Merge branch 'main' into symlink-plugin-in-example-files

Co-authored-by: zach <zach@dylib.so>

.github/workflows/browser-ci.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest]
         rust:
           - stable
     steps:

.github/workflows/ci-go.yml

@@ -34,6 +34,6 @@ jobs:
       - name: Test Go Host SDK
         run: |
           go version
-          cd go
-          LD_LIBRARY_PATH=/usr/local/lib go run main.go
           LD_LIBRARY_PATH=/usr/local/lib go test
+          cd go
+          LD_LIBRARY_PATH=/usr/local/lib go run main.go | grep "Hello from Go!"

.github/workflows/ci-java.yml

@@ -18,7 +18,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        version: [8, 11, 17]
+        version: [11, 17]
         rust:
           - stable
     steps:
@@ -33,10 +33,5 @@ jobs:
       - name: Test Java
         run: |
           cd java
-          cat pom.xml | sed 's/<java.version>17/<java.version>${{ matrix.version }}/' > updated.xml
-          mv updated.xml pom.xml
           mvn --batch-mode -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn verify
-      #- name: Examine logs
-      #  if: success() || failure()
-      #  run: |
-      #    cat /tmp/extism.log
+

.github/workflows/ci-zig.yml

@@ -18,6 +18,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]
+        zig_version: ["master"] # eventually use multiple versions once stable
         rust:
           - stable
     steps:
@@ -26,6 +27,8 @@ jobs:
       - uses: ./.github/actions/extism
       - name: Setup Zig env
         uses: goto-bus-stop/setup-zig@v2
+        with: 
+          version: ${{ matrix.zig_version }}
 
       - name: Test Zig Host SDK
         run: |

.github/workflows/release-haskell.yaml

@@ -1,7 +1,7 @@
 on:
   workflow_dispatch:
 
-name: Release Rust SDK
+name: Release Haskell SDK
 
 jobs:
   release-sdks:
@@ -10,7 +10,6 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
-      
       - uses: cachix/haskell-release-action@v1
         with:
           - hackage-token: "${{ secrets.HACKAGE_TOKEN }}"

.gitignore

@@ -36,3 +36,8 @@ vendor
 zig/zig-*
 zig/example-out/
 zig/*.log
+java/*.iml
+java/*.log
+java/.idea
+java/.DS_Store
+

Makefile

@@ -18,21 +18,19 @@ else
 	FEATURE_FLAGS=--features $(FEATURES)
 endif
 
-
-.PHONY: build
+build:
+	cargo build --release $(FEATURE_FLAGS) --manifest-path libextism/Cargo.toml
 
 lint:
 	cargo clippy --release --no-deps --manifest-path runtime/Cargo.toml
 
-build:
-	cargo build --release $(FEATURE_FLAGS) --manifest-path libextism/Cargo.toml
-
 debug:
 	RUSTFLAGS=-g $(MAKE) build
 
 install:
-	install runtime/extism.h $(DEST)/include
-	install target/release/libextism.$(SOEXT) $(DEST)/lib
+	mkdir -p $(DEST)/lib $(DEST)/include
+	install runtime/extism.h $(DEST)/include/extism.h
+	install target/release/libextism.$(SOEXT) $(DEST)/lib/libextism.$(SOEXT)
 
 uninstall:
 	rm -f $(DEST)/include/extism.h $(DEST)/lib/libextism.$(SOEXT)

README.md

@@ -1,6 +1,8 @@
 ### _Welcome!_
 
-**Please note:** this project still under active development. It's usable, but expect some rough edges while work is underway. If you're interested in working on or building with Extism, please join our [Discord](https://discord.gg/cx3usBCWnc) and let us know - we are happy to help get you started.
+**Please note:** This project still under active development and APIs may change until we hit v1.0.
+
+If you're interested in working on or building with Extism, please join our [Discord](https://discord.gg/cx3usBCWnc) and let us know - we are happy to help get you started.
 
 [![Discord](https://img.shields.io/discord/1011124058408112148?color=%23404eed&label=Community%20Chat&logo=Discord&logoColor=%23404eed)](https://discord.gg/cx3usBCWnc)
 
@@ -62,5 +64,4 @@ Extism is an open-source product from the team at:
 </p>
 
 
-
 _Reach out and tell us what you're building! We'd love to help._

browser/jest.config.js

@@ -1,5 +1,5 @@
 /** @type {import('ts-jest/dist/types').InitialOptionsTsJest} */
 module.exports = {
   preset: 'ts-jest',
-  testEnvironment: 'node',
+  testEnvironment: 'jsdom',
 };

browser/package.json

@@ -23,7 +23,9 @@
   "devDependencies": {
     "@types/jest": "^29.2.2",
     "esbuild": "^0.15.13",
+    "esbuild-jest": "^0.5.0",
     "jest": "^29.2.2",
+    "jest-environment-jsdom": "^29.3.1",
     "prettier": "^2.7.1",
     "ts-jest": "^29.0.3",
     "tslint": "^6.1.3",

browser/src/index.test.ts

@@ -8,16 +8,17 @@ function parse(bytes: Uint8Array): any {
 
 describe('', () => {
   it('can load and call a plugin', async () => {
-    const data = fs.readFileSync(path.join(__dirname, '..', 'data', 'code.wasm'));
-    const ctx = new ExtismContext();
-    const plugin = await ctx.newPlugin({ wasm: [{ data: data }] });
-    const functions = await plugin.getExports();
-    expect(Object.keys(functions).filter((x) => !x.startsWith('__') && x !== 'memory')).toEqual(['count_vowels']);
-    let output = await plugin.call('count_vowels', 'this is a test');
-    expect(parse(output)).toEqual({ count: 4 });
-    output = await plugin.call('count_vowels', 'this is a test again');
-    expect(parse(output)).toEqual({ count: 7 });
-    output = await plugin.call('count_vowels', 'this is a test thrice');
-    expect(parse(output)).toEqual({ count: 6 });
+    // const data = fs.readFileSync(path.join(__dirname, '..', 'data', 'code.wasm'));
+    // const ctx = new ExtismContext();
+    // const plugin = await ctx.newPlugin({ wasm: [{ data: data }] });
+    // const functions = await plugin.getExports();
+    // expect(Object.keys(functions).filter((x) => !x.startsWith('__') && x !== 'memory')).toEqual(['count_vowels']);
+    // let output = await plugin.call('count_vowels', 'this is a test');
+    // expect(parse(output)).toEqual({ count: 4 });
+    // output = await plugin.call('count_vowels', 'this is a test again');
+    // 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)
   });
 });

browser/src/plugin.ts

@@ -76,6 +76,9 @@ export default class ExtismPlugin {
       env: environment
     };
     this.module = await WebAssembly.instantiate(this.moduleData, env);
+    if (this.module.instance.exports._start) {
+      wasi.start(this.module.instance);
+    }
     return this.module;
   }
 

browser/tsconfig.json

@@ -1,13 +1,13 @@
 {
-    "compilerOptions": {
-      "target": "es2016", 
-      "module": "commonjs",  
-      "esModuleInterop": true,
-      "forceConsistentCasingInFileNames": true,
-      "declaration": true,
-      "strict": true,                   
-      "skipLibCheck": true,
-      "allowJs": true
-    },
-    "exclude": ["node_modules", "dist", "**/*.test.ts"]
-  }
+  "compilerOptions": {
+    "target": "es2016", 
+    "module": "commonjs",  
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "declaration": true,
+    "strict": true,                   
+    "skipLibCheck": true,
+    "allowJs": true
+  },
+  "exclude": ["node_modules", "dist", "**/*.test.ts"]
+}

c/Makefile

@@ -1,2 +1,2 @@
 build:
-	clang -o main main.c -lextism -L .
+	clang -g -o main main.c -lextism -L .

c/main.c

@@ -9,6 +9,21 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+void hello_world(ExtismCurrentPlugin *plugin, const ExtismVal *inputs,
+                 uint64_t n_inputs, ExtismVal *outputs, uint64_t n_outputs,
+                 void *data) {
+  puts("Hello from C!");
+  puts(data);
+
+  ExtismSize ptr_offs = inputs[0].v.i64;
+
+  uint8_t *buf = extism_current_plugin_memory(plugin) + ptr_offs;
+  uint64_t length = extism_current_plugin_memory_length(plugin, ptr_offs);
+  fwrite(buf, length, 1, stdout);
+  fputc('\n', stdout);
+  outputs[0].v.i64 = inputs[0].v.i64;
+}
+
 uint8_t *read_file(const char *filename, size_t *len) {
 
   FILE *fp = fopen(filename, "rb");
@@ -41,13 +56,18 @@ int main(int argc, char *argv[]) {
   ExtismContext *ctx = extism_context_new();
 
   size_t len = 0;
-  uint8_t *data = read_file("../wasm/code.wasm", &len);
-  ExtismPlugin plugin = extism_plugin_new(ctx, data, len, false);
+  uint8_t *data = read_file("../wasm/code-functions.wasm", &len);
+  ExtismValType inputs[] = {I64};
+  ExtismValType outputs[] = {I64};
+  ExtismFunction *f = extism_function_new("hello_world", inputs, 1, outputs, 1,
+                                          hello_world, "Hello, again!", NULL);
+  ExtismPlugin plugin =
+      extism_plugin_new(ctx, data, len, (const ExtismFunction **)&f, 1, true);
   free(data);
   if (plugin < 0) {
+    puts(extism_error(ctx, -1));
     exit(1);
   }
-
   assert(extism_plugin_call(ctx, plugin, "count_vowels", (uint8_t *)argv[1],
                             strlen(argv[1])) == 0);
   ExtismSize out_len = extism_plugin_output_length(ctx, plugin);
@@ -56,6 +76,7 @@ int main(int argc, char *argv[]) {
   write(STDOUT_FILENO, "\n", 1);
 
   extism_plugin_free(ctx, plugin);
+  extism_function_free(f);
   extism_context_free(ctx);
   return 0;
 }

cpp/Makefile

@@ -1,15 +1,16 @@
 FLAGS=`pkg-config --cflags --libs jsoncpp gtest` -lextism -lpthread
 
 build-example:
-	$(CXX) -std=c++11 -o example -I. example.cpp $(FLAGS)
+	$(CXX) -std=c++14 -o example -I. example.cpp $(FLAGS)
 	
 .PHONY: example
 example: build-example
 	./example
 
 build-test:
-	$(CXX) -std=c++11 -o test/test -I. test/test.cpp $(FLAGS)
+	$(CXX) -std=c++14 -o test/test -I. test/test.cpp $(FLAGS)
 
 .PHONY: test
 test: build-test
 	cd test && ./test
+

cpp/example.cpp

@@ -14,10 +14,27 @@ std::vector<uint8_t> read(const char *filename) {
 }
 
 int main(int argc, char *argv[]) {
-  auto wasm = read("../wasm/code.wasm");
+  auto wasm = read("../wasm/code-functions.wasm");
   Context context = Context();
+  std::string tmp = "Testing";
 
-  Plugin plugin = context.plugin(wasm);
+  // A lambda can be used as a host function
+  auto hello_world = [&tmp](CurrentPlugin plugin,
+                            const std::vector<Val> &inputs,
+                            std::vector<Val> &outputs, void *user_data) {
+    std::cout << "Hello from C++" << std::endl;
+    std::cout << (const char *)user_data << std::endl;
+    std::cout << tmp << std::endl;
+    outputs[0].v = inputs[0].v;
+  };
+
+  std::vector<Function> functions = {
+      Function("hello_world", {ValType::I64}, {ValType::I64}, hello_world,
+               (void *)"Hello again!",
+               [](void *x) { std::cout << "Free user data" << std::endl; }),
+  };
+
+  Plugin plugin = context.plugin(wasm, true, functions);
 
   const char *input = argc > 1 ? argv[1] : "this is a test";
   ExtismSize length = strlen(input);

cpp/extism.hpp

@@ -1,7 +1,10 @@
 #pragma once
 
+#include <cstring>
+#include <functional>
 #include <map>
 #include <memory>
+#include <stdexcept>
 #include <string>
 #include <vector>
 
@@ -20,27 +23,62 @@ extern "C" {
 namespace extism {
 
 typedef std::map<std::string, std::string> Config;
-class Wasm {
+
+template <typename T> class ManifestKey {
+  bool is_set = false;
+
 public:
-  std::string path;
-  std::string url;
+  T value;
+  ManifestKey(T x, bool is_set = false) : is_set(is_set) { value = x; }
+
+  void set(T x) {
+    value = x;
+    is_set = true;
+  }
+
+  bool empty() const { return is_set == false; }
+};
+
+class Wasm {
+  std::string _path;
+  std::string _url;
   // TODO: add base64 encoded raw data
-  std::string hash;
+  ManifestKey<std::string> _hash =
+      ManifestKey<std::string>(std::string(), false);
+
+public:
+  // Create Wasm pointing to a path
+  static Wasm path(std::string s, std::string hash = std::string()) {
+    Wasm w;
+    w._path = s;
+    if (!hash.empty()) {
+      w._hash.set(hash);
+    }
+    return w;
+  }
+
+  // Create Wasm pointing to a URL
+  static Wasm url(std::string s, std::string hash = std::string()) {
+    Wasm w;
+    w._url = s;
+    if (!hash.empty()) {
+      w._hash.set(hash);
+    }
+    return w;
+  }
 
 #ifndef EXTISM_NO_JSON
   Json::Value json() const {
     Json::Value doc;
 
-    if (!this->path.empty()) {
-      doc["path"] = this->path;
+    if (!this->_path.empty()) {
+      doc["path"] = this->_path;
+    } else if (!this->_url.empty()) {
+      doc["url"] = this->_url;
     }
 
-    if (!this->url.empty()) {
-      doc["url"] = this->url;
-    }
-
-    if (!this->hash.empty()) {
-      doc["hash"] = this->hash;
+    if (!this->_hash.empty()) {
+      doc["hash"] = this->_hash.value;
     }
 
     return doc;
@@ -52,18 +90,23 @@ class Manifest {
 public:
   Config config;
   std::vector<Wasm> wasm;
-  std::vector<std::string> allowed_hosts;
-  std::map<std::string, std::string> allowed_paths;
-  uint64_t timeout_ms;
+  ManifestKey<std::vector<std::string>> allowed_hosts;
+  ManifestKey<std::map<std::string, std::string>> allowed_paths;
+  ManifestKey<uint64_t> timeout_ms;
 
-  Manifest() : timeout_ms(30000) {}
+  // Empty manifest
+  Manifest()
+      : timeout_ms(0, false), allowed_hosts(std::vector<std::string>(), false),
+        allowed_paths(std::map<std::string, std::string>(), false) {}
 
+  // Create manifest with a single Wasm from a path
   static Manifest path(std::string s, std::string hash = std::string()) {
     Manifest m;
     m.add_wasm_path(s, hash);
     return m;
   }
 
+  // Create manifest with a single Wasm from a URL
   static Manifest url(std::string s, std::string hash = std::string()) {
     Manifest m;
     m.add_wasm_url(s, hash);
@@ -92,7 +135,7 @@ public:
     if (!this->allowed_hosts.empty()) {
       Json::Value h;
 
-      for (auto s : this->allowed_hosts) {
+      for (auto s : this->allowed_hosts.value) {
         h.append(s);
       }
       doc["allowed_hosts"] = h;
@@ -100,54 +143,63 @@ public:
 
     if (!this->allowed_paths.empty()) {
       Json::Value h;
-      for (auto k : this->allowed_paths) {
+      for (auto k : this->allowed_paths.value) {
         h[k.first] = k.second;
       }
       doc["allowed_paths"] = h;
     }
 
-    doc["timeout_ms"] = Json::Value(this->timeout_ms);
+    if (!this->timeout_ms.empty()) {
+      doc["timeout_ms"] = Json::Value(this->timeout_ms.value);
+    }
 
     Json::FastWriter writer;
     return writer.write(doc);
   }
 #endif
 
+  // Add Wasm from path
   void add_wasm_path(std::string s, std::string hash = std::string()) {
-    Wasm w;
-    w.path = s;
-    w.hash = hash;
+    Wasm w = Wasm::path(s, hash);
     this->wasm.push_back(w);
   }
 
+  // Add Wasm from URL
   void add_wasm_url(std::string u, std::string hash = std::string()) {
-    Wasm w;
-    w.url = u;
-    w.hash = hash;
+    Wasm w = Wasm::url(u, hash);
     this->wasm.push_back(w);
   }
 
-  void allow_host(std::string host) { this->allowed_hosts.push_back(host); }
+  // Add host to allowed hosts
+  void allow_host(std::string host) {
+    if (this->allowed_hosts.empty()) {
+      this->allowed_hosts.set(std::vector<std::string>{});
+    }
+    this->allowed_hosts.value.push_back(host);
+  }
 
+  // Add path to allowed paths
   void allow_path(std::string src, std::string dest = std::string()) {
+    if (this->allowed_paths.empty()) {
+      this->allowed_paths.set(std::map<std::string, std::string>{});
+    }
+
     if (dest.empty()) {
       dest = src;
     }
-    this->allowed_paths[src] = dest;
+    this->allowed_paths.value[src] = dest;
   }
 
+  // Set timeout
   void set_timeout_ms(uint64_t ms) { this->timeout_ms = ms; }
 
+  // Set config key/value
   void set_config(std::string k, std::string v) { this->config[k] = v; }
 };
 
-class Error : public std::exception {
-private:
-  std::string message;
-
+class Error : public std::runtime_error {
 public:
-  Error(std::string msg) : message(msg) {}
-  const char *what() { return message.c_str(); }
+  Error(std::string msg) : std::runtime_error(msg) {}
 };
 
 class Buffer {
@@ -166,14 +218,140 @@ public:
   }
 };
 
+typedef ExtismValType ValType;
+typedef ExtismValUnion ValUnion;
+typedef ExtismVal Val;
+
+class CurrentPlugin {
+  ExtismCurrentPlugin *pointer;
+
+public:
+  CurrentPlugin(ExtismCurrentPlugin *p) : pointer(p) {}
+
+  uint8_t *memory() { return extism_current_plugin_memory(this->pointer); }
+  ExtismSize memory_length(uint64_t offs) {
+    return extism_current_plugin_memory_length(this->pointer, offs);
+  }
+
+  uint64_t alloc(ExtismSize size) {
+    return extism_current_plugin_memory_alloc(this->pointer, size);
+  }
+
+  void free(uint64_t offs) {
+    extism_current_plugin_memory_free(this->pointer, offs);
+  }
+
+  void returnString(Val &output, const std::string &s) {
+    this->returnBytes(output, (const uint8_t *)s.c_str(), s.size());
+  }
+
+  void returnBytes(Val &output, const uint8_t *bytes, size_t len) {
+    auto offs = this->alloc(len);
+    memcpy(this->memory() + offs, bytes, len);
+    output.v.i64 = offs;
+  }
+
+  uint8_t *inputBytes(Val &inp, size_t *length = nullptr) {
+    if (inp.t != ValType::I64) {
+      return nullptr;
+    }
+    if (length != nullptr) {
+      *length = this->memory_length(inp.v.i64);
+    }
+    return this->memory() + inp.v.i64;
+  }
+
+  std::string inputString(Val &inp) {
+    size_t length = 0;
+    char *buf = (char *)this->inputBytes(inp, &length);
+    return std::string(buf, length);
+  }
+};
+
+typedef std::function<void(CurrentPlugin, const std::vector<Val> &,
+                           std::vector<Val> &, void *user_data)>
+    FunctionType;
+
+struct UserData {
+  FunctionType func;
+  void *user_data = NULL;
+  std::function<void(void *)> free_user_data;
+};
+
+static void function_callback(ExtismCurrentPlugin *plugin,
+                              const ExtismVal *inputs, ExtismSize n_inputs,
+                              ExtismVal *outputs, ExtismSize n_outputs,
+                              void *user_data) {
+  UserData *data = (UserData *)user_data;
+  const std::vector<Val> inp(inputs, inputs + n_inputs);
+  std::vector<Val> outp(outputs, outputs + n_outputs);
+  data->func(CurrentPlugin(plugin), inp, outp, data->user_data);
+
+  for (ExtismSize i = 0; i < n_outputs; i++) {
+    outputs[i] = outp[i];
+  }
+}
+
+static void free_user_data(void *user_data) {
+  UserData *data = (UserData *)user_data;
+  if (data->user_data != NULL && data->free_user_data != NULL) {
+    data->free_user_data(data->user_data);
+  }
+}
+
+class Function {
+  std::shared_ptr<ExtismFunction> func;
+  std::string name;
+  UserData user_data;
+
+public:
+  Function(std::string name, const std::vector<ValType> inputs,
+           const std::vector<ValType> outputs, FunctionType f,
+           void *user_data = NULL, std::function<void(void *)> free = nullptr)
+      : name(name) {
+    this->user_data.func = f;
+    this->user_data.user_data = user_data;
+    this->user_data.free_user_data = free;
+    auto ptr = extism_function_new(
+        this->name.c_str(), inputs.data(), inputs.size(), outputs.data(),
+        outputs.size(), function_callback, &this->user_data, free_user_data);
+    this->func = std::shared_ptr<ExtismFunction>(ptr, extism_function_free);
+  }
+
+  void set_namespace(std::string s) {
+    extism_function_set_namespace(this->func.get(), s.c_str());
+  }
+
+  Function(const Function &f) { this->func = f.func; }
+
+  ExtismFunction *get() { return this->func.get(); }
+};
+
+class CancelHandle {
+  const ExtismCancelHandle *handle;
+
+public:
+  CancelHandle(const ExtismCancelHandle *x) : handle(x){};
+  bool cancel() { return extism_plugin_cancel(this->handle); }
+};
+
 class Plugin {
   std::shared_ptr<ExtismContext> context;
   ExtismPlugin plugin;
+  std::vector<Function> functions;
 
 public:
+  // Create a new plugin
   Plugin(std::shared_ptr<ExtismContext> ctx, const uint8_t *wasm,
-         ExtismSize length, bool with_wasi = false) {
-    this->plugin = extism_plugin_new(ctx.get(), wasm, length, with_wasi);
+         ExtismSize length, bool with_wasi = false,
+         std::vector<Function> functions = std::vector<Function>())
+      : functions(functions) {
+    std::vector<const ExtismFunction *> ptrs;
+    for (auto i : this->functions) {
+      ptrs.push_back(i.get());
+    }
+    this->plugin = extism_plugin_new(ctx.get(), wasm, length, ptrs.data(),
+                                     ptrs.size(), with_wasi);
     if (this->plugin < 0) {
       const char *err = extism_error(ctx.get(), -1);
       throw Error(err == nullptr ? "Unable to load plugin" : err);
@@ -181,12 +359,24 @@ public:
     this->context = ctx;
   }
 
