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| 1 // Protocol Buffers - Google's data interchange format |
| 2 // Copyright 2008 Google Inc. All rights reserved. |
| 3 // https://developers.google.com/protocol-buffers/ |
| 4 // |
| 5 // Redistribution and use in source and binary forms, with or without |
| 6 // modification, are permitted provided that the following conditions are |
| 7 // met: |
| 8 // |
| 9 // * Redistributions of source code must retain the above copyright |
| 10 // notice, this list of conditions and the following disclaimer. |
| 11 // * Redistributions in binary form must reproduce the above |
| 12 // copyright notice, this list of conditions and the following disclaimer |
| 13 // in the documentation and/or other materials provided with the |
| 14 // distribution. |
| 15 // * Neither the name of Google Inc. nor the names of its |
| 16 // contributors may be used to endorse or promote products derived from |
| 17 // this software without specific prior written permission. |
| 18 // |
| 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 30 |
| 31 /** |
| 32 * @fileoverview BinaryEncode defines methods for encoding Javascript values |
| 33 * into arrays of bytes compatible with the Protocol Buffer wire format. |
| 34 * |
| 35 * @author aappleby@google.com (Austin Appleby) |
| 36 */ |
| 37 |
| 38 goog.provide('jspb.BinaryEncoder'); |
| 39 |
| 40 goog.require('goog.asserts'); |
| 41 goog.require('jspb.BinaryConstants'); |
| 42 goog.require('jspb.utils'); |
| 43 |
| 44 |
| 45 |
| 46 /** |
| 47 * BinaryEncoder implements encoders for all the wire types specified in |
| 48 * https://developers.google.com/protocol-buffers/docs/encoding. |
| 49 * |
| 50 * @constructor |
| 51 * @struct |
| 52 */ |
| 53 jspb.BinaryEncoder = function() { |
| 54 /** @private {!Array.<number>} */ |
| 55 this.buffer_ = []; |
| 56 }; |
| 57 |
| 58 |
| 59 /** |
| 60 * @return {number} |
| 61 */ |
| 62 jspb.BinaryEncoder.prototype.length = function() { |
| 63 return this.buffer_.length; |
| 64 }; |
| 65 |
| 66 |
| 67 /** |
| 68 * @return {!Array.<number>} |
| 69 */ |
| 70 jspb.BinaryEncoder.prototype.end = function() { |
| 71 var buffer = this.buffer_; |
| 72 this.buffer_ = []; |
| 73 return buffer; |
| 74 }; |
| 75 |
| 76 |
| 77 /** |
| 78 * Encodes a 64-bit integer in 32:32 split representation into its wire-format |
| 79 * varint representation and stores it in the buffer. |
| 80 * @param {number} lowBits The low 32 bits of the int. |
| 81 * @param {number} highBits The high 32 bits of the int. |
| 82 */ |
| 83 jspb.BinaryEncoder.prototype.writeSplitVarint64 = function(lowBits, highBits) { |
| 84 goog.asserts.assert(lowBits == Math.floor(lowBits)); |
| 85 goog.asserts.assert(highBits == Math.floor(highBits)); |
| 86 goog.asserts.assert((lowBits >= 0) && |
| 87 (lowBits < jspb.BinaryConstants.TWO_TO_32)); |
| 88 goog.asserts.assert((highBits >= 0) && |
| 89 (highBits < jspb.BinaryConstants.TWO_TO_32)); |
| 90 |
| 91 // Break the binary representation into chunks of 7 bits, set the 8th bit |
| 92 // in each chunk if it's not the final chunk, and append to the result. |
| 93 while (highBits > 0 || lowBits > 127) { |
| 94 this.buffer_.push((lowBits & 0x7f) | 0x80); |
