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LibJS: Add all of the DataView.prototype.get* methods

This commit is contained in:
Idan Horowitz 2021-06-14 01:57:15 +03:00 committed by Linus Groh
parent e4d267d4fb
commit c54b9a6920
6 changed files with 206 additions and 0 deletions

View file

@ -8,6 +8,7 @@
#include <AK/ByteBuffer.h>
#include <AK/Variant.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/Object.h>
namespace JS {
@ -33,6 +34,13 @@ public:
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);
private:
virtual void visit_edges(Visitor&) override;
@ -51,4 +59,53 @@ private:
Value m_detach_key;
};
// 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)
{
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]);
}
if constexpr (IsSame<T, float>) {
float value;
raw_value.span().copy_to({ &value, sizeof(float) });
if (isnan(value))
return js_nan();
return Value(value);
}
if constexpr (IsSame<T, double>) {
double value;
raw_value.span().copy_to({ &value, sizeof(double) });
if (isnan(value))
return js_nan();
return Value(value);
}
if constexpr (!IsIntegral<T>)
VERIFY_NOT_REACHED();
T int_value = 0;
raw_value.span().copy_to({ &int_value, sizeof(T) });
if constexpr (sizeof(T) == 8) {
if constexpr (IsSigned<T>)
return js_bigint(global_object.heap(), Crypto::SignedBigInteger::create_from(int_value));
else
return js_bigint(global_object.heap(), Crypto::SignedBigInteger { Crypto::UnsignedBigInteger::create_from(int_value) });
} else {
return Value(int_value);
}
}
// 25.1.2.10 GetValueFromBuffer ( arrayBuffer, byteIndex, type, isTypedArray, order [ , isLittleEndian ] ), https://tc39.es/ecma262/#sec-getvaluefrombuffer
template<typename T>
Value ArrayBuffer::get_value(size_t byte_index, [[maybe_unused]] bool is_typed_array, Order, bool is_little_endian)
{
auto element_size = sizeof(T);
// FIXME: Check for shared buffer
auto raw_value = buffer_impl().slice(byte_index, element_size);
return raw_bytes_to_numeric<T>(global_object(), move(raw_value), is_little_endian);
}
}