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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.
This commit is contained in:
Linus Groh 2021-10-09 12:31:13 +01:00
parent f8489da8ee
commit 1fba5ca8c3
2 changed files with 32 additions and 5 deletions

View file

@ -1,19 +1,20 @@
/*
* Copyright (c) 2020, Linus Groh <linusg@serenityos.org>
* 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_size)
ArrayBuffer* ArrayBuffer::create(GlobalObject& global_object, size_t byte_length)
{
auto buffer = ByteBuffer::create_zeroed(byte_size);
auto buffer = ByteBuffer::create_zeroed(byte_length);
if (!buffer.has_value()) {
global_object.vm().throw_exception<RangeError>(global_object, ErrorType::NotEnoughMemoryToAllocate, byte_size);
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());
@ -48,4 +49,24 @@ void ArrayBuffer::visit_edges(Cell::Visitor& 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;
}
}

View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2020, Linus Groh <linusg@serenityos.org>
* Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
@ -9,6 +9,7 @@
#include <AK/ByteBuffer.h>
#include <AK/Function.h>
#include <AK/Variant.h>
#include <LibJS/Runtime/Completion.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/Object.h>
@ -35,6 +36,9 @@ public:
ByteBuffer& buffer() { return buffer_impl(); }
const ByteBuffer& buffer() const { return buffer_impl(); }
// Used by allocate_array_buffer() to attach the data block after construction
void set_buffer(ByteBuffer buffer) { m_buffer = move(buffer); }
Value detach_key() const { return m_detach_key; }
void set_detach_key(Value detach_key) { m_detach_key = detach_key; }
@ -70,6 +74,8 @@ private:
Value m_detach_key;
};
ThrowCompletionOr<ArrayBuffer*> allocate_array_buffer(GlobalObject&, FunctionObject& constructor, size_t byte_length);
// 25.1.2.9 RawBytesToNumeric ( type, rawBytes, isLittleEndian ), https://tc39.es/ecma262/#sec-rawbytestonumeric
template<typename T>
static Value raw_bytes_to_numeric(GlobalObject& global_object, ByteBuffer raw_value, bool is_little_endian)