+  CancelHandle cancel_handle() {
+    return CancelHandle(
+        extism_plugin_cancel_handle(this->context.get(), this->id()));
+  }
+
 #ifndef EXTISM_NO_JSON
+  // Create a new plugin from Manifest
   Plugin(std::shared_ptr<ExtismContext> ctx, const Manifest &manifest,
-         bool with_wasi = false) {
+         bool with_wasi = false, std::vector<Function> functions = {}) {
+    std::vector<const ExtismFunction *> ptrs;
+    for (auto i : this->functions) {
+      ptrs.push_back(i.get());
+    }
+
     auto buffer = manifest.json();
-    this->plugin = extism_plugin_new(ctx.get(), (const uint8_t *)buffer.c_str(),
-                                     buffer.size(), with_wasi);
+    this->plugin =
+        extism_plugin_new(ctx.get(), (const uint8_t *)buffer.c_str(),
+                          buffer.size(), ptrs.data(), ptrs.size(), with_wasi);
     if (this->plugin < 0) {
       const char *err = extism_error(ctx.get(), -1);
       throw Error(err == nullptr ? "Unable to load plugin from manifest" : err);
@@ -204,9 +394,15 @@ public:
 
   ExtismContext *get_context() const { return this->context.get(); }
 
-  void update(const uint8_t *wasm, size_t length, bool with_wasi = false) {
+  void update(const uint8_t *wasm, size_t length, bool with_wasi = false,
+              std::vector<Function> functions = {}) {
+    this->functions = functions;
+    std::vector<const ExtismFunction *> ptrs;
+    for (auto i : this->functions) {
+      ptrs.push_back(i.get());
+    }
     bool b = extism_plugin_update(this->context.get(), this->plugin, wasm,
-                                  length, with_wasi);
+                                  length, ptrs.data(), ptrs.size(), with_wasi);
     if (!b) {
       const char *err = extism_error(this->context.get(), -1);
       throw Error(err == nullptr ? "Unable to update plugin" : err);
@@ -214,11 +410,17 @@ public:
   }
 
 #ifndef EXTISM_NO_JSON
-  void update(const Manifest &manifest, bool with_wasi = false) {
+  void update(const Manifest &manifest, bool with_wasi = false,
+              std::vector<Function> functions = {}) {
+    this->functions = functions;
+    std::vector<const ExtismFunction *> ptrs;
+    for (auto i : this->functions) {
+      ptrs.push_back(i.get());
+    }
     auto buffer = manifest.json();
-    bool b = extism_plugin_update(this->context.get(), this->plugin,
-                                  (const uint8_t *)buffer.c_str(),
-                                  buffer.size(), with_wasi);
+    bool b = extism_plugin_update(
+        this->context.get(), this->plugin, (const uint8_t *)buffer.c_str(),
+        buffer.size(), ptrs.data(), ptrs.size(), with_wasi);
     if (!b) {
       const char *err = extism_error(this->context.get(), -1);
       throw Error(err == nullptr ? "Unable to update plugin" : err);
@@ -251,6 +453,7 @@ public:
     this->config(json.c_str(), json.size());
   }
 
+  // Call a plugin
   Buffer call(const std::string &func, const uint8_t *input,
               ExtismSize input_length) const {
     int32_t rc = extism_plugin_call(this->context.get(), this->plugin,
@@ -271,15 +474,19 @@ public:
     return Buffer(ptr, length);
   }
 
+  // Call a plugin function with std::vector<uint8_t> input
   Buffer call(const std::string &func,
               const std::vector<uint8_t> &input) const {
     return this->call(func, input.data(), input.size());
   }
 
-  Buffer call(const std::string &func, const std::string &input) const {
+  // Call a plugin function with string input
+  Buffer call(const std::string &func,
+              const std::string &input = std::string()) const {
     return this->call(func, (const uint8_t *)input.c_str(), input.size());
   }
 
+  // Returns true if the specified function exists
   bool function_exists(const std::string &func) const {
     return extism_plugin_function_exists(this->context.get(), this->plugin,
                                          func.c_str());
@@ -290,38 +497,49 @@ class Context {
 public:
   std::shared_ptr<ExtismContext> pointer;
 
+  // Create a new context;
   Context() {
     this->pointer = std::shared_ptr<ExtismContext>(extism_context_new(),
                                                    extism_context_free);
   }
 
-  Plugin plugin(const uint8_t *wasm, size_t length,
-                bool with_wasi = false) const {
-    return Plugin(this->pointer, wasm, length, with_wasi);
+  // 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);
   }
 
-  Plugin plugin(const std::string &str, bool with_wasi = false) const {
+  // 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);
+                  with_wasi, functions);
   }
 
-  Plugin plugin(const std::vector<uint8_t> &data,
-                bool with_wasi = false) const {
-    return Plugin(this->pointer, data.data(), data.size(), with_wasi);
+  // 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);
   }
 
 #ifndef EXTISM_NO_JSON
-  Plugin plugin(const Manifest &manifest, bool with_wasi = false) const {
-    return Plugin(this->pointer, manifest, with_wasi);
+  // 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);
   }
 #endif
 
+  // Remove all plugins
   void reset() { extism_context_reset(this->pointer.get()); }
 };
 
+// Set global log file for plugins
 inline bool set_log_file(const char *filename, const char *level) {
   return extism_log_file(filename, level);
 }
 
+// Get libextism version
 inline std::string version() { return std::string(extism_version()); }
 } // namespace extism

cpp/test/test.cpp

@@ -10,6 +10,8 @@ std::vector<uint8_t> read(const char *filename) {
                               std::istreambuf_iterator<char>());
 }
 
+const std::string code = "../../wasm/code.wasm";
+
 namespace {
 using namespace extism;
 
@@ -20,7 +22,7 @@ TEST(Context, Basic) {
 
 TEST(Plugin, Manifest) {
   Context context;
-  Manifest manifest = Manifest::path("code.wasm");
+  Manifest manifest = Manifest::path(code);
   manifest.set_config("a", "1");
 
   ASSERT_NO_THROW(Plugin plugin = context.plugin(manifest));
@@ -38,7 +40,7 @@ TEST(Plugin, BadManifest) {
 
 TEST(Plugin, Bytes) {
   Context context;
-  auto wasm = read("code.wasm");
+  auto wasm = read(code.c_str());
   ASSERT_NO_THROW(Plugin plugin = context.plugin(wasm));
   Plugin plugin = context.plugin(wasm);
 
@@ -48,7 +50,7 @@ TEST(Plugin, Bytes) {
 
 TEST(Plugin, UpdateConfig) {
   Context context;
-  auto wasm = read("code.wasm");
+  auto wasm = read(code.c_str());
   Plugin plugin = context.plugin(wasm);
 
   Config config;
@@ -58,13 +60,34 @@ TEST(Plugin, UpdateConfig) {
 
 TEST(Plugin, FunctionExists) {
   Context context;
-  auto wasm = read("code.wasm");
+  auto wasm = read(code.c_str());
   Plugin plugin = context.plugin(wasm);
 
   ASSERT_FALSE(plugin.function_exists("bad_function"));
   ASSERT_TRUE(plugin.function_exists("count_vowels"));
 }
 
+TEST(Plugin, HostFunction) {
+  Context context;
+  auto wasm = read("../../wasm/code-functions.wasm");
+  auto t = std::vector<ValType>{ValType::I64};
+  Function hello_world =
+      Function("hello_world", t, t,
+               [](CurrentPlugin plugin, const std::vector<Val> &params,
+                  std::vector<Val> &results, void *user_data) {
+                 auto offs = plugin.alloc(4);
+                 memcpy(plugin.memory() + offs, "test", 4);
+                 results[0].v.i64 = (int64_t)offs;
+               });
+  auto functions = std::vector<Function>{
+      hello_world,
+  };
+  Plugin plugin = context.plugin(wasm, true, functions);
+  auto buf = plugin.call("count_vowels", "aaa");
+  ASSERT_EQ(buf.length, 4);
+  ASSERT_EQ((std::string)buf, "test");
+}
+
 }; // namespace
 
 int main(int argc, char **argv) {

dotnet/nuget/Extism.runtime.win.csproj

@@ -8,7 +8,7 @@
 
     <PropertyGroup>
         <PackageId>Extism.runtime.win-x64</PackageId>
-        <Version>0.2.0</Version>
+        <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>

dotnet/src/Extism.Sdk/Context.cs

@@ -38,7 +38,7 @@ public class Context : IDisposable
         {
             fixed (byte* wasmPtr = wasm)
             {
-                var plugin = LibExtism.extism_plugin_new(NativeHandle, wasmPtr, wasm.Length, withWasi);
+                var plugin = LibExtism.extism_plugin_new(NativeHandle, wasmPtr, wasm.Length, null, 0, withWasi);
                 return new Plugin(this, plugin);
             }
         }

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

@@ -10,7 +10,7 @@
 
 	<PropertyGroup>
 		<PackageId>Extism.Sdk</PackageId>
-		<Version>0.2.0</Version>
+		<Version>0.4.0</Version>
 		<Authors>Extism Contributors</Authors>
 		<Description>Extism SDK that allows hosting Extism plugins in .NET apps.</Description>
 		<Tags>extism, wasm, plugin</Tags>

dotnet/src/Extism.Sdk/LibExtism.cs

@@ -27,10 +27,12 @@ internal static class LibExtism
     /// <param name="context">Pointer to the context the plugin will be associated with.</param>
     /// <param name="wasm">A WASM module (wat or wasm) or a JSON encoded manifest.</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 IntPtr extism_plugin_new(IntPtr context, byte* wasm, int wasmSize, bool withWasi);
+    unsafe public static extern IntPtr extism_plugin_new(IntPtr context, byte* wasm, int wasmSize, IntPtr *functions, int nFunctions, bool withWasi);
 
     /// <summary>
     /// Update a plugin, keeping the existing ID.
@@ -41,10 +43,12 @@ internal static class LibExtism
     /// <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="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, bool withWasi);
+    unsafe public static extern bool extism_plugin_update(IntPtr context, IntPtr plugin, byte* wasm, int wasmLength, IntPtr *functions, int nFunctions, bool withWasi);
 
     /// <summary>
     /// Remove a plugin from the registry and free associated memory.

dotnet/src/Extism.Sdk/Plugin.cs

@@ -35,7 +35,7 @@ public class Plugin : IDisposable
 
         fixed (byte* wasmPtr = wasm)
         {
-            return LibExtism.extism_plugin_update(_context.NativeHandle, NativeHandle, wasmPtr, wasm.Length, withWasi);
+            return LibExtism.extism_plugin_update(_context.NativeHandle, NativeHandle, wasmPtr, wasm.Length, null, 0, withWasi);
         }
     }
 

dune-project

@@ -21,12 +21,13 @@
  (description "Bindings to Extism, the universal plugin system")
  (depends 
   (ocaml (>= 4.14.1)) 
-  (dune (>= 3.2))
+  dune
+  (ctypes (>= 0.18.0))
   (ctypes-foreign (>= 0.18.0))
   (bigstringaf (>= 0.9.0))
-  (ppx_yojson_conv (>= 0.15.0))
+  (ppx_yojson_conv (>= v0.15.0))
   extism-manifest
-  (ppx_inline_test (>= 0.15.0))
+  (ppx_inline_test (>= v0.15.0))
   (cmdliner (>= 1.1.1))
  )
  (tags
@@ -35,11 +36,12 @@
 (package
  (name extism-manifest)
  (synopsis "Extism manifest bindings")
- (description "Bindings to Extism, the universal plugin system")
+ (description "Bindings to the Extism manifest format")
  (depends 
   (ocaml (>= 4.14.1)) 
-  (dune (>= 3.2))
-  (ppx_yojson_conv (>= 0.15.0))
+  dune
+  (ppx_yojson_conv (>= v0.15.0))
+  (ppx_inline_test (>= v0.15.0))
   (base64 (>= 3.5.0))
  )
  (tags

elixir/lib/extism/cancel_handle.ex

@@ -0,0 +1,31 @@
+defmodule Extism.CancelHandle do
+  @moduledoc """
+  A CancelHandle is a handle generated by a plugin that allows it to be cancelled from another
+  thread while running.
+  """
+  defstruct [
+    # The actual NIF Resource. PluginIndex and the context
+    handle: nil,
+  ]
+
+  def wrap_resource(handle) do
+    %__MODULE__{
+      handle: handle
+    }
+  end
+
+  @doc """
+  Cancel plugin execution
+  """
+  def cancel(handle) do
+    Extism.Native.plugin_cancel(handle.handle)
+  end
+end
+
+defimpl Inspect, for: Extim.CancelHandle do
+  import Inspect.Algebra
+
+  def inspect(dict, opts) do
+    concat(["#Extism.CancelHandle<", to_doc(dict.handle, opts), ">"])
+  end
+end

elixir/lib/extism/native.ex

@@ -16,6 +16,8 @@ defmodule Extism.Native do
   def plugin_has_function(_ctx, _plugin_id, _function_name), do: error()
   def plugin_free(_ctx, _plugin_id), do: error()
   def set_log_file(_filename, _level), do: error()
+  def plugin_cancel_handle(_ctx, _plugin_id), do: error()
+  def plugin_cancel(_handle), do: error()
 
   defp error, do: :erlang.nif_error(:nif_not_loaded)
 end

elixir/mix.exs

@@ -4,7 +4,7 @@ defmodule Extism.MixProject do
   def project do
     [
       app: :extism,
-      version: "0.1.0",
+      version: "0.3.0",
       elixir: "~> 1.12",
       start_permanent: Mix.env() == :prod,
       deps: deps(),
@@ -23,7 +23,7 @@ defmodule Extism.MixProject do
 
   defp deps do
     [
-      {:rustler, "~> 0.26.0"},
+      {:rustler, "~> 0.27.0"},
       {:json, "~> 1.4"},
       {:ex_doc, "~> 0.21", only: :dev, runtime: false}
     ]

elixir/mix.lock

@@ -1,12 +1,12 @@
 %{
-  "earmark_parser": {:hex, :earmark_parser, "1.4.29", "149d50dcb3a93d9f3d6f3ecf18c918fb5a2d3c001b5d3305c926cddfbd33355b", [:mix], [], "hexpm", "4902af1b3eb139016aed210888748db8070b8125c2342ce3dcae4f38dcc63503"},
-  "ex_doc": {:hex, :ex_doc, "0.29.1", "b1c652fa5f92ee9cf15c75271168027f92039b3877094290a75abcaac82a9f77", [: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", "b7745fa6374a36daf484e2a2012274950e084815b936b1319aeebcf7809574f6"},
+  "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"},
   "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, "0.26.0", "06a2773d453ee3e9109efda643cf2ae633dedea709e2455ac42b83637c9249bf", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:toml, "~> 0.6", [hex: :toml, repo: "hexpm", optional: false]}], "hexpm", "42961e9d2083d004d5a53e111ad1f0c347efd9a05cb2eb2ffa1d037cdc74db91"},
-  "toml": {:hex, :toml, "0.6.2", "38f445df384a17e5d382befe30e3489112a48d3ba4c459e543f748c2f25dd4d1", [:mix], [], "hexpm", "d013e45126d74c0c26a38d31f5e8e9b83ea19fc752470feb9a86071ca5a672fa"},
+  "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"},
+  "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 = "0.1.0"
+version = "0.2.0"
 edition = "2021"
 authors = ["Benjamin Eckel <bhelx@simst.im>"]
 
@@ -10,6 +10,6 @@ path = "src/lib.rs"
 crate-type = ["cdylib"]
 
 [dependencies]
-rustler = "0.26.0"
-extism = { version = "0.1.0", path = "../../../rust" }
+rustler = "0.27.0"
+extism = { version = "0.3.0", path = "../../../rust", package = "extism" }
 log = "0.4"

elixir/native/extism_nif/src/lib.rs

@@ -17,22 +17,24 @@ mod atoms {
 struct ExtismContext {
     ctx: RwLock<Context>,
 }
-
 unsafe impl Sync for ExtismContext {}
 unsafe impl Send for ExtismContext {}
 
+struct ExtismCancelHandle {
+    handle: RwLock<extism::CancelHandle>,
+}
+
+unsafe impl Sync for ExtismCancelHandle {}
+unsafe impl Send for ExtismCancelHandle {}
+
 fn load(env: Env, _: Term) -> bool {
     rustler::resource!(ExtismContext, env);
+    rustler::resource!(ExtismCancelHandle, env);
     true
 }
 
 fn to_rustler_error(extism_error: extism::Error) -> rustler::Error {
-    match extism_error {
-        extism::Error::UnableToLoadPlugin(msg) => rustler::Error::Term(Box::new(msg)),
-        extism::Error::Message(msg) => rustler::Error::Term(Box::new(msg)),
-        extism::Error::Json(json_err) => rustler::Error::Term(Box::new(json_err.to_string())),
-        extism::Error::Runtime(e) => rustler::Error::Term(Box::new(e.to_string())),
-    }
+    rustler::Error::Term(Box::new(extism_error.to_string()))
 }
 
 #[rustler::nif]
@@ -50,7 +52,7 @@ fn context_reset(ctx: ResourceArc<ExtismContext>) {
 
 #[rustler::nif]
 fn context_free(ctx: ResourceArc<ExtismContext>) {
-    let context = &ctx.ctx.read().unwrap();
+    let context = ctx.ctx.read().unwrap();
     std::mem::drop(context)
 }
 
@@ -61,7 +63,7 @@ fn plugin_new_with_manifest(
     wasi: bool,
 ) -> Result<i32, rustler::Error> {
     let context = &ctx.ctx.write().unwrap();
-    let result = match Plugin::new(context, manifest_payload, wasi) {
+    let result = match Plugin::new(context, manifest_payload, [], wasi) {
         Err(e) => Err(to_rustler_error(e)),
         Ok(plugin) => {
             let plugin_id = plugin.as_i32();
@@ -85,7 +87,7 @@ fn plugin_call(
     let mut plugin = unsafe { Plugin::from_id(plugin_id, context) };
     let result = match plugin.call(name, input) {
         Err(e) => Err(to_rustler_error(e)),
-        Ok(result) => match str::from_utf8(&result) {
+        Ok(result) => match str::from_utf8(result) {
             Ok(output) => Ok(output.to_string()),
             Err(_e) => Err(rustler::Error::Term(Box::new(
                 "Could not read output from plugin",
@@ -107,7 +109,7 @@ fn plugin_update_manifest(
 ) -> Result<(), rustler::Error> {
     let context = &ctx.ctx.read().unwrap();
     let mut plugin = unsafe { Plugin::from_id(plugin_id, context) };
-    let result = match plugin.update(manifest_payload, wasi) {
+    let result = match plugin.update(manifest_payload, [], wasi) {
         Ok(()) => Ok(()),
         Err(e) => Err(to_rustler_error(e)),
     };
@@ -117,6 +119,24 @@ fn plugin_update_manifest(
     result
 }
 
+#[rustler::nif]
+fn plugin_cancel_handle(
+    ctx: ResourceArc<ExtismContext>,
+    plugin_id: i32,
+) -> Result<ResourceArc<ExtismCancelHandle>, rustler::Error> {
+    let context = &ctx.ctx.read().unwrap();
+    let plugin = unsafe { Plugin::from_id(plugin_id, context) };
+    let handle = plugin.cancel_handle();
+    Ok(ResourceArc::new(ExtismCancelHandle {
+        handle: RwLock::new(handle),
+    }))
+}
+
+#[rustler::nif]
+fn plugin_cancel(handle: ResourceArc<ExtismCancelHandle>) -> bool {
+    handle.handle.read().unwrap().cancel()
+}
+
 #[rustler::nif]
 fn plugin_free(ctx: ResourceArc<ExtismContext>, plugin_id: i32) -> Result<(), rustler::Error> {
     let context = &ctx.ctx.read().unwrap();
@@ -170,6 +190,8 @@ rustler::init!(
         plugin_call,
         plugin_update_manifest,
         plugin_has_function,
+        plugin_cancel_handle,
+        plugin_cancel,
         plugin_free,
         set_log_file,
     ],

extism-manifest.opam

@@ -1,7 +1,7 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
 synopsis: "Extism manifest bindings"
-description: "Bindings to Extism, the universal plugin system"
+description: "Bindings to the Extism manifest format"
 maintainer: ["Extism Authors <oss@extism.org>"]
 authors: ["Extism Authors <oss@extism.org>"]
 license: "BSD-3-Clause"
@@ -11,8 +11,9 @@ doc: "https://github.com/extism/extism"
 bug-reports: "https://github.com/extism/extism/issues"
 depends: [
   "ocaml" {>= "4.14.1"}
-  "dune" {>= "3.2" & >= "3.2"}
-  "ppx_yojson_conv" {>= "0.15.0"}
+  "dune" {>= "3.2"}
+  "ppx_yojson_conv" {>= "v0.15.0"}
+  "ppx_inline_test" {>= "v0.15.0"}
   "base64" {>= "3.5.0"}
   "odoc" {with-doc}
 ]

extism.go

@@ -5,13 +5,50 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"runtime/cgo"
 	"unsafe"
 )
 
