refactor reader and writer.
This commit is contained in:
Christopher Jeffrey
parent
7e4ac9b0ed
commit
f0c73f41a6
@ -31,6 +31,37 @@ function BufferReader(data, zeroCopy) {
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this.stack = [];
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}
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/**
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* Get total size of passed-in Buffer.
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* @returns {Buffer}
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*/
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BufferReader.prototype.getSize = function getSize() {
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return this.data.length;
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};
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/**
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* Calculate number of bytes left to read.
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* @returns {Number}
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*/
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BufferReader.prototype.left = function left() {
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assert(this.offset <= this.data.length);
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return this.data.length - this.offset;
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};
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/**
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* Seek to a position to read from by offset.
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* @param {Number} off - Offset (positive or negative).
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*/
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BufferReader.prototype.seek = function seek(off) {
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assert(this.offset + off >= 0);
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assert(this.offset + off <= this.data.length);
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this.offset += off;
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return off;
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};
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/**
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* Mark the current starting position.
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*/
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@ -384,167 +415,6 @@ BufferReader.prototype.read53BE = function read53BE() {
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return this.read64NBE(true);
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};
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/**
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* Read N bytes (will do a fast slice if zero copy).
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* @param {Number} size
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* @returns {Buffer}
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*/
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BufferReader.prototype.readBytes = function readBytes(size) {
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var ret;
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assert(size >= 0);
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assert(this.offset + size <= this.data.length);
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if (this.zeroCopy) {
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ret = this.data.slice(this.offset, this.offset + size);
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} else {
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ret = new Buffer(size);
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this.data.copy(ret, 0, this.offset, this.offset + size);
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}
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this.offset += size;
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return ret;
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};
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/**
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* Read a string.
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* @param {String} enc - Any buffer-supported encoding.
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* @param {Number} size
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* @returns {String}
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*/
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BufferReader.prototype.readString = function readString(enc, size) {
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var ret;
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assert(size >= 0);
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assert(this.offset + size <= this.data.length);
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ret = this.data.toString(enc, this.offset, this.offset + size);
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this.offset += size;
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return ret;
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};
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/**
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* Read a 32-byte hash.
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* @param {String} enc - `"hex"` or `null`.
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* @returns {Hash|Buffer}
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*/
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BufferReader.prototype.readHash = function readHash(enc) {
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if (enc)
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return this.readString(enc, 32);
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return this.readBytes(32);
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};
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/**
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* Read string of a varint length.
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* @param {String} enc - Any buffer-supported encoding.
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* @returns {String}
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*/
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BufferReader.prototype.readVarString = function readVarString(enc) {
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return this.readString(enc, this.readVarint());
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};
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/**
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* Read a varint number of bytes (will do a fast slice if zero copy).
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* @returns {Buffer}
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*/
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BufferReader.prototype.readVarBytes = function readVarBytes() {
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return this.readBytes(this.readVarint());
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};
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/**
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* Read a null-terminated string.
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* @param {String} enc - Any buffer-supported encoding.
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* @returns {String}
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*/
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BufferReader.prototype.readNullString = function readNullString(enc) {
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var i, ret;
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assert(this.offset + 1 <= this.data.length);
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for (i = this.offset; i < this.data.length; i++) {
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if (this.data[i] === 0)
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break;
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}
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assert(i !== this.data.length);
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ret = this.readString(enc, i - this.offset);
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this.offset = i + 1;
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return ret;
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};
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/**
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* Read a varint.
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* @param {Boolean?} big - Whether to read as a big number.
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* @returns {Number}
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*/
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BufferReader.prototype.readVarint = function readVarint(big) {
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var result;
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assert(this.offset + 1 <= this.data.length);
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result = utils.readVarint(this.data, this.offset, big);
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assert(result.off <= this.data.length);
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assert(result.r >= 0);
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this.offset = result.off;
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return result.r;
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};
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/**
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* Calculate number of bytes left to read.
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* @returns {Number}
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*/
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BufferReader.prototype.left = function left() {
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assert(this.offset <= this.data.length);
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return this.data.length - this.offset;
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};
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/**
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* Get total size of passed-in Buffer.
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* @returns {Buffer}
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*/
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BufferReader.prototype.getSize = function getSize() {
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return this.data.length;
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};
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/**
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* Seek to a position to read from by offset.
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* @param {Number} off - Offset (positive or negative).
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*/
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BufferReader.prototype.seek = function seek(off) {
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assert(this.offset + off >= 0);
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assert(this.offset + off <= this.data.length);
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this.offset += off;
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return off;
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};
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/**
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* Create a checksum from the last start position.
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* @returns {Number} Checksum.
