(())
-}
-
-/// Load an unsigned 64 bit integer from input
-/// Params: i64 (offset)
-/// Returns: i64 (int)
-pub(crate) fn input_load_u64(
-    caller: Caller<Internal>,
-    input: &[Val],
-    output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &Internal = caller.data();
-    if data.input.is_null() {
-        return Ok(());
-    }
-    let offs = args!(input, 0, i64) as usize;
-    let slice = unsafe { std::slice::from_raw_parts(data.input.add(offs), 8) };
-    let byte = u64::from_ne_bytes(slice.try_into().unwrap());
-    output[0] = Val::I64(byte as i64);
-    Ok(())
-}
-
-/// Store a byte in memory
-/// Params: i64 (offset), i32 (byte)
-/// Returns: none
-pub(crate) fn store_u8(
-    mut caller: Caller<Internal>,
-    input: &[Val],
-    _output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &mut Internal = caller.data_mut();
-    let (offset, byte) = args!(input, (0, i64), (1, i32));
-    data.memory_mut().store_u8(offset as usize, byte as u8)?;
-    Ok(())
-}
-
-/// Load a byte from memory
-/// Params: i64 (offset)
-/// Returns: i32 (byte)
-pub(crate) fn load_u8(
-    caller: Caller<Internal>,
-    input: &[Val],
-    output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &Internal = caller.data();
-    let offset = args!(input, 0, i64) as usize;
-    let byte = data.memory().load_u8(offset)?;
-    output[0] = Val::I32(byte as i32);
-    Ok(())
-}
-
-/// Store an unsigned 64 bit integer in memory
-/// Params: i64 (offset), i64 (int)
-/// Returns: none
-pub(crate) fn store_u64(
-    mut caller: Caller<Internal>,
-    input: &[Val],
-    _output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &mut Internal = caller.data_mut();
-    let (offset, b) = args!(input, (0, i64), (1, i64));
-    data.memory_mut().store_u64(offset as usize, b as u64)?;
-    Ok(())
-}
-
-/// Load an unsigned 64 bit integer from memory
-/// Params: i64 (offset)
-/// Returns: i64 (int)
-pub(crate) fn load_u64(
-    caller: Caller<Internal>,
-    input: &[Val],
-    output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &Internal = caller.data();
-    let offset = args!(input, 0, i64) as usize;
-    let byte = data.memory().load_u64(offset)?;
-    output[0] = Val::I64(byte as i64);
-    Ok(())
-}
-
-/// Set output offset and length
-/// Params: i64 (offset), i64 (length)
-/// Returns: none
-pub(crate) fn output_set(
-    mut caller: Caller<Internal>,
-    input: &[Val],
-    _output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &mut Internal = caller.data_mut();
-    let (offset, length) = args!(input, (0, i64), (1, i64));
-    data.output_offset = offset as usize;
-    data.output_length = length as usize;
-    Ok(())
-}
-
-/// Allocate bytes
-/// Params: i64 (length)
-/// Returns: i64 (offset)
-pub(crate) fn alloc(
-    mut caller: Caller<Internal>,
-    input: &[Val],
-    output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &mut Internal = caller.data_mut();
-    let offs = data.memory_mut().alloc(input[0].unwrap_i64() as _)?;
-    output[0] = Val::I64(offs.offset as i64);
-
-    Ok(())
-}
-
-/// Free memory
-/// Params: i64 (offset)
-/// Returns: none
-pub(crate) fn free(
-    mut caller: Caller<Internal>,
-    input: &[Val],
-    _output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &mut Internal = caller.data_mut();
-    let offset = args!(input, 0, i64) as usize;
-    data.memory_mut().free(offset);
-    Ok(())
-}
-
-/// Set the error message, this can be checked by the host program
-/// Params: i64 (offset)
-/// Returns: none
-pub(crate) fn error_set(
-    mut caller: Caller<Internal>,
-    input: &[Val],
-    _output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &mut Internal = caller.data_mut();
-    let offset = args!(input, 0, i64) as usize;
-
-    if offset == 0 {
-        data.plugin_mut().clear_error();
-        return Ok(());
-    }
-
-    let plugin = data.plugin_mut();
-    let s = plugin.memory.get_str(offset)?;
-    plugin.set_error(s);
-    Ok(())
-}
-
 /// Get a configuration value
 /// Params: i64 (offset)
 /// Returns: i64 (offset)
@@ -199,19 +27,25 @@ pub(crate) fn config_get(
     output: &mut [Val],
 ) -> Result<(), Error> {
     let data: &mut Internal = caller.data_mut();
-    let plugin = data.plugin_mut();
 
-    let offset = args!(input, 0, i64) as usize;
-    let key = plugin.memory.get_str(offset)?;
-    let val = plugin.manifest.as_ref().config.get(key);
-    let mem = match val {
-        Some(f) => plugin.memory.alloc_bytes(f)?,
+    let offset = args!(input, 0, i64) as u64;
+    let key = data.memory_read_str(offset)?;
+    let key = unsafe {
+        std::str::from_utf8_unchecked(std::slice::from_raw_parts(key.as_ptr(), key.len()))
+    };
+    let val = data.internal().manifest.as_ref().config.get(key);
+    let ptr = val.map(|x| (x.len(), x.as_ptr()));
+    let mem = match ptr {
+        Some((len, ptr)) => {
+            let bytes = unsafe { std::slice::from_raw_parts(ptr, len) };
+            data.memory_alloc_bytes(bytes)?
+        }
         None => {
             output[0] = Val::I64(0);
             return Ok(());
         }
     };
-    output[0] = Val::I64(mem.offset as i64);
+    output[0] = Val::I64(mem as i64);
     Ok(())
 }
 
@@ -224,21 +58,25 @@ pub(crate) fn var_get(
     output: &mut [Val],
 ) -> Result<(), Error> {
     let data: &mut Internal = caller.data_mut();
-    let plugin = data.plugin_mut();
 
-    let offset = args!(input, 0, i64) as usize;
-    let key = plugin.memory.get_str(offset)?;
-    let val = plugin.vars.get(key);
-
-    let mem = match val {
-        Some(f) => plugin.memory.alloc_bytes(f)?,
+    let offset = args!(input, 0, i64) as u64;
+    let key = data.memory_read_str(offset)?;
+    let key = unsafe {
+        std::str::from_utf8_unchecked(std::slice::from_raw_parts(key.as_ptr(), key.len()))
+    };
+    let val = data.internal().vars.get(key);
+    let ptr = val.map(|x| (x.len(), x.as_ptr()));
+    let mem = match ptr {
+        Some((len, ptr)) => {
+            let bytes = unsafe { std::slice::from_raw_parts(ptr, len) };
+            data.memory_alloc_bytes(bytes)?
+        }
         None => {
             output[0] = Val::I64(0);
             return Ok(());
         }
     };
-
-    output[0] = Val::I64(mem.offset as i64);
+    output[0] = Val::I64(mem as i64);
     Ok(())
 }
 
@@ -251,33 +89,38 @@ pub(crate) fn var_set(
     _output: &mut [Val],
 ) -> Result<(), Error> {
     let data: &mut Internal = caller.data_mut();
-    let plugin = data.plugin_mut();
 
     let mut size = 0;
-    for v in plugin.vars.values() {
+    for v in data.vars.values() {
         size += v.len();
     }
 
-    let voffset = args!(input, 1, i64) as usize;
+    let voffset = args!(input, 1, i64) as u64;
 
     // If the store is larger than 100MB then stop adding things
     if size > 1024 * 1024 * 100 && voffset != 0 {
         return Err(Error::msg("Variable store is full"));
     }
 
-    let key_offs = args!(input, 0, i64) as usize;
-    let key = plugin.memory.get_str(key_offs)?;
+    let key_offs = args!(input, 0, i64) as u64;
+    let key = {
+        let key = data.memory_read_str(key_offs)?;
+        let key_len = key.len();
+        let key_ptr = key.as_ptr();
+        unsafe { std::str::from_utf8_unchecked(std::slice::from_raw_parts(key_ptr, key_len)) }
+    };
 
     // Remove if the value offset is 0
     if voffset == 0 {
-        plugin.vars.remove(key);
+        data.vars.remove(key);
         return Ok(());
     }
 
-    let value = plugin.memory.get(voffset)?;
+    let vlen = data.memory_length(voffset);
+    let value = data.memory_read(voffset, vlen).to_vec();
 
     // Insert the value from memory into the `vars` map
-    plugin.vars.insert(key.to_string(), value.to_vec());
+    data.vars.insert(key.to_string(), value);
 
     Ok(())
 }
@@ -303,34 +146,38 @@ pub(crate) fn http_request(
     {
         use std::io::Read;
         let data: &mut Internal = caller.data_mut();
-        let http_req_offset = args!(input, 0, i64) as usize;
+        let http_req_offset = args!(input, 0, i64) as u64;
 
+        let http_req_len = data.memory_length(http_req_offset);
         let req: extism_manifest::HttpRequest =
-            serde_json::from_slice(data.memory().get(http_req_offset)?)?;
+            serde_json::from_slice(data.memory_read(http_req_offset, http_req_len))?;
 
-        let body_offset = args!(input, 1, i64) as usize;
+        let body_offset = args!(input, 1, i64) as u64;
 
         let url = match url::Url::parse(&req.url) {
             Ok(u) => u,
             Err(e) => return Err(Error::msg(format!("Invalid URL: {e:?}"))),
         };
-        let allowed_hosts = &data.plugin().manifest.as_ref().allowed_hosts;
+        let allowed_hosts = &data.internal().manifest.as_ref().allowed_hosts;
         let host_str = url.host_str().unwrap_or_default();
-        if let Some(allowed_hosts) = allowed_hosts {
-            let host_matches_allowed = allowed_hosts.iter().any(|url| {
+        let host_matches = if let Some(allowed_hosts) = allowed_hosts {
+            allowed_hosts.iter().any(|url| {
                 let pat = match glob::Pattern::new(url) {
                     Ok(x) => x,
                     Err(_) => return url == host_str,
                 };
 
                 pat.matches(host_str)
-            });
-            if !host_matches_allowed {
-                return Err(Error::msg(format!(
-                    "HTTP request to {} is not allowed",
-                    req.url
-                )));
-            }
+            })
+        } else {
+            false
+        };
+
+        if !host_matches {
+            return Err(Error::msg(format!(
+                "HTTP request to {} is not allowed",
+                req.url
+            )));
         }
 
         let mut r = ureq::request(req.method.as_deref().unwrap_or("GET"), &req.url);
@@ -340,23 +187,40 @@ pub(crate) fn http_request(
         }
 
         let res = if body_offset > 0 {
-            let buf = data.memory().get(body_offset)?;
-            let res = r.send_bytes(buf)?;
-            data.http_status = res.status();
-            res.into_reader()
+            let len = data.memory_length(body_offset);
+            let buf = data.memory_read(body_offset, len);
+            r.send_bytes(buf)
         } else {
-            let res = r.call()?;
-            data.http_status = res.status();
-            res.into_reader()
+            r.call()
         };
 
