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ngs/examples/singleon/chat/web/protocol.js

350 lines
9.1 KiB
JavaScript

(function (exports, ByteArray, global) {
var Protocol = exports;
var PKG_HEAD_BYTES = 4;
var MSG_FLAG_BYTES = 1;
var MSG_ROUTE_CODE_BYTES = 2;
var MSG_ID_MAX_BYTES = 5;
var MSG_ROUTE_LEN_BYTES = 1;
var MSG_ROUTE_CODE_MAX = 0xffff;
var MSG_COMPRESS_ROUTE_MASK = 0x1;
var MSG_TYPE_MASK = 0x7;
var Package = Protocol.Package = {};
var Message = Protocol.Message = {};
Package.TYPE_HANDSHAKE = 1;
Package.TYPE_HANDSHAKE_ACK = 2;
Package.TYPE_HEARTBEAT = 3;
Package.TYPE_DATA = 4;
Package.TYPE_KICK = 5;
Message.TYPE_REQUEST = 0;
Message.TYPE_NOTIFY = 1;
Message.TYPE_RESPONSE = 2;
Message.TYPE_PUSH = 3;
/**
* pomele client encode
* id message id;
* route message route
* msg message body
* socketio current support string
*/
Protocol.strencode = function(str) {
var byteArray = new ByteArray(str.length * 3);
var offset = 0;
for(var i = 0; i < str.length; i++){
var charCode = str.charCodeAt(i);
var codes = null;
if(charCode <= 0x7f){
codes = [charCode];
}else if(charCode <= 0x7ff){
codes = [0xc0|(charCode>>6), 0x80|(charCode & 0x3f)];
}else{
codes = [0xe0|(charCode>>12), 0x80|((charCode & 0xfc0)>>6), 0x80|(charCode & 0x3f)];
}
for(var j = 0; j < codes.length; j++){
byteArray[offset] = codes[j];
++offset;
}
}
var _buffer = new ByteArray(offset);
copyArray(_buffer, 0, byteArray, 0, offset);
return _buffer;
};
/**
* client decode
* msg String data
* return Message Object
*/
Protocol.strdecode = function(buffer) {
var bytes = new ByteArray(buffer);
var array = [];
var offset = 0;
var charCode = 0;
var end = bytes.length;
while(offset < end){
if(bytes[offset] < 128){
charCode = bytes[offset];
offset += 1;
}else if(bytes[offset] < 224){
charCode = ((bytes[offset] & 0x3f)<<6) + (bytes[offset+1] & 0x3f);
offset += 2;
}else{
charCode = ((bytes[offset] & 0x0f)<<12) + ((bytes[offset+1] & 0x3f)<<6) + (bytes[offset+2] & 0x3f);
offset += 3;
}
array.push(charCode);
}
return String.fromCharCode.apply(null, array);
};
/**
* Package protocol encode.
*
* Pomelo package format:
* +------+-------------+------------------+
* | type | body length | body |
* +------+-------------+------------------+
*
* Head: 4bytes
* 0: package type,
* 1 - handshake,
* 2 - handshake ack,
* 3 - heartbeat,
* 4 - data
* 5 - kick
* 1 - 3: big-endian body length
* Body: body length bytes
*
* @param {Number} type package type
* @param {ByteArray} body body content in bytes
* @return {ByteArray} new byte array that contains encode result
*/
Package.encode = function(type, body){
var length = body ? body.length : 0;
var buffer = new ByteArray(PKG_HEAD_BYTES + length);
var index = 0;
buffer[index++] = type & 0xff;
buffer[index++] = (length >> 16) & 0xff;
buffer[index++] = (length >> 8) & 0xff;
buffer[index++] = length & 0xff;
if(body) {
copyArray(buffer, index, body, 0, length);
}
return buffer;
};
/**
* Package protocol decode.
* See encode for package format.
*
* @param {ByteArray} buffer byte array containing package content
* @return {Object} {type: package type, buffer: body byte array}
*/
Package.decode = function(buffer){
var offset = 0;
var bytes = new ByteArray(buffer);
var length = 0;
var rs = [];
while(offset < bytes.length) {
var type = bytes[offset++];
length = ((bytes[offset++]) << 16 | (bytes[offset++]) << 8 | bytes[offset++]) >>> 0;
var body = length ? new ByteArray(length) : null;
copyArray(body, 0, bytes, offset, length);
offset += length;
rs.push({'type': type, 'body': body});
}
return rs.length === 1 ? rs[0]: rs;
};
/**
* Message protocol encode.
