feat: add default cache config (#615)

Co-authored-by: zach <zach@dylibso.com>

.github/workflows/release-elixir.yaml

@@ -10,13 +10,6 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
-      - name: Install extism shared library
-        shell: bash
-        run: |
-          mkdir -p /home/runner/.local/bin/  
-          export PATH="/home/runner/.local/bin/:$PATH"
-          curl https://raw.githubusercontent.com/extism/cli/main/install.sh | sh
-          extism --sudo --prefix /usr/local install
       - name: Setup Elixir Host SDK
         uses: erlef/setup-beam@v1
         with:

.github/workflows/release-rust.yaml

@@ -20,6 +20,7 @@ jobs:
           target: ${{ matrix.target }}
 
       - name: Release Rust Manifest Crate
+        if: always()
         env:
           CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_API_TOKEN }}
         run: |
@@ -29,6 +30,7 @@ jobs:
           sleep 5 
 
       - name: Release Rust Host SDK
+        if: always()
         env:
           CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_API_TOKEN }}
         run: |

elixir/mix.exs

@@ -4,7 +4,7 @@ defmodule Extism.MixProject do
   def project do
     [
       app: :extism,
-      version: "0.5.0",
+      version: "0.5.1",
       elixir: "~> 1.12",
       start_permanent: Mix.env() == :prod,
       deps: deps(),

elixir/native/extism_nif/Cargo.toml

@@ -13,6 +13,6 @@ crate-type = ["cdylib"]
 [workspace]
 
 [dependencies]
-rustler = "0.28.0"
-extism = "0.5.0"
+rustler = "0.29.1"
+extism = "0.5.2"
 log = "0.4"

kernel/src/lib.rs

@@ -17,13 +17,13 @@
 //! ## Input/Output
 //!
 //! Input and output are just allocated blocks of memory that are marked as either input or output using
-//! the `extism_input_set` or `extism_output_set` functions. The global variables `INPUT_OFFSET` contains
-//! the offset in memory to the input data and `INPUT_LENGTH` contains the size of the input data. `OUTPUT_OFFSET`
-//! and `OUTPUT_LENGTH` are used for the output data.
+//! the `extism_input_set` or `extism_output_set` functions. The MemoryRoot field `input_offset` contains
+//! the offset in memory to the input data and `input_length` contains the size of the input data. `output_offset`
+//! and `output_length` are used for the output data.
 //!
 //! ## Error handling
 //!
-//! The `ERROR` global is used to track the current error message. If it is set to `0` then there is no error.
+//! The `error` field is used to track the current error message. If it is set to `0` then there is no error.
 //! The length of the error message can be retreived using `extism_length`.
 //!
 //! ## Memory offsets
@@ -45,31 +45,6 @@ pub type Length = u64;
 /// WebAssembly page size
 const PAGE_SIZE: usize = 65536;
 
-/// Determines the amount of bytes that can be wasted by re-using a block. If more than this number is wasted by re-using
-/// a block then it will be split into two smaller blocks.
-const BLOCK_SPLIT_SIZE: usize = 128;
-
-/// Offset to the input data
-static mut INPUT_OFFSET: Pointer = 0;
-
-/// Length of the input data
-static mut INPUT_LENGTH: Length = 0;
-
-/// Offset to the output data
-static mut OUTPUT_OFFSET: Pointer = 0;
-
-/// Offset to the input data
-static mut OUTPUT_LENGTH: Length = 0;
-
-/// Current error message
-static mut ERROR: AtomicU64 = AtomicU64::new(0);
-
-/// Determines if the kernel has been initialized already
-static mut INITIALIZED: AtomicBool = AtomicBool::new(false);
-
-/// A pointer to the first page that will be managed by Extism, this is set during initialization
-static mut START_PAGE: usize = 0;
-
 /// Provides information about the usage status of a `MemoryBlock`
 #[repr(u8)]
 #[derive(PartialEq)]
@@ -87,19 +62,34 @@ pub enum MemoryStatus {
 ///
 /// The overall layout of the Extism-manged memory is organized like this:
 