-        let mut buf = Vec::new();
-        res.take(1024 * 1024 * 50) // TODO: make this limit configurable
-            .read_to_end(&mut buf)?;
+        let reader = match res {
+            Ok(res) => {
+                data.http_status = res.status();
+                Some(res.into_reader())
+            }
+            Err(e) => {
+                if let Some(res) = e.into_response() {
+                    data.http_status = res.status();
+                    Some(res.into_reader())
+                } else {
+                    None
+                }
+            }
+        };
 
-        let mem = data.memory_mut().alloc_bytes(buf)?;
+        if let Some(reader) = reader {
+            let mut buf = Vec::new();
+            reader
+                .take(1024 * 1024 * 50) // TODO: make this limit configurable
+                .read_to_end(&mut buf)?;
+
+            let mem = data.memory_alloc_bytes(buf)?;
+            output[0] = Val::I64(mem as i64);
+        } else {
+            output[0] = Val::I64(0);
+        }
 
-        output[0] = Val::I64(mem.offset as i64);
         Ok(())
     }
 }
@@ -374,39 +238,17 @@ pub(crate) fn http_status_code(
     Ok(())
 }
 
-/// Get the length of an allocated block given the offset
-/// Params: i64 (offset)
-/// Returns: i64 (length or 0)
-pub(crate) fn length(
-    mut caller: Caller<Internal>,
-    input: &[Val],
-    output: &mut [Val],
-) -> Result<(), Error> {
-    let data: &mut Internal = caller.data_mut();
-    let offset = args!(input, 0, i64) as usize;
-    if offset == 0 {
-        output[0] = Val::I64(0);
-        return Ok(());
-    }
-    let length = match data.memory().block_length(offset) {
-        Some(x) => x,
-        None => return Err(Error::msg("Unable to find length for offset")),
-    };
-    output[0] = Val::I64(length as i64);
-    Ok(())
-}
-
 pub fn log(
     level: log::Level,
-    caller: Caller<Internal>,
+    mut caller: Caller<Internal>,
     input: &[Val],
     _output: &mut [Val],
 ) -> Result<(), Error> {
-    let data: &Internal = caller.data();
-    let offset = args!(input, 0, i64) as usize;
-    let buf = data.memory().get(offset)?;
+    let data: &mut Internal = caller.data_mut();
+    let offset = args!(input, 0, i64) as u64;
+    let buf = data.memory_read_str(offset);
 
-    match std::str::from_utf8(buf) {
+    match buf {
         Ok(buf) => log::log!(level, "{}", buf),
         Err(_) => log::log!(level, "{:?}", buf),
     }

runtime/src/plugin.rs

@@ -4,97 +4,121 @@ use crate::*;
 
 /// Plugin contains everything needed to execute a WASM function
 pub struct Plugin {
-    pub module: Module,
+    /// All modules that were provided to the linker
+    pub modules: BTreeMap<String, Module>,
+
+    /// Used to define functions and create new instances
     pub linker: Linker<Internal>,
-    pub instance: Instance,
-    pub last_error: std::cell::RefCell<Option<std::ffi::CString>>,
-    pub memory: PluginMemory,
-    pub manifest: Manifest,
-    pub vars: BTreeMap<String, Vec<u8>>,
-    pub should_reinstantiate: bool,
+    pub store: Store<Internal>,
+
+    /// Instance provides the ability to call functions in a module
+    pub instance: Option<Instance>,
+    pub instance_pre: InstancePre<Internal>,
+
+    /// Keep track of the number of times we're instantiated, this exists
+    /// to avoid issues with memory piling up since `Instance`s are only
+    /// actually cleaned up along with a `Store`
+    instantiations: usize,
+
+    /// The ID used to identify this plugin with the `Timer`
     pub timer_id: uuid::Uuid,
+
+    /// A handle used to cancel execution of a plugin
     pub(crate) cancel_handle: sdk::ExtismCancelHandle,
+
+    /// Runtime determines any initialization functions needed
+    /// to run a module
+    pub(crate) runtime: Option<Runtime>,
 }
 
-pub struct Internal {
-    pub input_length: usize,
-    pub input: *const u8,
-    pub output_offset: usize,
-    pub output_length: usize,
-    pub plugin: *mut Plugin,
-    pub wasi: Option<Wasi>,
-    pub http_status: u16,
-}
-
-pub struct Wasi {
-    pub ctx: wasmtime_wasi::WasiCtx,
-    #[cfg(feature = "nn")]
-    pub nn: wasmtime_wasi_nn::WasiNnCtx,
-    #[cfg(not(feature = "nn"))]
-    pub nn: (),
-}
-
-impl Internal {
-    fn new(manifest: &Manifest, wasi: bool) -> Result<Self, Error> {
-        let wasi = if wasi {
-            let auth = wasmtime_wasi::ambient_authority();
-            let mut ctx = wasmtime_wasi::WasiCtxBuilder::new();
-            for (k, v) in manifest.as_ref().config.iter() {
-                ctx = ctx.env(k, v)?;
-            }
-
-            if let Some(a) = &manifest.as_ref().allowed_paths {
-                for (k, v) in a.iter() {
-                    let d = wasmtime_wasi::Dir::open_ambient_dir(k, auth)?;
-                    ctx = ctx.preopened_dir(d, v)?;
-                }
-            }
-
-            #[cfg(feature = "nn")]
-            let nn = wasmtime_wasi_nn::WasiNnCtx::new()?;
-
-            #[cfg(not(feature = "nn"))]
-            #[allow(clippy::let_unit_value)]
-            let nn = ();
-
-            Some(Wasi {
-                ctx: ctx.build(),
-                nn,
-            })
-        } else {
-            None
-        };
-
-        Ok(Internal {
-            input_length: 0,
-            output_offset: 0,
-            output_length: 0,
-            input: std::ptr::null(),
-            wasi,
-            plugin: std::ptr::null_mut(),
-            http_status: 0,
-        })
+impl InternalExt for Plugin {
+    fn store(&self) -> &Store<Internal> {
+        &self.store
     }
 
-    pub fn plugin(&self) -> &Plugin {
-        unsafe { &*self.plugin }
+    fn store_mut(&mut self) -> &mut Store<Internal> {
+        &mut self.store
     }
 
-    pub fn plugin_mut(&mut self) -> &mut Plugin {
-        unsafe { &mut *self.plugin }
+    fn linker(&self) -> &Linker<Internal> {
+        &self.linker
     }
 
-    pub fn memory(&self) -> &PluginMemory {
-        &self.plugin().memory
+    fn linker_mut(&mut self) -> &mut Linker<Internal> {
+        &mut self.linker
     }
 
-    pub fn memory_mut(&mut self) -> &mut PluginMemory {
-        &mut self.plugin_mut().memory
+    fn linker_and_store(&mut self) -> (&mut Linker<Internal>, &mut Store<Internal>) {
+        (&mut self.linker, &mut self.store)
     }
 }
 
 const EXPORT_MODULE_NAME: &str = "env";
 
+fn profiling_strategy() -> ProfilingStrategy {
+    match std::env::var("EXTISM_PROFILE").as_deref() {
+        Ok("perf") => ProfilingStrategy::PerfMap,
+        Ok(x) => {
+            log::warn!("Invalid value for EXTISM_PROFILE: {x}");
+            ProfilingStrategy::None
+        }
+        Err(_) => ProfilingStrategy::None,
+    }
+}
+
+fn calculate_available_memory(
+    available_pages: &mut Option<u32>,
+    modules: &BTreeMap<String, Module>,
+) -> anyhow::Result<()> {
+    let available_pages = match available_pages {
+        Some(p) => p,
+        None => return Ok(()),
+    };
+
+    let max_pages = *available_pages;
+    let mut fail_memory_check = false;
+    let mut total_memory_needed = 0;
+    for (name, module) in modules.iter() {
+        if name == "env" {
+            continue;
+        }
+        let mut memories = 0;
+        for export in module.exports() {
+            if let Some(memory) = export.ty().memory() {
+                memories += 1;
+                let memory_max = memory.maximum();
+                match memory_max {
+                    None => anyhow::bail!("Unbounded memory in module {name}, when `memory.max_pages` is set in the manifest all modules \
+                                           must have a maximum bound set on an exported memory"),
+                    Some(m) => {
+                        total_memory_needed += m;
+                        if !fail_memory_check {
+                            continue;
+                        }
+
+                        *available_pages = available_pages.saturating_sub(m as u32);
+                        if *available_pages == 0 {
+                            fail_memory_check = true;
+                        }
+                    }
+                }
+            }
+        }
+
+        if memories == 0 {
+            anyhow::bail!("No memory exported from module {name}, when `memory.max_pages` is set in the manifest all modules must \
+                           have a maximum bound set on an exported memory");
+        }
+    }
+
+    if fail_memory_check {
+        anyhow::bail!("Not enough memory configured to run the provided plugin, `memory.max_pages` is set to {max_pages} in the manifest \
+                       but {total_memory_needed} pages are needed by the plugin");
+    }
+
+    Ok(())
+}
+
 impl Plugin {
     /// Create a new plugin from the given WASM code
     pub fn new<'a>(
@@ -102,26 +126,37 @@ impl Plugin {
         imports: impl IntoIterator<Item = &'a Function>,
         with_wasi: bool,
     ) -> Result<Plugin, Error> {
+        // Create a new engine, if the `EXITSM_DEBUG` environment variable is set
+        // then we enable debug info
         let engine = Engine::new(
             Config::new()
                 .epoch_interruption(true)
-                .debug_info(std::env::var("EXTISM_DEBUG").is_ok()),
+                .debug_info(std::env::var("EXTISM_DEBUG").is_ok())
+                .profiler(profiling_strategy()),
         )?;
         let mut imports = imports.into_iter();
         let (manifest, modules) = Manifest::new(&engine, wasm.as_ref())?;
-        let mut store = Store::new(&engine, Internal::new(&manifest, with_wasi)?);
 
-        store.epoch_deadline_callback(|_internal| Err(Error::msg("timeout")));
+        // Calculate how much memory is available based on the value of `max_pages` and the exported
+        // memory of the modules. An error will be returned if a module doesn't have an exported memory
+        // or there is no maximum set for a module's exported memory.
+        let mut available_pages = manifest.as_ref().memory.max_pages;
+        calculate_available_memory(&mut available_pages, &modules)?;
+        log::trace!("Available pages: {available_pages:?}");
 
-        let memory = Memory::new(
-            &mut store,
-            MemoryType::new(4, manifest.as_ref().memory.max_pages),
-        )?;
-        let mut memory = PluginMemory::new(store, memory);
+        let mut store = Store::new(
+            &engine,
+            Internal::new(manifest, with_wasi, available_pages)?,
+        );
+        store.epoch_deadline_callback(|_internal| Ok(wasmtime::UpdateDeadline::Continue(1)));
 
+        if available_pages.is_some() {
+            store.limiter(|internal| internal.memory_limiter.as_mut().unwrap());
+        }
         let mut linker = Linker::new(&engine);
         linker.allow_shadowing(true);
 
+        // If wasi is enabled then add it to the linker
         if with_wasi {
             wasmtime_wasi::add_to_linker(&mut linker, |x: &mut Internal| {
                 &mut x.wasi.as_mut().unwrap().ctx
@@ -138,14 +173,14 @@ impl Plugin {
             (entry.0.as_str(), entry.1)
         });
 