*
* @param {Number} id message id
* @param {Number} type message type
* @param {Number} compressRoute whether compress route
* @param {Number|String} route route code or route string
* @param {Buffer} msg message body bytes
* @return {Buffer} encode result
*/
Message.encode = function(id, type, compressRoute, route, msg){
// caculate message max length
var idBytes = msgHasId(type) ? caculateMsgIdBytes(id) : 0;
var msgLen = MSG_FLAG_BYTES + idBytes;
if(msgHasRoute(type)) {
if(compressRoute) {
if(typeof route !== 'number'){
throw new Error('error flag for number route!');
}
msgLen += MSG_ROUTE_CODE_BYTES;
} else {
msgLen += MSG_ROUTE_LEN_BYTES;
if(route) {
route = Protocol.strencode(route);
if(route.length>255) {
throw new Error('route maxlength is overflow');
}
msgLen += route.length;
}
}
}
if(msg) {
msgLen += msg.length;
}
var buffer = new ByteArray(msgLen);
var offset = 0;
// add flag
offset = encodeMsgFlag(type, compressRoute, buffer, offset);
// add message id
if(msgHasId(type)) {
offset = encodeMsgId(id, buffer, offset);
}
// add route
if(msgHasRoute(type)) {
offset = encodeMsgRoute(compressRoute, route, buffer, offset);
}
// add body
if(msg) {
offset = encodeMsgBody(msg, buffer, offset);
}
return buffer;
};
/**
* Message protocol decode.
*
* @param {Buffer|Uint8Array} buffer message bytes
* @return {Object} message object
*/
Message.decode = function(buffer) {
var bytes = new ByteArray(buffer);
var bytesLen = bytes.length || bytes.byteLength;
var offset = 0;
var id = 0;
var route = null;
// parse flag
var flag = bytes[offset++];
var compressRoute = flag & MSG_COMPRESS_ROUTE_MASK;
var type = (flag >> 1) & MSG_TYPE_MASK;
// parse id
if(msgHasId(type)) {
var m = parseInt(bytes[offset]);
var i = 0;
do{
var m = parseInt(bytes[offset]);
id = id + ((m & 0x7f) * Math.pow(2,(7*i)));
offset++;
i++;
}while(m >= 128);
}
// parse route
if(msgHasRoute(type)) {
if(compressRoute) {
route = (bytes[offset++]) << 8 | bytes[offset++];
} else {
var routeLen = bytes[offset++];
if(routeLen) {
route = new ByteArray(routeLen);
copyArray(route, 0, bytes, offset, routeLen);
route = Protocol.strdecode(route);
} else {
route = '';
}
offset += routeLen;
}
}
// parse body
var bodyLen = bytesLen - offset;
var body = new ByteArray(bodyLen);
copyArray(body, 0, bytes, offset, bodyLen);
return {'id': id, 'type': type, 'compressRoute': compressRoute,
'route': route, 'body': body};
};
var copyArray = function(dest, doffset, src, soffset, length) {
if('function' === typeof src.copy) {
// Buffer
src.copy(dest, doffset, soffset, soffset + length);
} else {
// Uint8Array
for(var index=0; index<length; index++){
dest[doffset++] = src[soffset++];
}
}
};
var msgHasId = function(type) {
return type === Message.TYPE_REQUEST || type === Message.TYPE_RESPONSE;
};
var msgHasRoute = function(type) {
return type === Message.TYPE_REQUEST || type === Message.TYPE_NOTIFY ||
type === Message.TYPE_PUSH;
};
var caculateMsgIdBytes = function(id) {
var len = 0;
do {
len += 1;
id >>= 7;
} while(id > 0);
return len;
};
var encodeMsgFlag = function(type, compressRoute, buffer, offset) {
if(type !== Message.TYPE_REQUEST && type !== Message.TYPE_NOTIFY &&
type !== Message.TYPE_RESPONSE && type !== Message.TYPE_PUSH) {
throw new Error('unkonw message type: ' + type);
}
buffer[offset] = (type << 1) | (compressRoute ? 1 : 0);
return offset + MSG_FLAG_BYTES;
};
var encodeMsgId = function(id, buffer, offset) {
do{
var tmp = id % 128;
var next = Math.floor(id/128);
if(next !== 0){
tmp = tmp + 128;
}
buffer[offset++] = tmp;
id = next;
} while(id !== 0);
return offset;
};
var encodeMsgRoute = function(compressRoute, route, buffer, offset) {
if (compressRoute) {
if(route > MSG_ROUTE_CODE_MAX){
throw new Error('route number is overflow');
}
buffer[offset++] = (route >> 8) & 0xff;
buffer[offset++] = route & 0xff;
} else {
if(route) {
buffer[offset++] = route.length & 0xff;
copyArray(buffer, offset, route, 0, route.length);
offset += route.length;
} else {
buffer[offset++] = 0;
}
}
return offset;
};
var encodeMsgBody = function(msg, buffer, offset) {
copyArray(buffer, offset, msg, 0, msg.length);
return offset + msg.length;
};
if(typeof(window) != "undefined") {
window.Protocol = Protocol;
}
})(typeof(window)=="undefined" ? module.exports : (this.Protocol = {}),typeof(window)=="undefined" ? Buffer : Uint8Array, this);