/**
* ByteBuffer.js
* 1，字节流基本类型封装
* 2，long,int64类型实现
* 3，utf8编码实现
*
* 字节流打包:
* var buffer=new ByteBuffer(128);
* buffer.writeString("test string");
* buffer.writeHex(0x04);
* buffer.writeChar("|");
* buffer.writeUint32(1000);
buffer.writeInt64(-14725836936900);
socket.send(buffer.buffer,buffer.offset);
字节流解包:
var len=socket.read(data);
var buffer=new ByteBuffer(len);
buffer.setBufferData(data);
* var str=buffer.readString();
* var int32=buffer.readInt32();
* ....
*/
var ByteBuffer = function(length) {
this.buffer = new ArrayBuffer(length);
// this.byteStream=new Uint8Array(this.buffer);
this.dataView = new DataView(this.buffer);
// 缓冲区偏移量
this.offset = 0;
this.setBufferData = function(buffer) {
this.buffer = buffer;
this.dataView = new DataView(this.buffer);
this.offset = 0;
return this.dataView;
}
// copy buffer to another
// buffer,m.appendArrayBuffer(m.offset+2,n.buffer,0,5);
this.appendArrayBuffer = function(toPos, fromBuffer, fromPos, length) {
// console.log("appendArrayBuffer toPos=%d,fromPos=%d,length=%d
// \n",toPos,fromPos,length);
var uarr = new Uint8Array(fromBuffer);
for (var i = fromPos; i < length; i++) {
this.dataView.setInt8(toPos++, uarr[i], true);
}
}
// 将uarr复制到当前缓冲区
this.appendUint8Array = function(toPos, uarr) {
for (var i = 0; i < uarr.length; i++) {
this.dataView.setInt8(toPos++, uarr[i], true);
}
}
this.initHeader = function() {
this.offset += 9;
}
this.setHeader = function(input) {
this.dataView.setInt8(0, 0x7c, true);
this.dataView.setUint32(1, input, true);
this.dataView.setUint32(5, input - 5, true);
}
// writeChar("a")
this.writeChar = function(input) {
this.dataView.setInt8(this.offset++, input.charCodeAt(), true);
return this.offset;
}
// writeHex(0x04);
this.writeHex = function(input) {
this.dataView.setInt8(this.offset++, input);
return this.offset;
}
this.writeUint16 = function(input) {
this.dataView.setUint16(this.offset, input, true);
this.offset += 2;
return this.offset;
}
this.writeUint32 = function(input) {
this.dataView.setUint32(this.offset, input, true);
this.offset += 4;
}
this.writeInt32 = function(input) {
this.dataView.setInt32(this.offset, input, true);
this.offset += 4;
}
this.writeInt64 = function(input) {
var sign = input < 0;
if (sign)
input = -1 - input;
for (var i = 0; i < 8; i++) {
var mod = input % 0x100;
input = (input - mod) / 0x100;
var v = sign ? mod ^ 0xFF : mod;
this.dataView.setUint8(this.offset++, v);
}
return this.offset;
}
this.readInt64 = function() {
var bytes = new Uint8Array(this.buffer, this.offset, 8);
var sign = bytes[7] >> 7;
this.offset += 8;
var sum = 0;
var digits = 1;
for (var i = 0; i < 8; i++) {
var value = bytes[i];
sum += (sign ? value ^ 0xFF : value) * digits;
digits *= 0x100;
}
return sign ? -1 - sum : sum;
}
this.writeString = function(input) {
var utf8Length = this.UTF8Length(input);
this.offset = this.writeUint16(utf8Length);
this.stringToUTF8(input);
return this.offset;
}
// ======================
this.readUint32 = function() {
var ret = this.dataView.getUint32(this.offset, true);
this.offset += 4;
return ret;
}
this.readInt32 = function() {
var ret = this.dataView.getInt32(this.offset, true);
this.offset += 4;
return ret;
}
this.readInt16 = function() {
var ret = this.dataView.getInt16(this.offset, true);
this.offset += 2;
return ret;
}
this.readString = function() {
var length = this.readInt16();
var uint8Array = new Uint8Array(this.buffer, this.offset, length);
var ret = this.parseUTF8(uint8Array, 0, uint8Array.length);
this.offset += uint8Array.length;
return ret;
}
this.readFloat32 = function() {
var ret = this.dataView.getFloat32(this.offset, true);
this.offset += 4;
return ret;
}
this.readFloat64 = function() {
var ret = this.dataView.getFloat64(this.offset, true);
this.offset += 4;
return ret;
}
this.readList = function(types) {
if (types.length <= 0)
return;
var list = [];
var length = this.readInt16();
for (var row = 0; row < length; row++) {
var values = {};
for (var i = 0; i < types.length; i++) {
var type = types[i];
if (types[i] == "int") {
values[type] = this.readInt32();
} else if (types[i] == "short") {
values[type] = this.readInt16();
} else if (types[i] == "float") {
values[type] = this.readFloat32();
} else if (types[i] == "double") {
values[type] = this.readFloat64();
} else if (types[i] == "string") {
values[type] = this.readString();
}
}
list[row] = values;
}
return list;
}
this.stringToUTF8 = function(input) {
for (var i = 0; i < input.length; i++) {
var charCode = input.charCodeAt(i);
// Check for a surrogate pair.
