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 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 */ 107jspb.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 */ 126jspb.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 */ 155jspb.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 */ 171jspb.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 */ 186jspb.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 */ 200jspb.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 */ 215jspb.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 */ 227jspb.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 */ 240jspb.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 */ 256jspb.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 */ 271jspb.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 */ 283jspb.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 */ 296jspb.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 */ 312jspb.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 */ 327jspb.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 */ 340jspb.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 */ 353jspb.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 */ 363jspb.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 */ 375jspb.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 */ 385jspb.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 */ 397jspb.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 */ 410jspb.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}; 431