// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
/**
* @fileoverview BinaryEncode defines methods for encoding Javascript values
* into arrays of bytes compatible with the Protocol Buffer wire format.
*
* @author aappleby@google.com (Austin Appleby)
*/
goog.provide('jspb.BinaryEncoder');
goog.require('goog.asserts');
goog.require('jspb.BinaryConstants');
goog.require('jspb.utils');
/**
* BinaryEncoder implements encoders for all the wire types specified in
* https://developers.google.com/protocol-buffers/docs/encoding.
*
* @constructor
* @struct
*/
jspb.BinaryEncoder = function() {
/** @private {!Array.<number>} */
this.buffer_ = [];
};
/**
* @return {number}
*/
jspb.BinaryEncoder.prototype.length = function() {
return this.buffer_.length;
};
/**
* @return {!Array.<number>}
*/
jspb.BinaryEncoder.prototype.end = function() {
var buffer = this.buffer_;
this.buffer_ = [];
return buffer;
};
/**
* Encodes a 64-bit integer in 32:32 split representation into its wire-format
* varint representation and stores it in the buffer.
* @param {number} lowBits The low 32 bits of the int.
* @param {number} highBits The high 32 bits of the int.
*/
jspb.BinaryEncoder.prototype.writeSplitVarint64 = function(lowBits, highBits) {
goog.asserts.assert(lowBits == Math.floor(lowBits));
goog.asserts.assert(highBits == Math.floor(highBits));
goog.asserts.assert((lowBits >= 0) &&
(lowBits < jspb.BinaryConstants.TWO_TO_32));
goog.asserts.assert((highBits >= 0) &&
(highBits < jspb.BinaryConstants.TWO_TO_32));
// Break the binary representation into chunks of 7 bits, set the 8th bit
// in each chunk if it's not the final chunk, and append to the result.
while (highBits > 0 || lowBits > 127) {
this.buffer_.push((lowBits & 0x7f) | 0x80);
lowBits = ((lowBits >>> 7) | (highBits << 25)) >>> 0;
highBits = highBits >>> 7;
}
this.buffer_.push(lowBits);
};
/**
* Encodes a 32-bit unsigned integer into its wire-format varint representation
* and stores it in the buffer.
* @param {number} value The integer to convert.
*/
jspb.BinaryEncoder.prototype.writeUnsignedVarint32 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= 0) &&
(value < jspb.BinaryConstants.TWO_TO_32));
while (value > 127) {
this.buffer_.push((value & 0x7f) | 0x80);
value = value >>> 7;
}
this.buffer_.push(value);
};
/**
* Encodes a 32-bit signed integer into its wire-format varint representation
* and stores it in the buffer.
* @param {number} value The integer to convert.
*/
jspb.BinaryEncoder.prototype.writeSignedVarint32 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) &&
(value < jspb.BinaryConstants.TWO_TO_31));
// Use the unsigned version if the value is not negative.
if (value >= 0) {
this.writeUnsignedVarint32(value);
return;
}
// Write nine bytes with a _signed_ right shift so we preserve the sign bit.
for (var i = 0; i < 9; i++) {
this.buffer_.push((value & 0x7f) | 0x80);
value = value >> 7;
}
// The above loop writes out 63 bits, so the last byte is always the sign bit
// which is always set for negative numbers.
this.buffer_.push(1);
};
/**
* Encodes a 64-bit unsigned integer into its wire-format varint representation
* and stores it in the buffer. Integers that are not representable in 64 bits
* will be truncated.
* @param {number} value The integer to convert.
*/
jspb.BinaryEncoder.prototype.writeUnsignedVarint64 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= 0) &&
(value < jspb.BinaryConstants.TWO_TO_64));
jspb.utils.splitInt64(value);
this.writeSplitVarint64(jspb.utils.split64Low,
jspb.utils.split64High);
};
/**
* Encodes a 64-bit signed integer into its wire-format varint representation
* and stores it in the buffer. Integers that are not representable in 64 bits
* will be truncated.
* @param {number} value The integer to convert.
*/
jspb.BinaryEncoder.prototype.writeSignedVarint64 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) &&
(value < jspb.BinaryConstants.TWO_TO_63));
jspb.utils.splitInt64(value);
this.writeSplitVarint64(jspb.utils.split64Low,
jspb.utils.split64High);
};
/**
* Encodes a JavaScript integer into its wire-format, zigzag-encoded varint
* representation and stores it in the buffer.
* @param {number} value The integer to convert.
*/
jspb.BinaryEncoder.prototype.writeZigzagVarint32 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) &&
(value < jspb.BinaryConstants.TWO_TO_31));
this.writeUnsignedVarint32(((value << 1) ^ (value >> 31)) >>> 0);
};
/**
* Encodes a JavaScript integer into its wire-format, zigzag-encoded varint
* representation and stores it in the buffer. Integers not representable in 64
* bits will be truncated.
* @param {number} value The integer to convert.
