ArrayBuffer.h 12 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280
  1. /*
  2. * Copyright (c) 2020-2022, Linus Groh <linusg@serenityos.org>
  3. *
  4. * SPDX-License-Identifier: BSD-2-Clause
  5. */
  6. #pragma once
  7. #include <AK/ByteBuffer.h>
  8. #include <AK/Function.h>
  9. #include <AK/Variant.h>
  10. #include <LibJS/Runtime/BigInt.h>
  11. #include <LibJS/Runtime/Completion.h>
  12. #include <LibJS/Runtime/GlobalObject.h>
  13. #include <LibJS/Runtime/Object.h>
  14. namespace JS {
  15. struct ClampedU8 {
  16. };
  17. // 25.1.1 Notation (read-modify-write modification function), https://tc39.es/ecma262/#sec-arraybuffer-notation
  18. using ReadWriteModifyFunction = Function<ByteBuffer(ByteBuffer, ByteBuffer)>;
  19. class ArrayBuffer : public Object {
  20. JS_OBJECT(ArrayBuffer, Object);
  21. public:
  22. static ThrowCompletionOr<NonnullGCPtr<ArrayBuffer>> create(Realm&, size_t);
  23. static NonnullGCPtr<ArrayBuffer> create(Realm&, ByteBuffer);
  24. static NonnullGCPtr<ArrayBuffer> create(Realm&, ByteBuffer*);
  25. virtual ~ArrayBuffer() override = default;
  26. size_t byte_length() const { return buffer_impl().size(); }
  27. // [[ArrayBufferData]]
  28. ByteBuffer& buffer() { return buffer_impl(); }
  29. ByteBuffer const& buffer() const { return buffer_impl(); }
  30. // Used by allocate_array_buffer() to attach the data block after construction
  31. void set_buffer(ByteBuffer buffer) { m_buffer = move(buffer); }
  32. Value detach_key() const { return m_detach_key; }
  33. void set_detach_key(Value detach_key) { m_detach_key = detach_key; }
  34. void detach_buffer() { m_buffer = Empty {}; }
  35. // 25.1.2.2 IsDetachedBuffer ( arrayBuffer ), https://tc39.es/ecma262/#sec-isdetachedbuffer
  36. bool is_detached() const
  37. {
  38. // 1. If arrayBuffer.[[ArrayBufferData]] is null, return true.
  39. if (m_buffer.has<Empty>())
  40. return true;
  41. // 2. Return false.
  42. return false;
  43. }
  44. enum Order {
  45. SeqCst,
  46. Unordered
  47. };
  48. template<typename type>
  49. Value get_value(size_t byte_index, bool is_typed_array, Order, bool is_little_endian = true);
  50. template<typename type>
  51. void set_value(size_t byte_index, Value value, bool is_typed_array, Order, bool is_little_endian = true);
  52. template<typename T>
  53. Value get_modify_set_value(size_t byte_index, Value value, ReadWriteModifyFunction operation, bool is_little_endian = true);
  54. private:
  55. ArrayBuffer(ByteBuffer buffer, Object& prototype);
  56. ArrayBuffer(ByteBuffer* buffer, Object& prototype);
  57. virtual void visit_edges(Visitor&) override;
  58. ByteBuffer& buffer_impl()
  59. {
  60. ByteBuffer* ptr { nullptr };
  61. m_buffer.visit([&](Empty) { VERIFY_NOT_REACHED(); }, [&](auto* pointer) { ptr = pointer; }, [&](auto& value) { ptr = &value; });
  62. return *ptr;
  63. }
  64. ByteBuffer const& buffer_impl() const { return const_cast<ArrayBuffer*>(this)->buffer_impl(); }
  65. Variant<Empty, ByteBuffer, ByteBuffer*> m_buffer;
  66. // The various detach related members of ArrayBuffer are not used by any ECMA262 functionality,
  67. // but are required to be available for the use of various harnesses like the Test262 test runner.