+        // Define PDK functions
         macro_rules! define_funcs {
             ($m:expr, { $($name:ident($($args:expr),*) $(-> $($r:expr),*)?);* $(;)?}) => {
                 match $m {
                 $(
                     concat!("extism_", stringify!($name)) => {
                         let t = FuncType::new([$($args),*], [$($($r),*)?]);
-                        let f = Func::new(&mut memory.store, t, pdk::$name);
-                        linker.define(&mut memory.store, EXPORT_MODULE_NAME, concat!("extism_", stringify!($name)), Extern::Func(f))?;
+                        linker.func_new(EXPORT_MODULE_NAME, concat!("extism_", stringify!($name)), t, pdk::$name)?;
                         continue
                     }
                 )*
@@ -155,7 +190,10 @@ impl Plugin {
         }
 
         // Add builtins
-        for (_name, module) in modules.iter() {
+        for (name, module) in modules.iter() {
+            if name != main_name {
+                linker.module(&mut store, name, module)?;
+            }
             for import in module.imports() {
                 let module_name = import.module();
                 let name = import.name();
@@ -163,249 +201,291 @@ impl Plugin {
 
                 if module_name == EXPORT_MODULE_NAME {
                     define_funcs!(name,  {
-                        alloc(I64) -> I64;
-                        free(I64);
-                        load_u8(I64) -> I32;
-                        load_u64(I64) -> I64;
-                        store_u8(I64, I32);
-                        store_u64(I64, I64);
-                        input_length() -> I64;
-                        input_load_u8(I64) -> I32;
-                        input_load_u64(I64) -> I64;
-                        output_set(I64, I64);
-                        error_set(I64);
                         config_get(I64) -> I64;
                         var_get(I64) -> I64;
                         var_set(I64, I64);
                         http_request(I64, I64) -> I64;
                         http_status_code() -> I32;
-                        length(I64) -> I64;
                         log_warn(I64);
                         log_info(I64);
                         log_debug(I64);
                         log_error(I64);
                     });
-
-                    for f in &mut imports {
-                        let name = f.name().to_string();
-                        let ns = f.namespace().unwrap_or(EXPORT_MODULE_NAME);
-                        let func = Func::new(&mut memory.store, f.ty().clone(), unsafe {
-                            &*std::sync::Arc::as_ptr(&f.f)
-                        });
-                        linker.define(&mut memory.store, ns, &name, func)?;
-                    }
                 }
             }
         }
 
-        // Add modules to linker
-        for (name, module) in modules.iter() {
-            if name != main_name {
-                linker.module(&mut memory.store, name, module)?;
-                linker.alias_module(name, "env")?;
-            }
+        for f in &mut imports {
+            let name = f.name().to_string();
+            let ns = f.namespace().unwrap_or(EXPORT_MODULE_NAME);
+            linker.func_new(ns, &name, f.ty().clone(), unsafe {
+                &*std::sync::Arc::as_ptr(&f.f)
+            })?;
         }
 
-        let instance = linker.instantiate(&mut memory.store, main)?;
+        let instance_pre = linker.instantiate_pre(&main)?;
         let timer_id = uuid::Uuid::new_v4();
         let mut plugin = Plugin {
-            module: main.clone(),
+            modules,
             linker,
-            memory,
-            instance,
-            last_error: std::cell::RefCell::new(None),
-            manifest,
-            vars: BTreeMap::new(),
-            should_reinstantiate: false,
+            instance: None,
+            instance_pre,
+            store,
+            runtime: None,
             timer_id,
             cancel_handle: sdk::ExtismCancelHandle {
                 id: timer_id,
                 epoch_timer_tx: None,
             },
+            instantiations: 0,
         };
 
-        plugin.initialize_runtime()?;
-
+        plugin.internal_mut().store = &mut plugin.store;
+        plugin.internal_mut().linker = &mut plugin.linker;
         Ok(plugin)
     }
 
-    /// Get a function by name
-    pub fn get_func(&mut self, function: impl AsRef<str>) -> Option<Func> {
-        self.instance
-            .get_func(&mut self.memory.store, function.as_ref())
-    }
+    pub(crate) fn reset_store(&mut self) -> Result<(), Error> {
+        self.instance = None;
+        if self.instantiations > 5 {
+            let (main_name, main) = self
+                .modules
+                .get("main")
+                .map(|x| ("main", x))
+                .unwrap_or_else(|| {
+                    let entry = self.modules.iter().last().unwrap();
+                    (entry.0.as_str(), entry.1)
+                });
 
-    /// Set `last_error` field
-    pub fn set_error(&self, e: impl std::fmt::Debug) {
-        debug!("Set error: {:?}", e);
-        *self.last_error.borrow_mut() = Some(error_string(e));
-    }
+            let engine = self.store.engine().clone();
+            let internal = self.internal();
+            self.store = Store::new(
+                &engine,
+                Internal::new(
+                    internal.manifest.clone(),
+                    internal.wasi.is_some(),
+                    internal.available_pages,
+                )?,
+            );
+            self.store
+                .epoch_deadline_callback(|_internal| Ok(UpdateDeadline::Continue(1)));
 
-    pub fn error<E>(&self, e: impl std::fmt::Debug, x: E) -> E {
-        self.set_error(e);
-        x
-    }
+            if self.internal().available_pages.is_some() {
+                self.store
+                    .limiter(|internal| internal.memory_limiter.as_mut().unwrap());
+            }
 
-    /// Unset `last_error` field
-    pub fn clear_error(&self) {
-        *self.last_error.borrow_mut() = None;
-    }
+            for (name, module) in self.modules.iter() {
+                if name != main_name {
+                    self.linker.module(&mut self.store, name, module)?;
+                }
+            }
+            self.instantiations = 0;
+            self.instance_pre = self.linker.instantiate_pre(&main)?;
 
-    /// Store input in memory and initialize `Internal` pointer
-    pub fn set_input(&mut self, input: *const u8, mut len: usize) {
-        if input.is_null() {
-            len = 0;
+            let store = &mut self.store as *mut _;
+            let linker = &mut self.linker as *mut _;
+            let internal = self.internal_mut();
+            internal.store = store;
+            internal.linker = linker;
         }
-        let ptr = self as *mut _;
-        let internal = self.memory.store.data_mut();
-        internal.input = input;
-        internal.input_length = len;
-        internal.plugin = ptr;
+
+        Ok(())
     }
 
-    pub fn dump_memory(&self) {
-        self.memory.dump();
-    }
-
-    pub fn reinstantiate(&mut self) -> Result<(), Error> {
-        let instance = self
-            .linker
-            .instantiate(&mut self.memory.store, &self.module)?;
-        self.instance = instance;
+    pub(crate) fn instantiate(&mut self) -> Result<(), Error> {
+        self.instance = Some(self.instance_pre.instantiate(&mut self.store)?);
+        self.instantiations += 1;
+        if let Some(limiter) = &mut self.internal_mut().memory_limiter {
+            limiter.reset();
+        }
+        self.detect_runtime();
         self.initialize_runtime()?;
         Ok(())
     }
 
-    pub fn has_wasi(&self) -> bool {
-        self.memory.store.data().wasi.is_some()
-    }
-
-    fn detect_runtime(&mut self) -> Option<Runtime> {
-        // Check for Haskell runtime initialization functions
-        // Initialize Haskell runtime if `hs_init` and `hs_exit` are present,
-        // by calling the `hs_init` export
-        if let Some(init) = self.get_func("hs_init") {
-            if let Some(cleanup) = self.get_func("hs_exit") {
-                if init.typed::<(i32, i32), ()>(&self.memory.store).is_err() {
-                    trace!(
-                        "hs_init function found with type {:?}",
-                        init.ty(&self.memory.store)
-                    );
-                    return None;
-                }
-                return Some(Runtime::Haskell { init, cleanup });
+    /// Get a function by name
+    pub fn get_func(&mut self, function: impl AsRef<str>) -> Option<Func> {
+        if let None = &self.instance {
+            if let Err(e) = self.instantiate() {
+                error!("Unable to instantiate: {e}");
+                return None;
             }
         }
 
-        trace!("No runtime detected");
-        None
+        if let Some(instance) = &mut self.instance {
+            instance.get_func(&mut self.store, function.as_ref())
+        } else {
+            None
+        }
     }
 
-    fn initialize_runtime(&mut self) -> Result<(), Error> {
-        if let Some(runtime) = self.detect_runtime() {
-            if let Some(timer) = Context::timer().as_ref() {
-                self.memory.store.set_epoch_deadline(1);
-                self.start_timer(&timer.tx)?;
-                let x = runtime.init(self);
-                self.stop_timer()?;
-                self.memory.store.set_epoch_deadline(0);
-                return x;
+    /// Store input in memory and initialize `Internal` pointer
+    pub(crate) fn set_input(&mut self, input: *const u8, mut len: usize) -> Result<(), Error> {
+        if input.is_null() {
+            len = 0;
+        }
+
+        {
+            let store = &mut self.store as *mut _;
+            let linker = &mut self.linker as *mut _;
+            let internal = self.internal_mut();
+            internal.store = store;
+            internal.linker = linker;
+        }
+
+        let bytes = unsafe { std::slice::from_raw_parts(input, len) };
+        trace!("Input size: {}", bytes.len());
+
+        if let Some(f) = self.linker.get(&mut self.store, "env", "extism_reset") {
+            f.into_func().unwrap().call(&mut self.store, &[], &mut [])?;
+        } else {
+            error!("Call to extism_reset failed");
+        }
+
+        let offs = self.memory_alloc_bytes(bytes)?;
+
+        if let Some(f) = self.linker.get(&mut self.store, "env", "extism_input_set") {
+            f.into_func().unwrap().call(
+                &mut self.store,
+                &[Val::I64(offs as i64), Val::I64(len as i64)],
+                &mut [],
+            )?;
+        }
+
+        Ok(())
+    }
+
+    /// Determine if wasi is enabled
+    pub fn has_wasi(&self) -> bool {
+        self.internal().wasi.is_some()
+    }
+
+    fn detect_runtime(&mut self) {
+        // Check for Haskell runtime initialization functions
+        // Initialize Haskell runtime if `hs_init` is present,
+        // by calling the `hs_init` export
+        if let Some(init) = self.get_func("hs_init") {
+            let reactor_init = if let Some(init) = self.get_func("_initialize") {
+                if init.typed::<(), ()>(&self.store()).is_err() {
+                    trace!(
+                        "_initialize function found with type {:?}",
+                        init.ty(self.store())
+                    );
+                    None
+                } else {
+                    trace!("WASI reactor module detected");
+                    Some(init)
+                }
+            } else {
+                None
+            };
+            self.runtime = Some(Runtime::Haskell { init, reactor_init });
+            return;
+        }
+
+        // Check for `__wasm_call_ctors` or `_initialize`, this is used by WASI to
+        // initialize certain interfaces.
+        let init = if let Some(init) = self.get_func("__wasm_call_ctors") {
+            if init.typed::<(), ()>(&self.store()).is_err() {
+                trace!(
+                    "__wasm_call_ctors function found with type {:?}",
+                    init.ty(self.store())
+                );
+                return;
+            }
+            trace!("WASI runtime detected");
+            init
+        } else if let Some(init) = self.get_func("_initialize") {
+            if init.typed::<(), ()>(&self.store()).is_err() {
+                trace!(
+                    "_initialize function found with type {:?}",
+                    init.ty(self.store())
+                );
+                return;
+            }
+            trace!("Reactor module detected");
+            init
+        } else {
+            return;
+        };
+
+        self.runtime = Some(Runtime::Wasi { init });
+
+        trace!("No runtime detected");
+    }
+
+    pub(crate) fn initialize_runtime(&mut self) -> Result<(), Error> {
+        let mut store = &mut self.store;
+        if let Some(runtime) = &self.runtime {
+            trace!("Plugin::initialize_runtime");
+            match runtime {
+                Runtime::Haskell { init, reactor_init } => {
+                    if let Some(reactor_init) = reactor_init {
+                        reactor_init.call(&mut store, &[], &mut [])?;
+                    }
+                    let mut results = vec![Val::null(); init.ty(&store).results().len()];
+                    init.call(
+                        &mut store,
+                        &[Val::I32(0), Val::I32(0)],
+                        results.as_mut_slice(),
+                    )?;
+                    debug!("Initialized Haskell language runtime");
+                }
+                Runtime::Wasi { init } => {
+                    init.call(&mut store, &[], &mut [])?;
+                    debug!("Initialied WASI runtime");
+                }
             }
         }
 
