Jisi Liu | 3b3c8ab | 2016-03-30 11:39:59 -0700 | [diff] [blame] | 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 | }; |