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 "platform/PlatformExport.h"
30#include "wtf/OwnPtr.h"
31#include "wtf/PassOwnPtr.h"
32#include "wtf/RefPtr.h"
33#include "wtf/ThreadingPrimitives.h"
34#include "wtf/Vector.h"
35
36namespace blink {
37
38class SharedBuffer;
39
40// The purpose of this class is to allow the transfer of data stored in
41// SharedBuffer in a thread-safe manner, and to minimize memory copies
42// and thread contention.
43//
44// This class is designed such that there is only one producer and
45// one consumer.
46class PLATFORM_EXPORT ThreadSafeDataTransport {
47public:
48    ThreadSafeDataTransport();
49    ~ThreadSafeDataTransport();
50
51    // This method is being called subsequently with an expanding
52    // SharedBuffer.
53    void setData(SharedBuffer*, bool allDataReceived);
54
55    // Get the data submitted to this class so far.
56    void data(SharedBuffer**, bool* allDataReceived);
57
58    // Return true of there is new data submitted to this class
59    // since last time data() was called.
60    bool hasNewData();
61
62private:
63    Mutex m_mutex;
64
65    Vector<RefPtr<SharedBuffer> > m_newBufferQueue;
66    RefPtr<SharedBuffer> m_readBuffer;
67    bool m_allDataReceived;
68    size_t m_readPosition;
69};
70
71} // namespace blink
72
73#endif
74