ladybird/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp
Linus Groh 1fba5ca8c3 LibJS: Implement the AllocateArrayBuffer() AO
This should be used instead of ArrayBuffer::create() in most places, as
it uses OrdinaryCreateFromConstructor to allow for a custom prototype.

The data block (ByteBuffer) is allocated separately and attached
afterwards, if we didn't fail due to OOM.
2021-10-09 12:36:28 +01:00

72 lines
2.4 KiB
C++

/*
* Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/ArrayBuffer.h>
#include <LibJS/Runtime/GlobalObject.h>
namespace JS {
ArrayBuffer* ArrayBuffer::create(GlobalObject& global_object, size_t byte_length)
{
auto buffer = ByteBuffer::create_zeroed(byte_length);
if (!buffer.has_value()) {
global_object.vm().throw_exception<RangeError>(global_object, ErrorType::NotEnoughMemoryToAllocate, byte_length);
return nullptr;
}
return global_object.heap().allocate<ArrayBuffer>(global_object, buffer.release_value(), *global_object.array_buffer_prototype());
}
ArrayBuffer* ArrayBuffer::create(GlobalObject& global_object, ByteBuffer* buffer)
{
return global_object.heap().allocate<ArrayBuffer>(global_object, buffer, *global_object.array_buffer_prototype());
}
ArrayBuffer::ArrayBuffer(ByteBuffer buffer, Object& prototype)
: Object(prototype)
, m_buffer(move(buffer))
, m_detach_key(js_undefined())
{
}
ArrayBuffer::ArrayBuffer(ByteBuffer* buffer, Object& prototype)
: Object(prototype)
, m_buffer(buffer)
, m_detach_key(js_undefined())
{
}
ArrayBuffer::~ArrayBuffer()
{
}
void ArrayBuffer::visit_edges(Cell::Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(m_detach_key);
}
// 25.1.2.1 AllocateArrayBuffer ( constructor, byteLength ), https://tc39.es/ecma262/#sec-allocatearraybuffer
ThrowCompletionOr<ArrayBuffer*> allocate_array_buffer(GlobalObject& global_object, FunctionObject& constructor, size_t byte_length)
{
// 1. Let obj be ? OrdinaryCreateFromConstructor(constructor, "%ArrayBuffer.prototype%", « [[ArrayBufferData]], [[ArrayBufferByteLength]], [[ArrayBufferDetachKey]] »).
auto* obj = TRY(ordinary_create_from_constructor<ArrayBuffer>(global_object, constructor, &GlobalObject::array_buffer_prototype, nullptr));
// 2. Let block be ? CreateByteDataBlock(byteLength).
auto block = ByteBuffer::create_zeroed(byte_length);
if (!block.has_value())
return global_object.vm().throw_completion<RangeError>(global_object, ErrorType::NotEnoughMemoryToAllocate, byte_length);
// 3. Set obj.[[ArrayBufferData]] to block.
obj->set_buffer(move(*block));
// 4. Set obj.[[ArrayBufferByteLength]] to byteLength.
// 5. Return obj.
return obj;
}
}