Add v8::ArrayBuffer::Data (denoland#1068)

src/array_buffer.rs

@@ -36,6 +36,7 @@ extern "C" {
  backing_store: *const SharedRef<BackingStore>,
  ) -> *const ArrayBuffer;
  fn v8__ArrayBuffer__Detach(this: *const ArrayBuffer);
+ fn v8__ArrayBuffer__Data(this: *const ArrayBuffer) -> *mut c_void;
  fn v8__ArrayBuffer__IsDetachable(this: *const ArrayBuffer) -> bool;
  fn v8__ArrayBuffer__ByteLength(this: *const ArrayBuffer) -> usize;
  fn v8__ArrayBuffer__GetBackingStore(
@@ -391,6 +392,13 @@ impl ArrayBuffer {
  }
  }
 
+ /// More efficient shortcut for GetBackingStore()->Data().
+ /// The returned pointer is valid as long as the ArrayBuffer is alive.
+ #[inline]
+ pub fn data(&self) -> *mut c_void {
+ unsafe { v8__ArrayBuffer__Data(self) }
+ }
+
  /// Get a shared pointer to the backing store of this array buffer. This
  /// pointer coordinates the lifetime management of the internal storage
  /// with any live ArrayBuffers on the heap, even across isolates. The embedder

src/binding.cc

@@ -854,6 +854,10 @@ two_pointers_t v8__ArrayBuffer__GetBackingStore(const v8::ArrayBuffer& self) {
  return make_pod<two_pointers_t>(ptr_to_local(&self)->GetBackingStore());
 }
 
+void* v8__ArrayBuffer__Data(const v8::ArrayBuffer& self) {
+ return ptr_to_local(&self)->Data();
+}
+
 void v8__ArrayBuffer__Detach(const v8::ArrayBuffer& self) {
  ptr_to_local(&self)->Detach();
 }

tests/test_api.rs

@@ -6678,6 +6678,26 @@ fn backing_store_from_empty_vec() {
  let _ = v8::ArrayBuffer::with_backing_store(&mut scope, &store);
 }
 
+#[test]
+fn backing_store_data() {
+ let _setup_guard = setup();
+
+ let mut isolate = v8::Isolate::new(Default::default());
+ let mut scope = v8::HandleScope::new(&mut isolate);
+ let context = v8::Context::new(&mut scope);
+ let mut scope = v8::ContextScope::new(&mut scope, context);
+
+ let v = vec![1, 2, 3, 4, 5];
+ let len = v.len();
+ let store = v8::ArrayBuffer::new_backing_store_from_vec(v).make_shared();
+ let buf = v8::ArrayBuffer::with_backing_store(&mut scope, &store);
+ assert_eq!(buf.byte_length(), len);
+ assert_eq!(
+ unsafe { std::slice::from_raw_parts_mut(buf.data() as *mut u8, len) },
+ &[1, 2, 3, 4, 5]
+ );
+}
+
 #[test]
 fn current_stack_trace() {
  // Setup isolate