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 38goog.provide('jspb.BinaryEncoder'); 39 40goog.require('goog.asserts'); 41goog.require('jspb.BinaryConstants'); 42goog.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 */ 53jspb.BinaryEncoder = function() { 54 /** @private {!Array<number>} */ 55 this.buffer_ = []; 56}; 57 58 59/** 60 * @return {number} 61 */ 62jspb.BinaryEncoder.prototype.length = function() { 63 return this.buffer_.length; 64}; 65 66 67/** 68 * @return {!Array<number>} 69 */ 70jspb.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 */ 83jspb.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 64-bit integer in 32:32 split representation into its wire-format 104 * fixed representation and stores it in the buffer. 105 * @param {number} lowBits The low 32 bits of the int. 106 * @param {number} highBits The high 32 bits of the int. 107 */ 108jspb.BinaryEncoder.prototype.writeSplitFixed64 = function(lowBits, highBits) { 109 goog.asserts.assert(lowBits == Math.floor(lowBits)); 110 goog.asserts.assert(highBits == Math.floor(highBits)); 111 goog.asserts.assert((lowBits >= 0) && 112 (lowBits < jspb.BinaryConstants.TWO_TO_32)); 113 goog.asserts.assert((highBits >= 0) && 114 (highBits < jspb.BinaryConstants.TWO_TO_32)); 115 this.writeUint32(lowBits); 116 this.writeUint32(highBits); 117}; 118 119 120/** 121 * Encodes a 32-bit unsigned integer into its wire-format varint representation 122 * and stores it in the buffer. 123 * @param {number} value The integer to convert. 124 */ 125jspb.BinaryEncoder.prototype.writeUnsignedVarint32 = function(value) { 126 goog.asserts.assert(value == Math.floor(value)); 127 goog.asserts.assert((value >= 0) && 128 (value < jspb.BinaryConstants.TWO_TO_32)); 129 130 while (value > 127) { 131 this.buffer_.push((value & 0x7f) | 0x80); 132 value = value >>> 7; 133 } 134 135 this.buffer_.push(value); 136}; 137 138 139/** 140 * Encodes a 32-bit signed integer into its wire-format varint representation 141 * and stores it in the buffer. 142 * @param {number} value The integer to convert. 143 */ 144jspb.BinaryEncoder.prototype.writeSignedVarint32 = function(value) { 145 goog.asserts.assert(value == Math.floor(value)); 146 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) && 147 (value < jspb.BinaryConstants.TWO_TO_31)); 148 149 // Use the unsigned version if the value is not negative. 150 if (value >= 0) { 151 this.writeUnsignedVarint32(value); 152 return; 153 } 154 155 // Write nine bytes with a _signed_ right shift so we preserve the sign bit. 156 for (var i = 0; i < 9; i++) { 157 this.buffer_.push((value & 0x7f) | 0x80); 158 value = value >> 7; 159 } 160 161 // The above loop writes out 63 bits, so the last byte is always the sign bit 162 // which is always set for negative numbers. 163 this.buffer_.push(1); 164}; 165 166 167/** 168 * Encodes a 64-bit unsigned integer into its wire-format varint representation 169 * and stores it in the buffer. Integers that are not representable in 64 bits 170 * will be truncated. 171 * @param {number} value The integer to convert. 172 */ 173jspb.BinaryEncoder.prototype.writeUnsignedVarint64 = function(value) { 174 goog.asserts.assert(value == Math.floor(value)); 175 goog.asserts.assert((value >= 0) && 176 (value < jspb.BinaryConstants.TWO_TO_64)); 177 jspb.utils.splitInt64(value); 178 this.writeSplitVarint64(jspb.utils.split64Low, 179 jspb.utils.split64High); 180}; 181 182 183/** 184 * Encodes a 64-bit signed integer into its wire-format varint representation 185 * and stores it in the buffer. Integers that are not representable in 64 bits 186 * will be truncated. 