         Ok(())
     }
 
+    /// Start the timer for a Plugin - this is used for both timeouts
+    /// and cancellation
     pub(crate) fn start_timer(
         &mut self,
         tx: &std::sync::mpsc::SyncSender<TimerAction>,
     ) -> Result<(), Error> {
         let duration = self
+            .internal()
             .manifest
             .as_ref()
             .timeout_ms
             .map(std::time::Duration::from_millis);
         self.cancel_handle.epoch_timer_tx = Some(tx.clone());
-        self.memory.store.set_epoch_deadline(1);
-        let engine: Engine = self.memory.store.engine().clone();
+        self.store_mut().set_epoch_deadline(1);
+        self.store
+            .epoch_deadline_callback(|_internal| Err(Error::msg("timeout")));
+        let engine: Engine = self.store().engine().clone();
         tx.send(TimerAction::Start {
             id: self.timer_id,
             duration,
             engine,
         })?;
-
         Ok(())
     }
 
+    /// Send TimerAction::Stop
     pub(crate) fn stop_timer(&mut self) -> Result<(), Error> {
         if let Some(tx) = &self.cancel_handle.epoch_timer_tx {
             tx.send(TimerAction::Stop { id: self.timer_id })?;
         }
-
-        Ok(())
-    }
-
-    pub fn cancel(&self) -> Result<(), Error> {
-        if let Some(tx) = &self.cancel_handle.epoch_timer_tx {
-            tx.send(TimerAction::Cancel { id: self.timer_id })?;
-        }
-
+        self.store
+            .epoch_deadline_callback(|_internal| Ok(wasmtime::UpdateDeadline::Continue(1)));
         Ok(())
     }
 }
 
 // Enumerates the supported PDK language runtimes
-enum Runtime {
-    Haskell { init: Func, cleanup: Func },
-}
-
-impl Runtime {
-    fn init(&self, plugin: &mut Plugin) -> Result<(), Error> {
-        match self {
-            Runtime::Haskell { init, cleanup: _ } => {
-                let mut results = vec![Val::null(); init.ty(&plugin.memory.store).results().len()];
-                init.call(
-                    &mut plugin.memory.store,
-                    &[Val::I32(0), Val::I32(0)],
-                    results.as_mut_slice(),
-                )?;
-                debug!("Initialized Haskell language runtime");
-            }
-        }
-        Ok(())
-    }
-
-    fn cleanup(&self, plugin: &mut Plugin) -> Result<(), Error> {
-        match self {
-            // Cleanup Haskell runtime if `hs_exit` and `hs_exit` are present,
-            // by calling the `hs_exit` export
-            Runtime::Haskell { init: _, cleanup } => {
-                let mut results =
-                    vec![Val::null(); cleanup.ty(&plugin.memory.store).results().len()];
-                cleanup.call(&mut plugin.memory.store, &[], results.as_mut_slice())?;
-                debug!("Cleaned up Haskell language runtime");
-            }
-        }
-
-        Ok(())
-    }
-}
-
-impl Drop for Plugin {
-    fn drop(&mut self) {
-        if let Some(runtime) = self.detect_runtime() {
-            self.memory.store.set_epoch_deadline(1);
-            if let Some(timer) = Context::timer().as_ref() {
-                if self.start_timer(&timer.tx).is_ok() {
-                    if let Err(e) = runtime.cleanup(self) {
-                        error!("Unable to cleanup runtime: {e:?}");
-                    }
-
-                    if let Err(e) = self.stop_timer() {
-                        error!("Unable to stop timer in Plugin::drop: {e:?}");
-                    }
-                }
-            }
-        }
-    }
+#[derive(Clone)]
+pub(crate) enum Runtime {
+    Haskell {
+        init: Func,
+        reactor_init: Option<Func>,
+    },
+    Wasi {
+        init: Func,
+    },
 }

runtime/src/plugin_ref.rs

@@ -3,6 +3,7 @@ use crate::*;
 // PluginRef is used to access a plugin from a context-scoped plugin registry
 pub struct PluginRef<'a> {
     pub id: PluginIndex,
+    running: bool,
     pub(crate) epoch_timer_tx: std::sync::mpsc::SyncSender<TimerAction>,
     plugin: *mut Plugin,
     _t: std::marker::PhantomData<&'a ()>,
@@ -10,14 +11,25 @@ pub struct PluginRef<'a> {
 
 impl<'a> PluginRef<'a> {
     /// Initialize the plugin for a new call
-    ///
-    /// - Resets memory offsets
-    /// - Updates `input` pointer
-    pub fn init(mut self, data: *const u8, data_len: usize) -> Self {
-        trace!("PluginRef::init: {}", self.id,);
-        self.as_mut().memory.reset();
-        self.as_mut().set_input(data, data_len);
+    pub(crate) fn start_call(mut self, is_start: bool) -> Self {
+        trace!("PluginRef::start_call: {}", self.id,);
 
+        let plugin = unsafe { &mut *self.plugin };
+        if is_start {
+            if let Err(e) = plugin.reset_store() {
+                error!("Call to Plugin::reset_store failed: {e:?}");
+            }
+        }
+
+        if plugin.instance.is_none() {
+            trace!("Plugin::instance is none, instantiating");
+            if let Err(e) = plugin.instantiate() {
+                error!("Plugin::instantiate failed: {e:?}");
+                plugin.error(e, ());
+            }
+        }
+
+        self.running = true;
         self
     }
 
@@ -29,36 +41,20 @@ impl<'a> PluginRef<'a> {
 
         let epoch_timer_tx = ctx.epoch_timer_tx.clone();
 
-        if !ctx.plugin_exists(plugin_id) {
+        let plugin = if let Some(plugin) = ctx.plugin(plugin_id) {
+            plugin
+        } else {
             error!("Plugin does not exist: {plugin_id}");
             return ctx.error(format!("Plugin does not exist: {plugin_id}"), None);
-        }
+        };
+
+        let plugin = unsafe { &mut *plugin };
 
         if clear_error {
             trace!("Clearing context error");
             ctx.error = None;
-        }
-
-        // `unwrap` is okay here because we already checked with `ctx.plugin_exists` above
-        let plugin = ctx.plugin(plugin_id).unwrap();
-
-        {
-            let plugin = unsafe { &mut *plugin };
-            if clear_error {
-                trace!("Clearing plugin error: {plugin_id}");
-                plugin.clear_error();
-            }
-
-            // Reinstantiate plugin after calling _start because according to the WASI
-            // applicate ABI _start should be called "at most once":
-            // https://github.com/WebAssembly/WASI/blob/main/legacy/application-abi.md
-            if plugin.should_reinstantiate {
-                plugin.should_reinstantiate = false;
-                if let Err(e) = plugin.reinstantiate() {
-                    error!("Failed to reinstantiate: {e:?}");
-                    return plugin.error(format!("Failed to reinstantiate: {e:?}"), None);
-                }
-            }
+            trace!("Clearing plugin error: {plugin_id}");
+            plugin.clear_error();
         }
 
         Some(PluginRef {
@@ -66,6 +62,7 @@ impl<'a> PluginRef<'a> {
             plugin,
             epoch_timer_tx,
             _t: std::marker::PhantomData,
+            running: false,
         })
     }
 }
@@ -85,6 +82,14 @@ impl<'a> AsMut<Plugin> for PluginRef<'a> {
 impl<'a> Drop for PluginRef<'a> {
     fn drop(&mut self) {
         trace!("Dropping PluginRef {}", self.id);
-        // Cleanup?
+        if self.running {
+            let plugin = self.as_mut();
+
+            // Stop timer
+            if let Err(e) = plugin.stop_timer() {
+                let id = plugin.timer_id;
+                error!("Failed to stop timeout manager for {id}: {e:?}");
+            }
+        }
     }
 }

runtime/src/sdk.rs

@@ -33,7 +33,7 @@ impl From<Function> for ExtismFunction {
 
 /// Host function signature
 pub type ExtismFunctionType = extern "C" fn(
-    plugin: *mut Plugin,
+    plugin: *mut Internal,
     inputs: *const ExtismVal,
     n_inputs: Size,
     outputs: *mut ExtismVal,
@@ -93,60 +93,52 @@ pub unsafe extern "C" fn extism_context_free(ctx: *mut Context) {
 /// Returns a pointer to the memory of the currently running plugin
 /// NOTE: this should only be called from host functions.
 #[no_mangle]
-pub unsafe extern "C" fn extism_current_plugin_memory(plugin: *mut Plugin) -> *mut u8 {
+pub unsafe extern "C" fn extism_current_plugin_memory(plugin: *mut Internal) -> *mut u8 {
     if plugin.is_null() {
         return std::ptr::null_mut();
     }
 
     let plugin = &mut *plugin;
-    plugin.memory.data_mut().as_mut_ptr()
+    plugin.memory_ptr()
 }
 
 /// Allocate a memory block in the currently running plugin
 /// NOTE: this should only be called from host functions.
 #[no_mangle]
-pub unsafe extern "C" fn extism_current_plugin_memory_alloc(plugin: *mut Plugin, n: Size) -> u64 {
+pub unsafe extern "C" fn extism_current_plugin_memory_alloc(plugin: *mut Internal, n: Size) -> u64 {
     if plugin.is_null() {
         return 0;
     }
 
     let plugin = &mut *plugin;
-
-    let mem = match plugin.memory.alloc(n as usize) {
-        Ok(x) => x,
-        Err(e) => return plugin.error(e, 0),
-    };
-
-    mem.offset as u64
+    plugin.memory_alloc(n as u64).unwrap_or_default()
 }
 
 /// Get the length of an allocated block
 /// NOTE: this should only be called from host functions.
 #[no_mangle]
-pub unsafe extern "C" fn extism_current_plugin_memory_length(plugin: *mut Plugin, n: Size) -> Size {
+pub unsafe extern "C" fn extism_current_plugin_memory_length(
+    plugin: *mut Internal,
+    n: Size,
+) -> Size {
     if plugin.is_null() {
         return 0;
     }
 
     let plugin = &mut *plugin;
-
-    match plugin.memory.block_length(n as usize) {
-        Some(x) => x as Size,
-        None => 0,
-    }
+    plugin.memory_length(n)
 }
 