-/// |------|-------|---------|-------|--------------|
-/// | Root | Block |  Data   | Block |     Data     | ...
-/// |------|-------|---------|-------|--------------|
+/// |------|-------+---------|-------+--------------|
+/// | Root | Block +  Data   | Block +     Data     | ...
+/// |------|-------+---------|-------+--------------|
 ///
 /// Where `Root` and `Block` are fixed to the size of the `MemoryRoot` and `MemoryBlock` structs. But
 /// the size of `Data` is dependent on the allocation size.
+///
+/// This means that the offset of a `Block` is the size of `Root` plus the size of all existing `Blocks`
+/// including their data.
 #[repr(C)]
 pub struct MemoryRoot {
-    /// Position of the bump allocator, relative to `START_PAGE`
+    /// Set to true after initialization
+    pub initialized: AtomicBool,
+    /// Position of the bump allocator, relative to `blocks` field
     pub position: AtomicU64,
     /// The total size of all data allocated using this allocator
     pub length: AtomicU64,
-    /// A pointer to where the blocks begin
+    /// Offset of error block
+    pub error: AtomicU64,
+    /// Input position in memory
+    pub input_offset: Pointer,
+    /// Input length
+    pub input_length: Length,
+    /// Output position in memory
+    pub output_offset: Pointer,
+    /// Output length
+    pub output_length: Length,
+    /// A pointer to the start of the first block
     pub blocks: [MemoryBlock; 0],
 }
 
@@ -119,37 +109,50 @@ pub struct MemoryBlock {
 
 /// Returns the number of pages needed for the given number of bytes
 pub fn num_pages(nbytes: u64) -> usize {
-    let nbytes = nbytes as f64;
-    let page = PAGE_SIZE as f64;
-    ((nbytes / page) + 0.5) as usize
+    let npages = nbytes / PAGE_SIZE as u64;
+    let remainder = nbytes % PAGE_SIZE as u64;
+    if remainder != 0 {
+        (npages + 1) as usize
+    } else {
+        npages as usize
+    }
 }
 
-// Get the `MemoryRoot` at the correct offset in memory
+// Get the `MemoryRoot`, this is always stored at offset 1 in memory
 #[inline]
 unsafe fn memory_root() -> &'static mut MemoryRoot {
-    &mut *((START_PAGE * PAGE_SIZE) as *mut MemoryRoot)
+    &mut *(1 as *mut MemoryRoot)
 }
 
 impl MemoryRoot {
     /// Initialize or load the `MemoryRoot` from the correct position in memory
     pub unsafe fn new() -> &'static mut MemoryRoot {
+        let root = memory_root();
+
         // If this fails then `INITIALIZED` is already `true` and we can just return the
         // already initialized `MemoryRoot`
-        if INITIALIZED
+        if root
+            .initialized
             .compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed)
             .is_err()
         {
-            return memory_root();
+            return root;
         }
 
         // Ensure that at least one page is allocated to store the `MemoryRoot` data
-        START_PAGE = core::arch::wasm32::memory_grow(0, 1);
-        if START_PAGE == usize::MAX {
-            panic!("Out of memory");
+        if core::arch::wasm32::memory_size(0) == 0 {
+            if core::arch::wasm32::memory_grow(0, 1) == usize::MAX {
+                core::arch::wasm32::unreachable()
+            }
         }
 
+        root.input_offset = 0;
+        root.input_length = 0;
+        root.output_offset = 0;
+        root.output_length = 0;
+        root.error.store(0, Ordering::Release);
+
         // Initialize the `MemoryRoot` length, position and data
-        let root = memory_root();
         root.length.store(
             PAGE_SIZE as u64 - core::mem::size_of::<MemoryRoot>() as u64,
             Ordering::Release,
@@ -174,6 +177,27 @@ impl MemoryRoot {
             self.length.load(Ordering::Acquire) as usize,
         );
         self.position.store(0, Ordering::Release);
+        self.error.store(0, Ordering::Release);
+        self.input_offset = 0;
+        self.input_length = 0;
+        self.output_offset = 0;
+        self.output_length = 0;
+    }
+
+    #[inline(always)]
+    #[allow(unused)]
+    fn pointer_in_bounds(&self, p: Pointer) -> bool {
+        let start_ptr = self.blocks.as_ptr() as Pointer;
+        p >= start_ptr && p < start_ptr + self.length.load(Ordering::Acquire) as Pointer
+    }
+
+    #[inline(always)]
+    #[allow(unused)]
+    fn pointer_in_bounds_fast(p: Pointer) -> bool {
+        // Similar to `pointer_in_bounds` but less accurate on the upper bound. This uses the total memory size,
+        // instead of checking `MemoryRoot::length`
+        let end = core::arch::wasm32::memory_size(0) << 16;
+        p >= core::mem::size_of::<Self>() as Pointer && p <= end as Pointer
     }
 
