fix(napi): fallback to copy arraybuffer if zero copy is not allowed (#1455)

crates/napi/src/bindgen_runtime/js_values/arraybuffer.rs

@@ -316,7 +316,7 @@ macro_rules! impl_typed_array {
               sys::napi_create_arraybuffer(env, length, ptr::null_mut(), &mut arraybuffer_value)
             }
           } else {
-            unsafe {
+            let status = unsafe {
               sys::napi_create_external_arraybuffer(
                 env,
                 val_data as *mut c_void,
@@ -325,6 +325,22 @@ macro_rules! impl_typed_array {
                 hint_ptr as *mut c_void,
                 &mut arraybuffer_value,
               )
+            };
+            if status == napi_sys::Status::napi_no_external_buffers_allowed {
+              let hint = unsafe { Box::from_raw(hint_ptr) };
+              let mut underlying_data = ptr::null_mut();
+              let status = unsafe {
+                sys::napi_create_arraybuffer(
+                  env,
+                  length,
+                  &mut underlying_data,
+                  &mut arraybuffer_value,
+                )
+              };
+              unsafe { std::ptr::swap(hint.data, underlying_data as *mut _) };
+              status
+            } else {
+              status
             }
           },
           "Create external arraybuffer failed"

examples/napi/electron.js

@@ -5,6 +5,7 @@ const {
   readFileAsync,
   callThreadsafeFunction,
   withAbortController,
+  createExternalTypedArray,
 } = require('./index')
 
 const FILE_CONTENT = readFileSync(__filename, 'utf8')
@@ -43,6 +44,7 @@ async function main() {
     value ===
       Array.from({ length: 100 }, (_, i) => i + 1).reduce((a, b) => a + b),
   )
+  console.info(createExternalTypedArray())
   process.exit(0)
 }