| 95 lowBits = ((lowBits >>> 7) | (highBits << 25)) >>> 0; |
| 96 highBits = highBits >>> 7; |
| 97 } |
| 98 this.buffer_.push(lowBits); |
| 99 }; |
| 100 |
| 101 |
| 102 /** |
| 103 * Encodes a 32-bit unsigned integer into its wire-format varint representation |
| 104 * and stores it in the buffer. |
| 105 * @param {number} value The integer to convert. |
| 106 */ |
| 107 jspb.BinaryEncoder.prototype.writeUnsignedVarint32 = function(value) { |
| 108 goog.asserts.assert(value == Math.floor(value)); |
| 109 goog.asserts.assert((value >= 0) && |
| 110 (value < jspb.BinaryConstants.TWO_TO_32)); |
| 111 |
| 112 while (value > 127) { |
| 113 this.buffer_.push((value & 0x7f) | 0x80); |
| 114 value = value >>> 7; |
| 115 } |
| 116 |
| 117 this.buffer_.push(value); |
| 118 }; |
| 119 |
| 120 |
| 121 /** |
| 122 * Encodes a 32-bit signed integer into its wire-format varint representation |
| 123 * and stores it in the buffer. |
| 124 * @param {number} value The integer to convert. |
| 125 */ |
| 126 jspb.BinaryEncoder.prototype.writeSignedVarint32 = function(value) { |
| 127 goog.asserts.assert(value == Math.floor(value)); |
| 128 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) && |
| 129 (value < jspb.BinaryConstants.TWO_TO_31)); |
| 130 |
| 131 // Use the unsigned version if the value is not negative. |
| 132 if (value >= 0) { |
| 133 this.writeUnsignedVarint32(value); |
| 134 return; |
| 135 } |
| 136 |
| 137 // Write nine bytes with a _signed_ right shift so we preserve the sign bit. |
| 138 for (var i = 0; i < 9; i++) { |
| 139 this.buffer_.push((value & 0x7f) | 0x80); |
| 140 value = value >> 7; |
| 141 } |
| 142 |
| 143 // The above loop writes out 63 bits, so the last byte is always the sign bit |
| 144 // which is always set for negative numbers. |
| 145 this.buffer_.push(1); |
| 146 }; |
| 147 |
| 148 |
| 149 /** |
| 150 * Encodes a 64-bit unsigned integer into its wire-format varint representation |
| 151 * and stores it in the buffer. Integers that are not representable in 64 bits |
| 152 * will be truncated. |
| 153 * @param {number} value The integer to convert. |
| 154 */ |
| 155 jspb.BinaryEncoder.prototype.writeUnsignedVarint64 = function(value) { |
| 156 goog.asserts.assert(value == Math.floor(value)); |
| 157 goog.asserts.assert((value >= 0) && |
| 158 (value < jspb.BinaryConstants.TWO_TO_64)); |
| 159 jspb.utils.splitInt64(value); |
| 160 this.writeSplitVarint64(jspb.utils.split64Low, |
| 161 jspb.utils.split64High); |
| 162 }; |
| 163 |
| 164 |
| 165 /** |
| 166 * Encodes a 64-bit signed integer into its wire-format varint representation |
| 167 * and stores it in the buffer. Integers that are not representable in 64 bits |
| 168 * will be truncated. |
| 169 * @param {number} value The integer to convert. |
| 170 */ |
| 171 jspb.BinaryEncoder.prototype.writeSignedVarint64 = function(value) { |
| 172 goog.asserts.assert(value == Math.floor(value)); |
| 173 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) && |
| 174 (value < jspb.BinaryConstants.TWO_TO_63)); |
| 175 jspb.utils.splitInt64(value); |
| 176 this.writeSplitVarint64(jspb.utils.split64Low, |
| 177 jspb.utils.split64High); |
| 178 }; |
| 179 |
| 180 |
| 181 /** |
| 182 * Encodes a JavaScript integer into its wire-format, zigzag-encoded varint |
