2 files changed, 60 insertions, 9 deletions

diff --git a/ext/ffi/00_ffi.js b/ext/ffi/00_ffi.js
index c7fdd0e8c..25eba0233 100644
--- a/ext/ffi/00_ffi.js
+++ b/ext/ffi/00_ffi.js
@@ -4,7 +4,9 @@
 ((window) => {
   const core = window.Deno.core;
   const __bootstrap = window.__bootstrap;
-
+  const {
+    ArrayBuffer,
+  } = window.__bootstrap.primordials;
   class DynamicLibrary {
     #rid;
     symbols = {};
@@ -13,15 +15,40 @@
       this.#rid = core.opSync("op_ffi_load", { path, symbols });
 
       for (const symbol in symbols) {
-        this.symbols[symbol] = symbols[symbol].nonblocking
-          ? (...parameters) =>
-            core.opAsync("op_ffi_call_nonblocking", {
+        const isNonBlocking = symbols[symbol].nonblocking;
+
+        this.symbols[symbol] = (...args) => {
+          const parameters = [];
+          const buffers = [];
+
+          for (const arg of args) {
+            if (
+              arg?.buffer instanceof ArrayBuffer &&
+              arg.byteLength !== undefined
+            ) {
+              parameters.push(buffers.length);
+              buffers.push(arg);
+            } else {
+              parameters.push(arg);
+            }
+          }
+
+          if (isNonBlocking) {
+            return core.opAsync("op_ffi_call_nonblocking", {
+              rid: this.#rid,
+              symbol,
+              parameters,
+              buffers,
+            });
+          } else {
+            return core.opSync("op_ffi_call", {
               rid: this.#rid,
               symbol,
               parameters,
-            })
-          : (...parameters) =>
-            core.opSync("op_ffi_call", { rid: this.#rid, symbol, parameters });
+              buffers,
+            });
+          }
+        };
       }
     }
 
diff --git a/ext/ffi/lib.rs b/ext/ffi/lib.rs
index e1acd097a..ebf5572a7 100644
--- a/ext/ffi/lib.rs
+++ b/ext/ffi/lib.rs
@@ -11,6 +11,7 @@ use deno_core::Extension;
 use deno_core::OpState;
 use deno_core::Resource;
 use deno_core::ResourceId;
+use deno_core::ZeroCopyBuf;
 use dlopen::raw::Library;
 use libffi::middle::Arg;
 use serde::Deserialize;
@@ -131,6 +132,7 @@ enum NativeType {
   ISize,
   F32,
   F64,
+  Buffer,
 }
 
 impl From<NativeType> for libffi::middle::Type {
@@ -149,6 +151,7 @@ impl From<NativeType> for libffi::middle::Type {
       NativeType::ISize => libffi::middle::Type::isize(),
       NativeType::F32 => libffi::middle::Type::f32(),
       NativeType::F64 => libffi::middle::Type::f64(),
+      NativeType::Buffer => libffi::middle::Type::pointer(),
     }
   }
 }
@@ -168,6 +171,7 @@ union NativeValue {
   isize_value: isize,
   f32_value: f32,
   f64_value: f64,
+  buffer: *const u8,
 }
 
 impl NativeValue {
@@ -210,9 +214,14 @@ impl NativeValue {
       NativeType::F64 => Self {
         f64_value: value_as_f64(value),
       },
+      NativeType::Buffer => unreachable!(),
     }
   }
 
+  fn buffer(ptr: *const u8) -> Self {
+    Self { buffer: ptr }
+  }
+
   unsafe fn as_arg(&self, native_type: NativeType) -> Arg {
     match native_type {
       NativeType::Void => Arg::new(&self.void_value),
@@ -228,6 +237,7 @@ impl NativeValue {
       NativeType::ISize => Arg::new(&self.isize_value),
       NativeType::F32 => Arg::new(&self.f32_value),
       NativeType::F64 => Arg::new(&self.f64_value),
+      NativeType::Buffer => Arg::new(&self.buffer),
     }
   }
 }
@@ -257,6 +267,7 @@ fn value_as_f64(value: Value) -> f64 {
 }
 
 #[derive(Deserialize, Debug)]
+#[serde(rename_all = "camelCase")]
 struct ForeignFunction {
   parameters: Vec<NativeType>,
   result: NativeType,
@@ -293,20 +304,32 @@ where
   Ok(state.resource_table.add(resource))
 }
 
-#[derive(Deserialize, Debug)]
+#[derive(Deserialize)]
 #[serde(rename_all = "camelCase")]
 struct FfiCallArgs {
   rid: ResourceId,
   symbol: String,
   parameters: Vec<Value>,
+  buffers: Vec<ZeroCopyBuf>,
 }
 
 fn ffi_call(args: FfiCallArgs, symbol: &Symbol) -> Result<Value, AnyError> {
+  let buffers: Vec<&[u8]> =
+    args.buffers.iter().map(|buffer| &buffer[..]).collect();
+
   let native_values = symbol
     .parameter_types
     .iter()
     .zip(args.parameters.into_iter())
-    .map(|(&native_type, value)| NativeValue::new(native_type, value))
+    .map(|(&native_type, value)| {
+      if let NativeType::Buffer = native_type {
+        let idx: usize = value_as_uint(value);
+        let ptr = buffers[idx].as_ptr();
+        NativeValue::buffer(ptr)
+      } else {
+        NativeValue::new(native_type, value)
+      }
+    })
     .collect::<Vec<_>>();
 
   let call_args = symbol
@@ -358,6 +381,7 @@ fn ffi_call(args: FfiCallArgs, symbol: &Symbol) -> Result<Value, AnyError> {
     NativeType::F64 => {
       json!(unsafe { symbol.cif.call::<f64>(symbol.ptr, &call_args) })
     }
+    NativeType::Buffer => unreachable!(),
   })
 }