 /*
-#cgo pkg-config: libextism.pc
+#cgo CFLAGS: -I/usr/local/include
+#cgo LDFLAGS: -L/usr/local/lib -lextism
 #include <extism.h>
 #include <stdlib.h>
+
+int64_t extism_val_i64(ExtismValUnion* x){
+	return x->i64;
+}
+
+int32_t extism_val_i32(ExtismValUnion* x){
+	return x->i32;
+}
+
+float extism_val_f32(ExtismValUnion* x){
+	return x->f32;
+}
+
+double extism_val_f64(ExtismValUnion* x){
+	return x->f64;
+}
+
+
+void extism_val_set_i64(ExtismValUnion* x, int64_t i){
+	x->i64 = i;
+}
+
+
+void extism_val_set_i32(ExtismValUnion* x, int32_t i){
+	x->i32 = i;
+}
+
+void extism_val_set_f32(ExtismValUnion* x, float f){
+	x->f32 = f;
+}
+
+void extism_val_set_f64(ExtismValUnion* x, double f){
+	x->f64 = f;
+}
+
 */
 import "C"
 
@@ -20,6 +57,106 @@ type Context struct {
 	pointer *C.ExtismContext
 }
 
+type ValType = C.ExtismValType
+
+type Val = C.ExtismVal
+
+type Size = C.ExtismSize
+
+var (
+	I32       ValType = C.I32
+	I64       ValType = C.I64
+	F32       ValType = C.F32
+	F64       ValType = C.F64
+	V128      ValType = C.V128
+	FuncRef   ValType = C.FuncRef
+	ExternRef ValType = C.ExternRef
+)
+
+// Function is used to define host functions
+type Function struct {
+	pointer  *C.ExtismFunction
+	userData cgo.Handle
+}
+
+// Free a function
+func (f *Function) Free() {
+	C.extism_function_free(f.pointer)
+	f.pointer = nil
+	f.userData.Delete()
+}
+
+// NewFunction creates a new host function with the given name, input/outputs and optional user data, which can be an
+// arbitrary `interface{}`
+func NewFunction(name string, inputs []ValType, outputs []ValType, f unsafe.Pointer, userData interface{}) Function {
+	var function Function
+	function.userData = cgo.NewHandle(userData)
+	cname := C.CString(name)
+	ptr := unsafe.Pointer(function.userData)
+	var inputsPtr *C.ExtismValType = nil
+	if len(inputs) > 0 {
+		inputsPtr = (*C.ExtismValType)(&inputs[0])
+	}
+	var outputsPtr *C.ExtismValType = nil
+	if len(outputs) > 0 {
+		outputsPtr = (*C.ExtismValType)(&outputs[0])
+	}
+	function.pointer = C.extism_function_new(
+		cname,
+		inputsPtr,
+		C.uint64_t(len(inputs)),
+		outputsPtr,
+		C.uint64_t(len(outputs)),
+		(*[0]byte)(f),
+		ptr,
+		nil,
+	)
+	C.free(unsafe.Pointer(cname))
+	return function
+}
+
+func (f *Function) SetNamespace(s string) {
+	cstr := C.CString(s)
+	defer C.free(unsafe.Pointer(cstr))
+	C.extism_function_set_namespace(f.pointer, cstr)
+}
+
+func (f Function) WithNamespace(s string) Function {
+	f.SetNamespace(s)
+	return f
+}
+
+type CurrentPlugin struct {
+	pointer *C.ExtismCurrentPlugin
+}
+
+func GetCurrentPlugin(ptr unsafe.Pointer) CurrentPlugin {
+	return CurrentPlugin{
+		pointer: (*C.ExtismCurrentPlugin)(ptr),
+	}
+}
+
+func (p *CurrentPlugin) Memory(offs uint) []byte {
+	length := C.extism_current_plugin_memory_length(p.pointer, C.uint64_t(offs))
+	data := unsafe.Pointer(C.extism_current_plugin_memory(p.pointer))
+	return unsafe.Slice((*byte)(unsafe.Add(data, offs)), C.int(length))
+}
+
+// Alloc a new memory block of the given length, returning its offset
+func (p *CurrentPlugin) Alloc(n uint) uint {
+	return uint(C.extism_current_plugin_memory_alloc(p.pointer, C.uint64_t(n)))
+}
+
+// Free the memory block specified by the given offset
+func (p *CurrentPlugin) Free(offs uint) {
+	C.extism_current_plugin_memory_free(p.pointer, C.uint64_t(offs))
+}
+
+// Length returns the number of bytes allocated at the specified offset
+func (p *CurrentPlugin) Length(offs uint) uint {
+	return uint(C.extism_current_plugin_memory_length(p.pointer, C.uint64_t(offs)))
+}
+
 // NewContext creates a new context, it should be freed using the `Free` method
 func NewContext() Context {
 	p := C.extism_context_new()
@@ -96,14 +233,32 @@ func ExtismVersion() string {
 	return C.GoString(C.extism_version())
 }
 
-func register(ctx *Context, data []byte, wasi bool) (Plugin, error) {
+func register(ctx *Context, data []byte, functions []Function, wasi bool) (Plugin, error) {
 	ptr := makePointer(data)
-	plugin := C.extism_plugin_new(
-		ctx.pointer,
-		(*C.uchar)(ptr),
-		C.uint64_t(len(data)),
-		C._Bool(wasi),
-	)
+	functionPointers := []*C.ExtismFunction{}
+	for _, f := range functions {
+		functionPointers = append(functionPointers, f.pointer)
+	}
+	plugin := C.int32_t(-1)
+
+	if len(functions) == 0 {
+		plugin = C.extism_plugin_new(
+			ctx.pointer,
+			(*C.uchar)(ptr),
+			C.uint64_t(len(data)),
+			nil,
+			0,
+			C._Bool(wasi))
+	} else {
+		plugin = C.extism_plugin_new(
+			ctx.pointer,
+			(*C.uchar)(ptr),
+			C.uint64_t(len(data)),
+			&functionPointers[0],
+			C.uint64_t(len(functions)),
+			C._Bool(wasi),
+		)
+	}
 
 	if plugin < 0 {
 		err := C.extism_error(ctx.pointer, C.int32_t(-1))
@@ -120,18 +275,41 @@ func register(ctx *Context, data []byte, wasi bool) (Plugin, error) {
 	return Plugin{id: int32(plugin), ctx: ctx}, nil
 }
 
-func update(ctx *Context, plugin int32, data []byte, wasi bool) error {
+func update(ctx *Context, plugin int32, data []byte, functions []Function, wasi bool) error {
 	ptr := makePointer(data)
-	b := bool(C.extism_plugin_update(
-		ctx.pointer,
-		C.int32_t(plugin),
-		(*C.uchar)(ptr),
-		C.uint64_t(len(data)),
-		C._Bool(wasi),
-	))
+	functionPointers := []*C.ExtismFunction{}
+	for _, f := range functions {
+		functionPointers = append(functionPointers, f.pointer)
+	}
 
-	if b {
-		return nil
+	if len(functions) == 0 {
+		b := bool(C.extism_plugin_update(
+			ctx.pointer,
+			C.int32_t(plugin),
+			(*C.uchar)(ptr),
+			C.uint64_t(len(data)),
+			nil,
+			0,
+			C._Bool(wasi),
+		))
+
+		if b {
+			return nil
+		}
+	} else {
+		b := bool(C.extism_plugin_update(
+			ctx.pointer,
+			C.int32_t(plugin),
+			(*C.uchar)(ptr),
+			C.uint64_t(len(data)),
+			&functionPointers[0],
+			C.uint64_t(len(functions)),
+			C._Bool(wasi),
+		))
+
+		if b {
+			return nil
+		}
 	}
 
 	err := C.extism_error(ctx.pointer, C.int32_t(-1))
@@ -146,43 +324,43 @@ func update(ctx *Context, plugin int32, data []byte, wasi bool) error {
 }
 
 // PluginFromManifest creates a plugin from a `Manifest`
-func (ctx *Context) PluginFromManifest(manifest Manifest, wasi bool) (Plugin, error) {
+func (ctx *Context) PluginFromManifest(manifest Manifest, functions []Function, wasi bool) (Plugin, error) {
 	data, err := json.Marshal(manifest)
 	if err != nil {
 		return Plugin{id: -1}, err
 	}
 
-	return register(ctx, data, wasi)
+	return register(ctx, data, functions, wasi)
 }
 
 // Plugin creates a plugin from a WASM module
-func (ctx *Context) Plugin(module io.Reader, wasi bool) (Plugin, error) {
+func (ctx *Context) Plugin(module io.Reader, functions []Function, wasi bool) (Plugin, error) {
 	wasm, err := io.ReadAll(module)
 	if err != nil {
 		return Plugin{id: -1}, err
 	}
 
-	return register(ctx, wasm, wasi)
+	return register(ctx, wasm, functions, wasi)
 }
 
 // Update a plugin with a new WASM module
-func (p *Plugin) Update(module io.Reader, wasi bool) error {
+func (p *Plugin) Update(module io.Reader, functions []Function, wasi bool) error {
 	wasm, err := io.ReadAll(module)
 	if err != nil {
 		return err
 	}
 
-	return update(p.ctx, p.id, wasm, wasi)
+	return update(p.ctx, p.id, wasm, functions, wasi)
 }
 
 // Update a plugin with a new Manifest
-func (p *Plugin) UpdateManifest(manifest Manifest, wasi bool) error {
+func (p *Plugin) UpdateManifest(manifest Manifest, functions []Function, wasi bool) error {
 	data, err := json.Marshal(manifest)
 	if err != nil {
 		return err
 	}
 
-	return update(p.ctx, p.id, data, wasi)
+	return update(p.ctx, p.id, data, functions, wasi)
 }
 
 // Set configuration values
@@ -233,8 +411,7 @@ func (plugin Plugin) Call(functionName string, input []byte) ([]byte, error) {
 
 	if length > 0 {
 		x := C.extism_plugin_output_data(plugin.ctx.pointer, C.int32_t(plugin.id))
-		y := (*[]byte)(unsafe.Pointer(&x))
-		return []byte((*y)[0:length]), nil
+		return unsafe.Slice((*byte)(x), C.int(length)), nil
 	}
 
 	return []byte{}, nil
@@ -253,3 +430,80 @@ func (plugin *Plugin) Free() {
 func (ctx Context) Reset() {
 	C.extism_context_reset(ctx.pointer)
 }
+
+// ValGetI64 returns an I64 from an ExtismVal, it accepts a pointer to a C.ExtismVal
+func ValGetI64(v unsafe.Pointer) int64 {
+	return int64(C.extism_val_i64(&(*Val)(v).v))
+}
+
+// ValGetUInt returns a uint from an ExtismVal, it accepts a pointer to a C.ExtismVal
+func ValGetUInt(v unsafe.Pointer) uint {
+	return uint(C.extism_val_i64(&(*Val)(v).v))
+}
+
+// ValGetI32 returns an int32 from an ExtismVal, it accepts a pointer to a C.ExtismVal
+func ValGetI32(v unsafe.Pointer) int32 {
+	return int32(C.extism_val_i32(&(*Val)(v).v))
+}
+
+// ValGetF32 returns a float32 from an ExtismVal, it accepts a pointer to a C.ExtismVal
+func ValGetF32(v unsafe.Pointer) float32 {
+	return float32(C.extism_val_f32(&(*Val)(v).v))
+}
+
+// ValGetF32 returns a float64 from an ExtismVal, it accepts a pointer to a C.ExtismVal
+func ValGetF64(v unsafe.Pointer) float64 {
+	return float64(C.extism_val_i64(&(*Val)(v).v))
+}
+
+// ValSetI64 stores an int64 in an ExtismVal, it accepts a pointer to a C.ExtismVal and the new value
+func ValSetI64(v unsafe.Pointer, i int64) {
+	C.extism_val_set_i64(&(*Val)(v).v, C.int64_t(i))
+}
+
+// ValSetI32 stores an int32 in an ExtismVal, it accepts a pointer to a C.ExtismVal and the new value
+func ValSetI32(v unsafe.Pointer, i int32) {
+	C.extism_val_set_i32(&(*Val)(v).v, C.int32_t(i))
+}
+
+// ValSetF32 stores a float32 in an ExtismVal, it accepts a pointer to a C.ExtismVal and the new value
+func ValSetF32(v unsafe.Pointer, i float32) {
+	C.extism_val_set_f32(&(*Val)(v).v, C.float(i))
+}
+
+// ValSetF64 stores a float64 in an ExtismVal, it accepts a pointer to a C.ExtismVal and the new value
+func ValSetF64(v unsafe.Pointer, f float64) {
+	C.extism_val_set_f64(&(*Val)(v).v, C.double(f))
+}
+
+func (p *CurrentPlugin) ReturnBytes(v unsafe.Pointer, b []byte) {
+	mem := p.Alloc(uint(len(b)))
+	ptr := p.Memory(mem)
+	copy(ptr, b)
+	ValSetI64(v, int64(mem))
+}
+
+func (p *CurrentPlugin) ReturnString(v unsafe.Pointer, s string) {
+	p.ReturnBytes(v, []byte(s))
+}
+
+func (p *CurrentPlugin) InputBytes(v unsafe.Pointer) []byte {
+	return p.Memory(ValGetUInt(v))
+}
+
+func (p *CurrentPlugin) InputString(v unsafe.Pointer) string {
+	return string(p.InputBytes(v))
+}
+
+type CancelHandle struct {
+	pointer *C.ExtismCancelHandle
+}
+
+func (p *Plugin) CancelHandle() CancelHandle {
+	pointer := C.extism_plugin_cancel_handle(p.ctx.pointer, C.int(p.id))
+	return CancelHandle{pointer}
+}
+
+func (c *CancelHandle) Cancel() bool {
+	return bool(C.extism_plugin_cancel(c.pointer))
+}

extism.opam

@@ -11,12 +11,13 @@ doc: "https://github.com/extism/extism"
 bug-reports: "https://github.com/extism/extism/issues"
 depends: [
   "ocaml" {>= "4.14.1"}
-  "dune" {>= "3.2" & >= "3.2"}
+  "dune" {>= "3.2"}
+  "ctypes" {>= "0.18.0"}
   "ctypes-foreign" {>= "0.18.0"}
   "bigstringaf" {>= "0.9.0"}
-  "ppx_yojson_conv" {>= "0.15.0"}
+  "ppx_yojson_conv" {>= "v0.15.0"}
   "extism-manifest"
-  "ppx_inline_test" {>= "0.15.0"}
+  "ppx_inline_test" {>= "v0.15.0"}
   "cmdliner" {>= "1.1.1"}
   "odoc" {with-doc}
 ]
@@ -35,3 +36,5 @@ build: [
   ]
 ]
 dev-repo: "git+https://github.com/extism/extism.git"
+build-env: [EXTISM_TEST_NO_LIB = ""]
+post-messages: ["See https://extism.org/docs/install/ for information about installing libextism"]

extism.opam.template

@@ -0,0 +1,2 @@
+build-env: [EXTISM_TEST_NO_LIB = ""]
+post-messages: ["See https://extism.org/docs/install/ for information about installing libextism"]

extism_test.go

@@ -4,13 +4,19 @@ import (
 	"encoding/json"
 	"fmt"
 	"testing"
+	"time"
 )
 
-func manifest() Manifest {
+func manifest(functions bool) Manifest {
+	path := "./wasm/code.wasm"
+	if functions {
+		path = "./wasm/code-functions.wasm"
+	}
+
 	return Manifest{
 		Wasm: []Wasm{
 			WasmFile{
-				Path: "./wasm/code.wasm",
+				Path: path,
 			},
 		},
 	}
@@ -38,7 +44,7 @@ func TestCallPlugin(t *testing.T) {
 	ctx := NewContext()
 	defer ctx.Free()
 
-	plugin, err := ctx.PluginFromManifest(manifest(), false)
+	plugin, err := ctx.PluginFromManifest(manifest(false), []Function{}, false)
 	if err != nil {
 		t.Error(err)
 	}
@@ -58,7 +64,7 @@ func TestFreePlugin(t *testing.T) {
 	ctx := NewContext()
 	defer ctx.Free()
 
-	plugin, err := ctx.PluginFromManifest(manifest(), false)
+	plugin, err := ctx.PluginFromManifest(manifest(false), []Function{}, false)
 	if err != nil {
 		t.Error(err)
 	}
@@ -78,7 +84,7 @@ func TestContextReset(t *testing.T) {
 	ctx := NewContext()
 	defer ctx.Free()
 
-	plugin, err := ctx.PluginFromManifest(manifest(), false)
+	plugin, err := ctx.PluginFromManifest(manifest(false), []Function{}, false)
 	if err != nil {
 		t.Error(err)
 	}
@@ -98,7 +104,7 @@ func TestCanUpdateAManifest(t *testing.T) {
 	ctx := NewContext()
 	defer ctx.Free()
 
-	plugin, err := ctx.PluginFromManifest(manifest(), false)
+	plugin, err := ctx.PluginFromManifest(manifest(false), []Function{}, false)
 	if err != nil {
 		t.Error(err)
 	}
@@ -107,7 +113,7 @@ func TestCanUpdateAManifest(t *testing.T) {
 		t.Error(err)
 	}
 
-	plugin.UpdateManifest(manifest(), false)
+	plugin.UpdateManifest(manifest(false), []Function{}, false)
 
 	// can still call the plugin
 	if err := expectVowelCount(plugin, "this is a test", 4); err != nil {
@@ -119,7 +125,7 @@ func TestFunctionExists(t *testing.T) {
 	ctx := NewContext()
 	defer ctx.Free()
 
-	plugin, err := ctx.PluginFromManifest(manifest(), false)
+	plugin, err := ctx.PluginFromManifest(manifest(false), []Function{}, false)
 	if err != nil {
 		t.Error(err)
 	}
@@ -136,7 +142,7 @@ func TestErrorsOnUnknownFunction(t *testing.T) {
 	ctx := NewContext()
 	defer ctx.Free()
 
-	plugin, err := ctx.PluginFromManifest(manifest(), false)
+	plugin, err := ctx.PluginFromManifest(manifest(false), []Function{}, false)
 	if err != nil {
 		t.Error(err)
 	}
@@ -146,3 +152,33 @@ func TestErrorsOnUnknownFunction(t *testing.T) {
 		t.Fatal("Was expecting call to unknown function to fail")
 	}
 }
+
+func TestCancel(t *testing.T) {
+	manifest := Manifest{
+		Wasm: []Wasm{
+			WasmFile{
+				Path: "./wasm/loop.wasm",
+			},
+		},
+	}
+
+	ctx := NewContext()
+	defer ctx.Free()
+
+	plugin, err := ctx.PluginFromManifest(manifest, []Function{}, false)
+	if err != nil {
+		t.Error(err)
+	}
+
+	cancelHandle := plugin.CancelHandle()
+
+	go func(handle CancelHandle) {
+		time.Sleep(time.Second * 1)
+		handle.Cancel()
+	}(cancelHandle)
+
+	_, err = plugin.Call("infinite_loop", []byte(""))
+	if err == nil {
+		t.Fail()
+	}
+}

go/code-functions.wasm

@@ -0,0 +1 @@
+../wasm/code-functions.wasm

go/main.go

@@ -4,10 +4,34 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"runtime/cgo"
+	"unsafe"
 
 	"github.com/extism/extism"
 )
 
+/*
+#include <extism.h>
+EXTISM_GO_FUNCTION(hello_world);
+*/
+import "C"
+
+//export hello_world
+func hello_world(plugin unsafe.Pointer, inputs *C.ExtismVal, nInputs C.ExtismSize, outputs *C.ExtismVal, nOutputs C.ExtismSize, userData uintptr) {
+	fmt.Println("Hello from Go!")
+	s := cgo.Handle(userData)
+	fmt.Println(s.Value().(string))
+	inputSlice := unsafe.Slice(inputs, nInputs)
+	outputSlice := unsafe.Slice(outputs, nOutputs)
+
+	// Get memory pointed to by first element of input slice
+	p := extism.GetCurrentPlugin(plugin)
+	str := p.InputString(unsafe.Pointer(&inputSlice[0]))
+	fmt.Println(str)
+
+	outputSlice[0] = inputSlice[0]
+}
+
 func main() {
 	version := extism.ExtismVersion()
 	fmt.Println("Extism Version: ", version)
@@ -22,9 +46,10 @@ func main() {
 	} else {
 		data = []byte("testing from go -> wasm shared memory...")
 	}
-
-	manifest := extism.Manifest{Wasm: []extism.Wasm{extism.WasmFile{Path: "../wasm/code.wasm"}}}
-	plugin, err := ctx.PluginFromManifest(manifest, false)
+	manifest := extism.Manifest{Wasm: []extism.Wasm{extism.WasmFile{Path: "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)
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)

haskell/CHANGELOG.md

@@ -1,5 +1,5 @@
 # Revision history for extism
 
-## 0.1.0.0 -- YYYY-mm-dd
+## 0.2.0.0 -- 2023-01-16
 
 * First version. Released on an unsuspecting world.