if (0xD800 <= charCode && charCode <= 0xDBFF) {
var lowCharCode = input.charCodeAt(++i);
if (isNaN(lowCharCode)) {
throw new Error(format(ERROR.MALFORMED_UNICODE, [ charCode,
lowCharCode ]));
}
charCode = ((charCode - 0xD800) << 10) + (lowCharCode - 0xDC00)
+ 0x10000;
}
if (charCode <= 0x7F) {
this.writeHex(charCode);
} else if (charCode <= 0x7FF) {
this.writeHex(charCode >> 6 & 0x1F | 0xC0);
this.writeHex(charCode & 0x3F | 0x80);
} else if (charCode <= 0xFFFF) {
this.writeHex(charCode >> 12 & 0x0F | 0xE0);
this.writeHex(charCode >> 6 & 0x3F | 0x80);
this.writeHex(charCode & 0x3F | 0x80);
} else {
this.writeHex(charCode >> 18 & 0x07 | 0xF0);
this.writeHex(charCode >> 12 & 0x3F | 0x80);
this.writeHex(charCode >> 6 & 0x3F | 0x80);
this.writeHex(charCode & 0x3F | 0x80);
}
;
}
return this.byteStream;
}
this.UTF8Length = function(input) {
var output = 0;
for (var i = 0; i < input.length; i++) {
var charCode = input.charCodeAt(i);
if (charCode > 0x7FF) {
// Surrogate pair means its a 4 byte character
if (0xD800 <= charCode && charCode <= 0xDBFF) {
i++;
output++;
}
output += 3;
} else if (charCode > 0x7F)
output += 2;
else
output++;
}
return output;
}
this.parseUTF8 = function(input, offset, length) {
var output = "";
var utf16;
var pos = offset;
while (pos < offset + length) {
var byte1 = input[pos++];
if (byte1 < 128)
utf16 = byte1;
else {
var byte2 = input[pos++] - 128;
if (byte2 < 0)
throw new Error(format(ERROR.MALFORMED_UTF, [
byte1.toString(16), byte2.toString(16), "" ]));
if (byte1 < 0xE0) // 2 byte character
utf16 = 64 * (byte1 - 0xC0) + byte2;
else {
var byte3 = input[pos++] - 128;
if (byte3 < 0)
throw new Error(format(ERROR.MALFORMED_UTF, [
byte1.toString(16), byte2.toString(16),
byte3.toString(16) ]));
if (byte1 < 0xF0) // 3 byte character
utf16 = 4096 * (byte1 - 0xE0) + 64 * byte2 + byte3;
else {
var byte4 = input[pos++] - 128;
if (byte4 < 0)
throw new Error(format(ERROR.MALFORMED_UTF, [
byte1.toString(16), byte2.toString(16),
byte3.toString(16), byte4.toString(16) ]));
if (byte1 < 0xF8) // 4 byte character
utf16 = 262144 * (byte1 - 0xF0) + 4096 * byte2 + 64
* byte3 + byte4;
else
// longer encodings are not supported
throw new Error(format(ERROR.MALFORMED_UTF, [
byte1.toString(16), byte2.toString(16),
byte3.toString(16), byte4.toString(16) ]));
}
}
}
if (utf16 > 0xFFFF) // 4 byte character - express as a surrogate
// pair
{
utf16 -= 0x10000;
output += String.fromCharCode(0xD800 + (utf16 >> 10)); // lead
// character
utf16 = 0xDC00 + (utf16 & 0x3FF); // trail character
}
output += String.fromCharCode(utf16);
}
return output;
}
this.encode = function(bytes) {
for (var i = 0; i < bytes.length; i++) {
bytes[i] ^= 0xFF;
}
return bytes;
}
}