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*/
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BufferReader.prototype.createChecksum = function createChecksum() {
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var start = this.stack[this.stack.length - 1] || 0;
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var data = this.data.slice(start, this.offset);
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return utils.readU32(utils.checksum(data), 0);
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};
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/**
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* Verify a 4-byte checksum against a calculated checksum.
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* @returns {Number} checksum
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* @throws on bad checksum
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*/
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BufferReader.prototype.verifyChecksum = function verifyChecksum() {
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var chk = this.createChecksum();
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var checksum = this.readU32();
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assert(chk === checksum, 'Checksum mismatch.');
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return checksum;
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};
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/**
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* Read float le.
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* @returns {Number}
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@ -597,6 +467,136 @@ BufferReader.prototype.readDoubleBE = function readDoubleBE() {
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return ret;
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};
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/**
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* Read a varint.
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* @param {Boolean?} big - Whether to read as a big number.
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* @returns {Number}
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*/
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BufferReader.prototype.readVarint = function readVarint(big) {
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var result;
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assert(this.offset + 1 <= this.data.length);
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result = utils.readVarint(this.data, this.offset, big);
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assert(result.off <= this.data.length);
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assert(result.r >= 0);
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this.offset = result.off;
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return result.r;
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};
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/**
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* Read N bytes (will do a fast slice if zero copy).
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* @param {Number} size
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* @returns {Buffer}
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*/
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BufferReader.prototype.readBytes = function readBytes(size) {
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var ret;
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assert(size >= 0);
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assert(this.offset + size <= this.data.length);
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if (this.zeroCopy) {
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ret = this.data.slice(this.offset, this.offset + size);
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} else {
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ret = new Buffer(size);
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this.data.copy(ret, 0, this.offset, this.offset + size);
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}
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this.offset += size;
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return ret;
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};
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/**
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* Read a varint number of bytes (will do a fast slice if zero copy).
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* @returns {Buffer}
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*/
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BufferReader.prototype.readVarBytes = function readVarBytes() {
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return this.readBytes(this.readVarint());
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};
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/**
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* Read a string.
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* @param {String} enc - Any buffer-supported encoding.
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* @param {Number} size
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* @returns {String}
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*/
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BufferReader.prototype.readString = function readString(enc, size) {
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var ret;
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assert(size >= 0);
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assert(this.offset + size <= this.data.length);
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ret = this.data.toString(enc, this.offset, this.offset + size);
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this.offset += size;
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return ret;
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};
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/**
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* Read a 32-byte hash.
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* @param {String} enc - `"hex"` or `null`.
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* @returns {Hash|Buffer}
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*/
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BufferReader.prototype.readHash = function readHash(enc) {
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if (enc)
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return this.readString(enc, 32);
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return this.readBytes(32);
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};
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/**
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* Read string of a varint length.
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* @param {String} enc - Any buffer-supported encoding.
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* @returns {String}
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*/
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BufferReader.prototype.readVarString = function readVarString(enc) {
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return this.readString(enc, this.readVarint());
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};
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/**
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* Read a null-terminated string.
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* @param {String} enc - Any buffer-supported encoding.
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* @returns {String}
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*/
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BufferReader.prototype.readNullString = function readNullString(enc) {
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var i, ret;
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assert(this.offset + 1 <= this.data.length);
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for (i = this.offset; i < this.data.length; i++) {
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if (this.data[i] === 0)
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break;
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}
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assert(i !== this.data.length);
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ret = this.readString(enc, i - this.offset);
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this.offset = i + 1;
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return ret;
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};
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/**
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* Create a checksum from the last start position.
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* @returns {Number} Checksum.
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*/
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BufferReader.prototype.createChecksum = function createChecksum() {
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var start = this.stack[this.stack.length - 1] || 0;
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var data = this.data.slice(start, this.offset);
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return utils.readU32(utils.checksum(data), 0);
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};
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/**
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* Verify a 4-byte checksum against a calculated checksum.
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* @returns {Number} checksum
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* @throws on bad checksum
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*/
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BufferReader.prototype.verifyChecksum = function verifyChecksum() {
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var chk = this.createChecksum();
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var checksum = this.readU32();
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assert(chk === checksum, 'Checksum mismatch.');
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return checksum;
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};
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/*
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* Expose
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*/
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@ -86,6 +86,24 @@ BufferWriter.prototype.render = function render(keep) {
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return data;
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};
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/**
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* Get size of data written so far.
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* @returns {Number}
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*/
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BufferWriter.prototype.getSize = function getSize() {
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return this.written;
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};
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/*
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* Seek to relative offset.
