The Tor Browser: testing/xpcshell/node-spdy/lib/spdy/parser.js@b8a032363ba2 (annotated)

testing/xpcshell/node-spdy/lib/spdy/parser.js@b8a032363ba2 (annotated)

testing/xpcshell/node-spdy/lib/spdy/parser.js

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 var parser = exports;
 var spdy = require('../spdy'),
     util = require('util'),
     stream = require('stream'),
     Buffer = require('buffer').Buffer;
 var legacy = !stream.Duplex;
 if (legacy) {
   var DuplexStream = stream;
 } else {
   var DuplexStream = stream.Duplex;
 }
 //
 // ### function Parser (connection)
 // #### @connection {spdy.Connection} connection
 // SPDY protocol frames parser's @constructor
 //
 function Parser(connection) {
   DuplexStream.call(this);
   this.drained = true;
   this.paused = false;
   this.buffer = [];
   this.buffered = 0;
   this.waiting = 8;
   this.state = { type: 'frame-head' };
   this.socket = connection.socket;
   this.connection = connection;
   this.framer = null;
   this.connection = connection;
   if (legacy) {
     this.readable = this.writable = true;
   }
 }
 util.inherits(Parser, DuplexStream);
 //
 // ### function create (connection)
 // #### @connection {spdy.Connection} connection
 // @constructor wrapper
 //
 parser.create = function create(connection) {
   return new Parser(connection);
 };
 //
 // ### function destroy ()
 // Just a stub.
 //
 Parser.prototype.destroy = function destroy() {
 };
 //
 // ### function _write (data, encoding, cb)
 // #### @data {Buffer} chunk of data
 // #### @encoding {Null} encoding
 // #### @cb {Function} callback
 // Writes or buffers data to parser
 //
 Parser.prototype._write = function write(data, encoding, cb) {
   // Legacy compatibility
   if (!cb) cb = function() {};
   if (data !== undefined) {
     // Buffer data
     this.buffer.push(data);
     this.buffered += data.length;
   }
   // Notify caller about state (for piping)
   if (this.paused) return false;
   // We shall not do anything until we get all expected data
   if (this.buffered < this.waiting) return cb();
   // Mark parser as not drained
   if (data !== undefined) this.drained = false;
   var self = this,
       buffer = new Buffer(this.waiting),
       sliced = 0,
       offset = 0;
   while (this.waiting > offset && sliced < this.buffer.length) {
     var chunk = this.buffer[sliced++],
         overmatched = false;
     // Copy chunk into `buffer`
     if (chunk.length > this.waiting - offset) {
       chunk.copy(buffer, offset, 0, this.waiting - offset);
       this.buffer[--sliced] = chunk.slice(this.waiting - offset);
       this.buffered += this.buffer[sliced].length;
       overmatched = true;
     } else {
       chunk.copy(buffer, offset);
     }
     // Move offset and decrease amount of buffered data
     offset += chunk.length;
     this.buffered -= chunk.length;
     if (overmatched) break;
   }
   // Remove used buffers
   this.buffer = this.buffer.slice(sliced);
   // Executed parser for buffered data
   this.paused = true;
   this.execute(this.state, buffer, function (err, waiting) {
     // And unpause once execution finished
     self.paused = false;
     // Propagate errors
     if (err) {
       cb();
       return self.emit('error', err);
     }
     // Set new `waiting`
     self.waiting = waiting;
     if (self.waiting <= self.buffered) {
       self._write(undefined, null, cb);
     } else {
       process.nextTick(function() {
         if (self.drained) return;
         // Mark parser as drained
         self.drained = true;
         self.emit('drain');
       });
       cb();
     }
   });
 };
 if (legacy) {
   //
   // ### function write (data, encoding, cb)
   // #### @data {Buffer} chunk of data
   // #### @encoding {Null} encoding
   // #### @cb {Function} callback
   // Legacy method
   //
   Parser.prototype.write = Parser.prototype._write;
   //
   // ### function end ()
   // Stream's end() implementation
   //
   Parser.prototype.end = function end() {
     this.emit('end');
   };
 }
 //
 // ### function createFramer (version)
 // #### @version {Number} Protocol version, either 2 or 3
 // Sets framer instance on Parser's instance
 //
 Parser.prototype.createFramer = function createFramer(version) {
   if (spdy.protocol[version]) {
     this.emit('version', version);
     this.framer = new spdy.protocol[version].Framer(
       spdy.utils.zwrap(this.connection._deflate),
       spdy.utils.zwrap(this.connection._inflate)
     );
     // Propagate framer to connection
     this.connection._framer = this.framer;
     this.emit('framer', this.framer);
   } else {
     this.emit(
       'error',
       new Error('Unknown protocol version requested: ' + version)
     );
   }
 };
 //
 // ### function execute (state, data, callback)
 // #### @state {Object} Parser's state
 // #### @data {Buffer} Incoming data
 // #### @callback {Function} continuation callback
 // Parse buffered data
 //
 Parser.prototype.execute = function execute(state, data, callback) {
   if (state.type === 'frame-head') {
     var header = state.header = spdy.protocol.generic.parseHeader(data);
     // Lazily create framer
     if (!this.framer && header.control) {
       this.createFramer(header.version);
     }
     state.type = 'frame-body';
     callback(null, header.length);
   } else if (state.type === 'frame-body') {
     var self = this;
     // Data frame
     if (!state.header.control) {
       return onFrame(null, {
         type: 'DATA',
         id: state.header.id,
         fin: (state.header.flags & 0x01) === 0x01,
         compressed: (state.header.flags & 0x02) === 0x02,
         data: data
       });
     } else {
     // Control frame
       this.framer.execute(state.header, data, onFrame);
     }
     function onFrame(err, frame) {
       if (err) return callback(err);
       self.emit('frame', frame);
       state.type = 'frame-head';
       callback(null, 8);
     };
   }
 };