Home | History | Annotate | Download | only in chromium 
      1 /*
      2  * Copyright (C) 2012 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef ThreadSafeDataTransport_h
     27 #define ThreadSafeDataTransport_h
     28 
     29 #include "wtf/OwnPtr.h"
     30 #include "wtf/PassOwnPtr.h"
     31 #include "wtf/RefPtr.h"
     32 #include "wtf/ThreadingPrimitives.h"
     33 #include "wtf/Vector.h"
     34 
     35 namespace WebCore {
     36 
     37 class SharedBuffer;
     38 
     39 // The purpose of this class is to allow the transfer of data stored in
     40 // SharedBuffer in a thread-safe manner, and to minimize memory copies
     41 // and thread contention.
     42 //
     43 // This class is designed such that there is only one producer and
     44 // one consumer.
     45 class ThreadSafeDataTransport {
     46 public:
     47     ThreadSafeDataTransport();
     48     ~ThreadSafeDataTransport();
     49 
     50     // This method is being called subsequently with an expanding
     51     // SharedBuffer.
     52     void setData(SharedBuffer*, bool allDataReceived);
     53 
     54     // Get the data submitted to this class so far.
     55     void data(SharedBuffer**, bool* allDataReceived);
     56 
     57     // Return true of there is new data submitted to this class
     58     // since last time data() was called.
     59     bool hasNewData();
     60 
     61 private:
     62     Mutex m_mutex;
     63 
     64     Vector<RefPtr<SharedBuffer> > m_newBufferQueue;
     65     RefPtr<SharedBuffer> m_readBuffer;
     66     bool m_allDataReceived;
     67     size_t m_readPosition;
     68 };
     69 
     70 } // namespace WebCore
     71 
     72 #endif
     73