michael@0: var spdy = require('../spdy'),
michael@0:     utils = exports;
michael@0: 
michael@0: var zlib = require('zlib'),
michael@0:     Buffer = require('buffer').Buffer;
michael@0: 
michael@0: //
michael@0: // ### function createDeflate ()
michael@0: // Creates deflate stream with SPDY dictionary
michael@0: //
michael@0: utils.createDeflate = function createDeflate(version) {
michael@0:   var deflate = zlib.createDeflate({
michael@0:     dictionary: spdy.protocol[version].dictionary,
michael@0:     windowBits: 11
michael@0:   });
michael@0: 
michael@0:   // Define lock information early
michael@0:   deflate.locked = false;
michael@0:   deflate.lockBuffer = [];
michael@0: 
michael@0:   return deflate;
michael@0: };
michael@0: 
michael@0: //
michael@0: // ### function createInflate ()
michael@0: // Creates inflate stream with SPDY dictionary
michael@0: //
michael@0: utils.createInflate = function createInflate(version) {
michael@0:   var inflate = zlib.createInflate({
michael@0:     dictionary: spdy.protocol[version].dictionary,
michael@0:     windowBits: 15
michael@0:   });
michael@0: 
michael@0:   // Define lock information early
michael@0:   inflate.locked = false;
michael@0:   inflate.lockBuffer = [];
michael@0: 
michael@0:   return inflate;
michael@0: };
michael@0: 
michael@0: //
michael@0: // ### function resetZlibStream (stream)
michael@0: // #### @stream {zlib.Stream} stream
michael@0: // Resets zlib stream and associated locks
michael@0: //
michael@0: utils.resetZlibStream = function resetZlibStream(stream, callback) {
michael@0:   if (stream.locked) {
michael@0:     stream.lockBuffer.push(function() {
michael@0:       resetZlibStream(stream, callback);
michael@0:     });
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   stream.reset();
michael@0:   stream.lockBuffer = [];
michael@0: 
michael@0:   callback(null);
michael@0: };
michael@0: 
michael@0: var delta = 0;
michael@0: //
michael@0: // ### function zstream (stream, buffer, callback)
michael@0: // #### @stream {Deflate|Inflate} One of streams above
michael@0: // #### @buffer {Buffer} Input data (to compress or to decompress)
michael@0: // #### @callback {Function} Continuation to callback
michael@0: // Compress/decompress data and pass it to callback
michael@0: //
michael@0: utils.zstream = function zstream(stream, buffer, callback) {
michael@0:   var flush = stream._flush,
michael@0:       chunks = [],
michael@0:       total = 0;
michael@0: 
michael@0:   if (stream.locked) {
michael@0:     stream.lockBuffer.push(function() {
michael@0:       zstream(stream, buffer, callback);
michael@0:     });
michael@0:     return;
michael@0:   }
michael@0:   stream.locked = true;
michael@0: 
michael@0:   function collect(chunk) {
michael@0:     chunks.push(chunk);
michael@0:     total += chunk.length;
michael@0:   }
michael@0:   stream.on('data', collect);
michael@0:   stream.write(buffer);
michael@0: 
michael@0:   stream.once('error', function(err) {
michael@0:     stream.removeAllListeners('data');
michael@0:     callback(err);
michael@0:   });
michael@0: 
michael@0:   stream.flush(function() {
michael@0:     stream.removeAllListeners('data');
michael@0:     stream.removeAllListeners('error');
michael@0:     stream._flush = flush;
michael@0: 
michael@0:     callback(null, chunks, total);
michael@0: 
michael@0:     stream.locked = false;
michael@0:     var deferred = stream.lockBuffer.shift();
michael@0:     if (deferred) deferred();
michael@0:   });
michael@0: };
michael@0: 
michael@0: //
michael@0: // ### function zwrap (stream)
michael@0: // #### @stream {zlib.Stream} stream to wrap
michael@0: // Wraps stream within function to allow simple deflate/inflate
michael@0: //
michael@0: utils.zwrap = function zwrap(stream) {
michael@0:   return function(data, callback) {
michael@0:     utils.zstream(stream, data, callback);
michael@0:   };
michael@0: };