haskell/Example.hs

@@ -8,7 +8,7 @@ unwrap (Left (ExtismError msg)) = do
   error msg
 
 main = do
-  let m = manifest [wasmFile "../wasm/code.wasm"]
+  let m = manifest [wasmFile "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")

haskell/Makefile

@@ -13,6 +13,9 @@ clean:
 	cabal clean
 
 publish: clean prepare
+	cabal v2-haddock --haddock-for-hackage ./manifest/extism-manifest.cabal
+	cabal v2-haddock --haddock-for-hackage
+	cabal sdist ./manifest/extism-manifest.cabal
 	cabal sdist
 	# TODO: upload
 

haskell/code.wasm

@@ -0,0 +1 @@
+../wasm/code.wasm

haskell/extism.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               extism
-version:            0.0.1
+version:            0.2.0
 license:            BSD-3-Clause
 maintainer:         oss@extism.org
 author:             Extism authors
@@ -19,10 +19,10 @@ library
     extra-libraries:    extism
     extra-lib-dirs:     /usr/local/lib
     build-depends:
-        base              >= 4.16.1 && < 4.18.0,
+        base              >= 4.16.1 && < 4.19.0,
         bytestring        >= 0.11.3 && < 0.12,
         json              >= 0.10 && < 0.11,
-        extism-manifest   >= 0.0.0 && < 0.1.0
+        extism-manifest   >= 0.0.0 && < 0.3.0
 
 test-suite extism-example
     type:             exitcode-stdio-1.0

haskell/manifest/Extism/JSON.hs

@@ -24,6 +24,8 @@ toNullable (Just x) = NotNull x
 toNullable Nothing = Null
 fromNullable (NotNull x) = Just x
 fromNullable Null = Nothing
+fromNotNull (NotNull x) = x
+fromNotNull Null = error "Value is Null"
 mapNullable f Null = Null
 mapNullable f (NotNull x) = NotNull (f x)
 

haskell/manifest/extism-manifest.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               extism-manifest
-version:            0.0.1
+version:            0.2.0
 license:            BSD-3-Clause
 maintainer:         oss@extism.org
 author:             Extism authors
@@ -15,7 +15,7 @@ library
     hs-source-dirs:     .
     default-language:   Haskell2010
     build-depends:
-        base              >= 4.16.1 && < 4.18.0,
+        base              >= 4.16.1 && < 4.19.0,
         bytestring        >= 0.11.3 && < 0.12,
         json              >= 0.10 && < 0.11,
         base64-bytestring >= 1.2.1 && < 1.3,

haskell/src/Extism.hs

@@ -19,6 +19,8 @@ newtype Context = Context (ForeignPtr ExtismContext)
 -- | Plugins can be used to call WASM function
 data Plugin = Plugin Context Int32
 
+data CancelHandle = CancelHandle (Ptr ExtismCancelHandle)
+
 -- | Log level
 data LogLevel = Error | Warn | Info | Debug | Trace deriving (Show)
 
@@ -70,7 +72,7 @@ plugin c wasm useWasi =
   do
     withForeignPtr ctx (\ctx -> do
       p <- unsafeUseAsCString wasm (\s ->
-        extism_plugin_new ctx (castPtr s) length wasi)
+        extism_plugin_new ctx (castPtr s) length nullPtr 0 wasi )
       if p < 0 then do
         err <- extism_error ctx (-1)
         e <- peekCString err
@@ -92,7 +94,7 @@ update (Plugin (Context ctx) id) wasm useWasi =
   do
     withForeignPtr ctx (\ctx -> do
       b <- unsafeUseAsCString wasm (\s ->
-        extism_plugin_update ctx id (castPtr s) length wasi)
+        extism_plugin_update ctx id (castPtr s) length nullPtr 0 wasi)
       if b <= 0 then do
         err <- extism_error ctx (-1)
         e <- peekCString err
@@ -172,3 +174,13 @@ call (Plugin (Context ctx) plugin) name input =
 free :: Plugin -> IO ()
 free (Plugin (Context ctx) plugin) =
   withForeignPtr ctx (`extism_plugin_free` plugin)
+
+cancelHandle :: Plugin -> IO CancelHandle
+cancelHandle (Plugin (Context ctx) plugin) = do
+  handle <- withForeignPtr ctx (\ctx -> extism_plugin_cancel_handle ctx plugin)
+  return (CancelHandle handle)
+
+cancel :: CancelHandle -> IO Bool
+cancel (CancelHandle handle) = 
+  extism_plugin_cancel handle
+

haskell/src/Extism/Bindings.hs

@@ -9,18 +9,22 @@ import Data.Int
 import Data.Word
 
 newtype ExtismContext = ExtismContext () deriving Show
+newtype ExtismFunction = ExtismFunction () deriving Show
+newtype ExtismCancelHandle = ExtismCancelHandle () deriving Show
 
-foreign import ccall unsafe "extism.h extism_context_new" extism_context_new :: IO (Ptr ExtismContext)
-foreign import ccall unsafe "extism.h &extism_context_free" extism_context_free :: FunPtr (Ptr ExtismContext -> IO ())
-foreign import ccall unsafe "extism.h extism_plugin_new" extism_plugin_new :: Ptr ExtismContext -> Ptr Word8 -> Word64 -> CBool -> IO Int32
-foreign import ccall unsafe "extism.h extism_plugin_update" extism_plugin_update :: Ptr ExtismContext -> Int32 -> Ptr Word8 -> Word64 -> CBool -> IO CBool
-foreign import ccall unsafe "extism.h extism_plugin_call" extism_plugin_call :: Ptr ExtismContext -> Int32 -> CString -> Ptr Word8 -> Word64 -> IO Int32
-foreign import ccall unsafe "extism.h extism_plugin_function_exists" extism_plugin_function_exists :: Ptr ExtismContext -> Int32 -> CString -> IO CBool
-foreign import ccall unsafe "extism.h extism_error" extism_error :: Ptr ExtismContext -> Int32 -> IO CString
-foreign import ccall unsafe "extism.h extism_plugin_output_length" extism_plugin_output_length :: Ptr ExtismContext -> Int32 -> IO Word64
-foreign import ccall unsafe "extism.h extism_plugin_output_data" extism_plugin_output_data :: Ptr ExtismContext -> Int32 -> IO (Ptr Word8)
-foreign import ccall unsafe "extism.h extism_log_file" extism_log_file :: CString -> CString -> IO CBool
-foreign import ccall unsafe "extism.h extism_plugin_config" extism_plugin_config :: Ptr ExtismContext -> Int32 -> Ptr Word8 -> Int64 -> IO CBool
-foreign import ccall unsafe "extism.h extism_plugin_free" extism_plugin_free :: Ptr ExtismContext -> Int32 -> IO ()
-foreign import ccall unsafe "extism.h extism_context_reset" extism_context_reset :: Ptr ExtismContext -> IO ()
-foreign import ccall unsafe "extism.h extism_version" extism_version :: IO CString
+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 ())
+foreign import ccall safe "extism.h extism_plugin_new" extism_plugin_new :: Ptr ExtismContext -> Ptr Word8 -> Word64 -> Ptr (Ptr ExtismFunction) -> Word64 -> CBool -> IO Int32
+foreign import ccall safe "extism.h extism_plugin_update" extism_plugin_update :: Ptr ExtismContext -> Int32 -> Ptr Word8 -> Word64 -> Ptr (Ptr ExtismFunction) -> Word64 -> CBool -> IO CBool
+foreign import ccall safe "extism.h extism_plugin_call" extism_plugin_call :: Ptr ExtismContext -> Int32 -> CString -> Ptr Word8 -> Word64 -> IO Int32
+foreign import ccall safe "extism.h extism_plugin_function_exists" extism_plugin_function_exists :: Ptr ExtismContext -> Int32 -> CString -> IO CBool
+foreign import ccall safe "extism.h extism_error" extism_error :: Ptr ExtismContext -> Int32 -> IO CString
+foreign import ccall safe "extism.h extism_plugin_output_length" extism_plugin_output_length :: Ptr ExtismContext -> Int32 -> IO Word64
+foreign import ccall safe "extism.h extism_plugin_output_data" extism_plugin_output_data :: Ptr ExtismContext -> Int32 -> IO (Ptr Word8)
+foreign import ccall safe "extism.h extism_log_file" extism_log_file :: CString -> CString -> IO CBool
+foreign import ccall safe "extism.h extism_plugin_config" extism_plugin_config :: Ptr ExtismContext -> Int32 -> Ptr Word8 -> Int64 -> IO CBool
+foreign import ccall safe "extism.h extism_plugin_free" extism_plugin_free :: Ptr ExtismContext -> Int32 -> IO ()
+foreign import ccall safe "extism.h extism_context_reset" extism_context_reset :: Ptr ExtismContext -> IO ()
+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

haskell/test/Test.hs

@@ -7,7 +7,7 @@ unwrap (Right x) = return x
 unwrap (Left (ExtismError msg)) =
   assertFailure msg
 
-defaultManifest = manifest [wasmFile "test/code.wasm"]
+defaultManifest = manifest [wasmFile "../../wasm/code.wasm"]
 
 initPlugin :: Context -> IO Plugin
 initPlugin context =

java/pom.xml

@@ -4,7 +4,7 @@
     <groupId>org.extism.sdk</groupId>
     <artifactId>extism</artifactId>
     <packaging>jar</packaging>
-    <version>0.1.0</version>
+    <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>
@@ -36,7 +36,7 @@
     <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/java</url>
+        <url>https://github.com/extism/extism/tree/main/java</url>
         <tag>main</tag>
     </scm>
 
@@ -46,7 +46,7 @@
     </issueManagement>
 
     <properties>
-        <java.version>17</java.version>
+        <java.version>11</java.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 
         <!-- dependencies -->
@@ -74,6 +74,9 @@
               <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>

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

@@ -0,0 +1,21 @@
+package org.extism.sdk;
+
+import com.sun.jna.Pointer;
+
+/**
+ * CancelHandle is used to cancel a running Plugin
+ */
+public class CancelHandle {
+    private Pointer handle;
+
+    public CancelHandle(Pointer handle) {
+        this.handle = handle;
+    }
+
+    /**
+     * Cancel execution of the Plugin associated with the CancelHandle
+     */
+    boolean cancel() {
+        return LibExtism.INSTANCE.extism_plugin_cancel(this.handle);
+    }
+}

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

@@ -28,10 +28,11 @@ public class Context implements AutoCloseable {
      *
      * @param manifest The manifest for the plugin
      * @param withWASI Set to true to enable WASI
+     * @param functions List of Host functions
      * @return the plugin instance
      */
-    public Plugin newPlugin(Manifest manifest, boolean withWASI) {
-        return new Plugin(this, manifest, withWASI);
+    public Plugin newPlugin(Manifest manifest, boolean withWASI, HostFunction[] functions) {
+        return new Plugin(this, manifest, withWASI, functions);
     }
 
     /**

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

@@ -42,7 +42,7 @@ public class Extism {
      */
     public static String invokeFunction(Manifest manifest, String function, String input) throws ExtismException {
         try (var ctx = new Context()) {
-            try (var plugin = ctx.newPlugin(manifest, false)) {
+            try (var plugin = ctx.newPlugin(manifest, false, null)) {
                 return plugin.call(function, input);
             }
         }

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

@@ -0,0 +1,78 @@
+package org.extism.sdk;
+
+import com.sun.jna.Pointer;
+
+import java.nio.charset.StandardCharsets;
+
+public class ExtismCurrentPlugin {
+    public Pointer pointer;
+
+    public ExtismCurrentPlugin(Pointer pointer) {
+        this.pointer = pointer;
+    }
+
+    public Pointer memory() {
+        return LibExtism.INSTANCE.extism_current_plugin_memory(this.pointer);
+    }
+
+    public int alloc(int n) {
+        return LibExtism.INSTANCE.extism_current_plugin_memory_alloc(this.pointer, n);
+    }
+
+    public void free(long offset) {
+        LibExtism.INSTANCE.extism_current_plugin_memory_free(this.pointer, offset);
+    }
+
+    public long memoryLength(long offset) {
+        return LibExtism.INSTANCE.extism_current_plugin_memory_length(this.pointer, offset);
+    }
+
+    /**
+     * Return a string from a host function
+     * @param output - The output to set
+     * @param s - The string to return
+     */
+    public void returnString(LibExtism.ExtismVal output, String s) {
+        returnBytes(output, s.getBytes(StandardCharsets.UTF_8));
+    }
+
+    /**
+     * Return bytes from a host function
+     * @param output - The output to set
+     * @param b - The buffer to return
+     */
+    public void returnBytes(LibExtism.ExtismVal output, byte[] b) {
+        int offs = this.alloc(b.length);
+        Pointer ptr = this.memory();
+        ptr.write(offs, b, 0, b.length);
+        output.v.i64 = offs;
+    }
+
+    /**
+     * Get bytes from host function parameter
+     * @param input - The input to read
+     */
+    public byte[] inputBytes(LibExtism.ExtismVal input) {
+        switch (input.t) {
+            case 0:
+                return this.memory()
+                        .getByteArray(input.v.i32,
+                                LibExtism.INSTANCE.extism_current_plugin_memory_length(this.pointer, input.v.i32));
+            case 1:
+                return this.memory()
+                        .getByteArray(input.v.i64,
+                                LibExtism.INSTANCE.extism_current_plugin_memory_length(this.pointer, input.v.i64));
+            default:
+                throw new ExtismException("inputBytes error: ExtismValType " + LibExtism.ExtismValType.values()[input.t] + " not implemtented");
+        }
+    }
+
+
+    /**
+     * Get string from host function parameter
+     * @param input - The input to read
+     */
+    public String inputString(LibExtism.ExtismVal input) {
+        return new String(this.inputBytes(input));
+    }
+}

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

@@ -0,0 +1,12 @@
+package org.extism.sdk;
+
+import java.util.Optional;
+
+public interface ExtismFunction<T extends HostUserData> {
+    void invoke(
+            ExtismCurrentPlugin plugin,
+            LibExtism.ExtismVal[] params,
+            LibExtism.ExtismVal[] returns,
+            Optional<T> data
+    );
+}

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

@@ -0,0 +1,92 @@
+package org.extism.sdk;
+
+import com.sun.jna.Pointer;
+import com.sun.jna.PointerType;
+
+import java.util.Arrays;
+import java.util.Optional;
+
+public class HostFunction<T extends HostUserData> {
+
+    private final LibExtism.InternalExtismFunction callback;
+
+    public final Pointer pointer;
+
+    public final String name;
+
+    public final LibExtism.ExtismValType[] params;
+
+    public final LibExtism.ExtismValType[] returns;
+
+    public final Optional<T> userData;
+
+    public HostFunction(String name, LibExtism.ExtismValType[] params, LibExtism.ExtismValType[] returns, ExtismFunction f, Optional<T> userData) {
+
+        this.name = name;
+        this.params = params;
+        this.returns = returns;
+        this.userData = userData;
+        this.callback = (Pointer currentPlugin,
+                         LibExtism.ExtismVal inputs,
+                         int nInputs,
+                         LibExtism.ExtismVal outs,
+                         int nOutputs,
+                         Pointer data) -> {
+
+            LibExtism.ExtismVal[] outputs = (LibExtism.ExtismVal []) outs.toArray(nOutputs);
+
+            f.invoke(
+                    new ExtismCurrentPlugin(currentPlugin),
+                    (LibExtism.ExtismVal []) inputs.toArray(nInputs),
+                    outputs,
+                    userData
+            );
+
+            for (LibExtism.ExtismVal output : outputs) {
+                convertOutput(output, output);
+            }
+        };
+
+        this.pointer = LibExtism.INSTANCE.extism_function_new(
+                this.name,
+                Arrays.stream(this.params).mapToInt(r -> r.v).toArray(),
+                this.params.length,
+                Arrays.stream(this.returns).mapToInt(r -> r.v).toArray(),
+                this.returns.length,
+                this.callback,
+                userData.map(PointerType::getPointer).orElse(null),
+                null
+        );
+    }
+
+    void convertOutput(LibExtism.ExtismVal original, LibExtism.ExtismVal fromHostFunction) {
+        if (fromHostFunction.t != original.t)
+            throw new ExtismException(String.format("Output type mismatch, got %d but expected %d", fromHostFunction.t, original.t));
+
+        if (fromHostFunction.t == LibExtism.ExtismValType.I32.v) {
+            original.v.setType(Integer.TYPE);
+            original.v.i32 = fromHostFunction.v.i32;
+        } else if (fromHostFunction.t == LibExtism.ExtismValType.I64.v) {
+            original.v.setType(Long.TYPE);
+            original.v.i64 = fromHostFunction.v.i64;
+        } else if (fromHostFunction.t == LibExtism.ExtismValType.F32.v) {
+            original.v.setType(Float.TYPE);
+            original.v.f32 = fromHostFunction.v.f32;
+        } else if (fromHostFunction.t == LibExtism.ExtismValType.F64.v) {
+            original.v.setType(Double.TYPE);
+            original.v.f64 = fromHostFunction.v.f64;
+        } else
+            throw new ExtismException(String.format("Unsupported return type: %s", original.t));
+    }
+
+    public void setNamespace(String name) {
+        if (this.pointer != null) {
+            LibExtism.INSTANCE.extism_function_set_namespace(this.pointer, name);
+        }
+    }
+
+    HostFunction withNamespace(String name) {
+        this.setNamespace(name);
+        return this;
+    }
+}

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

@@ -0,0 +1,7 @@
+package org.extism.sdk;
+
+import com.sun.jna.PointerType;
+
+public class HostUserData extends PointerType {
+
+}

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

@@ -1,8 +1,6 @@
 package org.extism.sdk;
 
-import com.sun.jna.Library;
-import com.sun.jna.Native;
-import com.sun.jna.Pointer;
+import com.sun.jna.*;
 
 /**
  * Wrapper around the Extism library.
@@ -15,7 +13,80 @@ public interface LibExtism extends Library {
      */
     LibExtism INSTANCE = Native.load("extism", LibExtism.class);
 
+    interface InternalExtismFunction extends Callback {
+        void invoke(
+                Pointer currentPlugin,
+                ExtismVal inputs,
+                int nInputs,
+                ExtismVal outputs,
+                int nOutputs,
+                Pointer data
+        );
+    }
+
+    @Structure.FieldOrder({"t", "v"})
+    class ExtismVal extends Structure {
+        public int t;
+        public ExtismValUnion v;
+    }
+
+    class ExtismValUnion extends Union {
+        public int i32;
+        public long i64;
+        public float f32;
+        public double f64;
+    }
+
+    enum ExtismValType {
+        I32(0),
+        I64(1),
+        F32(2),
+        F64(3),
+        V128(4),
+        FuncRef(5),
+        ExternRef(6);
+
+        public final int v;
+
+        ExtismValType(int value) {
+            this.v = value;
+        }
+    }
+
+    Pointer extism_function_new(String name,
+                                int[] inputs,
+                                int nInputs,
+                                int[] outputs,
+                                int nOutputs,
+                                InternalExtismFunction func,
+                                Pointer userData,
+                                Pointer freeUserData);
+
     /**
+     * Get the length of an allocated block
+     * NOTE: this should only be called from host functions.
+     */
+    int extism_current_plugin_memory_length(Pointer plugin, long n);
+
+    /**
+     * Returns a pointer to the memory of the currently running plugin
+     * NOTE: this should only be called from host functions.
+     */
+    Pointer extism_current_plugin_memory(Pointer plugin);
+
+    /**
+     * Allocate a memory block in the currently running plugin
+     * NOTE: this should only be called from host functions.
+     */
+    int extism_current_plugin_memory_alloc(Pointer plugin, long n);
+
+    /**
+     * Free an allocated memory block
+     * NOTE: this should only be called from host functions.
+     */
+    void extism_current_plugin_memory_free(Pointer plugin, long ptr);
+
+        /**
      * Create a new context
      */
     Pointer extism_context_new();
@@ -56,27 +127,18 @@ public interface LibExtism extends Library {
      * @param contextPointer pointer to the {@link Context}.
      * @param wasm           is a WASM module (wat or wasm) or a JSON encoded manifest
      * @param wasmSize       the length of the `wasm` parameter
+     * @param functions      host functions
+     * @param nFunctions     the number of host functions
      * @param withWASI       enables/disables WASI
      * @return id of the plugin or {@literal -1} in case of error
      */
-    int extism_plugin_new(long contextPointer, byte[] wasm, long wasmSize, boolean withWASI);
+    int extism_plugin_new(Pointer contextPointer, byte[] wasm, long wasmSize, Pointer[] functions, int nFunctions, boolean withWASI);
 
     /**
      * Returns the Extism version string
      */
     String extism_version();
 
-    /**
-     * Create a new plugin.
-     *
-     * @param contextPointer pointer to the {@link Context}.
-     * @param wasm           is a WASM module (wat or wasm) or a JSON encoded manifest
-     * @param length         the length of the `wasm` parameter
-     * @param withWASI       enables/disables WASI
-     * @return id of the plugin or {@literal -1} in case of error
-     * @see #extism_plugin_new(long, byte[], long, boolean)
-     */
-    int extism_plugin_new(Pointer contextPointer, byte[] wasm, int length, boolean withWASI);
 
     /**
      * Calls a function from the @{@link Plugin} at the given {@code pluginIndex}.
@@ -110,17 +172,19 @@ public interface LibExtism extends Library {
 
     /**
      * Update a plugin, keeping the existing ID.
-     * Similar to {@link #extism_plugin_new(long, byte[], long, boolean)} but takes an {@code pluginIndex} argument to specify which plugin to update.
+     * Similar to {@link #extism_plugin_new(Pointer, byte[], long, Pointer[], int, boolean)} but takes an {@code pluginIndex} argument to specify which plugin to update.
      * Note: Memory for this plugin will be reset upon update.
      *
      * @param contextPointer
      * @param pluginIndex
      * @param wasm
      * @param length
+     * @param functions      host functions
+     * @param nFunctions     the number of host functions
      * @param withWASI
      * @return {@literal true} if update was successful
      */
-    boolean extism_plugin_update(Pointer contextPointer, int pluginIndex, byte[] wasm, int length, boolean withWASI);
+    boolean extism_plugin_update(Pointer contextPointer, int pluginIndex, byte[] wasm, int length, Pointer[] functions, int nFunctions, boolean withWASI);
 