 /// Free an allocated memory block
 /// NOTE: this should only be called from host functions.
 #[no_mangle]
-pub unsafe extern "C" fn extism_current_plugin_memory_free(plugin: *mut Plugin, ptr: u64) {
+pub unsafe extern "C" fn extism_current_plugin_memory_free(plugin: *mut Internal, ptr: u64) {
     if plugin.is_null() {
         return;
     }
 
     let plugin = &mut *plugin;
-
-    plugin.memory.free(ptr as usize);
+    plugin.memory_free(ptr);
 }
 
 /// Create a new host function
@@ -339,8 +331,7 @@ pub unsafe extern "C" fn extism_plugin_update(
         return false;
     }
 
-    ctx.plugins
-        .insert(index, std::cell::UnsafeCell::new(plugin));
+    ctx.plugins.insert(index, plugin);
 
     debug!("Plugin updated: {index}");
     true
@@ -412,44 +403,49 @@ pub unsafe extern "C" fn extism_plugin_config(
     json_size: Size,
 ) -> bool {
     let ctx = &mut *ctx;
-    let mut plugin = match PluginRef::new(ctx, plugin, true) {
+    let mut plugin_ref = match PluginRef::new(ctx, plugin, true) {
         None => return false,
         Some(p) => p,
     };
-
     trace!(
         "Call to extism_plugin_config for {} with json pointer {:?}",
-        plugin.id,
+        plugin_ref.id,
         json
     );
+    let plugin = plugin_ref.as_mut();
 
     let data = std::slice::from_raw_parts(json, json_size as usize);
     let json: std::collections::BTreeMap<String, Option<String>> =
         match serde_json::from_slice(data) {
             Ok(x) => x,
             Err(e) => {
-                return plugin.as_mut().error(e, false);
+                return plugin.error(e, false);
             }
         };
 
-    let plugin = plugin.as_mut();
+    let wasi = &mut plugin.internal_mut().wasi;
+    if let Some(Wasi { ctx, .. }) = wasi {
+        for (k, v) in json.iter() {
+            match v {
+                Some(v) => {
+                    let _ = ctx.push_env(k, v);
+                }
+                None => {
+                    let _ = ctx.push_env(k, "");
+                }
+            }
+        }
+    }
 
-    let wasi = &mut plugin.memory.store.data_mut().wasi;
-    let config = &mut plugin.manifest.as_mut().config;
+    let config = &mut plugin.internal_mut().manifest.as_mut().config;
     for (k, v) in json.into_iter() {
         match v {
             Some(v) => {
                 trace!("Config, adding {k}");
-                if let Some(Wasi { ctx, .. }) = wasi {
-                    let _ = ctx.push_env(&k, &v);
-                }
                 config.insert(k, v);
             }
             None => {
                 trace!("Config, removing {k}");
-                if let Some(Wasi { ctx, .. }) = wasi {
-                    let _ = ctx.push_env(&k, "");
-                }
                 config.remove(&k);
             }
         }
@@ -499,77 +495,60 @@ pub unsafe extern "C" fn extism_plugin_call(
 ) -> i32 {
     let ctx = &mut *ctx;
 
+    // Get function name
+    let name = std::ffi::CStr::from_ptr(func_name);
+    let name = match name.to_str() {
+        Ok(name) => name,
+        Err(e) => return ctx.error(e, -1),
+    };
+    let is_start = name == "_start";
+
     // Get a `PluginRef` and call `init` to set up the plugin input and memory, this is only
     // needed before a new call
     let mut plugin_ref = match PluginRef::new(ctx, plugin_id, true) {
         None => return -1,
-        Some(p) => p.init(data, data_len as usize),
+        Some(p) => p.start_call(is_start),
     };
+    let tx = plugin_ref.epoch_timer_tx.clone();
+    let plugin = plugin_ref.as_mut();
 
-    // Find function
-    let name = std::ffi::CStr::from_ptr(func_name);
-    let name = match name.to_str() {
-        Ok(name) => name,
-        Err(e) => return plugin_ref.as_ref().error(e, -1),
-    };
-
-    debug!("Calling function: {name} in plugin {plugin_id}");
-
-    let func = match plugin_ref.as_mut().get_func(name) {
+    let func = match plugin.get_func(name) {
         Some(x) => x,
-        None => {
-            return plugin_ref
-                .as_ref()
-                .error(format!("Function not found: {name}"), -1)
-        }
+        None => return plugin.error(format!("Function not found: {name}"), -1),
     };
 
     // Check the number of results, reject functions with more than 1 result
-    let n_results = func.ty(&plugin_ref.as_ref().memory.store).results().len();
+    let n_results = func.ty(plugin.store()).results().len();
     if n_results > 1 {
-        return plugin_ref.as_ref().error(
+        return plugin.error(
             format!("Function {name} has {n_results} results, expected 0 or 1"),
             -1,
         );
     }
 
-    // Start timer
-    let tx = plugin_ref.epoch_timer_tx.clone();
-    if let Err(e) = plugin_ref.as_mut().start_timer(&tx) {
-        let id = plugin_ref.as_ref().timer_id;
-        return plugin_ref.as_ref().error(
-            format!("Unable to start timeout manager for {id}: {e:?}"),
-            -1,
-        );
+    if let Err(e) = plugin.set_input(data, data_len as usize) {
+        return plugin.error(e, -1);
     }
 
+    if plugin.has_error() {
+        return -1;
+    }
+
+    // Start timer, this will be stopped when PluginRef goes out of scope
+    if let Err(e) = plugin.start_timer(&tx) {
+        return plugin.error(e, -1);
+    }
+
+    debug!("Calling function: {name} in plugin {plugin_id}");
+
     // Call the function
     let mut results = vec![wasmtime::Val::null(); n_results];
-    let res = func.call(
-        &mut plugin_ref.as_mut().memory.store,
-        &[],
-        results.as_mut_slice(),
-    );
-
-    plugin_ref.as_ref().dump_memory();
-
-    if plugin_ref.as_ref().has_wasi() && name == "_start" {
-        plugin_ref.as_mut().should_reinstantiate = true;
-    }
-
-    // Stop timer
-    if let Err(e) = plugin_ref.as_mut().stop_timer() {
-        let id = plugin_ref.as_ref().timer_id;
-        return plugin_ref.as_ref().error(
-            format!("Failed to stop timeout manager for {id}: {e:?}"),
-            -1,
-        );
-    }
+    let res = func.call(plugin.store_mut(), &[], results.as_mut_slice());
 
     match res {
         Ok(()) => (),
         Err(e) => {
-            let plugin = plugin_ref.as_ref();
+            plugin.store.set_epoch_deadline(1);
             if let Some(exit) = e.downcast_ref::<wasmtime_wasi::I32Exit>() {
                 trace!("WASI return code: {}", exit.0);
                 if exit.0 != 0 {
@@ -619,19 +598,27 @@ pub unsafe extern "C" fn extism_error(ctx: *mut Context, plugin: PluginIndex) ->
         return get_context_error(ctx);
     }
 
-    let plugin = match PluginRef::new(ctx, plugin, false) {
+    let mut plugin_ref = match PluginRef::new(ctx, plugin, false) {
         None => return std::ptr::null(),
         Some(p) => p,
     };
-
-    let err = plugin.as_ref().last_error.borrow();
-    match err.as_ref() {
-        Some(e) => e.as_ptr() as *const _,
-        None => {
-            trace!("Error is NULL");
-            std::ptr::null()
-        }
+    let plugin = plugin_ref.as_mut();
+    let output = &mut [Val::I64(0)];
+    if let Some(f) = plugin
+        .linker
+        .get(&mut plugin.store, "env", "extism_error_get")
+    {
+        f.into_func()
+            .unwrap()
+            .call(&mut plugin.store, &[], output)
+            .unwrap();
     }
+    if output[0].unwrap_i64() == 0 {
+        trace!("Error is NULL");
+        return std::ptr::null();
+    }
+
+    plugin.memory_ptr().add(output[0].unwrap_i64() as usize) as *const _
 }
 
 /// Get the length of a plugin's output data
@@ -643,17 +630,25 @@ pub unsafe extern "C" fn extism_plugin_output_length(
     trace!("Call to extism_plugin_output_length for plugin {plugin}");
 
     let ctx = &mut *ctx;
-    let plugin = match PluginRef::new(ctx, plugin, true) {
+    let mut plugin_ref = match PluginRef::new(ctx, plugin, true) {
         None => return 0,
         Some(p) => p,
     };
-
-    let len = plugin.as_ref().memory.store.data().output_length as Size;
+    let plugin = plugin_ref.as_mut();
+    let out = &mut [Val::I64(0)];
+    let _ = plugin
+        .linker
+        .get(&mut plugin.store, "env", "extism_output_length")
+        .unwrap()
+        .into_func()
+        .unwrap()
+        .call(&mut plugin.store_mut(), &[], out);
+    let len = out[0].unwrap_i64() as Size;
     trace!("Output length: {len}");
     len
 }
 
-/// Get the length of a plugin's output data
+/// Get a pointer to the output data
 #[no_mangle]
 pub unsafe extern "C" fn extism_plugin_output_data(
     ctx: *mut Context,
@@ -662,18 +657,26 @@ pub unsafe extern "C" fn extism_plugin_output_data(
     trace!("Call to extism_plugin_output_data for plugin {plugin}");
 
     let ctx = &mut *ctx;
-    let plugin = match PluginRef::new(ctx, plugin, true) {
+    let mut plugin_ref = match PluginRef::new(ctx, plugin, true) {
         None => return std::ptr::null(),
         Some(p) => p,
     };
-    let data = plugin.as_ref().memory.store.data();
-
+    let plugin = plugin_ref.as_mut();
+    let ptr = plugin.memory_ptr();
+    let out = &mut [Val::I64(0)];
+    let mut store = &mut *(plugin.store_mut() as *mut Store<_>);
     plugin
-        .as_ref()
-        .memory
-        .ptr(MemoryBlock::new(data.output_offset, data.output_length))
-        .map(|x| x as *const _)
-        .unwrap_or(std::ptr::null())
+        .linker
+        .get(&mut store, "env", "extism_output_offset")
+        .unwrap()
+        .into_func()
+        .unwrap()
+        .call(&mut store, &[], out)
+        .unwrap();
+
+    let offs = out[0].unwrap_i64() as usize;
+    trace!("Output offset: {}", offs);
+    ptr.add(offs)
 }
 
 /// Set log file and level
@@ -700,9 +703,7 @@ pub unsafe extern "C" fn extism_log_file(
         "stderr"
     };
 
-    let level = if log_level.is_null() {
-        "error"
-    } else {
+    let level = if !log_level.is_null() {
         let level = std::ffi::CStr::from_ptr(log_level);
         match level.to_str() {
             Ok(x) => x,
@@ -710,6 +711,8 @@ pub unsafe extern "C" fn extism_log_file(
                 return false;
             }
         }
+    } else {
+        "error"
     };
 
     let level = match LevelFilter::from_str(level) {

runtime/src/timer.rs

@@ -20,6 +20,7 @@ pub(crate) struct Timer {
     pub thread: Option<std::thread::JoinHandle<()>>,
 }
 
+#[cfg(not(target_family = "windows"))]
 extern "C" fn cleanup_timer() {
     drop(Context::timer().take())
 }
@@ -90,6 +91,7 @@ impl Timer {
             tx: tx.clone(),
         });
 
