368 lines
12 KiB
JavaScript
368 lines
12 KiB
JavaScript
// Generated by CoffeeScript 1.6.3
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/*
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# a collection of utility methods for Buffer
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#
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# 这个工具类的设计以实现两个目地
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# 1. 读写方法，匹配 Actionscript 的 ByteArray 读写方法
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# 2. ActionScript 的默认采用 big endian，这个工具方法，对此进行封装，以是外部不用关心 endian
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#
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*/
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(function() {
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module.exports = {
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readUTF: function(buf, offset) {
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var len;
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if (!Buffer.isBuffer(buf)) {
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return null;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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if (buf.length <= offset + 2) {
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return null;
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}
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len = buf.readUInt16BE(offset);
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if (buf.length < len + offset) {
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return null;
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}
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offset += 2;
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buf.position = offset + len;
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return buf.toString('utf8', offset, offset + len);
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},
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readUTFBytes: function(buf, length, offset) {
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if (!Buffer.isBuffer(buf)) {
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return null;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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if (buf.length <= offset) {
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return null;
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}
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buf.position = offset + length;
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return buf.toString('utf8', offset, offset + length);
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},
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readFixLengthASCII: function(buf, offset) {
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var len;
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if (!Buffer.isBuffer(buf)) {
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return null;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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if (buf.length <= offset + 2) {
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return null;
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}
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len = buf.readUInt8(offset);
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if (buf.length < len + offset) {
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return null;
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}
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offset += 1;
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buf.position = offset + len;
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return buf.toString('utf8', offset, offset + len);
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},
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readUnsignedShort: function(buf, offset) {
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if (!Buffer.isBuffer(buf)) {
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return 0;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.position = offset + 2;
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return buf.readUInt16BE(offset);
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},
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readShort: function(buf, offset) {
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if (!Buffer.isBuffer(buf)) {
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return 0;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.position = offset + 2;
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return buf.readInt16BE(offset);
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},
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readUnsignedByte: function(buf, offset) {
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if (!Buffer.isBuffer(buf)) {
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return 0;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.position = offset + 1;
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return buf.readUInt8(offset);
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},
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readByte: function(buf, offset) {
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if (!Buffer.isBuffer(buf)) {
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return 0;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.position = offset + 1;
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return buf.readInt8(offset);
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},
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readUnsignedInt: function(buf, offset) {
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if (!Buffer.isBuffer(buf)) {
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return 0;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.position = offset + 4;
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return buf.readUInt32BE(offset);
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},
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readInt: function(buf, offset) {
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if (!Buffer.isBuffer(buf)) {
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return 0;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.position = offset + 4;
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return buf.readInt32BE(offset);
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},
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readFloat: function(buf, offset) {
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if (!Buffer.isBuffer(buf)) {
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return 0;
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}
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.position = offset + 4;
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return buf.readFloatLE(offset);
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},
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readUnsignedIntArray: function(buf, offset) {
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var a, arr, len;
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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len = buf.readUInt16BE(offset) >>> 2;
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offset += 2;
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arr = [];
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if (len === 0 || len > 1024) {
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buf.position = offset;
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return arr;
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}
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while (len > 0) {
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a = buf.readUInt32BE(offset);
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arr.push(a);
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offset += 4;
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len -= 1;
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}
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buf.position = offset;
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return arr;
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},
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writeUnsignedInt: function(buf, value, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.writeUInt32BE(value, offset);
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buf.position = offset + 4;
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},
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writeInt: function(buf, value, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.writeInt32BE(value, offset);
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buf.position = offset + 4;
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},
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writeFloat: function(buf, value, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.writeFloatLE(value, offset);
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buf.position = offset + 4;
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},
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writeUnsignedShort: function(buf, value, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.writeUInt16BE(value, offset);
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buf.position = offset + 2;
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},
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writeShort: function(buf, value, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.writeInt16BE(value, offset);
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buf.position = offset + 2;
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},
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writeUnsignedByte: function(buf, value, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.writeUInt8(value, offset);
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buf.position = offset + 1;
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},
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writeByte: function(buf, value, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.writeInt8(value, offset);
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buf.position = offset + 1;
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},
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writeBoolean: function(buf, value, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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value = value ? 1 : 0;
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buf.writeInt8(value, offset);
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buf.position = offset + 1;
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},
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writeFixLengthASCII: function(buf, str, maxNumOfChar, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.writeUInt8(maxNumOfChar, offset);
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offset += 1;
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buf.fill(0x20, offset, offset + maxNumOfChar);
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buf.write(str, offset, maxNumOfChar, 'ascii');
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buf.position = offset + maxNumOfChar;
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},
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writeFixLengthUTF: function(buf, str, maxNumOfChar, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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maxNumOfChar *= 6;
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buf.writeUInt16BE(maxNumOfChar, offset);
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offset += 2;
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buf.fill(0x20, offset, offset + maxNumOfChar);
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buf.write(str, offset, maxNumOfChar, 'utf8');
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buf.position = offset + maxNumOfChar;
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},
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writeUTF: function(buf, str, offset) {
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var byteLength;
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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byteLength = Buffer.byteLength(str);
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buf.writeUInt16BE(byteLength, offset);
