feat(ext/ffi): add support for buffer arguments (#12335)

This commit adds support for passing buffer arguments across 
FFI boundary.


Co-authored-by: eliassjogreen <eliassjogreen1@gmail.com>
Co-authored-by: Bert Belder <bertbelder@gmail.com>

1 files changed, 34 insertions, 7 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,
+            });
+          }
+        };
       }
     }