+        #[cfg(not(target_family = "windows"))]
         unsafe {
             libc::atexit(cleanup_timer);
         }

rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "extism"
-version = "0.3.0"
+version = "0.5.1"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"
@@ -9,8 +9,8 @@ repository = "https://github.com/extism/extism"
 description = "Extism Host SDK for Rust"
 
 [dependencies]
-extism-manifest = { version = "0.3.0", path = "../manifest" }
-extism-runtime = { version = "0.3.0", path = "../runtime"}
+extism-manifest = { version = "0.5.0", path = "../manifest" }
+extism-runtime = { version = "0.5.2", path = "../runtime"}
 serde_json = "1"
 log = "0.4"
 anyhow = "1"

rust/src/bindings.rs

@@ -1,45 +1,260 @@
-/* automatically generated by rust-bindgen 0.60.1 */
+/* automatically generated by rust-bindgen 0.65.1 */
 
-pub type __uint8_t = ::std::os::raw::c_uchar;
-pub type __int32_t = ::std::os::raw::c_int;
-pub type __uint64_t = ::std::os::raw::c_ulong;
+#[doc = " Signed 32 bit integer."]
+pub const ExtismValType_I32: ExtismValType = 0;
+#[doc = " Signed 64 bit integer."]
+pub const ExtismValType_I64: ExtismValType = 1;
+#[doc = " Floating point 32 bit integer."]
+pub const ExtismValType_F32: ExtismValType = 2;
+#[doc = " Floating point 64 bit integer."]
+pub const ExtismValType_F64: ExtismValType = 3;
+#[doc = " A 128 bit number."]
+pub const ExtismValType_V128: ExtismValType = 4;
+#[doc = " A reference to a Wasm function."]
+pub const ExtismValType_FuncRef: ExtismValType = 5;
+#[doc = " A reference to opaque data in the Wasm instance."]
+pub const ExtismValType_ExternRef: ExtismValType = 6;
+#[doc = " A list of all possible value types in WebAssembly."]
+pub type ExtismValType = ::std::os::raw::c_uint;
 #[repr(C)]
 #[derive(Debug, Copy, Clone)]
 pub struct ExtismContext {
     _unused: [u8; 0],
 }
-pub type ExtismPlugin = i32;
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct ExtismCancelHandle {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct ExtismFunction {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct ExtismCurrentPlugin {
+    _unused: [u8; 0],
+}
 pub type ExtismSize = u64;
+#[doc = " A union type for host function argument/return values"]
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub union ExtismValUnion {
+    pub i32_: i32,
+    pub i64_: i64,
+    pub f32_: f32,
+    pub f64_: f64,
+}
+#[test]
+fn bindgen_test_layout_ExtismValUnion() {
+    const UNINIT: ::std::mem::MaybeUninit<ExtismValUnion> = ::std::mem::MaybeUninit::uninit();
+    let ptr = UNINIT.as_ptr();
+    assert_eq!(
+        ::std::mem::size_of::<ExtismValUnion>(),
+        8usize,
+        concat!("Size of: ", stringify!(ExtismValUnion))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<ExtismValUnion>(),
+        8usize,
+        concat!("Alignment of ", stringify!(ExtismValUnion))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).i32_) as usize - ptr as usize },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(ExtismValUnion),
+            "::",
+            stringify!(i32_)
+        )
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).i64_) as usize - ptr as usize },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(ExtismValUnion),
+            "::",
+            stringify!(i64_)
+        )
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).f32_) as usize - ptr as usize },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(ExtismValUnion),
+            "::",
+            stringify!(f32_)
+        )
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).f64_) as usize - ptr as usize },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(ExtismValUnion),
+            "::",
+            stringify!(f64_)
+        )
+    );
+}
+#[doc = " `ExtismVal` holds the type and value of a function argument/return"]
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct ExtismVal {
+    pub t: ExtismValType,
+    pub v: ExtismValUnion,
+}
+#[test]
+fn bindgen_test_layout_ExtismVal() {
+    const UNINIT: ::std::mem::MaybeUninit<ExtismVal> = ::std::mem::MaybeUninit::uninit();
+    let ptr = UNINIT.as_ptr();
+    assert_eq!(
+        ::std::mem::size_of::<ExtismVal>(),
+        16usize,
+        concat!("Size of: ", stringify!(ExtismVal))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<ExtismVal>(),
+        8usize,
+        concat!("Alignment of ", stringify!(ExtismVal))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).t) as usize - ptr as usize },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(ExtismVal),
+            "::",
+            stringify!(t)
+        )
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).v) as usize - ptr as usize },
+        8usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(ExtismVal),
+            "::",
+            stringify!(v)
+        )
+    );
+}
+#[doc = " Host function signature"]
+pub type ExtismFunctionType = ::std::option::Option<
+    unsafe extern "C" fn(
+        plugin: *mut ExtismCurrentPlugin,
+        inputs: *const ExtismVal,
+        n_inputs: ExtismSize,
+        outputs: *mut ExtismVal,
+        n_outputs: ExtismSize,
+        data: *mut ::std::os::raw::c_void,
+    ),
+>;
+pub type ExtismPlugin = i32;
 extern "C" {
+    #[doc = " Create a new context"]
     pub fn extism_context_new() -> *mut ExtismContext;
 }
 extern "C" {
+    #[doc = " Free a context"]
     pub fn extism_context_free(ctx: *mut ExtismContext);
 }
 extern "C" {
+    #[doc = " Returns a pointer to the memory of the currently running plugin\n NOTE: this should only be called from host functions."]
+    pub fn extism_current_plugin_memory(plugin: *mut ExtismCurrentPlugin) -> *mut u8;
+}
+extern "C" {
+    #[doc = " Allocate a memory block in the currently running plugin\n NOTE: this should only be called from host functions."]
+    pub fn extism_current_plugin_memory_alloc(
+        plugin: *mut ExtismCurrentPlugin,
+        n: ExtismSize,
+    ) -> u64;
+}
+extern "C" {
+    #[doc = " Get the length of an allocated block\n NOTE: this should only be called from host functions."]
+    pub fn extism_current_plugin_memory_length(
+        plugin: *mut ExtismCurrentPlugin,
+        n: ExtismSize,
+    ) -> ExtismSize;
+}
+extern "C" {
+    #[doc = " Free an allocated memory block\n NOTE: this should only be called from host functions."]
+    pub fn extism_current_plugin_memory_free(plugin: *mut ExtismCurrentPlugin, ptr: u64);
+}
+extern "C" {
+    #[doc = " Create a new host function\n\n Arguments\n - `name`: function name, this should be valid UTF-8\n - `inputs`: argument types\n - `n_inputs`: number of argument types\n - `outputs`: return types\n - `n_outputs`: number of return types\n - `func`: the function to call\n - `user_data`: a pointer that will be passed to the function when it's called\n    this value should live as long as the function exists\n - `free_user_data`: a callback to release the `user_data` value when the resulting\n   `ExtismFunction` is freed.\n\n Returns a new `ExtismFunction` or `null` if the `name` argument is invalid."]
+    pub fn extism_function_new(
+        name: *const ::std::os::raw::c_char,
+        inputs: *const ExtismValType,
+        n_inputs: ExtismSize,
+        outputs: *const ExtismValType,
+        n_outputs: ExtismSize,
+        func: ExtismFunctionType,
+        user_data: *mut ::std::os::raw::c_void,
+        free_user_data: ::std::option::Option<
+            unsafe extern "C" fn(__: *mut ::std::os::raw::c_void),
+        >,
+    ) -> *mut ExtismFunction;
+}
+extern "C" {
+    #[doc = " Set the namespace of an `ExtismFunction`"]
+    pub fn extism_function_set_namespace(
+        ptr: *mut ExtismFunction,
+        namespace_: *const ::std::os::raw::c_char,
+    );
+}
+extern "C" {
+    #[doc = " Free an `ExtismFunction`"]
+    pub fn extism_function_free(ptr: *mut ExtismFunction);
+}
+extern "C" {
+    #[doc = " Create a new plugin with additional host functions\n\n `wasm`: is a WASM module (wat or wasm) or a JSON encoded manifest\n `wasm_size`: the length of the `wasm` parameter\n `functions`: an array of `ExtismFunction*`\n `n_functions`: the number of functions provided\n `with_wasi`: enables/disables WASI"]
     pub fn extism_plugin_new(
         ctx: *mut ExtismContext,
         wasm: *const u8,
         wasm_size: ExtismSize,
+        functions: *mut *const ExtismFunction,
+        n_functions: ExtismSize,
         with_wasi: bool,
     ) -> ExtismPlugin;
 }
 extern "C" {
+    #[doc = " Update a plugin, keeping the existing ID\n\n Similar to `extism_plugin_new` but takes an `index` argument to specify\n which plugin to update\n\n Memory for this plugin will be reset upon update"]
     pub fn extism_plugin_update(
         ctx: *mut ExtismContext,
         index: ExtismPlugin,
         wasm: *const u8,
         wasm_size: ExtismSize,
+        functions: *mut *const ExtismFunction,
+        nfunctions: ExtismSize,
         with_wasi: bool,
     ) -> bool;
 }
 extern "C" {
+    #[doc = " Remove a plugin from the registry and free associated memory"]
     pub fn extism_plugin_free(ctx: *mut ExtismContext, plugin: ExtismPlugin);
 }
 extern "C" {
+    #[doc = " Get plugin ID for cancellation"]
+    pub fn extism_plugin_cancel_handle(
+        ctx: *mut ExtismContext,
+        plugin: ExtismPlugin,
+    ) -> *const ExtismCancelHandle;
+}
+extern "C" {
+    #[doc = " Cancel a running plugin"]
+    pub fn extism_plugin_cancel(handle: *const ExtismCancelHandle) -> bool;
+}
+extern "C" {
+    #[doc = " Remove all plugins from the registry"]
     pub fn extism_context_reset(ctx: *mut ExtismContext);
 }
 extern "C" {
+    #[doc = " Update plugin config values, this will merge with the existing values"]
     pub fn extism_plugin_config(
         ctx: *mut ExtismContext,
         plugin: ExtismPlugin,
@@ -48,6 +263,7 @@ extern "C" {
     ) -> bool;
 }
 extern "C" {
+    #[doc = " Returns true if `func_name` exists"]
     pub fn extism_plugin_function_exists(
         ctx: *mut ExtismContext,
         plugin: ExtismPlugin,
@@ -55,6 +271,7 @@ extern "C" {
     ) -> bool;
 }
 extern "C" {
+    #[doc = " Call a function\n\n `func_name`: is the function to call\n `data`: is the input data\n `data_len`: is the length of `data`"]
     pub fn extism_plugin_call(
         ctx: *mut ExtismContext,
         plugin_id: ExtismPlugin,
@@ -64,26 +281,29 @@ extern "C" {
     ) -> i32;
 }
 extern "C" {
+    #[doc = " Get the error associated with a `Context` or `Plugin`, if `plugin` is `-1` then the context\n error will be returned"]
     pub fn extism_error(
         ctx: *mut ExtismContext,
         plugin: ExtismPlugin,
     ) -> *const ::std::os::raw::c_char;
 }
 extern "C" {
+    #[doc = " Get the length of a plugin's output data"]
     pub fn extism_plugin_output_length(ctx: *mut ExtismContext, plugin: ExtismPlugin)
         -> ExtismSize;
 }
 extern "C" {
+    #[doc = " Get a pointer to the output data"]
     pub fn extism_plugin_output_data(ctx: *mut ExtismContext, plugin: ExtismPlugin) -> *const u8;
 }
 extern "C" {
+    #[doc = " Set log file and level"]
     pub fn extism_log_file(
         filename: *const ::std::os::raw::c_char,
         log_level: *const ::std::os::raw::c_char,
     ) -> bool;
 }
-
 extern "C" {
-    pub fn extism_version(
-    ) -> *const ::std::os::raw::c_char;
+    #[doc = " Get the Extism version string"]
+    pub fn extism_version() -> *const ::std::os::raw::c_char;
 }

rust/src/context.rs

@@ -1,5 +1,6 @@
 use crate::*;
 