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* @param {Number} offset
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*/
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// BufferWriter.prototype.seek = function seek(offset) {
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// this.data.push(['seek', offset]);
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// };
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/**
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* Destroy the buffer writer. Remove references to `data`.
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*/
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@ -236,6 +254,61 @@ BufferWriter.prototype.write64BE = function write64BE(value) {
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this.data.push(['64be', value]);
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};
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/**
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* Write float le.
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* @param {Number} value
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*/
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BufferWriter.prototype.writeFloat = function writeFloat(value) {
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assert(typeof value === 'number');
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this.written += 4;
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this.data.push(['f', value]);
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};
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/**
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* Write float be.
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* @param {Number} value
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*/
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BufferWriter.prototype.writeFloatBE = function writeFloatBE(value) {
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assert(typeof value === 'number');
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this.written += 4;
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this.data.push(['fbe', value]);
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};
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/**
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* Write double le.
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* @param {Number} value
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*/
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BufferWriter.prototype.writeDouble = function writeDouble(value) {
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assert(typeof value === 'number');
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this.written += 8;
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this.data.push(['d', value]);
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};
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/**
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* Write double be.
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* @param {Number} value
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*/
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BufferWriter.prototype.writeDoubleBE = function writeDoubleBE(value) {
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assert(typeof value === 'number');
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this.written += 8;
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this.data.push(['dbe', value]);
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};
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/**
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* Write a varint.
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* @param {BN|Number} value
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*/
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BufferWriter.prototype.writeVarint = function writeVarint(value) {
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assert(value >= 0);
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this.written += utils.sizeVarint(value);
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this.data.push(['varint', value]);
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};
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/**
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* Write bytes.
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* @param {Buffer} value
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@ -247,12 +320,15 @@ BufferWriter.prototype.writeBytes = function writeBytes(value) {
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};
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/**
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* Get size of data written so far.
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* @returns {Number}
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* Write bytes with a varint length before them.
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* @param {Buffer} value
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*/
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BufferWriter.prototype.getSize = function getSize() {
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return this.written;
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BufferWriter.prototype.writeVarBytes = function writeVarBytes(value) {
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this.written += utils.sizeVarint(value.length);
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this.written += value.length;
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this.data.push(['varint', value.length]);
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this.data.push(['bytes', value]);
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};
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/**
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@ -298,18 +374,6 @@ BufferWriter.prototype.writeVarString = function writeVarString(value, enc) {
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this.data.push(['str', value, enc]);
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};
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/**
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* Write bytes with a varint length before them.
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* @param {Buffer} value
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*/
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BufferWriter.prototype.writeVarBytes = function writeVarBytes(value) {
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this.written += utils.sizeVarint(value.length);
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this.written += value.length;
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this.data.push(['varint', value.length]);
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this.data.push(['bytes', value]);
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};
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/**
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* Write a null-terminated string.
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* @param {String|Buffer}
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@ -321,17 +385,6 @@ BufferWriter.prototype.writeNullString = function writeNullString(value, enc) {
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this.writeU8(0);
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};
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/**
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* Write a varint.
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* @param {BN|Number} value
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*/
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BufferWriter.prototype.writeVarint = function writeVarint(value) {
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assert(value >= 0);
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this.written += utils.sizeVarint(value);
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this.data.push(['varint', value]);
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};
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/**
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* Calculate and write a checksum for the data written so far.
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*/
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@ -365,59 +418,6 @@ BufferWriter.prototype.fill = function fill(value, size) {
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// this.data.push(['fill', value, size]);
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// };
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/*
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* Seek to relative offset.
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* @param {Number} offset
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*/
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// BufferWriter.prototype.seek = function seek(offset) {
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// this.data.push(['seek', offset]);
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// };
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/**
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* Write float le.
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* @param {Number} value
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*/
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BufferWriter.prototype.writeFloat = function writeFloat(value) {
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assert(typeof value === 'number');
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this.written += 4;
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this.data.push(['f', value]);
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};
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/**
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* Write float be.
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* @param {Number} value
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*/
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BufferWriter.prototype.writeFloatBE = function writeFloatBE(value) {
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assert(typeof value === 'number');
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this.written += 4;
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this.data.push(['fbe', value]);
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};
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/**
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* Write double le.
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* @param {Number} value
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*/
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BufferWriter.prototype.writeDouble = function writeDouble(value) {
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assert(typeof value === 'number');
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this.written += 8;
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this.data.push(['d', value]);
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};
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/**
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* Write double be.
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* @param {Number} value
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*/
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BufferWriter.prototype.writeDoubleBE = function writeDoubleBE(value) {
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assert(typeof value === 'number');
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this.written += 8;
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this.data.push(['dbe', value]);
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};
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/*
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* Expose
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*/
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