| 183 * representation and stores it in the buffer. |
| 184 * @param {number} value The integer to convert. |
| 185 */ |
| 186 jspb.BinaryEncoder.prototype.writeZigzagVarint32 = function(value) { |
| 187 goog.asserts.assert(value == Math.floor(value)); |
| 188 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) && |
| 189 (value < jspb.BinaryConstants.TWO_TO_31)); |
| 190 this.writeUnsignedVarint32(((value << 1) ^ (value >> 31)) >>> 0); |
| 191 }; |
| 192 |
| 193 |
| 194 /** |
| 195 * Encodes a JavaScript integer into its wire-format, zigzag-encoded varint |
| 196 * representation and stores it in the buffer. Integers not representable in 64 |
| 197 * bits will be truncated. |
| 198 * @param {number} value The integer to convert. |
| 199 */ |
| 200 jspb.BinaryEncoder.prototype.writeZigzagVarint64 = function(value) { |
| 201 goog.asserts.assert(value == Math.floor(value)); |
| 202 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) && |
| 203 (value < jspb.BinaryConstants.TWO_TO_63)); |
| 204 jspb.utils.splitZigzag64(value); |
| 205 this.writeSplitVarint64(jspb.utils.split64Low, |
| 206 jspb.utils.split64High); |
| 207 }; |
| 208 |
| 209 |
| 210 /** |
| 211 * Writes a 8-bit unsigned integer to the buffer. Numbers outside the range |
| 212 * [0,2^8) will be truncated. |
| 213 * @param {number} value The value to write. |
| 214 */ |
| 215 jspb.BinaryEncoder.prototype.writeUint8 = function(value) { |
| 216 goog.asserts.assert(value == Math.floor(value)); |
| 217 goog.asserts.assert((value >= 0) && (value < 256)); |
| 218 this.buffer_.push((value >>> 0) & 0xFF); |
| 219 }; |
| 220 |
| 221 |
| 222 /** |
| 223 * Writes a 16-bit unsigned integer to the buffer. Numbers outside the |
| 224 * range [0,2^16) will be truncated. |
| 225 * @param {number} value The value to write. |
| 226 */ |
| 227 jspb.BinaryEncoder.prototype.writeUint16 = function(value) { |
| 228 goog.asserts.assert(value == Math.floor(value)); |
| 229 goog.asserts.assert((value >= 0) && (value < 65536)); |
| 230 this.buffer_.push((value >>> 0) & 0xFF); |
| 231 this.buffer_.push((value >>> 8) & 0xFF); |
| 232 }; |
| 233 |
| 234 |
| 235 /** |
| 236 * Writes a 32-bit unsigned integer to the buffer. Numbers outside the |
| 237 * range [0,2^32) will be truncated. |
| 238 * @param {number} value The value to write. |
| 239 */ |
| 240 jspb.BinaryEncoder.prototype.writeUint32 = function(value) { |
| 241 goog.asserts.assert(value == Math.floor(value)); |
| 242 goog.asserts.assert((value >= 0) && |
| 243 (value < jspb.BinaryConstants.TWO_TO_32)); |
| 244 this.buffer_.push((value >>> 0) & 0xFF); |
| 245 this.buffer_.push((value >>> 8) & 0xFF); |
| 246 this.buffer_.push((value >>> 16) & 0xFF); |
| 247 this.buffer_.push((value >>> 24) & 0xFF); |
| 248 }; |
| 249 |
| 250 |
| 251 /** |
| 252 * Writes a 64-bit unsigned integer to the buffer. Numbers outside the |
| 253 * range [0,2^64) will be truncated. |
| 254 * @param {number} value The value to write. |
| 255 */ |
| 256 jspb.BinaryEncoder.prototype.writeUint64 = function(value) { |
| 257 goog.asserts.assert(value == Math.floor(value)); |
| 258 goog.asserts.assert((value >= 0) && |
| 259 (value < jspb.BinaryConstants.TWO_TO_64)); |
| 260 jspb.utils.splitUint64(value); |