187 * @param {number} value The integer to convert. 188 */ 189jspb.BinaryEncoder.prototype.writeSignedVarint64 = function(value) { 190 goog.asserts.assert(value == Math.floor(value)); 191 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) && 192 (value < jspb.BinaryConstants.TWO_TO_63)); 193 jspb.utils.splitInt64(value); 194 this.writeSplitVarint64(jspb.utils.split64Low, 195 jspb.utils.split64High); 196}; 197 198 199/** 200 * Encodes a JavaScript integer into its wire-format, zigzag-encoded varint 201 * representation and stores it in the buffer. 202 * @param {number} value The integer to convert. 203 */ 204jspb.BinaryEncoder.prototype.writeZigzagVarint32 = function(value) { 205 goog.asserts.assert(value == Math.floor(value)); 206 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) && 207 (value < jspb.BinaryConstants.TWO_TO_31)); 208 this.writeUnsignedVarint32(((value << 1) ^ (value >> 31)) >>> 0); 209}; 210 211 212/** 213 * Encodes a JavaScript integer into its wire-format, zigzag-encoded varint 214 * representation and stores it in the buffer. Integers not representable in 64 215 * bits will be truncated. 216 * @param {number} value The integer to convert. 217 */ 218jspb.BinaryEncoder.prototype.writeZigzagVarint64 = function(value) { 219 goog.asserts.assert(value == Math.floor(value)); 220 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) && 221 (value < jspb.BinaryConstants.TWO_TO_63)); 222 jspb.utils.splitZigzag64(value); 223 this.writeSplitVarint64(jspb.utils.split64Low, 224 jspb.utils.split64High); 225}; 226 227 228/** 229 * Encodes a JavaScript decimal string into its wire-format, zigzag-encoded 230 * varint representation and stores it in the buffer. Integers not representable 231 * in 64 bits will be truncated. 232 * @param {string} value The integer to convert. 233 */ 234jspb.BinaryEncoder.prototype.writeZigzagVarint64String = function(value) { 235 // TODO(haberman): write lossless 64-bit zig-zag math. 236 this.writeZigzagVarint64(parseInt(value, 10)); 237}; 238 239 240/** 241 * Writes a 8-bit unsigned integer to the buffer. Numbers outside the range 242 * [0,2^8) will be truncated. 243 * @param {number} value The value to write. 244 */ 245jspb.BinaryEncoder.prototype.writeUint8 = function(value) { 246 goog.asserts.assert(value == Math.floor(value)); 247 goog.asserts.assert((value >= 0) && (value < 256)); 248 this.buffer_.push((value >>> 0) & 0xFF); 249}; 250 251 252/** 253 * Writes a 16-bit unsigned integer to the buffer. Numbers outside the 254 * range [0,2^16) will be truncated. 255 * @param {number} value The value to write. 256 */ 257jspb.BinaryEncoder.prototype.writeUint16 = function(value) { 258 goog.asserts.assert(value == Math.floor(value)); 259 goog.asserts.assert((value >= 0) && (value < 65536)); 260 this.buffer_.push((value >>> 0) & 0xFF); 261 this.buffer_.push((value >>> 8) & 0xFF); 262}; 263 264 265/** 266 * Writes a 32-bit unsigned integer to the buffer. Numbers outside the 267 * range [0,2^32) will be truncated. 268 * @param {number} value The value to write. 269 */ 270jspb.BinaryEncoder.prototype.writeUint32 = function(value) { 271 goog.asserts.assert(value == Math.floor(value)); 272 goog.asserts.assert((value >= 0) && 273 (value < jspb.BinaryConstants.TWO_TO_32)); 274 this.buffer_.push((value >>> 0) & 0xFF); 275 this.buffer_.push((value >>> 8) & 0xFF); 276 this.buffer_.push((value >>> 16) & 0xFF); 277 this.buffer_.push((value >>> 24) & 0xFF); 278}; 279 280 281/** 282 * Writes a 64-bit unsigned integer to the buffer. Numbers outside the 283 * range [0,2^64) will be truncated. 