array-buffer.js 8.9 KB

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  1. 'use strict';
  2. var global = require('../internals/global');
  3. var DESCRIPTORS = require('../internals/descriptors');
  4. var NATIVE_ARRAY_BUFFER = require('../internals/array-buffer-native');
  5. var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
  6. var redefineAll = require('../internals/redefine-all');
  7. var fails = require('../internals/fails');
  8. var anInstance = require('../internals/an-instance');
  9. var toInteger = require('../internals/to-integer');
  10. var toLength = require('../internals/to-length');
  11. var toIndex = require('../internals/to-index');
  12. var IEEE754 = require('../internals/ieee754');
  13. var getPrototypeOf = require('../internals/object-get-prototype-of');
  14. var setPrototypeOf = require('../internals/object-set-prototype-of');
  15. var getOwnPropertyNames = require('../internals/object-get-own-property-names').f;
  16. var defineProperty = require('../internals/object-define-property').f;
  17. var arrayFill = require('../internals/array-fill');
  18. var setToStringTag = require('../internals/set-to-string-tag');
  19. var InternalStateModule = require('../internals/internal-state');
  20. var getInternalState = InternalStateModule.get;
  21. var setInternalState = InternalStateModule.set;
  22. var ARRAY_BUFFER = 'ArrayBuffer';
  23. var DATA_VIEW = 'DataView';
  24. var PROTOTYPE = 'prototype';
  25. var WRONG_LENGTH = 'Wrong length';
  26. var WRONG_INDEX = 'Wrong index';
  27. var NativeArrayBuffer = global[ARRAY_BUFFER];
  28. var $ArrayBuffer = NativeArrayBuffer;
  29. var $DataView = global[DATA_VIEW];
  30. var $DataViewPrototype = $DataView && $DataView[PROTOTYPE];
  31. var ObjectPrototype = Object.prototype;
  32. var RangeError = global.RangeError;
  33. var packIEEE754 = IEEE754.pack;
  34. var unpackIEEE754 = IEEE754.unpack;
  35. var packInt8 = function (number) {
  36. return [number & 0xFF];
  37. };
  38. var packInt16 = function (number) {
  39. return [number & 0xFF, number >> 8 & 0xFF];
  40. };
  41. var packInt32 = function (number) {
  42. return [number & 0xFF, number >> 8 & 0xFF, number >> 16 & 0xFF, number >> 24 & 0xFF];
  43. };
  44. var unpackInt32 = function (buffer) {
  45. return buffer[3] << 24 | buffer[2] << 16 | buffer[1] << 8 | buffer[0];
  46. };
  47. var packFloat32 = function (number) {
  48. return packIEEE754(number, 23, 4);
  49. };
  50. var packFloat64 = function (number) {
  51. return packIEEE754(number, 52, 8);
  52. };
  53. var addGetter = function (Constructor, key) {
  54. defineProperty(Constructor[PROTOTYPE], key, { get: function () { return getInternalState(this)[key]; } });
  55. };
  56. var get = function (view, count, index, isLittleEndian) {
  57. var intIndex = toIndex(index);
  58. var store = getInternalState(view);
  59. if (intIndex + count > store.byteLength) throw RangeError(WRONG_INDEX);
  60. var bytes = getInternalState(store.buffer).bytes;
  61. var start = intIndex + store.byteOffset;
  62. var pack = bytes.slice(start, start + count);
  63. return isLittleEndian ? pack : pack.reverse();
  64. };
  65. var set = function (view, count, index, conversion, value, isLittleEndian) {
  66. var intIndex = toIndex(index);
  67. var store = getInternalState(view);
  68. if (intIndex + count > store.byteLength) throw RangeError(WRONG_INDEX);
  69. var bytes = getInternalState(store.buffer).bytes;
  70. var start = intIndex + store.byteOffset;
  71. var pack = conversion(+value);
  72. for (var i = 0; i < count; i++) bytes[start + i] = pack[isLittleEndian ? i : count - i - 1];
  73. };
  74. if (!NATIVE_ARRAY_BUFFER) {
  75. $ArrayBuffer = function ArrayBuffer(length) {
  76. anInstance(this, $ArrayBuffer, ARRAY_BUFFER);
  77. var byteLength = toIndex(length);
  78. setInternalState(this, {
  79. bytes: arrayFill.call(new Array(byteLength), 0),
  80. byteLength: byteLength
  81. });
  82. if (!DESCRIPTORS) this.byteLength = byteLength;
  83. };
  84. $DataView = function DataView(buffer, byteOffset, byteLength) {
  85. anInstance(this, $DataView, DATA_VIEW);
  86. anInstance(buffer, $ArrayBuffer, DATA_VIEW);
  87. var bufferLength = getInternalState(buffer).byteLength;
  88. var offset = toInteger(byteOffset);
  89. if (offset < 0 || offset > bufferLength) throw RangeError('Wrong offset');
  90. byteLength = byteLength === undefined ? bufferLength - offset : toLength(byteLength);
  91. if (offset + byteLength > bufferLength) throw RangeError(WRONG_LENGTH);
  92. setInternalState(this, {
  93. buffer: buffer,
  94. byteLength: byteLength,
  95. byteOffset: offset
  96. });
  97. if (!DESCRIPTORS) {
  98. this.buffer = buffer;
  99. this.byteLength = byteLength;
  100. this.byteOffset = offset;
  101. }
  102. };
  103. if (DESCRIPTORS) {
  104. addGetter($ArrayBuffer, 'byteLength');
  105. addGetter($DataView, 'buffer');
  106. addGetter($DataView, 'byteLength');