+#[derive(Clone)]
 pub struct Context(pub(crate) std::sync::Arc<std::sync::Mutex<extism_runtime::Context>>);
 
 impl Default for Context {
@@ -8,6 +9,9 @@ impl Default for Context {
     }
 }
 
+unsafe impl Sync for Context {}
+unsafe impl Send for Context {}
+
 impl Context {
     /// Create a new context
     pub fn new() -> Context {

rust/src/lib.rs

@@ -1,6 +1,6 @@
 pub use extism_manifest::{self as manifest, Manifest};
 pub use extism_runtime::{
-    sdk as bindings, Function, MemoryBlock, Plugin as CurrentPlugin, UserData, Val, ValType,
+    sdk as bindings, Function, Internal as CurrentPlugin, InternalExt, UserData, Val, ValType,
 };
 
 mod context;
@@ -21,13 +21,20 @@ pub fn extism_version() -> String {
 
 /// Set the log file and level, this is a global setting
 pub fn set_log_file(filename: impl AsRef<std::path::Path>, log_level: Option<log::Level>) -> bool {
-    let log_level = log_level.map(|x| x.as_str());
-    unsafe {
-        return bindings::extism_log_file(
-            filename.as_ref().as_os_str().to_string_lossy().as_ptr() as *const _,
-            log_level.map(|x| x.as_ptr()).unwrap_or(std::ptr::null()) as *const _,
-        );
+    if let Ok(filename) = std::ffi::CString::new(filename.as_ref().to_string_lossy().as_bytes()) {
+        let log_level_s = log_level.map(|x| x.as_str());
+        let log_level_c = log_level_s.map(|x| std::ffi::CString::new(x));
+        if let Some(Ok(log_level_c)) = log_level_c {
+            unsafe {
+                return bindings::extism_log_file(filename.as_ptr(), log_level_c.as_ptr());
+            }
+        } else {
+            unsafe {
+                return bindings::extism_log_file(filename.as_ptr(), std::ptr::null());
+            }
+        }
     }
+    false
 }
 
 #[cfg(test)]
@@ -37,14 +44,20 @@ mod tests {
 
     const WASM: &[u8] = include_bytes!("../../wasm/code-functions.wasm");
     const WASM_LOOP: &[u8] = include_bytes!("../../wasm/loop.wasm");
+    const WASM_GLOBALS: &[u8] = include_bytes!("../../wasm/globals.wasm");
+    const REFLECT_WASM: &[u8] = include_bytes!("../../wasm/reflect.wasm");
 
     fn hello_world(
-        _plugin: &mut CurrentPlugin,
+        plugin: &mut CurrentPlugin,
         inputs: &[Val],
         outputs: &mut [Val],
         _user_data: UserData,
     ) -> Result<(), Error> {
-        outputs[0] = inputs[0].clone();
+        let input_offs = inputs[0].unwrap_i64() as u64;
+        let length = plugin.memory_length(input_offs);
+        let input = plugin.memory_read(input_offs, length).to_vec();
+        let output = plugin.memory_alloc_bytes(&input).unwrap();
+        outputs[0] = Val::I64(output as i64);
         Ok(())
     }
 
@@ -60,7 +73,7 @@ mod tests {
     #[test]
     fn it_works() {
         let wasm_start = Instant::now();
-        set_log_file("test.log", Some(log::Level::Info));
+        assert!(set_log_file("test.log", Some(log::Level::Trace)));
         let context = Context::new();
         let f = Function::new(
             "hello_world",
@@ -79,8 +92,7 @@ mod tests {
         )
         .with_namespace("test");
 
-        let functions = [&f, &g];
-        let mut plugin = Plugin::new(&context, WASM, functions, true).unwrap();
+        let mut plugin = Plugin::new(&context, WASM, [f, g], true).unwrap();
         println!("register loaded plugin: {:?}", wasm_start.elapsed());
 
         let repeat = 1182;
@@ -168,7 +180,7 @@ mod tests {
     }
 
     #[test]
-    fn test_threads() {
+    fn test_context_threads() {
         use std::io::Write;
         std::thread::spawn(|| {
             let context = Context::new();
@@ -179,7 +191,7 @@ mod tests {
                 None,
                 hello_world,
             );
-            let mut plugin = Plugin::new(&context, WASM, [&f], true).unwrap();
+            let mut plugin = Plugin::new(&context, WASM, [f], true).unwrap();
             let output = plugin.call("count_vowels", "this is a test").unwrap();
             std::io::stdout().write_all(output).unwrap();
         });
@@ -192,22 +204,63 @@ mod tests {
             hello_world,
         );
 
-        let g = f.clone();
-        std::thread::spawn(move || {
-            let context = Context::new();
-            let mut plugin = PluginBuilder::new_with_module(WASM)
-                .with_function(&g)
-                .with_wasi(true)
-                .build(&context)
-                .unwrap();
-            let output = plugin.call("count_vowels", "this is a test aaa").unwrap();
-            std::io::stdout().write_all(output).unwrap();
-        });
-
+        // One context shared between two threads
         let context = Context::new();
-        let mut plugin = Plugin::new(&context, WASM, [&f], true).unwrap();
-        let output = plugin.call("count_vowels", "abc123").unwrap();
-        std::io::stdout().write_all(output).unwrap();
+        let mut threads = vec![];
+        for _ in 0..3 {
+            let ctx = context.clone();
+            let g = f.clone();
+            let a = std::thread::spawn(move || {
+                let mut plugin = PluginBuilder::new_with_module(WASM)
+                    .with_function(g)
+                    .with_wasi(true)
+                    .build(Some(&ctx))
+                    .unwrap();
+                for _ in 0..10 {
+                    let output = plugin.call("count_vowels", "this is a test aaa").unwrap();
+                    assert_eq!(b"{\"count\": 7}", output);
+                }
+            });
+            threads.push(a);
+        }
+        for thread in threads {
+            thread.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn test_plugin_threads() {
+        let f = Function::new(
+            "hello_world",
+            [ValType::I64],
+            [ValType::I64],
+            None,
+            hello_world,
+        );
+
+        let p = std::sync::Arc::new(std::sync::Mutex::new(
+            PluginBuilder::new_with_module(WASM)
+                .with_function(f)
+                .with_wasi(true)
+                .build(None)
+                .unwrap(),
+        ));
+
+        let mut threads = vec![];
+        for _ in 0..3 {
+            let plugin = p.clone();
+            let a = std::thread::spawn(move || {
+                let mut plugin = plugin.lock().unwrap();
+                for _ in 0..10 {
+                    let output = plugin.call("count_vowels", "this is a test aaa").unwrap();
+                    assert_eq!(b"{\"count\": 7}", output);
+                }
+            });
+            threads.push(a);
+        }
+        for thread in threads {
+            thread.join().unwrap();
+        }
     }
 
     #[test]
@@ -221,7 +274,7 @@ mod tests {
         );
 
         let context = Context::new();
-        let mut plugin = Plugin::new(&context, WASM_LOOP, [&f], true).unwrap();
+        let mut plugin = Plugin::new(&context, WASM_LOOP, [f], true).unwrap();
         let handle = plugin.cancel_handle();
 
         std::thread::spawn(move || {
@@ -236,4 +289,57 @@ mod tests {
         println!("Cancelled plugin ran for {:?}", time);
         // std::io::stdout().write_all(output).unwrap();
     }
+
+    #[test]
+    fn test_multiple_instantiations() {
+        let f = Function::new(
+            "hello_world",
+            [ValType::I64],
+            [ValType::I64],
+            None,
+            hello_world,
+        );
+
+        let context = Context::new();
+        let mut plugin = Plugin::new(&context, WASM, [f], true).unwrap();
+
+        // This is 10,001 because the wasmtime store limit is 10,000 - we want to test
+        // that our reinstantiation process is working and that limit is never hit.
+        for _ in 0..10001 {
+            let _output = plugin.call("count_vowels", "abc123").unwrap();
+        }
+    }
+
+    #[test]
+    fn test_globals() {
+        let context = Context::new();
+        let mut plugin = Plugin::new(&context, WASM_GLOBALS, [], true).unwrap();
+        for i in 0..1000 {
+            let output = plugin.call("globals", "").unwrap();
+            let count: serde_json::Value = serde_json::from_slice(&output).unwrap();
+            assert_eq!(count.get("count").unwrap().as_i64().unwrap(), i);
+        }
+    }
+
+    #[test]
+    fn test_fuzz_reflect_plugin() {
+        // assert!(set_log_file("stdout", Some(log::Level::Trace)));
+        let f = Function::new(
+            "host_reflect",
+            [ValType::I64],
+            [ValType::I64],
+            None,
+            hello_world,
+        );
+
+        let context = Context::new();
+        let mut plugin = Plugin::new(&context, REFLECT_WASM, [f], true).unwrap();
+
+        for i in 1..65540 {
+            let input = "a".repeat(i);
+            let output = plugin.call("reflect", input.clone());
+            let output = std::str::from_utf8(output.unwrap()).unwrap();
+            assert_eq!(output, input);
+        }
+    }
 }

rust/src/plugin.rs

@@ -1,9 +1,36 @@
 use crate::*;
 use std::collections::BTreeMap;
 
+enum RefOrOwned<'a, T> {
+    Ref(&'a T),
+    Owned(T),
+}
+
 pub struct Plugin<'a> {
     id: extism_runtime::PluginIndex,
-    context: &'a Context,
+    context: RefOrOwned<'a, Context>,
+    functions: Vec<Function>,
+}
+
+impl<'a, T> From<&'a T> for RefOrOwned<'a, T> {
+    fn from(value: &'a T) -> Self {
+        RefOrOwned::Ref(value)
+    }
+}
+
+impl<'a, T> From<T> for RefOrOwned<'a, T> {
+    fn from(value: T) -> Self {
+        RefOrOwned::Owned(value)
+    }
+}
+
+impl<'a, T> AsRef<T> for RefOrOwned<'a, T> {
+    fn as_ref(&self) -> &T {
+        match self {
+            RefOrOwned::Ref(x) => x,
+            RefOrOwned::Owned(x) => x,
+        }
+    }
 }
 
 pub struct CancelHandle(pub(crate) *const extism_runtime::sdk::ExtismCancelHandle);
@@ -23,32 +50,44 @@ impl<'a> Plugin<'a> {
     /// # Safety
     /// This function does not check to ensure the provided ID is valid
     pub unsafe fn from_id(id: i32, context: &'a Context) -> Plugin<'a> {
-        Plugin { id, context }
+        let context = RefOrOwned::Ref(context);
+        Plugin {
+            id,
+            context,
+            functions: vec![],
+        }
+    }
+
+    pub fn context(&self) -> &Context {
+        match &self.context {
+            RefOrOwned::Ref(x) => x,
+            RefOrOwned::Owned(x) => x,
+        }
     }
 
     pub fn as_i32(&self) -> i32 {
         self.id
     }
 
-    /// Create a new plugin from the given manifest
-    pub fn new_with_manifest(
-        ctx: &'a Context,
+    /// Create a new plugin from the given manifest in its own context
+    pub fn create_with_manifest(
         manifest: &Manifest,
-        functions: impl IntoIterator<Item = &'a extism_runtime::Function>,
+        functions: impl IntoIterator<Item = Function>,
         wasi: bool,
     ) -> Result<Plugin<'a>, Error> {
         let data = serde_json::to_vec(manifest)?;
-        Self::new(ctx, data, functions, wasi)
+        Self::create(data, functions, wasi)
     }
 