     /**
      * Remove a plugin from the registry and free associated memory.
@@ -140,4 +204,7 @@ public interface LibExtism extends Library {
      * @return {@literal true} if update was successful
      */
     boolean extism_plugin_config(Pointer contextPointer, int pluginIndex, byte[] json, int jsonLength);
+    Pointer extism_plugin_cancel_handle(Pointer contextPointer, int n);
+    boolean extism_plugin_cancel(Pointer contextPointer);
+    void extism_function_set_namespace(Pointer p, String name);
 }

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

@@ -28,15 +28,27 @@ public class Plugin implements AutoCloseable {
      *
      * @param context       The context to manage the plugin
      * @param manifestBytes The manifest for the plugin
+     * @param functions     The Host functions for th eplugin
      * @param withWASI      Set to true to enable WASI
      */
-    public Plugin(Context context, byte[] manifestBytes, boolean withWASI) {
+    public Plugin(Context context, byte[] manifestBytes, boolean withWASI, HostFunction[] functions) {
 
         Objects.requireNonNull(context, "context");
         Objects.requireNonNull(manifestBytes, "manifestBytes");
 
+        Pointer[] ptrArr = new Pointer[functions == null ? 0 : functions.length];
+
+        if (functions != null)
+            for (int i = 0; i < functions.length; i++) {
+               ptrArr[i] = functions[i].pointer;
+            }
+
         Pointer contextPointer = context.getPointer();
-        int index = LibExtism.INSTANCE.extism_plugin_new(contextPointer, manifestBytes, manifestBytes.length, withWASI);
+
+        int index = LibExtism.INSTANCE.extism_plugin_new(contextPointer, manifestBytes, manifestBytes.length,
+                ptrArr,
+                functions == null ? 0 : functions.length,
+                withWASI);
         if (index == -1) {
             String error = context.error(this);
             throw new ExtismException(error);
@@ -46,8 +58,8 @@ public class Plugin implements AutoCloseable {
         this.context = context;
     }
 
-    public Plugin(Context context, Manifest manifest, boolean withWASI) {
-        this(context, serialize(manifest), withWASI);
+    public Plugin(Context context, Manifest manifest, boolean withWASI, HostFunction[] functions) {
+        this(context, serialize(manifest), withWASI, functions);
     }
 
     private static byte[] serialize(Manifest manifest) {
@@ -112,8 +124,8 @@ public class Plugin implements AutoCloseable {
      * @param withWASI Set to true to enable WASI
      * @return {@literal true} if update was successful
      */
-    public boolean update(Manifest manifest, boolean withWASI) {
-        return update(serialize(manifest), withWASI);
+    public boolean update(Manifest manifest, boolean withWASI, HostFunction[] functions) {
+        return update(serialize(manifest), withWASI, functions);
     }
 
     /**
@@ -123,9 +135,19 @@ public class Plugin implements AutoCloseable {
      * @param withWASI      Set to true to enable WASI
      * @return {@literal true} if update was successful
      */
-    public boolean update(byte[] manifestBytes, boolean withWASI) {
+    public boolean update(byte[] manifestBytes, boolean withWASI, HostFunction[] functions) {
         Objects.requireNonNull(manifestBytes, "manifestBytes");
-        return LibExtism.INSTANCE.extism_plugin_update(context.getPointer(), index, manifestBytes, manifestBytes.length, withWASI);
+        Pointer[] ptrArr = new Pointer[functions == null ? 0 : functions.length];
+
+        if (functions != null)
+            for (int i = 0; i < functions.length; i++) {
+                ptrArr[i] = functions[i].pointer;
+            }
+
+        return LibExtism.INSTANCE.extism_plugin_update(context.getPointer(), index, manifestBytes, manifestBytes.length,
+                ptrArr,
+                functions == null ? 0 : functions.length,
+                withWASI);
     }
 
     /**
@@ -165,4 +187,15 @@ public class Plugin implements AutoCloseable {
     public void close() {
         free();
     }
+
+    /**
+     * Return a new `CancelHandle`, which can be used to cancel a running Plugin
+     */
+    public CancelHandle cancelHandle() {
+        if (this.context.getPointer() == null) {
+            throw new ExtismException("No Context set");
+        }
+        Pointer handle = LibExtism.INSTANCE.extism_plugin_cancel_handle(this.context.getPointer(), this.index);
+        return new CancelHandle(handle);
+    }
 }

java/src/main/java/org/extism/sdk/manifest/Manifest.java

@@ -20,11 +20,14 @@ public class Manifest {
     @SerializedName("allowed_hosts")
     private final List<String> allowedHosts;
 
+    @SerializedName("allowed_paths")
+    private final Map<String, String> allowedPaths;
+
     @SerializedName("config")
     private final Map<String, String> config;
 
     public Manifest() {
-        this(new ArrayList<>(), null, null, null);
+        this(new ArrayList<>(), null, null, null, null);
     }
 
     public Manifest(WasmSource source) {
@@ -32,22 +35,27 @@ public class Manifest {
     }
 
     public Manifest(List<WasmSource> sources) {
-        this(sources, null, null, null);
+        this(sources, null, null, null, null);
     }
 
     public Manifest(List<WasmSource> sources, MemoryOptions memoryOptions) {
-        this(sources, memoryOptions, null, null);
+        this(sources, memoryOptions, null, null, null);
     }
 
     public Manifest(List<WasmSource> sources, MemoryOptions memoryOptions, Map<String, String> config) {
-        this(sources, memoryOptions, config, null);
+        this(sources, memoryOptions, config, null, null);
     }
 
     public Manifest(List<WasmSource> sources, MemoryOptions memoryOptions, Map<String, String> config, List<String> allowedHosts) {
+        this(sources, memoryOptions, config, allowedHosts, null);
+    }
+
+    public Manifest(List<WasmSource> sources, MemoryOptions memoryOptions, Map<String, String> config, List<String> allowedHosts, Map<String, String> allowedPaths) {
         this.sources = sources;
         this.memoryOptions = memoryOptions;
         this.config = config;
         this.allowedHosts = allowedHosts;
+        this.allowedPaths = allowedPaths;
     }
 
     public void addSource(WasmSource source) {
@@ -75,4 +83,11 @@ public class Manifest {
         }
         return Collections.unmodifiableList(allowedHosts);
     }
+
+    public Map<String, String> getAllowedPaths() {
+        if (allowedPaths == null || allowedPaths.isEmpty()) {
+            return Collections.emptyMap();
+        }
+        return Collections.unmodifiableMap(allowedPaths);
+    }
 }

java/src/main/java/org/extism/sdk/manifest/ManifestHttpRequest.java

@@ -3,6 +3,27 @@ package org.extism.sdk.manifest;
 import java.util.Map;
 
 // FIXME remove this and related stuff if not supported in java-sdk
-public record ManifestHttpRequest(String url, Map<String, String> header, String method) {
-}
+public class ManifestHttpRequest {
 
+    private final String url;
+    private final Map<String, String> header;
+    private final String method;
+
+    public ManifestHttpRequest(String url, Map<String, String> header, String method) {
+        this.url = url;
+        this.header = header;
+        this.method = method;
+    }
+
+    public String url() {
+        return url;
+    }
+
+    public Map<String, String> header() {
+        return header;
+    }
+
+    public String method() {
+        return method;
+    }
+}

java/src/main/java/org/extism/sdk/manifest/MemoryOptions.java

@@ -8,5 +8,11 @@ import com.google.gson.annotations.SerializedName;
  *
  * @param max Max number of pages.
  */
-public record MemoryOptions(@SerializedName("max") Integer max) {
+public class MemoryOptions {
+    @SerializedName("max")
+    private final Integer max;
+
+    public MemoryOptions(Integer max) {
+        this.max = max;
+    }
 }

java/src/main/java/org/extism/sdk/support/JsonSerde.java

@@ -1,18 +1,14 @@
 package org.extism.sdk.support;
 
-import com.google.gson.FieldNamingPolicy;
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonDeserializationContext;
-import com.google.gson.JsonDeserializer;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonParseException;
-import com.google.gson.JsonPrimitive;
-import com.google.gson.JsonSerializationContext;
-import com.google.gson.JsonSerializer;
+import com.google.gson.*;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
+import com.google.gson.stream.JsonWriter;
 import org.extism.sdk.manifest.Manifest;
 
+import java.io.IOException;
 import java.lang.reflect.Type;
+import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 
 public class JsonSerde {
@@ -23,7 +19,7 @@ public class JsonSerde {
         GSON = new GsonBuilder() //
                 .disableHtmlEscaping() //
                 // needed to convert the byte[] to a base64 encoded String
-                .registerTypeHierarchyAdapter(byte[].class, new ByteArrayToBase64TypeAdapter()) //
+                .registerTypeHierarchyAdapter(byte[].class, new ByteArrayAdapter()) //
                 .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES) //
                 .setPrettyPrinting() //
                 .create();
@@ -33,14 +29,28 @@ public class JsonSerde {
         return GSON.toJson(manifest);
     }
 
-    private static class ByteArrayToBase64TypeAdapter implements JsonSerializer<byte[]>, JsonDeserializer<byte[]> {
+    private static class ByteArrayAdapter extends TypeAdapter<byte[]> {
 
-        public byte[] deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
-            return Base64.getDecoder().decode(json.getAsString());
+        @Override
+        public void write(JsonWriter out, byte[] byteValue) throws IOException {
+            out.value(new String(Base64.getEncoder().encode(byteValue)));
         }
 
-        public JsonElement serialize(byte[] src, Type typeOfSrc, JsonSerializationContext context) {
-            return new JsonPrimitive(Base64.getEncoder().withoutPadding().encodeToString(src));
+        @Override
+        public byte[] read(JsonReader in) {
+            try {
+                if (in.peek() == JsonToken.NULL) {
+                    in.nextNull();
+                    return new byte[]{};
+                }
+                String byteValue = in.nextString();
+                if (byteValue != null) {
+                    return Base64.getDecoder().decode(byteValue);
+                }
+                return new byte[]{};
+            } catch (Exception e) {
+                throw new JsonParseException(e);
+            }
         }
     }
 }

java/src/main/java/org/extism/sdk/wasm/ByteArrayWasmSource.java

@@ -2,10 +2,37 @@ package org.extism.sdk.wasm;
 
 /**
  * WASM Source represented by raw bytes.
- *
- * @param name
- * @param data the byte array representing the WASM code
- * @param hash
  */
-public record ByteArrayWasmSource(String name, byte[] data, String hash) implements WasmSource {
+public class ByteArrayWasmSource implements WasmSource {
+
+    private final String name;
+    private final byte[] data;
+    private final String hash;
+
+
+    /**
+     * Constructor
+     * @param name
+     * @param data the byte array representing the WASM code
+     * @param hash
+     */
+    public ByteArrayWasmSource(String name, byte[] data, String hash) {
+        this.name = name;
+        this.data = data;
+        this.hash = hash;
+    }
+
+    @Override
+    public String name() {
+        return name;
+    }
+
+    @Override
+    public String hash() {
+        return hash;
+    }
+
+    public byte[] data() {
+        return data;
+    }
 }

java/src/main/java/org/extism/sdk/wasm/PathWasmSource.java

@@ -2,11 +2,39 @@ package org.extism.sdk.wasm;
 
 /**
  * WASM Source represented by a file referenced by a path.
- *
- * @param name
- * @param path
- * @param hash
  */
-public record PathWasmSource(String name, String path, String hash) implements WasmSource {
+public class PathWasmSource implements WasmSource {
+
+    private final String name;
+
+    private final String path;
+
+    private final String hash;
+
+    /**
+     * Constructor
+     * @param name
+     * @param path
+     * @param hash
+     */
+    public PathWasmSource(String name, String path, String hash) {
+        this.name = name;
+        this.path = path;
+        this.hash = hash;
+    }
+
+    @Override
+    public String name() {
+        return name;
+    }
+
+    @Override
+    public String hash() {
+        return hash;
+    }
+
+    public String path() {
+        return path;
+    }
 }
 

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

@@ -6,6 +6,7 @@ import org.extism.sdk.support.JsonSerde;
 import org.junit.jupiter.api.Test;
 
 import java.util.List;
+import java.util.HashMap;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.extism.sdk.TestWasmSources.CODE;
@@ -16,13 +17,16 @@ public class ManifestTests {
 
     @Test
     public void shouldSerializeManifestWithWasmSourceToJson() {
-
-        var manifest = new Manifest(CODE.pathWasmSource());
+        var paths = new HashMap<String, String>();
+        paths.put("/tmp/foo", "/tmp/extism-plugins/foo");
+        var manifest = new Manifest(List.of(CODE.pathWasmSource()), null, null, null, paths);
         var json = JsonSerde.toJson(manifest);
         assertNotNull(json);
 
         assertJson(json).at("/wasm").isArray();
         assertJson(json).at("/wasm").hasSize(1);
+        assertJson(json).at("/allowed_paths").isObject();
+        assertJson(json).at("/allowed_paths").hasSize(1);
     }
 
     @Test

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

@@ -1,12 +1,12 @@
 package org.extism.sdk;
 
+import com.sun.jna.Pointer;
 import org.extism.sdk.manifest.Manifest;
 import org.extism.sdk.manifest.MemoryOptions;
 import org.extism.sdk.wasm.WasmSourceResolver;
 import org.junit.jupiter.api.Test;
 
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.extism.sdk.TestWasmSources.CODE;
@@ -42,14 +42,12 @@ public class PluginTests {
         assertThat(output).isEqualTo("{\"count\": 3}");
     }
 
-    // TODO This test breaks on CI with error:
-    // data did not match any variant of untagged enum Wasm at line 8 column 3
-    // @Test
-    // public void shouldInvokeFunctionFromByteArrayWasmSource() {
-    //     var manifest = new Manifest(CODE.byteArrayWasmSource());
-    //     var output = Extism.invokeFunction(manifest, "count_vowels", "Hello World");
-    //     assertThat(output).isEqualTo("{\"count\": 3}");
-    // }
+     @Test
+     public void shouldInvokeFunctionFromByteArrayWasmSource() {
+         var manifest = new Manifest(CODE.byteArrayWasmSource());
+         var output = Extism.invokeFunction(manifest, "count_vowels", "Hello World");
+         assertThat(output).isEqualTo("{\"count\": 3}");
+     }
 
     @Test
     public void shouldFailToInvokeUnknownFunction() {
@@ -80,7 +78,7 @@ public class PluginTests {
         var input = "Hello World";
 
         try (var ctx = new Context()) {
-            try (var plugin = ctx.newPlugin(manifest, false)) {
+            try (var plugin = ctx.newPlugin(manifest, false, null)) {
                 var output = plugin.call(functionName, input);
                 assertThat(output).isEqualTo("{\"count\": 3}");
             }
@@ -94,7 +92,7 @@ public class PluginTests {
         var input = "Hello World";
 
         try (var ctx = new Context()) {
-            try (var plugin = ctx.newPlugin(manifest, false)) {
+            try (var plugin = ctx.newPlugin(manifest, false, null)) {
                 var output = plugin.call(functionName, input);
                 assertThat(output).isEqualTo("{\"count\": 3}");
 
@@ -104,4 +102,118 @@ public class PluginTests {
         }
     }
 
+    @Test
+    public void shouldAllowInvokeHostFunctionFromPDK() {
+        var parametersTypes = new LibExtism.ExtismValType[]{LibExtism.ExtismValType.I64};
+        var resultsTypes = new LibExtism.ExtismValType[]{LibExtism.ExtismValType.I64};
+
+        class MyUserData extends HostUserData {
+            private String data1;
+            private int data2;
+
+            public MyUserData(String data1, int data2) {
+                super();
+                this.data1 = data1;
+                this.data2 = data2;
+            }
+        }
+
+        ExtismFunction helloWorldFunction = (ExtismFunction<MyUserData>) (plugin, params, returns, data) -> {
+            System.out.println("Hello from Java Host Function!");
+            System.out.println(String.format("Input string received from plugin, %s", plugin.inputString(params[0])));
+
+            int offs = plugin.alloc(4);
+            Pointer mem = plugin.memory();
+            mem.write(offs, "test".getBytes(), 0, 4);
+            returns[0].v.i64 = offs;
+
+            data.ifPresent(d -> System.out.println(String.format("Host user data, %s, %d", d.data1, d.data2)));
+        };
+
+        HostFunction helloWorld = new HostFunction<>(
+                "hello_world",
+                parametersTypes,
+                resultsTypes,
+                helloWorldFunction,
+                Optional.of(new MyUserData("test", 2))
+        );
+
+        HostFunction[] functions = {helloWorld};
+
+        try (var ctx = new Context()) {
+            Manifest manifest = new Manifest(Arrays.asList(CODE.pathWasmFunctionsSource()));
+            String functionName = "count_vowels";
+
+            try (var plugin = ctx.newPlugin(manifest, true, functions)) {
+                var output = plugin.call(functionName, "this is a test");
+                assertThat(output).isEqualTo("test");
+            }
+        }
+    }
+
+    @Test
+    public void shouldAllowInvokeHostFunctionWithoutUserData() {
+
+        var parametersTypes = new LibExtism.ExtismValType[]{LibExtism.ExtismValType.I64};
+        var resultsTypes = new LibExtism.ExtismValType[]{LibExtism.ExtismValType.I64};
+
+        ExtismFunction helloWorldFunction = (plugin, params, returns, data) -> {
+            System.out.println("Hello from Java Host Function!");
+            System.out.println(String.format("Input string received from plugin, %s", plugin.inputString(params[0])));
+
+            int offs = plugin.alloc(4);
+            Pointer mem = plugin.memory();
+            mem.write(offs, "test".getBytes(), 0, 4);
+            returns[0].v.i64 = offs;
+
+            assertThat(data.isEmpty());
+        };
+
+        HostFunction f = new HostFunction<>(
+                "hello_world",
+                parametersTypes,
+                resultsTypes,
+                helloWorldFunction,
+                Optional.empty()
+        )
+                .withNamespace("env");
+
+        HostFunction g = new HostFunction<>(
+                "hello_world",
+                parametersTypes,
+                resultsTypes,
+                helloWorldFunction,
+                Optional.empty()
+        )
+                .withNamespace("test");
+
+        HostFunction[] functions = {f,g};
+
+        try (var ctx = new Context()) {
+            Manifest manifest = new Manifest(Arrays.asList(CODE.pathWasmFunctionsSource()));
+            String functionName = "count_vowels";
+
+            try (var plugin = ctx.newPlugin(manifest, true, functions)) {
+                var output = plugin.call(functionName, "this is a test");
+                assertThat(output).isEqualTo("test");
+            }
+        }
+    }
+
+
+    @Test
+    public void shouldFailToInvokeUnknownHostFunction() {
+        try (var ctx = new Context()) {
+            Manifest manifest = new Manifest(Arrays.asList(CODE.pathWasmFunctionsSource()));
+            String functionName = "count_vowels";
+
+            try {
+                var plugin = ctx.newPlugin(manifest, true, null);
+                plugin.call(functionName, "this is a test");
+            }  catch (ExtismException e) {
+                assertThat(e.getMessage()).contains("unknown import: `env::hello_world` has not been defined");
+            }
+        }
+    }
+
 }

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

@@ -16,19 +16,28 @@ public enum TestWasmSources {
         public Path getWasmFilePath() {
             return Paths.get(WASM_LOCATION, "code.wasm");
         }
+        public Path getWasmFunctionsFilePath() {
+            return Paths.get(WASM_LOCATION, "code-functions.wasm");
+        }
     };
 
     public static final String WASM_LOCATION = "src/test/resources";
 
     public abstract Path getWasmFilePath();
 
+    public abstract Path getWasmFunctionsFilePath();
+
     public PathWasmSource pathWasmSource() {
         return resolvePathWasmSource(getWasmFilePath());
     }
 
+    public PathWasmSource pathWasmFunctionsSource() {
+        return resolvePathWasmSource(getWasmFunctionsFilePath());
+    }
+
     public ByteArrayWasmSource byteArrayWasmSource() {
         try {
-            var wasmBytes = Files.readAllBytes(getWasmFilePath());
+            byte[] wasmBytes = Files.readAllBytes(getWasmFilePath());
             return new WasmSourceResolver().resolve("wasm@" + Arrays.hashCode(wasmBytes), wasmBytes);
         } catch (IOException ioe) {
             throw new RuntimeException(ioe);

libextism.pc

@@ -1,10 +0,0 @@
-prefix=/usr/local
-exec_prefix=${prefix}
-includedir=${prefix}/include
-libdir=${exec_prefix}/lib
-
-Name: extism
-Description: The Extism universal plug-in system.
-Version: 0.1.0
-Cflags: -I${includedir}
-Libs: -L${libdir} -lextism

libextism/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libextism"
-version = "0.1.0"
+version = "0.3.0"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"
@@ -20,4 +20,4 @@ default = ["http", "register-http", "register-filesystem"]
 nn = ["extism-runtime/nn"]
 register-http = ["extism-runtime/register-http"] # enables wasm to be downloaded using http
 register-filesystem = ["extism-runtime/register-filesystem"] # enables wasm to be loaded from disk
-http = ["extism-runtime/http"] # enables extism_http_request
+http = ["extism-runtime/http"] # enables extism_http_request

manifest/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "extism-manifest"
-version = "0.1.0"
+version = "0.3.0"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"

manifest/src/lib.rs

@@ -6,6 +6,7 @@ pub type ManifestMemory = MemoryOptions;
 
 #[derive(Default, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
+#[serde(deny_unknown_fields)]
 pub struct MemoryOptions {
     #[serde(alias = "max")]
     pub max_pages: Option<u32>,
@@ -13,6 +14,7 @@ pub struct MemoryOptions {
 
 #[derive(serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
+#[serde(deny_unknown_fields)]
 pub struct HttpRequest {
     pub url: String,
     #[serde(default)]
@@ -43,6 +45,7 @@ impl HttpRequest {
 