  107. addGetter($DataView, 'byteOffset');
  108. }
  109. redefineAll($DataView[PROTOTYPE], {
  110. getInt8: function getInt8(byteOffset) {
  111. return get(this, 1, byteOffset)[0] << 24 >> 24;
  112. },
  113. getUint8: function getUint8(byteOffset) {
  114. return get(this, 1, byteOffset)[0];
  115. },
  116. getInt16: function getInt16(byteOffset /* , littleEndian */) {
  117. var bytes = get(this, 2, byteOffset, arguments.length > 1 ? arguments[1] : undefined);
  118. return (bytes[1] << 8 | bytes[0]) << 16 >> 16;
  119. },
  120. getUint16: function getUint16(byteOffset /* , littleEndian */) {
  121. var bytes = get(this, 2, byteOffset, arguments.length > 1 ? arguments[1] : undefined);
  122. return bytes[1] << 8 | bytes[0];
  123. },
  124. getInt32: function getInt32(byteOffset /* , littleEndian */) {
  125. return unpackInt32(get(this, 4, byteOffset, arguments.length > 1 ? arguments[1] : undefined));
  126. },
  127. getUint32: function getUint32(byteOffset /* , littleEndian */) {
  128. return unpackInt32(get(this, 4, byteOffset, arguments.length > 1 ? arguments[1] : undefined)) >>> 0;
  129. },
  130. getFloat32: function getFloat32(byteOffset /* , littleEndian */) {
  131. return unpackIEEE754(get(this, 4, byteOffset, arguments.length > 1 ? arguments[1] : undefined), 23);
  132. },
  133. getFloat64: function getFloat64(byteOffset /* , littleEndian */) {
  134. return unpackIEEE754(get(this, 8, byteOffset, arguments.length > 1 ? arguments[1] : undefined), 52);
  135. },
  136. setInt8: function setInt8(byteOffset, value) {
  137. set(this, 1, byteOffset, packInt8, value);
  138. },
  139. setUint8: function setUint8(byteOffset, value) {
  140. set(this, 1, byteOffset, packInt8, value);
  141. },
  142. setInt16: function setInt16(byteOffset, value /* , littleEndian */) {
  143. set(this, 2, byteOffset, packInt16, value, arguments.length > 2 ? arguments[2] : undefined);
  144. },
  145. setUint16: function setUint16(byteOffset, value /* , littleEndian */) {
  146. set(this, 2, byteOffset, packInt16, value, arguments.length > 2 ? arguments[2] : undefined);
  147. },
  148. setInt32: function setInt32(byteOffset, value /* , littleEndian */) {
  149. set(this, 4, byteOffset, packInt32, value, arguments.length > 2 ? arguments[2] : undefined);
  150. },
  151. setUint32: function setUint32(byteOffset, value /* , littleEndian */) {
  152. set(this, 4, byteOffset, packInt32, value, arguments.length > 2 ? arguments[2] : undefined);
  153. },
  154. setFloat32: function setFloat32(byteOffset, value /* , littleEndian */) {
  155. set(this, 4, byteOffset, packFloat32, value, arguments.length > 2 ? arguments[2] : undefined);
  156. },
  157. setFloat64: function setFloat64(byteOffset, value /* , littleEndian */) {
  158. set(this, 8, byteOffset, packFloat64, value, arguments.length > 2 ? arguments[2] : undefined);
  159. }
  160. });
  161. } else {
  162. /* eslint-disable no-new -- required for testing */
  163. if (!fails(function () {
  164. NativeArrayBuffer(1);
  165. }) || !fails(function () {
  166. new NativeArrayBuffer(-1);
  167. }) || fails(function () {
  168. new NativeArrayBuffer();
  169. new NativeArrayBuffer(1.5);
  170. new NativeArrayBuffer(NaN);
  171. return NativeArrayBuffer.name != ARRAY_BUFFER;
  172. })) {
  173. /* eslint-enable no-new -- required for testing */
  174. $ArrayBuffer = function ArrayBuffer(length) {
  175. anInstance(this, $ArrayBuffer);
  176. return new NativeArrayBuffer(toIndex(length));
  177. };
  178. var ArrayBufferPrototype = $ArrayBuffer[PROTOTYPE] = NativeArrayBuffer[PROTOTYPE];
  179. for (var keys = getOwnPropertyNames(NativeArrayBuffer), j = 0, key; keys.length > j;) {
  180. if (!((key = keys[j++]) in $ArrayBuffer)) {
  181. createNonEnumerableProperty($ArrayBuffer, key, NativeArrayBuffer[key]);
  182. }
  183. }
  184. ArrayBufferPrototype.constructor = $ArrayBuffer;
  185. }
  186. // WebKit bug - the same parent prototype for typed arrays and data view
  187. if (setPrototypeOf && getPrototypeOf($DataViewPrototype) !== ObjectPrototype) {
  188. setPrototypeOf($DataViewPrototype, ObjectPrototype);
  189. }
  190. // iOS Safari 7.x bug
  191. var testView = new $DataView(new $ArrayBuffer(2));
  192. var $setInt8 = $DataViewPrototype.setInt8;
  193. testView.setInt8(0, 2147483648);
  194. testView.setInt8(1, 2147483649);
  195. if (testView.getInt8(0) || !testView.getInt8(1)) redefineAll($DataViewPrototype, {
  196. setInt8: function setInt8(byteOffset, value) {
  197. $setInt8.call(this, byteOffset, value << 24 >> 24);
  198. },
  199. setUint8: function setUint8(byteOffset, value) {
  200. $setInt8.call(this, byteOffset, value << 24 >> 24);
  201. }
  202. }, { unsafe: true });
  203. }
  204. setToStringTag($ArrayBuffer, ARRAY_BUFFER);
  205. setToStringTag($DataView, DATA_VIEW);
  206. module.exports = {
  207. ArrayBuffer: $ArrayBuffer,
  208. DataView: $DataView
  209. };