     // Find a block that is free to use, this can be a new block or an existing freed block. The `self_position` argument
@@ -190,6 +214,7 @@ impl MemoryRoot {
         while (block as u64) < self.blocks.as_ptr() as u64 + self_position {
             let b = &mut *block;
 
+            // Get the block status, this lets us know if we are able to re-use it
             let status = b.status.load(Ordering::Acquire);
 
             // An unused block is safe to use
@@ -200,7 +225,7 @@ impl MemoryRoot {
             // Re-use freed blocks when they're large enough
             if status == MemoryStatus::Free as u8 && b.size >= length as usize {
                 // Split block if there is too much excess
-                if b.size - length as usize >= BLOCK_SPLIT_SIZE {
+                if b.size - length as usize >= 128 {
                     b.size -= length as usize;
                     b.used = 0;
 
@@ -242,13 +267,13 @@ impl MemoryRoot {
         let curr = self.blocks.as_ptr() as u64 + self_position;
 
         // Get the number of bytes available
-        let mem_left = self_length - self_position;
+        let mem_left = self_length - self_position - core::mem::size_of::<MemoryRoot>() as u64;
 
         // When the allocation is larger than the number of bytes available
         // we will need to try to grow the memory
         if length >= mem_left {
             // Calculate the number of pages needed to cover the remaining bytes
-            let npages = num_pages(length);
+            let npages = num_pages(length - mem_left);
             let x = core::arch::wasm32::memory_grow(0, npages);
             if x == usize::MAX {
                 return None;
@@ -276,8 +301,7 @@ impl MemoryRoot {
 
     /// Finds the block at an offset in memory
     pub unsafe fn find_block(&mut self, offs: Pointer) -> Option<&mut MemoryBlock> {
-        if offs >= self.blocks.as_ptr() as Pointer + self.length.load(Ordering::Acquire) as Pointer
-        {
+        if !Self::pointer_in_bounds_fast(offs) {
             return None;
         }
         let ptr = offs - core::mem::size_of::<MemoryBlock>() as u64;
@@ -293,9 +317,7 @@ impl MemoryBlock {
     /// is calculated based on metadata provided by the current block
     #[inline]
     pub unsafe fn next_ptr(&mut self) -> *mut MemoryBlock {
-        self.data
-            .as_mut_ptr()
-            .add(self.size + core::mem::size_of::<MemoryBlock>()) as *mut MemoryBlock
+        self.data.as_mut_ptr().add(self.size) as *mut MemoryBlock
     }
 
     /// Mark a block as free
@@ -305,11 +327,14 @@ impl MemoryBlock {
     }
 }
 
-// Extism functions - these functions should be
+// Extism functions
 
 /// Allocate a block of memory and return the offset
 #[no_mangle]
 pub unsafe fn extism_alloc(n: Length) -> Pointer {
+    if n == 0 {
+        return 0;
+    }
     let region = MemoryRoot::new();
     let block = region.alloc(n);
     match block {
@@ -321,9 +346,19 @@ pub unsafe fn extism_alloc(n: Length) -> Pointer {
 /// Free allocated memory
 #[no_mangle]
 pub unsafe fn extism_free(p: Pointer) {
-    let block = MemoryRoot::new().find_block(p);
+    if p == 0 {
+        return;
+    }
+    let root = MemoryRoot::new();
+    let block = root.find_block(p);
     if let Some(block) = block {
         block.free();
+
+        // If the input pointer is freed for some reason, make sure the input length to 0
+        // since the original data is gone
+        if p == root.input_offset {
+            root.input_length = 0;
+        }
     }
 }
 