*/
jspb.BinaryEncoder.prototype.writeZigzagVarint64 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) &&
(value < jspb.BinaryConstants.TWO_TO_63));
jspb.utils.splitZigzag64(value);
this.writeSplitVarint64(jspb.utils.split64Low,
jspb.utils.split64High);
};
/**
* Writes a 8-bit unsigned integer to the buffer. Numbers outside the range
* [0,2^8) will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeUint8 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= 0) && (value < 256));
this.buffer_.push((value >>> 0) & 0xFF);
};
/**
* Writes a 16-bit unsigned integer to the buffer. Numbers outside the
* range [0,2^16) will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeUint16 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= 0) && (value < 65536));
this.buffer_.push((value >>> 0) & 0xFF);
this.buffer_.push((value >>> 8) & 0xFF);
};
/**
* Writes a 32-bit unsigned integer to the buffer. Numbers outside the
* range [0,2^32) will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeUint32 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= 0) &&
(value < jspb.BinaryConstants.TWO_TO_32));
this.buffer_.push((value >>> 0) & 0xFF);
this.buffer_.push((value >>> 8) & 0xFF);
this.buffer_.push((value >>> 16) & 0xFF);
this.buffer_.push((value >>> 24) & 0xFF);
};
/**
* Writes a 64-bit unsigned integer to the buffer. Numbers outside the
* range [0,2^64) will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeUint64 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= 0) &&
(value < jspb.BinaryConstants.TWO_TO_64));
jspb.utils.splitUint64(value);
this.writeUint32(jspb.utils.split64Low);
this.writeUint32(jspb.utils.split64High);
};
/**
* Writes a 8-bit integer to the buffer. Numbers outside the range
* [-2^7,2^7) will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeInt8 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -128) && (value < 128));
this.buffer_.push((value >>> 0) & 0xFF);
};
/**
* Writes a 16-bit integer to the buffer. Numbers outside the range
* [-2^15,2^15) will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeInt16 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -32768) && (value < 32768));
this.buffer_.push((value >>> 0) & 0xFF);
this.buffer_.push((value >>> 8) & 0xFF);
};
/**
* Writes a 32-bit integer to the buffer. Numbers outside the range
* [-2^31,2^31) will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeInt32 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) &&
(value < jspb.BinaryConstants.TWO_TO_31));
this.buffer_.push((value >>> 0) & 0xFF);
this.buffer_.push((value >>> 8) & 0xFF);
this.buffer_.push((value >>> 16) & 0xFF);
this.buffer_.push((value >>> 24) & 0xFF);
};
/**
* Writes a 64-bit integer to the buffer. Numbers outside the range
* [-2^63,2^63) will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeInt64 = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_63) &&
(value < jspb.BinaryConstants.TWO_TO_63));
jspb.utils.splitInt64(value);
this.writeUint32(jspb.utils.split64Low);
this.writeUint32(jspb.utils.split64High);
};
/**
* Writes a single-precision floating point value to the buffer. Numbers
* requiring more than 32 bits of precision will be truncated.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeFloat = function(value) {
goog.asserts.assert((value >= -jspb.BinaryConstants.FLOAT32_MAX) &&
(value <= jspb.BinaryConstants.FLOAT32_MAX));
jspb.utils.splitFloat32(value);
this.writeUint32(jspb.utils.split64Low);
};
/**
* Writes a double-precision floating point value to the buffer. As this is
* the native format used by JavaScript, no precision will be lost.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeDouble = function(value) {
goog.asserts.assert((value >= -jspb.BinaryConstants.FLOAT64_MAX) &&
(value <= jspb.BinaryConstants.FLOAT64_MAX));
jspb.utils.splitFloat64(value);
this.writeUint32(jspb.utils.split64Low);
this.writeUint32(jspb.utils.split64High);
};
/**
* Writes a boolean value to the buffer as a varint.
* @param {boolean} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeBool = function(value) {
goog.asserts.assert(goog.isBoolean(value));
this.buffer_.push(value ? 1 : 0);
};
/**
* Writes an enum value to the buffer as a varint.
* @param {number} value The value to write.
*/
jspb.BinaryEncoder.prototype.writeEnum = function(value) {
goog.asserts.assert(value == Math.floor(value));
goog.asserts.assert((value >= -jspb.BinaryConstants.TWO_TO_31) &&
(value < jspb.BinaryConstants.TWO_TO_31));
this.writeSignedVarint32(value);
};
/**
* Writes an arbitrary byte array to the buffer.
* @param {!Uint8Array} bytes The array of bytes to write.
*/
jspb.BinaryEncoder.prototype.writeBytes = function(bytes) {
this.buffer_.push.apply(this.buffer_, bytes);
};
/**
* Writes a 64-bit hash string (8 characters @ 8 bits of data each) to the
* buffer as a varint.
* @param {string} hash The hash to write.
*/
jspb.BinaryEncoder.prototype.writeVarintHash64 = function(hash) {
jspb.utils.splitHash64(hash);
this.writeSplitVarint64(jspb.utils.split64Low,
jspb.utils.split64High);
};
/**
* Writes a 64-bit hash string (8 characters @ 8 bits of data each) to the
* buffer as a fixed64.
* @param {string} hash The hash to write.
*/
jspb.BinaryEncoder.prototype.writeFixedHash64 = function(hash) {
jspb.utils.splitHash64(hash);
this.writeUint32(jspb.utils.split64Low);
this.writeUint32(jspb.utils.split64High);
};
/**
* Writes a UTF16 Javascript string to the buffer encoded as UTF8.
* TODO(aappleby): Add support for surrogate pairs, reject unpaired surrogates.
* @param {string} value The string to write.
* @return {number} The number of bytes used to encode the string.
*/
jspb.BinaryEncoder.prototype.writeString = function(value) {
var oldLength = this.buffer_.length;
// UTF16 to UTF8 conversion loop swiped from goog.crypt.stringToUtf8ByteArray.
for (var i = 0; i < value.length; i++) {
var c = value.charCodeAt(i);
if (c < 128) {
this.buffer_.push(c);
} else if (c < 2048) {
this.buffer_.push((c >> 6) | 192);
this.buffer_.push((c & 63) | 128);
} else {
this.buffer_.push((c >> 12) | 224);
this.buffer_.push(((c >> 6) & 63) | 128);
this.buffer_.push((c & 63) | 128);
}
}
var length = this.buffer_.length - oldLength;
return length;
};