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offset += 2;
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buf.write(str, offset);
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buf.position = offset + byteLength;
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},
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writeUTFBytes: function(buf, str, offset) {
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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buf.write(str, offset);
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buf.position = offset + Buffer.byteLength(str);
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},
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writeUTFArray: function(buf, strArray, offset) {
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var byteLength, str, _i, _len;
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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if (!((strArray != null) && strArray.length > 0)) {
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buf.writeUInt16BE(0, offset);
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buf.position = offset + 2;
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return;
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}
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buf.writeUInt16BE(strArray.length, offset);
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offset += 2;
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for (_i = 0, _len = strArray.length; _i < _len; _i++) {
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str = strArray[_i];
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byteLength = Buffer.byteLength(str);
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buf.writeUInt16BE(byteLength, offset);
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offset += 2;
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buf.write(str, offset);
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offset += byteLength;
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}
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return buf.position = offset;
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},
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getByteLengthOfUTFArray: function(strArray) {
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var len, str, _i, _len;
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len = 2;
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if (!((strArray != null) && strArray.length > 0)) {
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return len;
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}
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for (_i = 0, _len = strArray.length; _i < _len; _i++) {
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str = strArray[_i];
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len = len + 2 + Buffer.byteLength(str);
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}
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return len;
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},
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writeUnsignedIntArray: function(buf, arr, fixedLength, offset) {
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var i, n, _i, _len;
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if (fixedLength == null) {
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fixedLength = -1;
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}
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arr = arr || [];
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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n = arr.length;
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if (fixedLength > 0 && fixedLength !== n) {
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if (fixedLength < n) {
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arr = arr.slice(0, fixedLength);
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} else {
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arr = arr.concat();
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arr.length = fixedLength;
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}
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n = fixedLength;
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}
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n = n << 2;
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buf.writeUInt16BE(n, offset);
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offset += 2;
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for (_i = 0, _len = arr.length; _i < _len; _i++) {
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i = arr[_i];
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buf.writeUInt32BE(parseInt(i, 10) || 0, offset);
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offset += 4;
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}
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buf.position = offset;
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},
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getByteLengthOfIntArray: function(arr) {
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return (arr.length << 2) + 2;
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},
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writeUnsignedShortArray: function(buf, arr, fixedLength, offset) {
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var i, n, _i, _len;
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if (fixedLength == null) {
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fixedLength = -1;
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}
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arr = arr || [];
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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n = arr.length;
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if (fixedLength > 0 && fixedLength !== n) {
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if (fixedLength < n) {
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arr = arr.slice(0, fixedLength);
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} else {
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arr = arr.concat();
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arr.length = fixedLength;
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}
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n = fixedLength;
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}
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n = n << 1;
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buf.writeUInt16BE(n, offset);
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offset += 2;
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for (_i = 0, _len = arr.length; _i < _len; _i++) {
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i = arr[_i];
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buf.writeUInt16BE(parseInt(i, 10) || 0, offset);
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offset += 2;
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}
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buf.position = offset;
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},
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getBytesAvailable: function(buf) {
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if (buf != null) {
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return buf.length - (buf.position || 0);
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} else {
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return 0;
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}
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},
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scrap: function(buf, length) {
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var offset, result;
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if (!((buf != null) && length > 0)) {
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return null;
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}
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offset = buf.position || 0;
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if (length + offset > buf.length) {
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return null;
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}
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result = new Buffer(length);
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buf.copy(result, 0, offset, offset + length);
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buf.position = offset + length;
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return result;
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},
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duplicate: function(buf) {
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var n, result;
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n = buf.length || 0;
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if (n === 0) {
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return null;
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}
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result = new Buffer(n);
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buf.copy(result, 0, 0, n);
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return result;
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},
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utfStringToBuf: function(str) {
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var buf, n;
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str = String(str || '');
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n = Buffer.byteLength(str, 'utf8');
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buf = new Buffer(n + 2);
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buf.writeUInt16BE(n, 0);
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buf.write(str, 2);
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return buf;
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},
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isAvailableBuf: function(buf) {
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return Buffer.isBuffer(buf) && buf.length > 0;
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},
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writeIntArray: function(buf, arr, fixedLength, offset) {
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var i, n, _i, _len;
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if (fixedLength == null) {
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fixedLength = -1;
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}
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arr = arr || [];
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offset = offset < 0 ? buf.length + offset : (offset === 0 ? 0 : offset || buf.position || 0);
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n = arr.length;
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if (fixedLength > 0 && fixedLength !== n) {
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if (fixedLength < n) {
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arr = arr.slice(0, fixedLength);
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} else {
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arr = arr.concat();
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arr.length = fixedLength;
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}
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n = fixedLength;
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}
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n = n << 2;
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buf.writeUInt16BE(n, offset);
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offset += 2;
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for (_i = 0, _len = arr.length; _i < _len; _i++) {
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i = arr[_i];
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buf.writeInt32BE(parseInt(i, 10) || 0, offset);
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offset += 4;
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}
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buf.position = offset;
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}
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};
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}).call(this);
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