284 * @param {number} value The value to write. 285 */ 286jspb.BinaryEncoder.prototype.writeUint64 = function(value) { 287 goog.asserts.assert(value == Math.floor(value)); 288 goog.asserts.assert((value >= 0) && 289 (value < jspb.BinaryConstants.TWO_TO_64)); 290 jspb.utils.splitUint64(value); 291 this.writeUint32(jspb.utils.split64Low); 292 this.writeUint32(jspb.utils.split64High); 293}; 294 295 296/** 297 * Writes a 8-bit integer to the buffer. Numbers outside the range 298 * [-2^7,2^7) will be truncated. 299 * @param {number} value The value to write. 300 */ 301jspb.BinaryEncoder.prototype.writeInt8 = function(value) { 302 goog.asserts.assert(value == Math.floor(value)); 303 goog.asserts.assert((value >= -128) && (value < 128)); 304 this.buffer_.push((value >>> 0) & 0xFF); 305}; 306 307 308/** 309 * Writes a 16-bit integer to the buffer. Numbers outside the range 310 * [-2^15,2^15) will be truncated. 311 * @param {number} value The value to write. 312 */ 313jspb.BinaryEncoder.prototype.writeInt16 = function(value) { 314 goog.asserts.assert(value == Math.floor(value)); 315 goog.asserts.assert((value >= -32768) && (value < 32768)); 316 this.buffer_.push((value >>> 0) & 0xFF); 317 this.buffer_.push((value >>> 8) & 0xFF); 318}; 319 320 321/** 322 * Writes a 32-bit integer to the buffer. Numbers outside the range 323 * [-2^31,2^31) will be truncated. 324 * @param {number} value The value to write. 325 */ 326jspb.BinaryEncoder.prototype.writeInt32 = function(value) { 327 goog.asserts.assert(value == Math.floor(value)); 328 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) && 329 (value < jspb.BinaryConstants.TWO_TO_31)); 330 this.buffer_.push((value >>> 0) & 0xFF); 331 this.buffer_.push((value >>> 8) & 0xFF); 332 this.buffer_.push((value >>> 16) & 0xFF); 333 this.buffer_.push((value >>> 24) & 0xFF); 334}; 335 336 337/** 338 * Writes a 64-bit integer to the buffer. Numbers outside the range 339 * [-2^63,2^63) will be truncated. 340 * @param {number} value The value to write. 341 */ 342jspb.BinaryEncoder.prototype.writeInt64 = function(value) { 343 goog.asserts.assert(value == Math.floor(value)); 344 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) && 345 (value < jspb.BinaryConstants.TWO_TO_63)); 346 jspb.utils.splitInt64(value); 347 this.writeSplitFixed64(jspb.utils.split64Low, jspb.utils.split64High); 348}; 349 350 351/** 352 * Writes a 64-bit integer decimal strings to the buffer. Numbers outside the 353 * range [-2^63,2^63) will be truncated. 354 * @param {string} value The value to write. 355 */ 356jspb.BinaryEncoder.prototype.writeInt64String = function(value) { 357 goog.asserts.assert(value == Math.floor(value)); 358 goog.asserts.assert((+value >= -jspb.BinaryConstants.TWO_TO_63) && 359 (+value < jspb.BinaryConstants.TWO_TO_63)); 360 jspb.utils.splitHash64(jspb.utils.decimalStringToHash64(value)); 361 this.writeSplitFixed64(jspb.utils.split64Low, jspb.utils.split64High); 362}; 363 364 365/** 366 * Writes a single-precision floating point value to the buffer. Numbers 367 * requiring more than 32 bits of precision will be truncated. 368 * @param {number} value The value to write. 369 */ 370jspb.BinaryEncoder.prototype.writeFloat = function(value) { 371 goog.asserts.assert((value >= -jspb.BinaryConstants.FLOAT32_MAX) && 372 (value <= jspb.BinaryConstants.FLOAT32_MAX)); 373 jspb.utils.splitFloat32(value); 374 this.writeUint32(jspb.utils.split64Low); 375}; 376 377 378/** 379 * Writes a double-precision floating point value to the buffer. As this is 380 * the native format used by JavaScript, no precision will be lost. 381 * @param {number} value The value to write. 