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/*
* Copyright (c) 2020-2022, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#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>
namespace JS {
struct ClampedU8 {
};
// 25.1.1 Notation (read-modify-write modification function), https://tc39.es/ecma262/#sec-arraybuffer-notation
using ReadWriteModifyFunction = Function<ByteBuffer(ByteBuffer, ByteBuffer)>;
class ArrayBuffer : public Object {
JS_OBJECT(ArrayBuffer, Object);
public:
static ThrowCompletionOr<NonnullGCPtr<ArrayBuffer>> create(Realm&, size_t);
static NonnullGCPtr<ArrayBuffer> create(Realm&, ByteBuffer);
static NonnullGCPtr<ArrayBuffer> create(Realm&, ByteBuffer*);
virtual ~ArrayBuffer() override = default;
size_t byte_length() const { return buffer_impl().size(); }
ByteBuffer& buffer() { return buffer_impl(); }
ByteBuffer const& 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; }
void detach_buffer() { m_buffer = Empty {}; }
bool is_detached() const { return m_buffer.has<Empty>(); }
enum Order {
SeqCst,
Unordered
};
template<typename type>
Value get_value(size_t byte_index, bool is_typed_array, Order, bool is_little_endian = true);
template<typename type>
void set_value(size_t byte_index, Value value, bool is_typed_array, Order, bool is_little_endian = true);
template<typename T>
Value get_modify_set_value(size_t byte_index, Value value, ReadWriteModifyFunction operation, bool is_little_endian = true);
private:
ArrayBuffer(ByteBuffer buffer, Object& prototype);
ArrayBuffer(ByteBuffer* buffer, Object& prototype);
virtual void visit_edges(Visitor&) override;
ByteBuffer& buffer_impl()
{
ByteBuffer* ptr { nullptr };
m_buffer.visit([&](Empty) { VERIFY_NOT_REACHED(); }, [&](auto* pointer) { ptr = pointer; }, [&](auto& value) { ptr = &value; });
return *ptr;
}
ByteBuffer const& buffer_impl() const { return const_cast<ArrayBuffer*>(this)->buffer_impl(); }
Variant<Empty, ByteBuffer, ByteBuffer*> m_buffer;
// The various detach related members of ArrayBuffer are not used by any ECMA262 functionality,
// but are required to be available for the use of various harnesses like the Test262 test runner.
Value m_detach_key;
};
ThrowCompletionOr<ArrayBuffer*> allocate_array_buffer(VM&, FunctionObject& constructor, size_t byte_length);
ThrowCompletionOr<void> detach_array_buffer(VM&, ArrayBuffer& array_buffer, Optional<Value> key = {});
ThrowCompletionOr<ArrayBuffer*> clone_array_buffer(VM&, ArrayBuffer& source_buffer, size_t source_byte_offset, size_t source_length);
// 25.1.2.9 RawBytesToNumeric ( type, rawBytes, isLittleEndian ), https://tc39.es/ecma262/#sec-rawbytestonumeric
template<typename T>
static Value raw_bytes_to_numeric(VM& vm, ByteBuffer raw_value, bool is_little_endian)
{
if (!is_little_endian) {
VERIFY(raw_value.size() % 2 == 0);
for (size_t i = 0; i < raw_value.size() / 2; ++i)
swap(raw_value[i], raw_value[raw_value.size() - 1 - i]);
}
using UnderlyingBufferDataType = Conditional<IsSame<ClampedU8, T>, u8, T>;
if constexpr (IsSame<UnderlyingBufferDataType, float>) {
float value;
raw_value.span().copy_to({ &value, sizeof(float) });
if (isnan(value))
return js_nan();
return Value(value);
}
if constexpr (IsSame<UnderlyingBufferDataType, double>) {
double value;
raw_value.span().copy_to({ &value, sizeof(double) });
if (isnan(value))
return js_nan();
return Value(value);
}
if constexpr (!IsIntegral<UnderlyingBufferDataType>)
VERIFY_NOT_REACHED();
UnderlyingBufferDataType int_value = 0;
raw_value.span().copy_to({ &int_value, sizeof(UnderlyingBufferDataType) });
if constexpr (sizeof(UnderlyingBufferDataType) == 8) {
if constexpr (IsSigned<UnderlyingBufferDataType>) {
static_assert(IsSame<UnderlyingBufferDataType, i64>);
return BigInt::create(vm, Crypto::SignedBigInteger { int_value });
} else {
static_assert(IsOneOf<UnderlyingBufferDataType, u64, double>);
return BigInt::create(vm, Crypto::SignedBigInteger { Crypto::UnsignedBigInteger { int_value } });
}
} else {
return Value(int_value);
}
}
// Implementation for 25.1.2.10 GetValueFromBuffer, used in TypedArray<T>::get_value_from_buffer().
template<typename T>
Value ArrayBuffer::get_value(size_t byte_index, [[maybe_unused]] bool is_typed_array, Order, bool is_little_endian)
{
auto& vm = this->vm();
auto element_size = sizeof(T);
// FIXME: Check for shared buffer
// FIXME: Propagate errors.