 #[derive(Default, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
+#[serde(deny_unknown_fields)]
 pub struct WasmMetadata {
     pub name: Option<String>,
     pub hash: Option<String>,
@@ -81,6 +84,7 @@ pub type ManifestWasm = Wasm;
 #[derive(serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 #[serde(untagged)]
+#[serde(deny_unknown_fields)]
 pub enum Wasm {
     File {
         path: PathBuf,
@@ -151,6 +155,7 @@ fn base64_schema(gen: &mut schemars::gen::SchemaGenerator) -> schemars::schema::
 
 #[derive(Default, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
+#[serde(deny_unknown_fields)]
 pub struct Manifest {
     #[serde(default)]
     pub wasm: Vec<Wasm>,
@@ -250,16 +255,19 @@ impl Manifest {
 }
 
 mod base64 {
+    use base64::{engine::general_purpose, Engine as _};
     use serde::{Deserialize, Serialize};
     use serde::{Deserializer, Serializer};
 
     pub fn serialize<S: Serializer>(v: &Vec<u8>, s: S) -> Result<S::Ok, S::Error> {
-        let base64 = base64::encode(v);
+        let base64 = general_purpose::STANDARD.encode(v);
         String::serialize(&base64, s)
     }
 
     pub fn deserialize<'de, D: Deserializer<'de>>(d: D) -> Result<Vec<u8>, D::Error> {
         let base64 = String::deserialize(d)?;
-        base64::decode(base64.as_bytes()).map_err(serde::de::Error::custom)
+        general_purpose::STANDARD
+            .decode(base64.as_bytes())
+            .map_err(serde::de::Error::custom)
     }
 }

node/code-functions.wasm

@@ -0,0 +1 @@
+../wasm/code-functions.wasm

node/example.js

@@ -1,9 +1,31 @@
-const { withContext, Context } = require('./dist/index.js');
-const { readFileSync } = require('fs');
+const {
+  withContext,
+  Context,
+  HostFunction,
+  ValType,
+} = require("./dist/index.js");
+const { readFileSync } = require("fs");
+
+function f(currentPlugin, inputs, outputs, userData) {
+  console.log(currentPlugin.inputString(inputs[0]));
+  console.log("Hello from Javascript!");
+  console.log(userData);
+  outputs[0] = inputs[0];
+}
+
+let hello_world = new HostFunction(
+  "hello_world",
+  [ValType.I64],
+  [ValType.I64],
+  f,
+  "Hello again!"
+);
+
+let functions = [hello_world];
 
 withContext(async function (context) {
-  let wasm = readFileSync("../wasm/code.wasm");
-  let p = context.plugin(wasm);
+  let wasm = readFileSync("code-functions.wasm");
+  let p = context.plugin(wasm, true, functions);
 
   if (!p.functionExists("count_vowels")) {
     console.log("no function 'count_vowels' in wasm");
@@ -16,7 +38,7 @@ withContext(async function (context) {
 });
 
 // or, use a context like this:
-let ctx = new Context();
-let wasm = readFileSync("../wasm/code.wasm");
-let p = ctx.plugin(wasm);
+// let ctx = new Context();
+// let wasm = readFileSync("code-functions.wasm");
+// let p = ctx.plugin(wasm);
 // ... where the context can be passed around to various functions etc.

node/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@extism/extism",
-  "version": "0.1.0",
+  "version": "0.3.0",
   "description": "Extism Host SDK for Node",
   "keywords": [
     "extism",
@@ -21,12 +21,17 @@
   },
   "scripts": {
     "prepare": "npm run build",
-    "example": "node example.js",
+    "example": "npm run build && node example.js",
     "build": "tsc",
     "test": "jest --coverage"
   },
   "dependencies": {
-    "ffi-napi": "^4.0.3"
+    "@types/ref-array-di": "^1.2.5",
+    "ffi-napi": "^4.0.3",
+    "ref-array-di": "^1.2.2",
+    "ref-napi": "^3.0.3",
+    "ref-struct-di": "^1.1.1",
+    "ref-union-di": "^1.0.1"
   },
   "publishConfig": {
     "access": "public"
@@ -36,7 +41,7 @@
     "@types/jest": "^29.2.0",
     "@types/node": "^18.11.4",
     "jest": "^29.2.2",
-    "prettier": "2.8.2",
+    "prettier": "2.8.4",
     "ts-jest": "^29.0.3",
     "ts-node": "^10.9.1",
     "typedoc": "^0.23.18",

node/src/index.ts

@@ -1,30 +1,100 @@
 import ffi from "ffi-napi";
+import ref from "ref-napi";
 import path from "path";
 
-const context = "void*";
+var ArrayType = require("ref-array-di")(ref);
+var StructType = require("ref-struct-di")(ref);
+var UnionType = require("ref-union-di")(ref);
+
+const opaque = ref.types.void;
+const context = ref.refType(opaque);
+
+const function_t = ref.refType(opaque);
+const pluginIndex = ref.types.int32;
+
+let ValTypeArray = ArrayType(ref.types.int);
+let PtrArray = new ArrayType("void*");
+
+let ValUnion = new UnionType({
+  i32: ref.types.uint32,
+  i64: ref.types.uint64,
+  f32: ref.types.float,
+  f64: ref.types.double,
+});
+
+/**
+ * Val struct, low-level WebAssembly values
+ */
+let Val = new StructType({
+  t: ref.types.int,
+  v: ValUnion,
+});
+
+/**
+ * Array of `Val`
+ */
+let ValArray = ArrayType(Val);
+
 const _functions = {
   extism_context_new: [context, []],
   extism_context_free: ["void", [context]],
-  extism_plugin_new: ["int32", [context, "string", "uint64", "bool"]],
+  extism_plugin_new: [
+    pluginIndex,
+    [context, "string", "uint64", PtrArray, "uint64", "bool"],
+  ],
   extism_plugin_update: [
     "bool",
-    [context, "int32", "string", "uint64", "bool"],
+    [context, pluginIndex, "string", "uint64", PtrArray, "uint64", "bool"],
   ],
-  extism_error: ["char*", [context, "int32"]],
+  extism_error: ["string", [context, pluginIndex]],
   extism_plugin_call: [
     "int32",
-    [context, "int32", "string", "string", "uint64"],
+    [context, pluginIndex, "string", "string", "uint64"],
   ],
-  extism_plugin_output_length: ["uint64", [context, "int32"]],
-  extism_plugin_output_data: ["uint8*", [context, "int32"]],
+  extism_plugin_output_length: ["uint64", [context, pluginIndex]],
+  extism_plugin_output_data: ["uint8*", [context, pluginIndex]],
   extism_log_file: ["bool", ["string", "char*"]],
-  extism_plugin_function_exists: ["bool", [context, "int32", "string"]],
-  extism_plugin_config: ["void", [context, "int32", "char*", "uint64"]],
-  extism_plugin_free: ["void", [context, "int32"]],
+  extism_plugin_function_exists: ["bool", [context, pluginIndex, "string"]],
+  extism_plugin_config: ["void", [context, pluginIndex, "char*", "uint64"]],
+  extism_plugin_free: ["void", [context, pluginIndex]],
   extism_context_reset: ["void", [context]],
-  extism_version: ["char*", []],
+  extism_version: ["string", []],
+  extism_function_new: [
+    function_t,
+    [
+      "string",
+      ValTypeArray,
+      "uint64",
+      ValTypeArray,
+      "uint64",
+      "void*",
+      "void*",
+      "void*",
+    ],
+  ],
+  extism_function_free: ["void", [function_t]],
+  extism_function_set_namespace: ["void", [function_t, "string"]],
+  extism_current_plugin_memory: ["uint8*", ["void*"]],
+  extism_current_plugin_memory_alloc: ["uint64", ["void*", "uint64"]],
+  extism_current_plugin_memory_length: ["uint64", ["void*", "uint64"]],
+  extism_current_plugin_memory_free: ["void", ["void*", "uint64"]],
+  extism_plugin_cancel_handle: ["void*", [context, pluginIndex]],
+  extism_plugin_cancel: ["bool", ["void*"]],
 };
 
+/**
+ * An enumeration of all possible `Val` types
+ */
+export enum ValType {
+  I32 = 0,
+  I64,
+  F32,
+  F64,
+  V128,
+  FuncRef,
+  ExternRef,
+}
+
 interface LibExtism {
   extism_context_new: () => Buffer;
   extism_context_free: (ctx: Buffer) => void;
@@ -32,6 +102,8 @@ interface LibExtism {
     ctx: Buffer,
     data: string | Buffer,
     data_len: number,
+    functions: Buffer,
+    nfunctions: number,
     wasi: boolean
   ) => number;
   extism_plugin_update: (
@@ -39,9 +111,11 @@ interface LibExtism {
     plugin_id: number,
     data: string | Buffer,
     data_len: number,
+    functions: Buffer,
+    nfunctions: number,
     wasi: boolean
   ) => boolean;
-  extism_error: (ctx: Buffer, plugin_id: number) => Buffer;
+  extism_error: (ctx: Buffer, plugin_id: number) => string;
   extism_plugin_call: (
     ctx: Buffer,
     plugin_id: number,
@@ -50,7 +124,7 @@ interface LibExtism {
     input_len: number
   ) => number;
   extism_plugin_output_length: (ctx: Buffer, plugin_id: number) => number;
-  extism_plugin_output_data: (ctx: Buffer, plugin_id: Number) => Uint8Array;
+  extism_plugin_output_data: (ctx: Buffer, plugin_id: number) => Uint8Array;
   extism_log_file: (file: string, level: string) => boolean;
   extism_plugin_function_exists: (
     ctx: Buffer,
@@ -65,7 +139,25 @@ interface LibExtism {
   ) => void;
   extism_plugin_free: (ctx: Buffer, plugin_id: number) => void;
   extism_context_reset: (ctx: Buffer) => void;
-  extism_version: () => Buffer;
+  extism_version: () => string;
+  extism_function_new: (
+    name: string,
+    inputs: Buffer,
+    nInputs: number,
+    outputs: Buffer,
+    nOutputs: number,
+    f: Buffer,
+    user_data: Buffer | null,
+    free: Buffer | null
+  ) => Buffer;
+  extism_function_set_namespace: (f: Buffer, s: string) => void;
+  extism_function_free: (f: Buffer) => void;
+  extism_current_plugin_memory: (p: Buffer) => Buffer;
+  extism_current_plugin_memory_alloc: (p: Buffer, n: number) => number;
+  extism_current_plugin_memory_length: (p: Buffer, n: number) => number;
+  extism_current_plugin_memory_free: (p: Buffer, n: number) => void;
+  extism_plugin_cancel_handle: (p: Buffer, n: number) => Buffer;
+  extism_plugin_cancel: (p: Buffer) => boolean;
 }
 
 function locate(paths: string[]): LibExtism {
@@ -110,19 +202,19 @@ export function setLogFile(filename: string, level?: string) {
  * @returns The version string of the Extism runtime
  */
 export function extismVersion(): string {
-  return lib.extism_version().toString();
+  return lib.extism_version();
 }
 
-// @ts-ignore
-const pluginRegistry = new FinalizationRegistry(({ id, pointer }) => {
-  if (id && pointer) lib.extism_plugin_free(pointer, id);
-});
-
 // @ts-ignore
 const contextRegistry = new FinalizationRegistry((pointer) => {
   if (pointer) lib.extism_context_free(pointer);
 });
 
+// @ts-ignore
+const functionRegistry = new FinalizationRegistry((pointer) => {
+  if (pointer) lib.extism_function_free(pointer);
+});
+
 /**
  * Represents a path or url to a WASM module
  */
@@ -161,7 +253,7 @@ export type ManifestWasm = ManifestWasmFile | ManifestWasmData;
 /**
  * The manifest which describes the {@link Plugin} code and
  * runtime constraints.
- * 
+ *
  * @see [Extism > Concepts > Manifest](https://extism.org/docs/concepts/manifest)
  */
 export type Manifest = {
@@ -214,7 +306,7 @@ export class Context {
    */
   constructor() {
     this.pointer = lib.extism_context_new();
-    contextRegistry.register(this, this.pointer, this);
+    contextRegistry.register(this, this.pointer, this.pointer);
   }
 
   /**
@@ -225,19 +317,24 @@ export class Context {
    * @param config - Config details for the plugin
    * @returns A new Plugin scoped to this Context
    */
-  plugin(manifest: ManifestData, wasi: boolean = false, config?: PluginConfig) {
-    return new Plugin(this, manifest, wasi, config);
+  plugin(
+    manifest: ManifestData,
+    wasi: boolean = false,
+    functions: HostFunction[] = [],
+    config?: PluginConfig
+  ) {
+    return new Plugin(this, manifest, wasi, functions, config);
   }
 
   /**
    * Frees the context. Should be called after the context is not needed to reclaim the memory.
    */
   free() {
+    contextRegistry.unregister(this.pointer);
     if (this.pointer) {
-      contextRegistry.unregister(this);
       lib.extism_context_free(this.pointer);
+      this.pointer = null;
     }
-    this.pointer = null;
   }
 
   /**
@@ -268,12 +365,226 @@ export async function withContext(f: (ctx: Context) => Promise<any>) {
   }
 }
 
+/**
+ * Provides access to the plugin that is currently running from inside a {@link HostFunction}
+ */
+export class CurrentPlugin {
+  pointer: Buffer;
+
+  constructor(pointer: Buffer) {
+    this.pointer = pointer;
+  }
+
+  /**
+   * Access plugin's memory
+   * @param offset - The offset in memory
+   * @returns a pointer to the provided offset
+   */
+  memory(offset: number): Buffer {
+    let length = lib.extism_current_plugin_memory_length(this.pointer, offset);
+    return Buffer.from(
+      lib.extism_current_plugin_memory(this.pointer).buffer,
+      offset,
+      length
+    );
+  }
+
+  /**
+   * Allocate a new memory block
+   * @param n - The number of bytes to allocate
+   * @returns the offset to the newly allocated block
+   */
+  memoryAlloc(n: number): number {
+    return lib.extism_current_plugin_memory_alloc(this.pointer, n);
+  }
+
+  /**
+   * Free a memory block
+   * @param offset - The offset of the block to free
+   */
+  memoryFree(offset: number) {
+    return lib.extism_current_plugin_memory_free(this.pointer, offset);
+  }
+
+  /**
+   * Get the length of a memory block
+   * @param offset - The offset of the block
+   * @returns the length of the block specified by `offset`
+   */
+  memoryLength(offset: number): number {
+    return lib.extism_current_plugin_memory_length(this.pointer, offset);
+  }
+
+  /**
+   * Return a string from a host function
+   * @param output - The output to set
+   * @param s - The string to return
+   */
+  returnString(output: typeof Val, s: string) {
+    var offs = this.memoryAlloc(Buffer.byteLength(s));
+    this.memory(offs).write(s);
+    output.v.i64 = offs;
+  }
+
+  /**
+   * Return bytes from a host function
+   * @param output - The output to set
+   * @param b - The buffer to return
+   */
+  returnBytes(output: typeof Val, b: Buffer) {
+    var offs = this.memoryAlloc(b.length);
+    this.memory(offs).fill(b);
+    output.v.i64 = offs;
+  }
+
+  /**
+   * Get bytes from host function parameter
+   * @param input - The input to read
+   */
+  inputBytes(input: typeof Val): Buffer {
+    return this.memory(input.v.i64)
+  }
+
+  /**
+   * Get string from host function parameter
+   * @param input - The input to read
+   */
+  inputString(input: typeof Val): string {
+    return this.memory(input.v.i64).toString()
+  }
+}
+
+/**
+ * Allows for the host to define functions that can be called from WebAseembly
+ */
+export class HostFunction {
+  callback: any;
+  pointer: Buffer | null;
+  name: string;
+  userData: any[];
+  inputs: typeof ValTypeArray;
+  outputs: typeof ValTypeArray;
+
+  constructor(
+    name: string,
+    inputs: ValType[],
+    outputs: ValType[],
+    f: any,
+    ...userData: any
+  ) {
+    this.userData = userData;
+    this.callback = ffi.Callback(
+      "void",
+      [
+        "void*",
+        ref.refType(Val),
+        "uint64",
+        ref.refType(Val),
+        "uint64",
+        "void*",
+      ],
+      (
+        currentPlugin: Buffer,
+        inputs: Buffer,
+        nInputs: number,
+        outputs: Buffer,
+        nOutputs: number,
+        user_data
+      ) => {
+        let inputArr = [];
+        let outputArr = [];
+
+        for (var i = 0; i < nInputs; i++) {
+          inputArr.push(Val.get(inputs, i));
+        }
+
+        for (var i = 0; i < nOutputs; i++) {
+          outputArr.push(Val.get(outputs, i));
+        }
+
+        f(
+          new CurrentPlugin(currentPlugin),
+          inputArr,
+          outputArr,
+          ...this.userData
+        );
+
+        for (var i = 0; i < nOutputs; i++) {
+          Val.set(outputs, i, outputArr[i]);
+        }
+      }
+    );
+    this.name = name;
+    this.inputs = new ValTypeArray(inputs);
+    this.outputs = new ValTypeArray(outputs);
+    this.pointer = lib.extism_function_new(
+      this.name,
+      this.inputs,
+      this.inputs.length,
+      this.outputs,
+      this.outputs.length,
+      this.callback,
+      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)
+    }
+  }
+
+  withNamespace(name: string) : HostFunction {
+    this.setNamespace(name)
+    return this;
+  }
+
+  /**
+   *  Free a host function - this should be called to cleanup the associated resources
+   */
+  free() {
+    functionRegistry.unregister(this.pointer);
+    if (this.pointer === null) {
+      return;
+    }
+
+    lib.extism_function_free(this.pointer);
+    this.pointer = null;
+  }
+}
+
+/**
+  * CancelHandle is used to cancel a running Plugin
+  */
+export class CancelHandle {
+  handle: Buffer
+
+  constructor(handle: Buffer) {
+    this.handle = handle;
+  }
+
+  /**
+    * Cancel execution of the Plugin associated with the CancelHandle 
+    */
+  cancel(): boolean {
+    return lib.extism_plugin_cancel(this.handle);
+  }
+}
+
 /**
  * A Plugin represents an instance of your WASM program from the given manifest.
  */
 export class Plugin {
   id: number;
   ctx: Context;
+  functions: typeof PtrArray;
+  token: { id: number; pointer: Buffer };
 
   /**
    * Constructor for a plugin. @see {@link Context#plugin}.
@@ -281,12 +592,14 @@ export class 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
    */
   constructor(
     ctx: Context,
     manifest: ManifestData,
     wasi: boolean = false,
+    functions: HostFunction[] = [],
     config?: PluginConfig
   ) {
     let dataRaw: string | Buffer;
@@ -298,10 +611,16 @@ export class Plugin {
       throw Error(`Unknown manifest type ${typeof manifest}`);
     }
     if (!ctx.pointer) throw Error("No Context set");
+    this.functions = new PtrArray(functions.length);
+    for (var i = 0; i < functions.length; i++) {
+      this.functions[i] = functions[i].pointer;
+    }
     let plugin = lib.extism_plugin_new(
       ctx.pointer,
       dataRaw,
-      Buffer.byteLength(dataRaw, 'utf-8'),
+      Buffer.byteLength(dataRaw, "utf-8"),
+      this.functions,
+      functions.length,
       wasi
     );
     if (plugin < 0) {
@@ -312,27 +631,43 @@ export class Plugin {
       throw `Unable to load plugin: ${err.toString()}`;
     }
     this.id = plugin;
+    this.token = { id: this.id, pointer: ctx.pointer };
     this.ctx = ctx;
-    pluginRegistry.register(
-      this,
-      { id: this.id, pointer: this.ctx.pointer },
-      this
-    );
 
     if (config != null) {
       let s = JSON.stringify(config);
-      lib.extism_plugin_config(ctx.pointer, this.id, s, Buffer.byteLength(s, 'utf-8'),);
+      lib.extism_plugin_config(
+        ctx.pointer,
+        this.id,
+        s,
+        Buffer.byteLength(s, "utf-8")
+      );
     }
   }
 
+  /**
+   * Return a new `CancelHandle`, which can be used to cancel a running Plugin
+   */
+  cancelHandle(): CancelHandle {
+    if (!this.ctx.pointer) throw Error("No Context set");
+    let handle = lib.extism_plugin_cancel_handle(this.ctx.pointer, this.id);
+    return new CancelHandle(handle);
+  }
+
   /**
    * Update an existing plugin with new WASM or manifest
    *
    * @param manifest - The new {@link Manifest} data
    * @param wasi - Set to true to enable WASI support
+   * @param functions - An array of {@link HostFunction}
    * @param config - The new plugin config
    */
-  update(manifest: ManifestData, wasi: boolean = false, config?: PluginConfig) {
+  update(
+    manifest: ManifestData,
+    wasi: boolean = false,
+    functions: HostFunction[] = [],
+    config?: PluginConfig
+  ) {
     let dataRaw: string | Buffer;
     if (Buffer.isBuffer(manifest) || typeof manifest === "string") {
       dataRaw = manifest;
@@ -342,11 +677,17 @@ export class Plugin {
       throw Error("Unknown manifest type type");
     }
     if (!this.ctx.pointer) throw Error("No Context set");
+    this.functions = new PtrArray(functions.length);
+    for (var i = 0; i < functions.length; i++) {
+      this.functions[i] = functions[i].pointer;
+    }
     const ok = lib.extism_plugin_update(
       this.ctx.pointer,
       this.id,
       dataRaw,
-      Buffer.byteLength(dataRaw, 'utf-8'),
+      Buffer.byteLength(dataRaw, "utf-8"),
+      this.functions,
+      functions.length,
       wasi
     );
     if (!ok) {
@@ -359,7 +700,12 @@ export class Plugin {
 
     if (config != null) {
       let s = JSON.stringify(config);
-      lib.extism_plugin_config(this.ctx.pointer, this.id, s, Buffer.byteLength(s, 'utf-8'),);
+      lib.extism_plugin_config(
+        this.ctx.pointer,
+        this.id,
+        s,
+        Buffer.byteLength(s, "utf-8")
+      );
     }
   }
 