382 */ 383jspb.BinaryEncoder.prototype.writeDouble = function(value) { 384 goog.asserts.assert((value >= -jspb.BinaryConstants.FLOAT64_MAX) && 385 (value <= jspb.BinaryConstants.FLOAT64_MAX)); 386 jspb.utils.splitFloat64(value); 387 this.writeUint32(jspb.utils.split64Low); 388 this.writeUint32(jspb.utils.split64High); 389}; 390 391 392/** 393 * Writes a boolean value to the buffer as a varint. We allow numbers as input 394 * because the JSPB code generator uses 0/1 instead of true/false to save space 395 * in the string representation of the proto. 396 * @param {boolean|number} value The value to write. 397 */ 398jspb.BinaryEncoder.prototype.writeBool = function(value) { 399 goog.asserts.assert(goog.isBoolean(value) || goog.isNumber(value)); 400 this.buffer_.push(value ? 1 : 0); 401}; 402 403 404/** 405 * Writes an enum value to the buffer as a varint. 406 * @param {number} value The value to write. 407 */ 408jspb.BinaryEncoder.prototype.writeEnum = function(value) { 409 goog.asserts.assert(value == Math.floor(value)); 410 goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) && 411 (value < jspb.BinaryConstants.TWO_TO_31)); 412 this.writeSignedVarint32(value); 413}; 414 415 416/** 417 * Writes an arbitrary byte array to the buffer. 418 * @param {!Uint8Array} bytes The array of bytes to write. 419 */ 420jspb.BinaryEncoder.prototype.writeBytes = function(bytes) { 421 this.buffer_.push.apply(this.buffer_, bytes); 422}; 423 424 425/** 426 * Writes a 64-bit hash string (8 characters @ 8 bits of data each) to the 427 * buffer as a varint. 428 * @param {string} hash The hash to write. 429 */ 430jspb.BinaryEncoder.prototype.writeVarintHash64 = function(hash) { 431 jspb.utils.splitHash64(hash); 432 this.writeSplitVarint64(jspb.utils.split64Low, 433 jspb.utils.split64High); 434}; 435 436 437/** 438 * Writes a 64-bit hash string (8 characters @ 8 bits of data each) to the 439 * buffer as a fixed64. 440 * @param {string} hash The hash to write. 441 */ 442jspb.BinaryEncoder.prototype.writeFixedHash64 = function(hash) { 443 jspb.utils.splitHash64(hash); 444 this.writeUint32(jspb.utils.split64Low); 445 this.writeUint32(jspb.utils.split64High); 446}; 447 448 449/** 450 * Writes a UTF16 Javascript string to the buffer encoded as UTF8. 451 * TODO(aappleby): Add support for surrogate pairs, reject unpaired surrogates. 452 * @param {string} value The string to write. 453 * @return {number} The number of bytes used to encode the string. 454 */ 455jspb.BinaryEncoder.prototype.writeString = function(value) { 456 var oldLength = this.buffer_.length; 457 458 for (var i = 0; i < value.length; i++) { 459 460 var c = value.charCodeAt(i); 461 462 if (c < 128) { 463 this.buffer_.push(c); 464 } else if (c < 2048) { 465 this.buffer_.push((c >> 6) | 192); 466 this.buffer_.push((c & 63) | 128); 467 } else if (c < 65536) { 468 // Look for surrogates 469 if (c >= 0xD800 && c <= 0xDBFF && i + 1 < value.length) { 470 var second = value.charCodeAt(i + 1); 471 if (second >= 0xDC00 && second <= 0xDFFF) { // low surrogate 472 // http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae 473 c = (c - 0xD800) * 0x400 + second - 0xDC00 + 0x10000; 474 475 this.buffer_.push((c >> 18) | 240); 476 this.buffer_.push(((c >> 12) & 63 ) | 128); 477 this.buffer_.push(((c >> 6) & 63) | 128); 478 this.buffer_.push((c & 63) | 128); 479 i++; 480 } 481 } 482 else { 483 this.buffer_.push((c >> 12) | 224); 484 this.buffer_.push(((c >> 6) & 63) | 128); 485 this.buffer_.push((c & 63) | 128); 486 } 487 } 488 } 489 490 var length = this.buffer_.length - oldLength; 491 return length; 492}; 493