@@ -343,100 +378,144 @@ pub unsafe fn extism_length(p: Pointer) -> Length {
 /// Load a byte from Extism-managed memory
 #[no_mangle]
 pub unsafe fn extism_load_u8(p: Pointer) -> u8 {
+    #[cfg(feature = "bounds-checking")]
+    if !MemoryRoot::pointer_in_bounds_fast(p) {
+        return 0;
+    }
     *(p as *mut u8)
 }
 
 /// Load a u64 from Extism-managed memory
 #[no_mangle]
 pub unsafe fn extism_load_u64(p: Pointer) -> u64 {
+    #[cfg(feature = "bounds-checking")]
+    if !MemoryRoot::pointer_in_bounds_fast(p + core::mem::size_of::<u64>() as u64 - 1) {
+        return 0;
+    }
     *(p as *mut u64)
 }
 
 /// Load a byte from the input data
 #[no_mangle]
 pub unsafe fn extism_input_load_u8(p: Pointer) -> u8 {
-    *((INPUT_OFFSET + p) as *mut u8)
+    let root = MemoryRoot::new();
+    #[cfg(feature = "bounds-checking")]
+    if p >= root.input_length {
+        return 0;
+    }
+    *((root.input_offset + p) as *mut u8)
 }
 
 /// Load a u64 from the input data
 #[no_mangle]
 pub unsafe fn extism_input_load_u64(p: Pointer) -> u64 {
-    *((INPUT_OFFSET + p) as *mut u64)
+    let root = MemoryRoot::new();
+    #[cfg(feature = "bounds-checking")]
+    if p + core::mem::size_of::<u64>() as Pointer > root.input_length {
+        return 0;
+    }
+    *((root.input_offset + p) as *mut u64)
 }
 
 /// Write a byte in Extism-managed memory
 #[no_mangle]
 pub unsafe fn extism_store_u8(p: Pointer, x: u8) {
+    #[cfg(feature = "bounds-checking")]
+    if !MemoryRoot::pointer_in_bounds_fast(p) {
+        return;
+    }
     *(p as *mut u8) = x;
 }
 
 /// Write a u64 in Extism-managed memory
 #[no_mangle]
 pub unsafe fn extism_store_u64(p: Pointer, x: u64) {
-    unsafe {
-        *(p as *mut u64) = x;
+    #[cfg(feature = "bounds-checking")]
+    if !MemoryRoot::pointer_in_bounds_fast(p + core::mem::size_of::<u64>() as u64 - 1) {
+        return;
     }
+    *(p as *mut u64) = x;
 }
 
 /// Set the range of the input data in memory
 #[no_mangle]
-pub fn extism_input_set(p: Pointer, len: Length) {
-    unsafe {
-        INPUT_OFFSET = p;
-        INPUT_LENGTH = len;
+pub unsafe fn extism_input_set(p: Pointer, len: Length) {
+    let root = MemoryRoot::new();
+    #[cfg(feature = "bounds-checking")]
+    {
+        if !root.pointer_in_bounds(p) || !root.pointer_in_bounds(p + len - 1) {
+            return;
+        }
     }
+    root.input_offset = p;
+    root.input_length = len;
 }
 
 /// Set the range of the output data in memory
 #[no_mangle]
-pub fn extism_output_set(p: Pointer, len: Length) {
-    unsafe {
-        OUTPUT_OFFSET = p;
-        OUTPUT_LENGTH = len;
+pub unsafe fn extism_output_set(p: Pointer, len: Length) {
+    let root = MemoryRoot::new();
+    #[cfg(feature = "bounds-checking")]
+    {
+        if !root.pointer_in_bounds(p) || !root.pointer_in_bounds(p + len - 1) {
+            return;
+        }
     }
+    root.output_offset = p;
+    root.output_length = len;
 }
 
 /// Get the input length
 #[no_mangle]
 pub fn extism_input_length() -> Length {
-    unsafe { INPUT_LENGTH }
+    unsafe { MemoryRoot::new().input_length }
 }
 
 /// Get the input offset in Exitsm-managed memory
 #[no_mangle]
 pub fn extism_input_offset() -> Length {
-    unsafe { INPUT_OFFSET }
+    unsafe { MemoryRoot::new().input_offset }
 }
 