auto raw_value = MUST(buffer_impl().slice(byte_index, element_size));
return raw_bytes_to_numeric<T>(vm, move(raw_value), is_little_endian);
}
// 25.1.2.11 NumericToRawBytes ( type, value, isLittleEndian ), https://tc39.es/ecma262/#sec-numerictorawbytes
template<typename T>
static ByteBuffer numeric_to_raw_bytes(VM& vm, Value value, bool is_little_endian)
{
VERIFY(value.is_number() || value.is_bigint());
using UnderlyingBufferDataType = Conditional<IsSame<ClampedU8, T>, u8, T>;
ByteBuffer raw_bytes = ByteBuffer::create_uninitialized(sizeof(UnderlyingBufferDataType)).release_value_but_fixme_should_propagate_errors(); // FIXME: Handle possible OOM situation.
auto flip_if_needed = [&]() {
if (is_little_endian)
return;
VERIFY(sizeof(UnderlyingBufferDataType) % 2 == 0);
for (size_t i = 0; i < sizeof(UnderlyingBufferDataType) / 2; ++i)
swap(raw_bytes[i], raw_bytes[sizeof(UnderlyingBufferDataType) - 1 - i]);
};
if constexpr (IsSame<UnderlyingBufferDataType, float>) {
float raw_value = MUST(value.to_double(vm));
ReadonlyBytes { &raw_value, sizeof(float) }.copy_to(raw_bytes);
flip_if_needed();
return raw_bytes;
}
if constexpr (IsSame<UnderlyingBufferDataType, double>) {
double raw_value = MUST(value.to_double(vm));
ReadonlyBytes { &raw_value, sizeof(double) }.copy_to(raw_bytes);
flip_if_needed();
return raw_bytes;
}
if constexpr (!IsIntegral<UnderlyingBufferDataType>)
VERIFY_NOT_REACHED();
if constexpr (sizeof(UnderlyingBufferDataType) == 8) {
UnderlyingBufferDataType int_value;
if constexpr (IsSigned<UnderlyingBufferDataType>)
int_value = MUST(value.to_bigint_int64(vm));
else
int_value = MUST(value.to_bigint_uint64(vm));
ReadonlyBytes { &int_value, sizeof(UnderlyingBufferDataType) }.copy_to(raw_bytes);
flip_if_needed();
return raw_bytes;
} else {
UnderlyingBufferDataType int_value;
if constexpr (IsSigned<UnderlyingBufferDataType>) {
if constexpr (sizeof(UnderlyingBufferDataType) == 4)
int_value = MUST(value.to_i32(vm));
else if constexpr (sizeof(UnderlyingBufferDataType) == 2)
int_value = MUST(value.to_i16(vm));
else
int_value = MUST(value.to_i8(vm));
} else {
if constexpr (sizeof(UnderlyingBufferDataType) == 4)
int_value = MUST(value.to_u32(vm));
else if constexpr (sizeof(UnderlyingBufferDataType) == 2)
int_value = MUST(value.to_u16(vm));
else if constexpr (!IsSame<T, ClampedU8>)
int_value = MUST(value.to_u8(vm));
else
int_value = MUST(value.to_u8_clamp(vm));
}
ReadonlyBytes { &int_value, sizeof(UnderlyingBufferDataType) }.copy_to(raw_bytes);
if constexpr (sizeof(UnderlyingBufferDataType) % 2 == 0)
flip_if_needed();
return raw_bytes;
}
}
// 25.1.2.12 SetValueInBuffer ( arrayBuffer, byteIndex, type, value, isTypedArray, order [ , isLittleEndian ] ), https://tc39.es/ecma262/#sec-setvalueinbuffer
template<typename T>
void ArrayBuffer::set_value(size_t byte_index, Value value, [[maybe_unused]] bool is_typed_array, Order, bool is_little_endian)
{
auto& vm = this->vm();
auto raw_bytes = numeric_to_raw_bytes<T>(vm, value, is_little_endian);
// FIXME: Check for shared buffer
raw_bytes.span().copy_to(buffer_impl().span().slice(byte_index));
}
// 25.1.2.13 GetModifySetValueInBuffer ( arrayBuffer, byteIndex, type, value, op [ , isLittleEndian ] ), https://tc39.es/ecma262/#sec-getmodifysetvalueinbuffer
template<typename T>
Value ArrayBuffer::get_modify_set_value(size_t byte_index, Value value, ReadWriteModifyFunction operation, bool is_little_endian)
{
auto& vm = this->vm();
auto raw_bytes = numeric_to_raw_bytes<T>(vm, value, is_little_endian);
// FIXME: Check for shared buffer
// FIXME: Propagate errors.
auto raw_bytes_read = MUST(buffer_impl().slice(byte_index, sizeof(T)));
auto raw_bytes_modified = operation(raw_bytes_read, raw_bytes);
raw_bytes_modified.span().copy_to(buffer_impl().span().slice(byte_index));
return raw_bytes_to_numeric<T>(vm, raw_bytes_read, is_little_endian);
}
}
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