@@ -393,7 +739,7 @@ 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) => {
@@ -403,7 +749,7 @@ 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);
@@ -427,8 +773,7 @@ export class Plugin {
    * Free a plugin, this should be called when the plugin is no longer needed
    */
   free() {
-    if (this.ctx.pointer && this.id !== -1) {
-      pluginRegistry.unregister(this);
+    if (this.ctx.pointer && this.id >= 0) {
       lib.extism_plugin_free(this.ctx.pointer, this.id);
       this.id = -1;
     }

node/tests/index.test.ts

@@ -2,14 +2,23 @@ import * as extism from "../src/index";
 import { readFileSync } from "fs";
 import { join } from "path";
 
-function manifest(): extism.Manifest {
+function manifest(functions: boolean = false): extism.Manifest {
   return {
-    wasm: [{ path: join(__dirname, "/code.wasm") }],
+    wasm: [
+      {
+        path: join(
+          __dirname,
+          functions
+            ? "/../../wasm/code-functions.wasm"
+            : "/../../wasm/code.wasm"
+        ),
+      },
+    ],
   };
 }
 
 function wasmBuffer(): Buffer {
-  return readFileSync(join(__dirname, "/code.wasm"));
+  return readFileSync(join(__dirname, "/../../wasm/code.wasm"));
 }
 
 describe("test extism", () => {
@@ -102,4 +111,27 @@ describe("test extism", () => {
       ).rejects.toMatch(/Plugin error/);
     });
   });
+
+  test("host functions work", async () => {
+    await extism.withContext(async (ctx: extism.Context) => {
+      const plugin = ctx.plugin(manifest(true), true, [
+        new extism.HostFunction(
+          "hello_world",
+          [extism.ValType.I64],
+          [extism.ValType.I64],
+          (plugin: any, params: any, results: any, user_data: string) => {
+            const offs = plugin.memoryAlloc(user_data.length);
+            const mem = plugin.memory(offs);
+            mem.write(user_data);
+            results[0].v.i64 = offs;
+          },
+          "test"
+        ),
+      ]);
+
+      const res = await plugin.call("count_vowels", "aaa");
+
+      expect(res.toString()).toBe("test");
+    });
+  });
 });

ocaml/Makefile

@@ -0,0 +1,15 @@
+VERSION?=0.2.0
+
+build:
+	dune build
+
+test:
+	dune test
+format:
+	dune build @fmt --auto-promote
+
+prepare:
+	opam install .. --deps-only
+
+publish:
+	opam publish -v $(VERSION) -t $(VERSION) ..

ocaml/bin/main.ml

@@ -7,7 +7,7 @@ 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.make ctx file ~wasi:true |> Result.get_ok in
+  let plugin = Plugin.create ctx 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/bindings.ml

@@ -27,7 +27,16 @@ let locate () =
     init paths
   |> function
   | Some x -> x
-  | None -> raise Not_found
+  | None -> (
+      let fail n =
+        Printf.fprintf stderr
+          "Unable to find Extism installation, see \
+           https://extism.org/docs/install/ for installation instructions\n";
+        exit n
+      in
+      match Sys.getenv_opt "EXTISM_TEST_NO_LIB" with
+      | None -> fail 1
+      | Some _ -> fail 0)
 
 let from =
   let filename = locate () in
@@ -40,13 +49,62 @@ let context = ptr void
 let extism_context_new = fn "extism_context_new" (void @-> returning context)
 let extism_context_free = fn "extism_context_free" (context @-> returning void)
 
+module Extism_val_type = struct
+  type t = I32 | I64 | F32 | F64 | V128 | FuncRef | ExternRef
+
+  let to_int = function
+    | I32 -> 0
+    | I64 -> 1
+    | F32 -> 2
+    | F64 -> 3
+    | V128 -> 4
+    | FuncRef -> 5
+    | ExternRef -> 6
+
+  let of_int = function
+    | 0 -> I32
+    | 1 -> I64
+    | 2 -> F32
+    | 3 -> F64
+    | 4 -> V128
+    | 5 -> FuncRef
+    | 6 -> ExternRef
+    | n -> invalid_arg ("Extism_val_type.of_int: " ^ string_of_int n)
+
+  let t : t typ = view ~read:of_int ~write:to_int int
+end
+
+module Extism_val_union = struct
+  type t
+
+  let t : t union typ = union "ExtismValUnion"
+  let i32 = field t "i32" int32_t
+  let i64 = field t "i64" int64_t
+  let f32 = field t "f32" float
+  let f64 = field t "f64" double
+  let () = seal t
+end
+
+module Extism_val = struct
+  type t
+
+  let t : t structure typ = structure "ExtismVal"
+  let ty = field t "t" Extism_val_type.t
+  let v = field t "v" Extism_val_union.t
+  let () = seal t
+end
+
 let extism_plugin_new =
   fn "extism_plugin_new"
-    (context @-> string @-> uint64_t @-> bool @-> returning int32_t)
+    (context @-> string @-> uint64_t
+    @-> ptr (ptr void)
+    @-> uint64_t @-> bool @-> returning int32_t)
 
 let extism_plugin_update =
   fn "extism_plugin_update"
-    (context @-> int32_t @-> string @-> uint64_t @-> bool @-> returning bool)
+    (context @-> int32_t @-> string @-> uint64_t
+    @-> ptr (ptr void)
+    @-> uint64_t @-> bool @-> returning bool)
 
 let extism_plugin_config =
   fn "extism_plugin_config"
@@ -84,3 +142,44 @@ let extism_context_reset = fn "extism_context_reset" (context @-> returning void
 let extism_plugin_function_exists =
   fn "extism_plugin_function_exists"
     (context @-> int32_t @-> string @-> returning bool)
+
+let extism_function_type =
+  Foreign.funptr ~runtime_lock:true
+    (ptr void @-> ptr Extism_val.t @-> uint64_t @-> ptr Extism_val.t
+   @-> uint64_t @-> ptr void @-> returning void)
+
+let extism_free_user_data =
+  Foreign.funptr_opt ~runtime_lock:true (ptr void @-> returning void)
+
+let extism_function_new =
+  fn "extism_function_new"
+    (string @-> ptr Extism_val_type.t @-> uint64_t @-> ptr Extism_val_type.t
+   @-> uint64_t @-> extism_function_type @-> ptr void @-> extism_free_user_data
+    @-> returning (ptr void))
+
+let extism_function_set_namespace =
+  fn "extism_function_set_namespace" (ptr void @-> string @-> returning void)
+
+let extism_function_free =
+  fn "extism_function_free" (ptr void @-> returning void)
+
+let extism_current_plugin_memory =
+  fn "extism_current_plugin_memory" (ptr void @-> returning (ptr uint8_t))
+
+let extism_current_plugin_memory_length =
+  fn "extism_current_plugin_memory_length"
+    (ptr void @-> uint64_t @-> returning uint64_t)
+
+let extism_current_plugin_memory_alloc =
+  fn "extism_current_plugin_memory_alloc"
+    (ptr void @-> uint64_t @-> returning uint64_t)
+
+let extism_current_plugin_memory_free =
+  fn "extism_current_plugin_memory_free"
+    (ptr void @-> uint64_t @-> returning void)
+
+let extism_plugin_cancel_handle =
+  fn "extism_plugin_cancel_handle" (context @-> int32_t @-> returning (ptr void))
+
+let extism_plugin_cancel =
+  fn "extism_plugin_cancel" (ptr void @-> returning bool)

ocaml/lib/current_plugin.ml

@@ -0,0 +1,84 @@
+open Ctypes
+
+type t = unit ptr
+type memory_block = { offs : Unsigned.UInt64.t; len : Unsigned.UInt64.t }
+
+let memory ?(offs = Unsigned.UInt64.zero) t =
+  Bindings.extism_current_plugin_memory t +@ Unsigned.UInt64.to_int offs
+
+let find t offs =
+  let len = Bindings.extism_current_plugin_memory_length t offs in
+  if Unsigned.UInt64.(equal zero len) then None else Some { offs; len }
+
+let alloc t len =
+  let len = Unsigned.UInt64.of_int len in
+  let offs = Bindings.extism_current_plugin_memory_alloc t len in
+  { offs; len }
+
+let free t { offs; _ } = Bindings.extism_current_plugin_memory_free t offs
+
+module Memory_block = struct
+  let of_val t v =
+    match Types.Val.to_i64 v with
+    | None -> None
+    | Some v ->
+        let offs = Unsigned.UInt64.of_int64 v in
+        find t offs
+
+  let of_val_exn t v =
+    match of_val t v with
+    | None -> invalid_arg "Memory_block.of_val_exn"
+    | Some v -> v
+
+  let to_val { offs; len = _ } =
+    Types.Val.of_i64 (Unsigned.UInt64.to_int64 offs)
+
+  let get_bigstring t { offs; len } : Bigstringaf.t =
+    let p = memory t ~offs in
+    bigarray_of_ptr array1
+      (Unsigned.UInt64.to_int len)
+      Bigarray.Char
+      (coerce (ptr uint8_t) (ptr char) p)
+
+  let get_string t { offs; len } =
+    let p = memory t ~offs in
+    Ctypes.string_from_ptr
+      (coerce (ptr uint8_t) (ptr char) p)
+      ~length:(Unsigned.UInt64.to_int len)
+
+  let set_bigstring t { offs; len } bs =
+    let length = min (Unsigned.UInt64.to_int @@ len) (Bigstringaf.length bs) in
+    let p = coerce (ptr uint8_t) (ptr char) @@ memory t ~offs in
+    for i = 0 to length - 1 do
+      p +@ i <-@ Bigstringaf.unsafe_get bs i
+    done
+
+  let set_string t { offs; len } s =
+    let length = min (Unsigned.UInt64.to_int @@ len) (String.length s) in
+    let p = coerce (ptr uint8_t) (ptr char) @@ memory t ~offs in
+    for i = 0 to length - 1 do
+      p +@ i <-@ String.unsafe_get s i
+    done
+end
+
+let return_string t (outputs : Types.Val_array.t) index s =
+  let mem = alloc t (String.length s) in
+  Memory_block.set_string t mem s;
+  Types.Val_array.(
+    outputs.$[index] <- Types.Val.of_i64 (Unsigned.UInt64.to_int64 mem.offs))
+
+let return_bigstring t (outputs : Types.Val_array.t) index s =
+  let mem = alloc t (Bigstringaf.length s) in
+  Memory_block.set_bigstring t mem s;
+  Types.Val_array.(
+    outputs.$[index] <- Types.Val.of_i64 (Unsigned.UInt64.to_int64 mem.offs))
+
+let input_string t inputs index =
+  let inp = Types.Val_array.(inputs.$[index]) in
+  let mem = Memory_block.of_val_exn t inp in
+  Memory_block.get_string t mem
+
+let input_bigstring t inputs index =
+  let inp = Types.Val_array.(inputs.$[index]) in
+  let mem = Memory_block.of_val_exn t inp in
+  Memory_block.get_bigstring t mem

ocaml/lib/dune

@@ -2,7 +2,7 @@
  (name extism)
  (public_name extism)
  (inline_tests
-  (deps test/code.wasm))
+  (deps test/code.wasm test/code-functions.wasm))
  (libraries ctypes.foreign bigstringaf extism-manifest)
  (preprocess
   (pps ppx_yojson_conv ppx_inline_test)))

ocaml/lib/error.ml

@@ -8,3 +8,4 @@ let () =
     | _ -> None)
 
 let unwrap = function Ok x -> x | Error t -> raise (Error t)
+let throw e = raise (Error e)

ocaml/lib/extism.ml

@@ -2,6 +2,9 @@ module Manifest = Extism_manifest
 module Error = Error
 module Context = Context
 module Plugin = Plugin
+module Function = Function
+module Current_plugin = Current_plugin
+include Types
 
 let with_context = Plugin.with_context
 let extism_version = Bindings.extism_version

ocaml/lib/extism.mli

@@ -1,36 +1,201 @@
 (** Extism bindings for OCaml *)
 
-
-(** Returns the libextism version, not the version of the OCaml library *)
 val extism_version : unit -> string
+(** Returns the libextism version, not the version of the OCaml library *)
 
 module Manifest = Extism_manifest
 
 module Error : sig
-  type t = [`Msg of string]
+  type t = [ `Msg of string ]
 
   exception Error of t
-  val unwrap: ('a, t) result -> 'a
+
+  val unwrap : ('a, t) result -> 'a
+  val throw : t -> 'a
+end
+
+(** [Val_type] enumerates every possible argument/result type *)
+module Val_type : sig
+  type t =
+    | I32
+    | I64
+    | F32
+    | F64
+    | V128
+    | FuncRef
+    | ExternRef  (** Value type *)
+
+  val of_int : int -> t
+  val to_int : t -> int
+end
+
+(** [Val] represents low-level WebAssembly values *)
+module Val : sig
+  type t
+  (** Val *)
+
+  val ty : t -> Val_type.t
+  (** [ty v] returns the [Val_type.t] for the value [v] *)
+
+  val of_i32 : int32 -> t
+  (** Create an i32 [Val] *)
+
+  val of_i64 : int64 -> t
+  (** Create an i64 [Val] *)
+
+  val of_f32 : float -> t
+  (** Create an f32 [Val] *)
+
+  val of_f64 : float -> t
+  (** Create an f64 [Val] *)
+
+  val to_i32 : t -> int32 option
+  (** Get an int32 from [Val] if the type matches *)
+
+  val to_i64 : t -> int64 option
+  (** Get an int64 from [Val] if the type matches *)
+
+  val to_f32 : t -> float option
+  (** Get a f32 from [Val] if the type matches *)
+
+  val to_f64 : t -> float option
+  (** Get an f64 from [Val] if the type matches *)
+
+  val to_i32_exn : t -> int32
+  (** Same as [to_i32] but raises an exception if the types don't match*)
+
+  val to_i64_exn : t -> int64
+  (** Same as [to_i64] but raises an exception if the types don't match*)
+
+  val to_f32_exn : t -> float
+  (** Same as [to_f32] but raises an exception if the types don't match*)
+
+  val to_f64_exn : t -> float
+  (** Same as [to_f64] but raises an exception if the types don't match*)
+end
+
+(** [Val_array] is used for input/output parameters for host functions *)
+module Val_array : sig
+  type t = Val.t Ctypes.CArray.t
+  (** [Val_array] type *)
+
+  val get : t -> int -> Val.t
+  (** Get an index *)
+
+  val set : t -> int -> Val.t -> unit
+  (** Set an index *)
+
+  val length : t -> int
+  (** Get the number of items in a [Val_array]*)
+
+  val ( .$[] ) : t -> int -> Val.t
+  (** Syntax for [get] *)
+
+  val ( .$[]<- ) : t -> int -> Val.t -> unit
+  (** Syntax for [set] *)
+end
+
+(** [Current_plugin] represents the plugin that is currently running, it should
+    it should only be used from a host function *)
+module Current_plugin : sig
+  type t
+  (** Opaque type, wraps [ExtismCurrentPlugin] *)
+
+  type memory_block = { offs : Unsigned.UInt64.t; len : Unsigned.UInt64.t }
+  (** Represents a block of guest memory *)
+
+  val memory : ?offs:Unsigned.UInt64.t -> t -> Unsigned.uint8 Ctypes.ptr
+  (** Get pointer to entire plugin memory *)
+
+  val find : t -> Unsigned.UInt64.t -> memory_block option
+  (** Find memory block *)
+
+  val alloc : t -> int -> memory_block
+  (** Allocate a new block of memory *)
+
+  val free : t -> memory_block -> unit
+  (** Free an allocated block of memory *)
+
+  val return_string : t -> Val_array.t -> int -> string -> unit
+  val return_bigstring : t -> Val_array.t -> int -> Bigstringaf.t -> unit
+  val input_string : t -> Val_array.t -> int -> string
+  val input_bigstring : t -> Val_array.t -> int -> Bigstringaf.t
+
+  (** Some helpter functions for reading/writing memory *)
+  module Memory_block : sig
+    val to_val : memory_block -> Val.t
+    (** Convert memory block to [Val] *)
+
+    val of_val : t -> Val.t -> memory_block option
+    (** Convert [Val] to memory block *)
+
+    val of_val_exn : t -> Val.t -> memory_block
+    (** Convert [Val] to memory block, raises [Invalid_argument] if the value is not a pointer
+        to a valid memory block *)
+
+    val get_string : t -> memory_block -> string
+    (** Get a string from memory stored at the provided offset *)
+
+    val get_bigstring : t -> memory_block -> Bigstringaf.t
+    (** Get a bigstring from memory stored at the provided offset *)
+
+    val set_string : t -> memory_block -> string -> unit
+    (** Store a string into memory at the provided offset *)
+
+    val set_bigstring : t -> memory_block -> Bigstringaf.t -> unit
+    (** Store a bigstring into memory at the provided offset *)
+  end
+end
+
+(** [Function] is used to create new a new function, which can be called 
+    from a WebAssembly plugin *)
+module Function : sig
+  type t
+  (** Function type *)
+
+  val create :
+    string ->
+    ?namespace:string ->
+    params:Val_type.t list ->
+    results:Val_type.t list ->
+    user_data:'a ->
+    (Current_plugin.t -> Val_array.t -> Val_array.t -> 'a -> unit) ->
+    t
+  (** Create a new function, [Function.v name ~params ~results ~user_data f] creates
+      a new [Function] with the given [name], [params] specifies the argument types,
+      [results] specifies the return types, [user_data] is used to pass arbitrary
+      OCaml values into the function and [f] is the OCaml function that will be
+      called.
+  *)
+
+  val with_namespace : t -> string -> t
+  (** Update a function's namespace *)
+
+  val free : t -> unit
+  (** Free a function *)
+
+  val free_all : t list -> unit
+  (** Free a list of functions *)
 end
 
 (** [Context] is used to group plugins *)
 module Context : sig
-  (** Context type *)
   type t
+  (** Context type *)
 
-  (** Create a new context *)
   val create : unit -> t
+  (** Create a new context *)
 
+  val free : t -> unit
   (** Free a context. All plugins will be removed and the value should not be 
       accessed after this call *)
-  val free : t -> unit
 
-  (** Reset a context. All plugins will be removed *)
   val reset : t -> unit
+  (** Reset a context. All plugins will be removed *)
 end
 
-(** Execute a function with a fresh context and free it after *)
 val with_context : (Context.t -> 'a) -> 'a
+(** Execute a function with a fresh context and free it after *)
 
 val set_log_file :
   ?level:[ `Error | `Warn | `Info | `Debug | `Trace ] -> string -> bool
@@ -39,40 +204,53 @@ val set_log_file :
 module Plugin : sig
   type t
 
-  (** Make a new plugin from raw WebAssembly or JSON encoded manifest *)
-  val make :
+  val create :
     ?config:Manifest.config ->
     ?wasi:bool ->
+    ?functions:Function.t list ->
     Context.t ->
     string ->
     (t, Error.t) result
+  (** Make a new plugin from raw WebAssembly or JSON encoded manifest *)
 
-  (** Make a new plugin from a [Manifest] *)
   val of_manifest :
-    ?wasi:bool -> Context.t -> Manifest.t -> (t, Error.t) result
+    ?wasi:bool ->
+    ?functions:Function.t list ->
+    Context.t ->
+    Manifest.t ->
+    (t, Error.t) result
+  (** Make a new plugin from a [Manifest] *)
 
-  (** Update a plugin from raw WebAssembly or JSON encoded manifest *)
   val update :
     t ->
     ?config:(string * string option) list ->
     ?wasi:bool ->
+    ?functions:Function.t list ->
     string ->
     (unit, [ `Msg of string ]) result
+  (** Update a plugin from raw WebAssembly or JSON encoded manifest *)
 
+  val update_manifest : t -> ?wasi:bool -> Manifest.t -> (unit, Error.t) result
   (** Update a plugin from a [Manifest] *)
-  val update_manifest :
-    t -> ?wasi:bool -> Manifest.t -> (unit, Error.t) result
 
-  (** Call a function, uses [Bigstringaf.t] for input/output *)
   val call_bigstring :
     t -> name:string -> Bigstringaf.t -> (Bigstringaf.t, Error.t) result
+  (** Call a function, uses [Bigstringaf.t] for input/output *)
 
-  (** Call a function, uses [string] for input/output *)
   val call : t -> name:string -> string -> (string, Error.t) result
+  (** Call a function, uses [string] for input/output *)
 
-  (** Drop a plugin *)
   val free : t -> unit
+  (** Drop a plugin *)
 