| 261 this.writeUint32(jspb.utils.split64Low); |
| 262 this.writeUint32(jspb.utils.split64High); |
| 263 }; |
| 264 |
| 265 |
| 266 /** |
| 267 * Writes a 8-bit integer to the buffer. Numbers outside the range |
| 268 * [-2^7,2^7) will be truncated. |
| 269 * @param {number} value The value to write. |
| 270 */ |
| 271 jspb.BinaryEncoder.prototype.writeInt8 = function(value) { |
| 272 goog.asserts.assert(value == Math.floor(value)); |
| 273 goog.asserts.assert((value >= -128) && (value < 128)); |
| 274 this.buffer_.push((value >>> 0) & 0xFF); |
| 275 }; |
| 276 |
| 277 |
| 278 /** |
| 279 * Writes a 16-bit integer to the buffer. Numbers outside the range |
| 280 * [-2^15,2^15) will be truncated. |
| 281 * @param {number} value The value to write. |
| 282 */ |
| 283 jspb.BinaryEncoder.prototype.writeInt16 = function(value) { |
| 284 goog.asserts.assert(value == Math.floor(value)); |
| 285 goog.asserts.assert((value >= -32768) && (value < 32768)); |
| 286 this.buffer_.push((value >>> 0) & 0xFF); |
| 287 this.buffer_.push((value >>> 8) & 0xFF); |
| 288 }; |
| 289 |
| 290 |
| 291 /** |
| 292 * Writes a 32-bit integer to the buffer. Numbers outside the range |
| 293 * [-2^31,2^31) will be truncated. |
| 294 * @param {number} value The value to write. |
| 295 */ |
| 296 jspb.BinaryEncoder.prototype.writeInt32 = function(value) { |
| 297 goog.asserts.assert(value == Math.floor(value)); |
| 298 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) && |
| 299 (value < jspb.BinaryConstants.TWO_TO_31)); |
| 300 this.buffer_.push((value >>> 0) & 0xFF); |
| 301 this.buffer_.push((value >>> 8) & 0xFF); |
| 302 this.buffer_.push((value >>> 16) & 0xFF); |
| 303 this.buffer_.push((value >>> 24) & 0xFF); |
| 304 }; |
| 305 |
| 306 |
| 307 /** |
| 308 * Writes a 64-bit integer to the buffer. Numbers outside the range |
| 309 * [-2^63,2^63) will be truncated. |
| 310 * @param {number} value The value to write. |
| 311 */ |
| 312 jspb.BinaryEncoder.prototype.writeInt64 = function(value) { |
| 313 goog.asserts.assert(value == Math.floor(value)); |
| 314 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) && |
| 315 (value < jspb.BinaryConstants.TWO_TO_63)); |
| 316 jspb.utils.splitInt64(value); |
| 317 this.writeUint32(jspb.utils.split64Low); |
| 318 this.writeUint32(jspb.utils.split64High); |
| 319 }; |
| 320 |
| 321 |
| 322 /** |
| 323 * Writes a single-precision floating point value to the buffer. Numbers |
| 324 * requiring more than 32 bits of precision will be truncated. |
| 325 * @param {number} value The value to write. |
| 326 */ |
| 327 jspb.BinaryEncoder.prototype.writeFloat = function(value) { |
| 328 goog.asserts.assert((value >= -jspb.BinaryConstants.FLOAT32_MAX) && |
| 329 (value <= jspb.BinaryConstants.FLOAT32_MAX)); |
| 330 jspb.utils.splitFloat32(value); |
| 331 this.writeUint32(jspb.utils.split64Low); |
| 332 }; |
| 333 |
| 334 |
| 335 /** |
| 336 * Writes a double-precision floating point value to the buffer. As this is |
| 337 * the native format used by JavaScript, no precision will be lost. |
| 338 * @param {number} value The value to write. |
| 339 */ |
| 340 jspb.BinaryEncoder.prototype.writeDouble = function(value) { |
| 341 goog.asserts.assert((value >= -jspb.BinaryConstants.FLOAT64_MAX) && |