 /// Get the output length
 #[no_mangle]
-pub fn extism_output_length() -> Length {
-    unsafe { OUTPUT_LENGTH }
+pub unsafe fn extism_output_length() -> Length {
+    unsafe { MemoryRoot::new().output_length }
 }
 
 /// Get the output offset in Extism-managed memory
 #[no_mangle]
-pub fn extism_output_offset() -> Length {
-    unsafe { OUTPUT_OFFSET }
+pub unsafe fn extism_output_offset() -> Length {
+    MemoryRoot::new().output_offset
 }
 
 /// Reset the allocator
 #[no_mangle]
 pub unsafe fn extism_reset() {
-    ERROR.store(0, Ordering::SeqCst);
     MemoryRoot::new().reset()
 }
 
 /// Set the error message offset
 #[no_mangle]
 pub unsafe fn extism_error_set(ptr: Pointer) {
-    ERROR.store(ptr, Ordering::SeqCst);
+    let root = MemoryRoot::new();
+
+    // Allow ERROR to be set to 0
+    if ptr == 0 {
+        root.error.store(ptr, Ordering::SeqCst);
+        return;
+    }
+
+    if !root.pointer_in_bounds(ptr) {
+        return;
+    }
+    root.error.store(ptr, Ordering::SeqCst);
 }
 
 /// Get the error message offset, if it's `0` then no error has been set
 #[no_mangle]
 pub unsafe fn extism_error_get() -> Pointer {
-    ERROR.load(Ordering::SeqCst)
+    MemoryRoot::new().error.load(Ordering::SeqCst)
 }
 
 /// Get the position of the allocator, this can be used as an indication of how many bytes are currently in-use

libextism/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libextism"
-version = "0.5.0"
+version = "0.5.4"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"

runtime/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "extism-runtime"
-version = "0.5.0"
+version = "0.5.5"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"

runtime/extism.h

@@ -81,7 +81,12 @@ typedef struct {
 /**
  * Host function signature
  */
-typedef void (*ExtismFunctionType)(ExtismCurrentPlugin *plugin, const ExtismVal *inputs, ExtismSize n_inputs, ExtismVal *outputs, ExtismSize n_outputs, void *data);
+typedef void (*ExtismFunctionType)(ExtismCurrentPlugin *plugin,
+                                   const ExtismVal *inputs,
+                                   ExtismSize n_inputs,
+                                   ExtismVal *outputs,
+                                   ExtismSize n_outputs,
+                                   void *data);
 
 typedef int32_t ExtismPlugin;
 

runtime/src/internal.rs

@@ -104,6 +104,9 @@ pub trait InternalExt {
     }
 
     fn memory_alloc(&mut self, n: Size) -> Result<u64, Error> {
+        if n == 0 {
+            return Ok(0);
+        }
         let (linker, mut store) = self.linker_and_store();
         let output = &mut [Val::I64(0)];
         linker
@@ -113,7 +116,7 @@ pub trait InternalExt {
             .unwrap()
             .call(&mut store, &[Val::I64(n as i64)], output)?;
         let offs = output[0].unwrap_i64() as u64;
-        if offs == 0 {
+        if offs == 0 && n > 0 {
             anyhow::bail!("out of memory")
         }
         trace!("memory_alloc: {}, {}", offs, n);

runtime/src/pdk.rs

@@ -200,6 +200,7 @@ pub(crate) fn http_request(
                 Some(res.into_reader())
             }
             Err(e) => {
+                log::error!("Unable to make HTTP request: {:?}", e);
                 if let Some(res) = e.into_response() {
                     data.http_status = res.status();
                     Some(res.into_reader())

runtime/src/plugin.rs

@@ -132,7 +132,8 @@ impl Plugin {
             Config::new()
                 .epoch_interruption(true)
                 .debug_info(std::env::var("EXTISM_DEBUG").is_ok())
-                .profiler(profiling_strategy()),
+                .profiler(profiling_strategy())
+                .cache_config_load_default()?,
         )?;
         let mut imports = imports.into_iter();
         let (manifest, modules) = Manifest::new(&engine, wasm.as_ref())?;
@@ -334,23 +335,25 @@ impl Plugin {
             internal.linker = linker;
         }
 
