michael@0: var protocol = exports;
michael@0: 
michael@0: //
michael@0: // ### function parseSynHead (type, flags, data)
michael@0: // #### @type {Number} Frame type
michael@0: // #### @flags {Number} Frame flags
michael@0: // #### @data {Buffer} input data
michael@0: // Returns parsed syn_* frame's head
michael@0: //
michael@0: protocol.parseSynHead = function parseSynHead(type, flags, data) {
michael@0:   var stream = type === 0x01;
michael@0: 
michael@0:   return {
michael@0:     type: stream ? 'SYN_STREAM' : 'SYN_REPLY',
michael@0:     id: data.readUInt32BE(0, true) & 0x7fffffff,
michael@0:     version: 3,
michael@0:     associated: stream ? data.readUInt32BE(4, true) & 0x7fffffff : 0,
michael@0:     priority: stream ? data[8] >> 5 : 0,
michael@0:     fin: (flags & 0x01) === 0x01,
michael@0:     unidir: (flags & 0x02) === 0x02,
michael@0:     _offset: stream ? 10 : 4
michael@0:   };
michael@0: };
michael@0: 
michael@0: //
michael@0: // ### function parseHeaders (pairs)
michael@0: // #### @pairs {Buffer} header pairs
michael@0: // Returns hashmap of parsed headers
michael@0: //
michael@0: protocol.parseHeaders = function parseHeaders(pairs) {
michael@0:   var count = pairs.readUInt32BE(0, true),
michael@0:       headers = {};
michael@0: 
michael@0:   pairs = pairs.slice(4);
michael@0: 
michael@0:   function readString() {
michael@0:     var len = pairs.readUInt32BE(0, true),
michael@0:         value = pairs.slice(4, 4 + len);
michael@0: 
michael@0:     pairs = pairs.slice(4 + len);
michael@0: 
michael@0:     return value.toString();
michael@0:   }
michael@0: 
michael@0:   while(count > 0) {
michael@0:     headers[readString().replace(/^:/, '')] = readString();
michael@0:     count--;
michael@0:   }
michael@0: 
michael@0:   return headers;
michael@0: };
michael@0: 
michael@0: //
michael@0: // ### function parsesRst frame
michael@0: protocol.parseRst = function parseRst(data) {
michael@0:   return {
michael@0:     type: 'RST_STREAM',
michael@0:     id: data.readUInt32BE(0, true) & 0x7fffffff,
michael@0:     status: data.readUInt32BE(4, true)
michael@0:   };
michael@0: };
michael@0: 
michael@0: protocol.parseSettings = function parseSettings(data) {
michael@0:   var settings = {},
michael@0:       number = data.readUInt32BE(0, true),
michael@0:       idMap = {
michael@0:         1: 'upload_bandwidth',
michael@0:         2: 'download_bandwidth',
michael@0:         3: 'round_trip_time',
michael@0:         4: 'max_concurrent_streams',
michael@0:         5: 'current_cwnd',
michael@0:         6: 'download_retrans_rate',
michael@0:         7: 'initial_window_size',
michael@0:         8: 'client_certificate_vector_size'
michael@0:       };
michael@0: 
michael@0:   for (var i=0; i<number; i++) {
michael@0:     var id = data.readUInt32BE(4 + (i*8), true) & 0x00ffffff,
michael@0:         flags = data.readUInt8(4 + (i*8), true),
michael@0:         name = idMap[id];
michael@0:     settings[id] = settings[name] = {
michael@0:       persist: !!(flags & 0x1),
michael@0:       persisted: !!(flags & 0x2),
michael@0:       value: data.readUInt32BE(8 + (i*8), true)
michael@0:     };
michael@0:   }
michael@0: 
michael@0:   return {
michael@0:     type: 'SETTINGS',
michael@0:     settings: settings
michael@0:   };
michael@0: };
michael@0: 
michael@0: protocol.parseGoaway = function parseGoaway(data) {
michael@0:   return {
michael@0:     type: 'GOAWAY',
michael@0:     lastId: data.readUInt32BE(0, true) & 0x7fffffff
michael@0:   };
michael@0: };
michael@0: 
michael@0: protocol.parseWindowUpdate = function parseWindowUpdate(data) {
michael@0:   var ret = {
michael@0:     type: 'WINDOW_UPDATE',
michael@0:     id: data.readUInt32BE(0, true) & 0x7fffffff,
michael@0:     delta: data.readUInt32BE(4, true) & 0x7fffffff
michael@0:   };
michael@0: 
michael@0:   return ret;
michael@0: };