| 342 (value <= jspb.BinaryConstants.FLOAT64_MAX)); |
| 343 jspb.utils.splitFloat64(value); |
| 344 this.writeUint32(jspb.utils.split64Low); |
| 345 this.writeUint32(jspb.utils.split64High); |
| 346 }; |
| 347 |
| 348 |
| 349 /** |
| 350 * Writes a boolean value to the buffer as a varint. |
| 351 * @param {boolean} value The value to write. |
| 352 */ |
| 353 jspb.BinaryEncoder.prototype.writeBool = function(value) { |
| 354 goog.asserts.assert(goog.isBoolean(value)); |
| 355 this.buffer_.push(value ? 1 : 0); |
| 356 }; |
| 357 |
| 358 |
| 359 /** |
| 360 * Writes an enum value to the buffer as a varint. |
| 361 * @param {number} value The value to write. |
| 362 */ |
| 363 jspb.BinaryEncoder.prototype.writeEnum = function(value) { |
| 364 goog.asserts.assert(value == Math.floor(value)); |
| 365 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) && |
| 366 (value < jspb.BinaryConstants.TWO_TO_31)); |
| 367 this.writeSignedVarint32(value); |
| 368 }; |
| 369 |
| 370 |
| 371 /** |
| 372 * Writes an arbitrary byte array to the buffer. |
| 373 * @param {!Uint8Array} bytes The array of bytes to write. |
| 374 */ |
| 375 jspb.BinaryEncoder.prototype.writeBytes = function(bytes) { |
| 376 this.buffer_.push.apply(this.buffer_, bytes); |
| 377 }; |
| 378 |
| 379 |
| 380 /** |
| 381 * Writes a 64-bit hash string (8 characters @ 8 bits of data each) to the |
| 382 * buffer as a varint. |
| 383 * @param {string} hash The hash to write. |
| 384 */ |
| 385 jspb.BinaryEncoder.prototype.writeVarintHash64 = function(hash) { |
| 386 jspb.utils.splitHash64(hash); |
| 387 this.writeSplitVarint64(jspb.utils.split64Low, |
| 388 jspb.utils.split64High); |
| 389 }; |
| 390 |
| 391 |
| 392 /** |
| 393 * Writes a 64-bit hash string (8 characters @ 8 bits of data each) to the |
| 394 * buffer as a fixed64. |
| 395 * @param {string} hash The hash to write. |
| 396 */ |
| 397 jspb.BinaryEncoder.prototype.writeFixedHash64 = function(hash) { |
| 398 jspb.utils.splitHash64(hash); |
| 399 this.writeUint32(jspb.utils.split64Low); |
| 400 this.writeUint32(jspb.utils.split64High); |
| 401 }; |
| 402 |
| 403 |
| 404 /** |
| 405 * Writes a UTF16 Javascript string to the buffer encoded as UTF8. |
| 406 * TODO(aappleby): Add support for surrogate pairs, reject unpaired surrogates. |
| 407 * @param {string} value The string to write. |
| 408 * @return {number} The number of bytes used to encode the string. |
| 409 */ |
| 410 jspb.BinaryEncoder.prototype.writeString = function(value) { |
| 411 var oldLength = this.buffer_.length; |
| 412 |
| 413 // UTF16 to UTF8 conversion loop swiped from goog.crypt.stringToUtf8ByteArray. |
| 414 for (var i = 0; i < value.length; i++) { |
| 415 var c = value.charCodeAt(i); |
| 416 if (c < 128) { |
| 417 this.buffer_.push(c); |
| 418 } else if (c < 2048) { |
| 419 this.buffer_.push((c >> 6) | 192); |
| 420 this.buffer_.push((c & 63) | 128); |
| 421 } else { |
| 422 this.buffer_.push((c >> 12) | 224); |
| 423 this.buffer_.push(((c >> 6) & 63) | 128); |
| 424 this.buffer_.push((c & 63) | 128); |
| 425 } |
| 426 } |
| 427 |
| 428 var length = this.buffer_.length - oldLength; |
| 429 return length; |
| 430 }; |
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