-    /// Create a new plugin from a WASM module
-    pub fn new(
-        ctx: &'a Context,
+    /// Create a new plugin from a WASM module in its own context
+    pub fn create(
         data: impl AsRef<[u8]>,
-        functions: impl IntoIterator<Item = &'a Function>,
+        functions: impl IntoIterator<Item = Function>,
         wasi: bool,
-    ) -> Result<Plugin, Error> {
-        let plugin = ctx.lock().new_plugin(data, functions, wasi);
+    ) -> Result<Plugin<'a>, Error> {
+        let ctx = Context::new();
+        let functions = functions.into_iter().collect();
+        let plugin = ctx.lock().new_plugin(data, &functions, wasi);
 
         if plugin < 0 {
             let err = unsafe { bindings::extism_error(&mut *ctx.lock(), -1) };
@@ -59,7 +98,43 @@ impl<'a> Plugin<'a> {
 
         Ok(Plugin {
             id: plugin,
-            context: ctx,
+            context: ctx.into(),
+            functions,
+        })
+    }
+
+    /// Create a new plugin from the given manifest
+    pub fn new_with_manifest(
+        ctx: &'a Context,
+        manifest: &Manifest,
+        functions: impl IntoIterator<Item = Function>,
+        wasi: bool,
+    ) -> Result<Plugin<'a>, Error> {
+        let data = serde_json::to_vec(manifest)?;
+        Self::new(ctx, data, functions, wasi)
+    }
+
+    /// Create a new plugin from a WASM module
+    pub fn new(
+        ctx: &'a Context,
+        data: impl AsRef<[u8]>,
+        functions: impl IntoIterator<Item = Function>,
+        wasi: bool,
+    ) -> Result<Plugin<'a>, Error> {
+        let functions = functions.into_iter().collect();
+        let plugin = ctx.lock().new_plugin(data, &functions, wasi);
+
+        if plugin < 0 {
+            let err = unsafe { bindings::extism_error(&mut *ctx.lock(), -1) };
+            let buf = unsafe { std::ffi::CStr::from_ptr(err) };
+            let buf = buf.to_str().unwrap();
+            return Err(Error::msg(buf));
+        }
+
+        Ok(Plugin {
+            id: plugin,
+            context: ctx.into(),
+            functions,
         })
     }
 
@@ -67,7 +142,7 @@ impl<'a> Plugin<'a> {
     pub fn update_with_manifest(
         &mut self,
         manifest: &Manifest,
-        functions: impl IntoIterator<Item = &'a Function>,
+        functions: impl IntoIterator<Item = Function>,
         wasi: bool,
     ) -> Result<(), Error> {
         let data = serde_json::to_vec(manifest)?;
@@ -78,11 +153,13 @@ impl<'a> Plugin<'a> {
     pub fn update(
         &mut self,
         data: impl AsRef<[u8]>,
-        functions: impl IntoIterator<Item = &'a Function>,
+        functions: impl IntoIterator<Item = Function>,
         wasi: bool,
     ) -> Result<(), Error> {
-        let functions = functions
-            .into_iter()
+        self.functions = functions.into_iter().collect();
+        let functions = self
+            .functions
+            .iter()
             .map(|x| bindings::ExtismFunction::from(x.clone()));
         let mut functions = functions
             .into_iter()
@@ -90,7 +167,7 @@ impl<'a> Plugin<'a> {
             .collect::<Vec<_>>();
         let b = unsafe {
             bindings::extism_plugin_update(
-                &mut *self.context.lock(),
+                &mut *self.context.as_ref().lock(),
                 self.id,
                 data.as_ref().as_ptr(),
                 data.as_ref().len() as u64,
@@ -103,7 +180,7 @@ impl<'a> Plugin<'a> {
             return Ok(());
         }
 
-        let err = unsafe { bindings::extism_error(&mut *self.context.lock(), -1) };
+        let err = unsafe { bindings::extism_error(&mut *self.context.as_ref().lock(), -1) };
         if !err.is_null() {
             let s = unsafe { std::ffi::CStr::from_ptr(err) };
             return Err(Error::msg(s.to_str().unwrap()));
@@ -117,7 +194,7 @@ impl<'a> Plugin<'a> {
         let encoded = serde_json::to_vec(config)?;
         unsafe {
             bindings::extism_plugin_config(
-                &mut *self.context.lock(),
+                &mut *self.context.as_ref().lock(),
                 self.id,
                 encoded.as_ptr() as *const _,
                 encoded.len() as u64,
@@ -137,7 +214,7 @@ impl<'a> Plugin<'a> {
         let name = std::ffi::CString::new(name.as_ref()).expect("Invalid function name");
         unsafe {
             bindings::extism_plugin_function_exists(
-                &mut *self.context.lock(),
+                &mut *self.context.as_ref().lock(),
                 self.id,
                 name.as_ptr() as *const _,
             )
@@ -145,18 +222,27 @@ impl<'a> Plugin<'a> {
     }
 
     pub fn cancel_handle(&self) -> CancelHandle {
-        let ptr =
-            unsafe { bindings::extism_plugin_cancel_handle(&mut *self.context.lock(), self.id) };
+        let ptr = unsafe {
+            bindings::extism_plugin_cancel_handle(&mut *self.context.as_ref().lock(), self.id)
+        };
 
         CancelHandle(ptr)
     }
 
-    /// Call a function with the given input
-    pub fn call(&mut self, name: impl AsRef<str>, input: impl AsRef<[u8]>) -> Result<&[u8], Error> {
+    /// Call a function with the given input and call a callback with the output, this should be preferred when
+    /// a single plugin may be acessed from multiple threads because the lock on the plugin is held during the
+    /// callback, ensuring the output value is protected from modification.
+    pub fn call_map<'b, T, F: FnOnce(&'b [u8]) -> Result<T, Error>>(
+        &'b mut self,
+        name: impl AsRef<str>,
+        input: impl AsRef<[u8]>,
+        f: F,
+    ) -> Result<T, Error> {
+        let context = &mut *self.context.as_ref().lock();
         let name = std::ffi::CString::new(name.as_ref()).expect("Invalid function name");
         let rc = unsafe {
             bindings::extism_plugin_call(
-                &mut *self.context.lock(),
+                context,
                 self.id,
                 name.as_ptr() as *const _,
                 input.as_ref().as_ptr() as *const _,
@@ -165,7 +251,7 @@ impl<'a> Plugin<'a> {
         };
 
         if rc != 0 {
-            let err = unsafe { bindings::extism_error(&mut *self.context.lock(), self.id) };
+            let err = unsafe { bindings::extism_error(context, self.id) };
             if !err.is_null() {
                 let s = unsafe { std::ffi::CStr::from_ptr(err) };
                 return Err(Error::msg(s.to_str().unwrap()));
@@ -174,17 +260,25 @@ impl<'a> Plugin<'a> {
             return Err(Error::msg("extism_call failed"));
         }
 
-        let out_len =
-            unsafe { bindings::extism_plugin_output_length(&mut *self.context.lock(), self.id) };
+        let out_len = unsafe { bindings::extism_plugin_output_length(context, self.id) };
         unsafe {
-            let ptr = bindings::extism_plugin_output_data(&mut *self.context.lock(), self.id);
-            Ok(std::slice::from_raw_parts(ptr, out_len as usize))
+            let ptr = bindings::extism_plugin_output_data(context, self.id);
+            f(std::slice::from_raw_parts(ptr, out_len as usize))
         }
     }
+
+    /// Call a function with the given input
+    pub fn call<'b>(
+        &'b mut self,
+        name: impl AsRef<str>,
+        input: impl AsRef<[u8]>,
+    ) -> Result<&'b [u8], Error> {
+        self.call_map(name, input, |x| Ok(x))
+    }
 }
 
 impl<'a> Drop for Plugin<'a> {
     fn drop(&mut self) {
-        unsafe { bindings::extism_plugin_free(&mut *self.context.lock(), self.id) }
+        unsafe { bindings::extism_plugin_free(&mut *self.context.as_ref().lock(), self.id) }
     }
 }

rust/src/plugin_builder.rs

@@ -6,13 +6,13 @@ enum Source {
 }
 
 /// PluginBuilder is used to configure and create `Plugin` instances
-pub struct PluginBuilder<'a> {
+pub struct PluginBuilder {
     source: Source,
     wasi: bool,
-    functions: Vec<&'a Function>,
+    functions: Vec<Function>,
 }
 
-impl<'a> PluginBuilder<'a> {
+impl PluginBuilder {
     /// Create a new `PluginBuilder` with the given WebAssembly module
     pub fn new_with_module(data: impl Into<Vec<u8>>) -> Self {
         PluginBuilder {
@@ -38,23 +38,29 @@ impl<'a> PluginBuilder<'a> {
     }
 
     /// Add a single host function
-    pub fn with_function(mut self, f: &'a Function) -> Self {
+    pub fn with_function(mut self, f: Function) -> Self {
         self.functions.push(f);
         self
     }
 
     /// Add multiple host functions
-    pub fn with_functions(mut self, f: impl IntoIterator<Item = &'a Function>) -> Self {
+    pub fn with_functions(mut self, f: impl IntoIterator<Item = Function>) -> Self {
         self.functions.extend(f);
         self
     }
 
-    pub fn build(self, context: &'a Context) -> Result<Plugin<'a>, Error> {
-        match self.source {
-            Source::Manifest(m) => {
-                Plugin::new_with_manifest(context, &m, self.functions, self.wasi)
-            }
-            Source::Data(d) => Plugin::new(context, d, self.functions, self.wasi),
+    pub fn build<'a>(self, context: Option<&'a Context>) -> Result<Plugin<'a>, Error> {
+        match context {
+            Some(context) => match self.source {
+                Source::Manifest(m) => {
+                    Plugin::new_with_manifest(context, &m, self.functions, self.wasi)
+                }
+                Source::Data(d) => Plugin::new(context, d, self.functions, self.wasi),
+            },
+            None => match self.source {
+                Source::Manifest(m) => Plugin::create_with_manifest(&m, self.functions, self.wasi),
+                Source::Data(d) => Plugin::create(d, self.functions, self.wasi),
+            },
         }
     }
 }