  68. Value m_detach_key;
  69. };
  70. void copy_data_block_bytes(ByteBuffer& to_block, u64 to_index, ByteBuffer& from_block, u64 from_index, u64 count);
  71. ThrowCompletionOr<ArrayBuffer*> allocate_array_buffer(VM&, FunctionObject& constructor, size_t byte_length);
  72. ThrowCompletionOr<void> detach_array_buffer(VM&, ArrayBuffer& array_buffer, Optional<Value> key = {});
  73. ThrowCompletionOr<ArrayBuffer*> clone_array_buffer(VM&, ArrayBuffer& source_buffer, size_t source_byte_offset, size_t source_length);
  74. // 25.1.2.9 RawBytesToNumeric ( type, rawBytes, isLittleEndian ), https://tc39.es/ecma262/#sec-rawbytestonumeric
  75. template<typename T>
  76. static Value raw_bytes_to_numeric(VM& vm, ByteBuffer raw_value, bool is_little_endian)
  77. {
  78. if (!is_little_endian) {
  79. VERIFY(raw_value.size() % 2 == 0);
  80. for (size_t i = 0; i < raw_value.size() / 2; ++i)
  81. swap(raw_value[i], raw_value[raw_value.size() - 1 - i]);
  82. }
  83. using UnderlyingBufferDataType = Conditional<IsSame<ClampedU8, T>, u8, T>;
  84. if constexpr (IsSame<UnderlyingBufferDataType, float>) {
  85. float value;
  86. raw_value.span().copy_to({ &value, sizeof(float) });
  87. if (isnan(value))
  88. return js_nan();
  89. return Value(value);
  90. }
  91. if constexpr (IsSame<UnderlyingBufferDataType, double>) {
  92. double value;
  93. raw_value.span().copy_to({ &value, sizeof(double) });
  94. if (isnan(value))
  95. return js_nan();
  96. return Value(value);
  97. }
  98. if constexpr (!IsIntegral<UnderlyingBufferDataType>)
  99. VERIFY_NOT_REACHED();
  100. UnderlyingBufferDataType int_value = 0;
  101. raw_value.span().copy_to({ &int_value, sizeof(UnderlyingBufferDataType) });
  102. if constexpr (sizeof(UnderlyingBufferDataType) == 8) {
  103. if constexpr (IsSigned<UnderlyingBufferDataType>) {
  104. static_assert(IsSame<UnderlyingBufferDataType, i64>);
  105. return BigInt::create(vm, Crypto::SignedBigInteger { int_value });
  106. } else {
  107. static_assert(IsOneOf<UnderlyingBufferDataType, u64, double>);
  108. return BigInt::create(vm, Crypto::SignedBigInteger { Crypto::UnsignedBigInteger { int_value } });
  109. }
  110. } else {
  111. return Value(int_value);
  112. }
  113. }
  114. // Implementation for 25.1.2.10 GetValueFromBuffer, used in TypedArray<T>::get_value_from_buffer().
  115. template<typename T>
  116. Value ArrayBuffer::get_value(size_t byte_index, [[maybe_unused]] bool is_typed_array, Order, bool is_little_endian)
  117. {
  118. auto& vm = this->vm();
  119. auto element_size = sizeof(T);
  120. // FIXME: Check for shared buffer
  121. // FIXME: Propagate errors.
  122. auto raw_value = MUST(buffer_impl().slice(byte_index, element_size));
  123. return raw_bytes_to_numeric<T>(vm, move(raw_value), is_little_endian);
  124. }
  125. // 25.1.2.11 NumericToRawBytes ( type, value, isLittleEndian ), https://tc39.es/ecma262/#sec-numerictorawbytes
  126. template<typename T>
  127. static ByteBuffer numeric_to_raw_bytes(VM& vm, Value value, bool is_little_endian)
  128. {
  129. VERIFY(value.is_number() || value.is_bigint());
  130. using UnderlyingBufferDataType = Conditional<IsSame<ClampedU8, T>, u8, T>;
  131. ByteBuffer raw_bytes = ByteBuffer::create_uninitialized(sizeof(UnderlyingBufferDataType)).release_value_but_fixme_should_propagate_errors(); // FIXME: Handle possible OOM situation.
  132. auto flip_if_needed = [&]() {
  133. if (is_little_endian)
  134. return;
  135. VERIFY(sizeof(UnderlyingBufferDataType) % 2 == 0);
  136. for (size_t i = 0; i < sizeof(UnderlyingBufferDataType) / 2; ++i)
  137. swap(raw_bytes[i], raw_bytes[sizeof(UnderlyingBufferDataType) - 1 - i]);
  138. };
  139. if constexpr (IsSame<UnderlyingBufferDataType, float>) {
  140. float raw_value = MUST(value.to_double(vm));
  141. ReadonlyBytes { &raw_value, sizeof(float) }.copy_to(raw_bytes);
  142. flip_if_needed();
  143. return raw_bytes;
  144. }
  145. if constexpr (IsSame<UnderlyingBufferDataType, double>) {
  146. double raw_value = MUST(value.to_double(vm));
  147. ReadonlyBytes { &raw_value, sizeof(double) }.copy_to(raw_bytes);
  148. flip_if_needed();
  149. return raw_bytes;
  150. }
  151. if constexpr (!IsIntegral<UnderlyingBufferDataType>)
  152. VERIFY_NOT_REACHED();
  153. if constexpr (sizeof(UnderlyingBufferDataType) == 8) {
  154. UnderlyingBufferDataType int_value;
  155. if constexpr (IsSigned<UnderlyingBufferDataType>)
  156. int_value = MUST(value.to_bigint_int64(vm));