-        let bytes = unsafe { std::slice::from_raw_parts(input, len) };
-        trace!("Input size: {}", bytes.len());
+        if len > 0 {
+            let bytes = unsafe { std::slice::from_raw_parts(input, len) };
+            trace!("Input size: {}", bytes.len());
 
-        if let Some(f) = self.linker.get(&mut self.store, "env", "extism_reset") {
-            f.into_func().unwrap().call(&mut self.store, &[], &mut [])?;
-        } else {
-            error!("Call to extism_reset failed");
-        }
+            if let Some(f) = self.linker.get(&mut self.store, "env", "extism_reset") {
+                f.into_func().unwrap().call(&mut self.store, &[], &mut [])?;
+            } else {
+                error!("Call to extism_reset failed");
+            }
 
-        let offs = self.memory_alloc_bytes(bytes)?;
+            let offs = self.memory_alloc_bytes(bytes)?;
 
-        if let Some(f) = self.linker.get(&mut self.store, "env", "extism_input_set") {
-            f.into_func().unwrap().call(
-                &mut self.store,
-                &[Val::I64(offs as i64), Val::I64(len as i64)],
-                &mut [],
-            )?;
+            if let Some(f) = self.linker.get(&mut self.store, "env", "extism_input_set") {
+                f.into_func().unwrap().call(
+                    &mut self.store,
+                    &[Val::I64(offs as i64), Val::I64(len as i64)],
+                    &mut [],
+                )?;
+            }
         }
 
         Ok(())

rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "extism"
-version = "0.5.0"
+version = "0.5.5"
 edition = "2021"
 authors = ["The Extism Authors", "oss@extism.org"]
 license = "BSD-3-Clause"
@@ -10,7 +10,7 @@ description = "Extism Host SDK for Rust"
 
 [dependencies]
 extism-manifest = { version = "0.5.0", path = "../manifest" }
-extism-runtime = { version = "0.5.0", path = "../runtime"}
+extism-runtime = { version = "0.5.5", path = "../runtime"}
 serde_json = "1"
 log = "0.4"
 anyhow = "1"

rust/src/lib.rs

@@ -45,6 +45,7 @@ mod tests {
     const WASM: &[u8] = include_bytes!("../../wasm/code-functions.wasm");
     const WASM_LOOP: &[u8] = include_bytes!("../../wasm/loop.wasm");
     const WASM_GLOBALS: &[u8] = include_bytes!("../../wasm/globals.wasm");
+    const REFLECT_WASM: &[u8] = include_bytes!("../../wasm/reflect.wasm");
 
     fn hello_world(
         plugin: &mut CurrentPlugin,
@@ -53,8 +54,8 @@ mod tests {
         _user_data: UserData,
     ) -> Result<(), Error> {
         let input_offs = inputs[0].unwrap_i64() as u64;
-        let input = plugin.memory_read_str(input_offs).unwrap().to_string();
-
+        let length = plugin.memory_length(input_offs);
+        let input = plugin.memory_read(input_offs, length).to_vec();
         let output = plugin.memory_alloc_bytes(&input).unwrap();
         outputs[0] = Val::I64(output as i64);
         Ok(())
@@ -282,7 +283,7 @@ mod tests {
         });
 
         let start = std::time::Instant::now();
-        let _output = plugin.call("infinite_loop", "abc123");
+        let _output = plugin.call("infinite_loop", "");
         let end = std::time::Instant::now();
         let time = end - start;
         println!("Cancelled plugin ran for {:?}", time);
@@ -319,4 +320,26 @@ mod tests {
             assert_eq!(count.get("count").unwrap().as_i64().unwrap(), i);
         }
     }
+
+    #[test]
+    fn test_fuzz_reflect_plugin() {
+        // assert!(set_log_file("stdout", Some(log::Level::Trace)));
+        let f = Function::new(
+            "host_reflect",
+            [ValType::I64],
+            [ValType::I64],
+            None,
+            hello_world,
+        );
+
+        let context = Context::new();
+        let mut plugin = Plugin::new(&context, REFLECT_WASM, [f], true).unwrap();
+
+        for i in 1..65540 {
+            let input = "a".repeat(i);
+            let output = plugin.call("reflect", input.clone());
+            let output = std::str::from_utf8(output.unwrap()).unwrap();
+            assert_eq!(output, input);
+        }
+    }
 }