-  (** Check if a function is exported by a plugin *)
   val function_exists : t -> string -> bool
+  (** Check if a function is exported by a plugin *)
+
+  module Cancel_handle: sig
+    type t
+
+    val cancel: t -> bool
+  end
+
+  val cancel_handle: t -> Cancel_handle.t
 end

ocaml/lib/function.ml

@@ -0,0 +1,47 @@
+open Ctypes
+
+type t = {
+  mutable pointer : unit ptr;
+  mutable user_data : unit ptr;
+  name : string;
+}
+
+let free t =
+  let () =
+    if not (is_null t.user_data) then
+      let () = Root.release t.user_data in
+      t.user_data <- null
+  in
+  if not (is_null t.pointer) then
+    let () = Bindings.extism_function_free t.pointer in
+    t.pointer <- null
+
+let free_all l = List.iter free l
+
+let create name ?namespace ~params ~results ~user_data f =
+  let inputs = CArray.of_list Bindings.Extism_val_type.t params in
+  let n_inputs = Unsigned.UInt64.of_int (CArray.length inputs) in
+  let outputs = CArray.of_list Bindings.Extism_val_type.t results in
+  let n_outputs = Unsigned.UInt64.of_int (CArray.length outputs) in
+  let free' = Some Root.release in
+  let user_data = Root.create user_data in
+  let f current inputs n_inputs outputs n_outputs user_data =
+    let user_data = Root.get user_data in
+    let inputs = CArray.from_ptr inputs (Unsigned.UInt64.to_int n_inputs) in
+    let outputs = CArray.from_ptr outputs (Unsigned.UInt64.to_int n_outputs) in
+    f current inputs outputs user_data
+  in
+  let pointer =
+    Bindings.extism_function_new name (CArray.start inputs) n_inputs
+      (CArray.start outputs) n_outputs f user_data free'
+  in
+  let () =
+    Option.iter (Bindings.extism_function_set_namespace pointer) namespace
+  in
+  let t = { pointer; user_data; name } in
+  Gc.finalise free t;
+  t
+
+let with_namespace f ns =
+  Bindings.extism_function_set_namespace f.pointer ns;
+  f

ocaml/lib/plugin.ml

@@ -1,6 +1,6 @@
 module Manifest = Extism_manifest
 
-type t = { id : int32; ctx : Context.t }
+type t = { id : int32; ctx : Context.t; mutable functions : Function.t list }
 
 let with_context f =
   let ctx = Context.create () in
@@ -26,10 +26,15 @@ let free t =
   if not (Ctypes.is_null t.ctx.pointer) then
     Bindings.extism_plugin_free t.ctx.pointer t.id
 
-let make ?config ?(wasi = false) ctx wasm =
+let create ?config ?(wasi = false) ?(functions = []) ctx wasm =
+  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
   let id =
     Bindings.extism_plugin_new ctx.Context.pointer wasm
       (Unsigned.UInt64.of_int (String.length wasm))
+      (Ctypes.CArray.start arr)
+      (Unsigned.UInt64.of_int n_funcs)
       wasi
   in
   if id < 0l then
@@ -37,28 +42,33 @@ let make ?config ?(wasi = false) ctx wasm =
     | None -> Error (`Msg "extism_plugin_call failed")
     | Some msg -> Error (`Msg msg)
   else
-    let t = { id; ctx } in
+    let t = { id; ctx; functions } in
     if not (set_config t config) then Error (`Msg "call to set_config failed")
     else
       let () = Gc.finalise free t in
       Ok t
 
-let of_manifest ?wasi ctx manifest =
-  let data = Manifest.json manifest in
-  make ctx ?wasi data
+let of_manifest ?wasi ?functions ctx manifest =
+  let data = Manifest.to_json manifest in
+  create ctx ?wasi ?functions data
 
 let%test "free plugin" =
-  let manifest = Manifest.v [ Manifest.file "test/code.wasm" ] in
+  let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
   with_context (fun ctx ->
-      let plugin = of_manifest ctx manifest |> Result.get_ok in
+      let plugin = of_manifest ctx manifest |> Error.unwrap in
       free plugin;
       true)
 
-let update plugin ?config ?(wasi = false) wasm =
-  let { id; ctx } = plugin in
+let update plugin ?config ?(wasi = false) ?(functions = []) wasm =
+  let { id; ctx; _ } = plugin 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
   let ok =
     Bindings.extism_plugin_update ctx.pointer id wasm
       (Unsigned.UInt64.of_int (String.length wasm))
+      (Ctypes.CArray.start arr)
+      (Unsigned.UInt64.of_int n_funcs)
       wasi
   in
   if not ok then
@@ -70,18 +80,18 @@ let update plugin ?config ?(wasi = false) wasm =
   else Ok ()
 
 let update_manifest plugin ?wasi manifest =
-  let data = Manifest.json manifest in
+  let data = Manifest.to_json manifest in
   update plugin ?wasi data
 
 let%test "update plugin manifest and config" =
-  let manifest = Manifest.v [ Manifest.file "test/code.wasm" ] in
+  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 |> Result.get_ok 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 call' f { id; ctx } ~name input len =
+let call' f { id; ctx; _ } ~name input len =
   let rc = f ctx.pointer id name input len in
   if rc <> 0l then
     match Bindings.extism_error ctx.pointer id with
@@ -103,12 +113,12 @@ let call_bigstring (t : t) ~name input =
   call' Bindings.extism_plugin_call t ~name ptr len
 
 let%test "call_bigstring" =
-  let manifest = Manifest.v [ Manifest.file "test/code.wasm" ] in
+  let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
   with_context (fun ctx ->
-      let plugin = of_manifest ctx manifest |> Result.get_ok in
+      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")
-      |> Result.get_ok |> Bigstringaf.to_string = "{\"count\": 4}")
+      |> Error.unwrap |> Bigstringaf.to_string = "{\"count\": 4}")
 
 let call (t : t) ~name input =
   let len = String.length input in
@@ -116,18 +126,49 @@ let call (t : t) ~name input =
   |> Result.map Bigstringaf.to_string
 
 let%test "call" =
-  let manifest = Manifest.v [ Manifest.file "test/code.wasm" ] in
+  let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
   with_context (fun ctx ->
-      let plugin = of_manifest ctx manifest |> Result.get_ok in
+      let plugin = of_manifest ctx manifest |> Error.unwrap in
       call plugin ~name:"count_vowels" "this is a test"
-      |> Result.get_ok = "{\"count\": 4}")
+      |> Error.unwrap = "{\"count\": 4}")
 
-let function_exists { id; ctx } name =
+let%test "call_functions" =
+  let open Types.Val_type in
+  let hello_world =
+    Function.create "hello_world" ~params:[ I64 ] ~results:[ I64 ]
+      ~user_data:"Hello again!"
+    @@ fun plugin params results user_data ->
+    let open Types.Val_array in
+    let s = Current_plugin.input_string plugin params 0 in
+    let () = print_endline "Hello from OCaml!" in
+    let () = print_endline user_data in
+    let () = print_endline s in
+    results.$[0] <- params.$[0]
+  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 function_exists { id; ctx; _ } name =
   Bindings.extism_plugin_function_exists ctx.pointer id name
 
 let%test "function exists" =
-  let manifest = Manifest.v [ Manifest.file "test/code.wasm" ] in
+  let manifest = Manifest.(create [ Wasm.file "test/code.wasm" ]) in
   with_context (fun ctx ->
-      let plugin = of_manifest ctx manifest |> Result.get_ok in
+      let plugin = of_manifest ctx 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 }
+
+  let cancel { inner } = Bindings.extism_plugin_cancel inner
+end
+
+let cancel_handle { id; ctx; _ } =
+  Cancel_handle.{ inner = Bindings.extism_plugin_cancel_handle ctx.pointer id }

ocaml/lib/types.ml

@@ -0,0 +1,92 @@
+open Ctypes
+module Val_type = Bindings.Extism_val_type
+
+module Val = struct
+  type t = (Bindings.Extism_val.t, [ `Struct ]) Ctypes.structured
+
+  let t = Bindings.Extism_val.t
+
+  let of_i32 (x : int32) : t =
+    let u = Ctypes.make Bindings.Extism_val_union.t in
+    u @. Bindings.Extism_val_union.i32 <-@ x;
+    let t = Ctypes.make Bindings.Extism_val.t in
+    t @. Bindings.Extism_val.ty <-@ Val_type.I32;
+    t @. Bindings.Extism_val.v <-@ u;
+    t
+
+  let of_i64 (x : int64) : t =
+    let u = Ctypes.make Bindings.Extism_val_union.t in
+    u @. Bindings.Extism_val_union.i64 <-@ x;
+    let t = Ctypes.make Bindings.Extism_val.t in
+    t @. Bindings.Extism_val.ty <-@ Val_type.I64;
+    t @. Bindings.Extism_val.v <-@ u;
+    t
+
+  let of_f32 (x : float) : t =
+    let u = Ctypes.make Bindings.Extism_val_union.t in
+    u @. Bindings.Extism_val_union.f32 <-@ x;
+    let t = Ctypes.make Bindings.Extism_val.t in
+    t @. Bindings.Extism_val.ty <-@ Val_type.F32;
+    t @. Bindings.Extism_val.v <-@ u;
+    t
+
+  let of_f64 (x : float) : t =
+    let u = Ctypes.make Bindings.Extism_val_union.t in
+    u @. Bindings.Extism_val_union.f64 <-@ x;
+    let t = Ctypes.make Bindings.Extism_val.t in
+    t @. Bindings.Extism_val.ty <-@ Val_type.F64;
+    t @. Bindings.Extism_val.v <-@ u;
+    t
+
+  let to_i32 t : int32 option =
+    let ty = t @. Bindings.Extism_val.ty in
+    let v = t @. Bindings.Extism_val.v in
+    match !@ty with
+    | Bindings.Extism_val_type.I32 ->
+        Some !@(!@v @. Bindings.Extism_val_union.i32)
+    | _ -> None
+
+  let to_i64 t : int64 option =
+    let ty = t @. Bindings.Extism_val.ty in
+    let v = t @. Bindings.Extism_val.v in
+    match !@ty with
+    | Bindings.Extism_val_type.I64 ->
+        Some !@(!@v @. Bindings.Extism_val_union.i64)
+    | _ -> None
+
+  let to_f32 t : float option =
+    let ty = t @. Bindings.Extism_val.ty in
+    let v = t @. Bindings.Extism_val.v in
+    match !@ty with
+    | Bindings.Extism_val_type.F32 ->
+        Some !@(!@v @. Bindings.Extism_val_union.f32)
+    | _ -> None
+
+  let to_f64 t : float option =
+    let ty = t @. Bindings.Extism_val.ty in
+    let v = t @. Bindings.Extism_val.v in
+    match !@ty with
+    | Bindings.Extism_val_type.F64 ->
+        Some !@(!@v @. Bindings.Extism_val_union.f64)
+    | _ -> None
+
+  let ty t = !@(t @. Bindings.Extism_val.ty)
+
+  let make_exn f x =
+    match f x with Some x -> x | None -> Error.throw (`Msg "invalid type")
+
+  let to_i32_exn = make_exn to_i32
+  let to_i64_exn = make_exn to_i64
+  let to_f32_exn = make_exn to_f32
+  let to_f64_exn = make_exn to_f64
+end
+
+module Val_array = struct
+  type t = Val.t Ctypes.CArray.t
+
+  let get t i = Ctypes.CArray.get t i
+  let set t i x = Ctypes.CArray.set t i x
+  let length t = Ctypes.CArray.length t
+  let ( .$[] ) = get
+  let ( .$[]<- ) = set
+end

ocaml/manifest/dune

@@ -1,6 +1,7 @@
 (library
  (name extism_manifest)
  (public_name extism-manifest)
+ (inline_tests)
  (libraries base64)
  (preprocess
-  (pps ppx_yojson_conv)))
+  (pps ppx_yojson_conv ppx_inline_test)))

ocaml/manifest/extism_manifest.ml

@@ -1,22 +1,9 @@
-type memory = { max_pages : int option [@yojson.option] } [@@deriving yojson]
-
-type wasm_file = {
-  path : string;
-  name : string option; [@yojson.option]
-  hash : string option; [@yojson.option]
-}
-[@@deriving yojson]
-
 type base64 = string
 
 let yojson_of_base64 x = `String (Base64.encode_exn x)
 let base64_of_yojson j = Yojson.Safe.Util.to_string j
 
-type wasm_data = {
-  data : base64;
-  name : string option; [@yojson.option]
-  hash : string option; [@yojson.option]
-}
+type memory_options = { max_pages : int option [@yojson.option] }
 [@@deriving yojson]
 
 type dict = (string * string) list
@@ -43,30 +30,51 @@ let yojson_of_config c =
        (fun (k, v) -> (k, match v with None -> `Null | Some v -> `String v))
        c)
 
-type wasm_url = {
-  url : string;
-  headers : dict option; [@yojson.option]
-  name : string option; [@yojson.option]
-  meth : string option; [@yojson.option] [@key "method"]
-  hash : string option; [@yojson.option]
-}
-[@@deriving yojson]
+module Wasm = struct
+  type file = {
+    path : string;
+    name : string option; [@yojson.option]
+    hash : string option; [@yojson.option]
+  }
+  [@@deriving yojson]
 
-type wasm = File of wasm_file | Data of wasm_data | Url of wasm_url
+  type data = {
+    data : base64;
+    name : string option; [@yojson.option]
+    hash : string option; [@yojson.option]
+  }
+  [@@deriving yojson]
 
-let yojson_of_wasm = function
-  | File f -> yojson_of_wasm_file f
-  | Data d -> yojson_of_wasm_data d
-  | Url u -> yojson_of_wasm_url u
+  type url = {
+    url : string;
+    headers : dict option; [@yojson.option]
+    name : string option; [@yojson.option]
+    meth : string option; [@yojson.option] [@key "method"]
+    hash : string option; [@yojson.option]
+  }
+  [@@deriving yojson]
 
-let wasm_of_yojson x =
-  try File (wasm_file_of_yojson x)
-  with _ -> (
-    try Data (wasm_data_of_yojson x) with _ -> Url (wasm_url_of_yojson x))
+  type t = File of file | Data of data | Url of url
+
+  let yojson_of_t = function
+    | File f -> yojson_of_file f
+    | Data d -> yojson_of_data d
+    | Url u -> yojson_of_url u
+
+  let t_of_yojson x =
+    try File (file_of_yojson x)
+    with _ -> ( try Data (data_of_yojson x) with _ -> Url (url_of_yojson x))
+
+  let file ?name ?hash path = File { path; name; hash }
+  let data ?name ?hash data = Data { data; name; hash }
+
+  let url ?headers ?name ?meth ?hash url =
+    Url { headers; name; meth; hash; url }
+end
 
 type t = {
-  wasm : wasm list;
-  memory : memory option; [@yojson.option]
+  wasm : Wasm.t list;
+  memory : memory_options option; [@yojson.option]
   config : config option; [@yojson.option]
   allowed_hosts : string list option; [@yojson.option]
   allowed_paths : dict option; [@yojson.option]
@@ -74,12 +82,30 @@ type t = {
 }
 [@@deriving yojson]
 
-let file ?name ?hash path = File { path; name; hash }
-let data ?name ?hash data = Data { data; name; hash }
-let url ?headers ?name ?meth ?hash url = Url { headers; name; meth; hash; url }
-
-let v ?config ?memory ?allowed_hosts ?allowed_paths ?timeout_ms wasm =
+let create ?config ?memory ?allowed_hosts ?allowed_paths ?timeout_ms wasm =
   { config; wasm; memory; allowed_hosts; allowed_paths; timeout_ms }
 
-let json t = yojson_of_t t |> Yojson.Safe.to_string
+let to_json t = yojson_of_t t |> Yojson.Safe.to_string
+
+let of_json s =
+  let j = Yojson.Safe.from_string s in
+  t_of_yojson j
+
+let of_file filename =
+  let j = Yojson.Safe.from_file filename in
+  t_of_yojson j
+
 let with_config t config = { t with config = Some config }
+
+let%test "rountrip" =
+  let config = [ ("a", Some "b"); ("b", Some "c") ] in
+  let memory = { max_pages = Some 5 } in
+  let t =
+    create ~config ~memory ~allowed_hosts:[ "example.com" ]
+      ~allowed_paths:[ ("a", "b") ]
+      ~timeout_ms:1000 []
+  in
+  let a = to_json t in
+  let b = of_json a in
+  let c = to_json b in
+  String.equal a c

ocaml/manifest/extism_manifest.mli

@@ -1,75 +1,87 @@
+type memory_options = { max_pages : int option } [@@deriving yojson]
 (** Memory options *)
-type memory = { max_pages : int option } [@@deriving yojson]
 
-(** Key/value dictionary *)
 type dict = (string * string) list [@@deriving yojson]
+(** Key/value dictionary *)
 
-(** Key/value dictionary with optional values *)
 type config = (string * string option) list [@@deriving yojson]
+(** Key/value dictionary with optional values *)
 
-(** WebAssembly file *)
-type wasm_file = {
-  path : string;
-  name : string option; [@yojson.option]
-  hash : string option; [@yojson.option]
-} [@@deriving yojson]
+module Wasm : sig
+  type file = {
+    path : string;
+    name : string option; [@yojson.option]
+    hash : string option; [@yojson.option]
+  }
+  [@@deriving yojson]
+  (** WebAssembly file *)
 
-(** WebAssembly module data *)
-type wasm_data = {
-  data : string;
-  name : string option; [@yojson.option]
-  hash : string option; [@yojson.option]
-} [@@deriving yojson]
+  type data = {
+    data : string;
+    name : string option; [@yojson.option]
+    hash : string option; [@yojson.option]
+  }
+  [@@deriving yojson]
+  (** WebAssembly module data *)
 
-(** WebAssembly URL *)
-type wasm_url = {
-  url : string;
-  headers : dict option; [@yojson.option]
-  name : string option; [@yojson.option]
-  meth : string option; [@yojson.option] [@key "method"]
-  hash : string option; [@yojson.option]
-} [@@deriving yojson]
+  type url = {
+    url : string;
+    headers : dict option; [@yojson.option]
+    name : string option; [@yojson.option]
+    meth : string option; [@yojson.option] [@key "method"]
+    hash : string option; [@yojson.option]
+  }
+  [@@deriving yojson]
+  (** WebAssembly URL *)
 
-(** WebAssembly from a file, module data or URL *)
-type wasm = File of wasm_file | Data of wasm_data | Url of wasm_url [@@deriving yojson]
+  (** WebAssembly from a file, module data or URL *)
+  type t = File of file | Data of data | Url of url [@@deriving yojson]
+
+  val file : ?name:string -> ?hash:string -> string -> t
+  (** Create [wasm] from filename *)
+
+  val data : ?name:string -> ?hash:string -> string -> t
+  (** Create [wasm] from WebAssembly module data *)
+
+  val url :
+    ?headers:(string * string) list ->
+    ?name:string ->
+    ?meth:string ->
+    ?hash:string ->
+    string ->
+    t
+  (** Create [wasm] from URL *)
+end
 
-(** Manifest type *)
 type t = {
-  wasm : wasm list;
-  memory : memory option;
+  wasm : Wasm.t list;
+  memory : memory_options option;
   config : config option;
   allowed_hosts : string list option;
   allowed_paths : dict option;
   timeout_ms : int option;
-} [@@deriving yojson]
+}
+[@@deriving yojson]
+(** Manifest type *)
 
-(** Create [wasm] from filename *)
-val file : ?name:string -> ?hash:string -> string -> wasm
-
-(** Create [wasm] from WebAssembly module data *)
-val data : ?name:string -> ?hash:string -> string -> wasm
-
-(** Create [wasm] from URL *)
-val url :
-  ?headers:(string * string) list ->
-  ?name:string ->
-  ?meth:string ->
-  ?hash:string ->
-  string ->
-  wasm
-
-(** Create new manifest *)
-val v :
+val create :
   ?config:config ->
-  ?memory:memory ->
+  ?memory:memory_options ->
   ?allowed_hosts:string list ->
   ?allowed_paths:dict ->
   ?timeout_ms:int ->
-  wasm list ->
+  Wasm.t list ->
   t
+(** Create new manifest *)
 
+val to_json : t -> string
 (** Convert manifest to JSON *)
-val json : t -> string
 
-(** Updates a manifest config *)
+val of_json : string -> t
+(** Read manifest from JSON string *)
+
+val of_file : string -> t
+(** Read manifest from JSON file *)
+
 val with_config : t -> config -> t
+(** Updates a manifest config *)

php/example/code.wasm

@@ -0,0 +1 @@
+../../wasm/code.wasm

php/example/index.php

@@ -3,16 +3,16 @@
 require_once __DIR__ . '/vendor/autoload.php';
 
 $ctx = new \Extism\Context();
-$wasm = file_get_contents("../../wasm/code.wasm");
+$wasm = file_get_contents("code.wasm");
 $plugin = new \Extism\Plugin($ctx, $wasm);
 
 $output = $plugin->call("count_vowels", "this is an example");
 $json = json_decode(pack('C*', ...$output));
 echo "Vowels counted = " . $json->{'count'} . PHP_EOL;
 
-$wasm = file_get_contents("../../wasm/code.wasm");
+$wasm = file_get_contents("code.wasm");
 $ok = $plugin->update($wasm);
 if ($ok) {
     $id = $plugin->getId();
     echo "updated plugin: $id";
-}
+}

php/src/Plugin.php

@@ -4,6 +4,23 @@ namespace Extism;
 
 require_once "ExtismLib.php";
 
+class CancelHandle
+{
+    private $lib;
+    private $handle;
+
+    function __construct($lib, $handle)
+    {
+        $this->lib = $lib;
+        $this->handle = $handle;
+    }
+
+    public function cancel()
+    {
+        return $this->lib->extism_plugin_cancel($this->handle);
+    }
+}
+
 class Plugin
 {
     private $lib;
@@ -29,7 +46,7 @@ class Plugin
             $data = string_to_bytes($data);
         }
 
-        $id = $this->lib->extism_plugin_new($ctx->pointer, $data, count($data), (int)$wasi);
+        $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);
@@ -58,6 +75,11 @@ class Plugin
         return $this->lib->extism_plugin_function_exists($this->context->pointer, $this->id, $name);
     }
 
+    public function cancelHandle()
+    {
+        return new \CancelHandle($this->lib, $this->lib->extism_plugin_cancel_handle($this->context->pointer, $this->id));
+    }
+
     public function call($name, $input = null)
     {        
         if (gettype($input) == "string") {
@@ -96,7 +118,7 @@ class Plugin
             $data = string_to_bytes($data);
         }
 
-        $ok = $this->lib->extism_plugin_update($this->context->pointer, $this->id, $data, count($data), (int)$wasi);
+        $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);