  157. else
  158. int_value = MUST(value.to_bigint_uint64(vm));
  159. ReadonlyBytes { &int_value, sizeof(UnderlyingBufferDataType) }.copy_to(raw_bytes);
  160. flip_if_needed();
  161. return raw_bytes;
  162. } else {
  163. UnderlyingBufferDataType int_value;
  164. if constexpr (IsSigned<UnderlyingBufferDataType>) {
  165. if constexpr (sizeof(UnderlyingBufferDataType) == 4)
  166. int_value = MUST(value.to_i32(vm));
  167. else if constexpr (sizeof(UnderlyingBufferDataType) == 2)
  168. int_value = MUST(value.to_i16(vm));
  169. else
  170. int_value = MUST(value.to_i8(vm));
  171. } else {
  172. if constexpr (sizeof(UnderlyingBufferDataType) == 4)
  173. int_value = MUST(value.to_u32(vm));
  174. else if constexpr (sizeof(UnderlyingBufferDataType) == 2)
  175. int_value = MUST(value.to_u16(vm));
  176. else if constexpr (!IsSame<T, ClampedU8>)
  177. int_value = MUST(value.to_u8(vm));
  178. else
  179. int_value = MUST(value.to_u8_clamp(vm));
  180. }
  181. ReadonlyBytes { &int_value, sizeof(UnderlyingBufferDataType) }.copy_to(raw_bytes);
  182. if constexpr (sizeof(UnderlyingBufferDataType) % 2 == 0)
  183. flip_if_needed();
  184. return raw_bytes;
  185. }
  186. }
  187. // 25.1.2.12 SetValueInBuffer ( arrayBuffer, byteIndex, type, value, isTypedArray, order [ , isLittleEndian ] ), https://tc39.es/ecma262/#sec-setvalueinbuffer
  188. template<typename T>
  189. void ArrayBuffer::set_value(size_t byte_index, Value value, [[maybe_unused]] bool is_typed_array, Order, bool is_little_endian)
  190. {
  191. auto& vm = this->vm();
  192. // 1. Assert: IsDetachedBuffer(arrayBuffer) is false.
  193. VERIFY(!is_detached());
  194. // 2. Assert: There are sufficient bytes in arrayBuffer starting at byteIndex to represent a value of type.
  195. VERIFY(buffer().bytes().slice(byte_index).size() >= sizeof(T));
  196. // 3. Assert: value is a BigInt if IsBigIntElementType(type) is true; otherwise, value is a Number.
  197. if constexpr (IsIntegral<T> && sizeof(T) == 8)
  198. VERIFY(value.is_bigint());
  199. else
  200. VERIFY(value.is_number());
  201. // 4. Let block be arrayBuffer.[[ArrayBufferData]].
  202. auto& block = buffer();
  203. // FIXME: 5. Let elementSize be the Element Size value specified in Table 70 for Element Type type.
  204. // 6. If isLittleEndian is not present, set isLittleEndian to the value of the [[LittleEndian]] field of the surrounding agent's Agent Record.
  205. // NOTE: Done by default parameter at declaration of this function.
  206. // 7. Let rawBytes be NumericToRawBytes(type, value, isLittleEndian).
  207. auto raw_bytes = numeric_to_raw_bytes<T>(vm, value, is_little_endian);
  208. // FIXME 8. If IsSharedArrayBuffer(arrayBuffer) is true, then
  209. if (false) {
  210. // FIXME: a. Let execution be the [[CandidateExecution]] field of the surrounding agent's Agent Record.
  211. // FIXME: b. Let eventsRecord be the Agent Events Record of execution.[[EventsRecords]] whose [[AgentSignifier]] is AgentSignifier().
  212. // FIXME: c. If isTypedArray is true and IsNoTearConfiguration(type, order) is true, let noTear be true; otherwise let noTear be false.
  213. // FIXME: d. Append WriteSharedMemory { [[Order]]: order, [[NoTear]]: noTear, [[Block]]: block, [[ByteIndex]]: byteIndex, [[ElementSize]]: elementSize, [[Payload]]: rawBytes } to eventsRecord.[[EventList]].
  214. }
  215. // 9. Else,
  216. else {
  217. // a. Store the individual bytes of rawBytes into block, starting at block[byteIndex].
  218. raw_bytes.span().copy_to(block.span().slice(byte_index));
  219. }
  220. // 10. Return unused.
  221. }
  222. // 25.1.2.13 GetModifySetValueInBuffer ( arrayBuffer, byteIndex, type, value, op [ , isLittleEndian ] ), https://tc39.es/ecma262/#sec-getmodifysetvalueinbuffer
  223. template<typename T>
  224. Value ArrayBuffer::get_modify_set_value(size_t byte_index, Value value, ReadWriteModifyFunction operation, bool is_little_endian)
  225. {
  226. auto& vm = this->vm();
  227. auto raw_bytes = numeric_to_raw_bytes<T>(vm, value, is_little_endian);
  228. // FIXME: Check for shared buffer
  229. // FIXME: Propagate errors.
  230. auto raw_bytes_read = MUST(buffer_impl().slice(byte_index, sizeof(T)));
  231. auto raw_bytes_modified = operation(raw_bytes_read, raw_bytes);
  232. raw_bytes_modified.span().copy_to(buffer_impl().span().slice(byte_index));
  233. return raw_bytes_to_numeric<T>(vm, raw_bytes_read, is_little_endian);
  234. }
  235. }