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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef WebSocketDeflater_h
32#define WebSocketDeflater_h
33
34#include "wtf/Noncopyable.h"
35#include "wtf/OwnPtr.h"
36#include "wtf/PassOwnPtr.h"
37#include "wtf/Vector.h"
38
39struct z_stream_s;
40typedef z_stream_s z_stream;
41
42namespace blink {
43
44class WebSocketDeflater {
45    WTF_MAKE_FAST_ALLOCATED;
46public:
47    // This enum is reused for histogram. When this needs to be modified, add a
48    // new enum for histogram and convert mode values into values in the new
49    // enum to keep new data consistent with old one.
50    enum ContextTakeOverMode {
51        DoNotTakeOverContext,
52        TakeOverContext,
53        ContextTakeOverModeMax,
54    };
55    static PassOwnPtr<WebSocketDeflater> create(int windowBits, ContextTakeOverMode = TakeOverContext);
56
57    ~WebSocketDeflater();
58
59    bool initialize();
60    bool addBytes(const char*, size_t);
61    bool finish();
62    const char* data() { return m_buffer.data(); }
63    size_t size() const { return m_buffer.size(); }
64    // Reset the deflate result.
65    void softReset();
66    // Reset the deflate result and internal state if the take over mode is DoNotTakeOverContext.
67    void reset();
68
69private:
70    WebSocketDeflater(int windowBits, ContextTakeOverMode);
71
72    int m_windowBits;
73    ContextTakeOverMode m_contextTakeOverMode;
74    bool m_isBytesAdded;
75    Vector<char> m_buffer;
76    OwnPtr<z_stream> m_stream;
77};
78
79class WebSocketInflater {
80    WTF_MAKE_FAST_ALLOCATED;
81public:
82    static PassOwnPtr<WebSocketInflater> create(int windowBits = 15);
83
84    ~WebSocketInflater();
85
86    bool initialize();
87    bool addBytes(const char*, size_t);
88    bool finish();
89    const char* data() { return m_buffer.data(); }
90    size_t size() const { return m_buffer.size(); }
91    // Reset the inflate result.
92    void reset();
93
94private:
95    explicit WebSocketInflater(int windowBits);
96
97    int m_windowBits;
98    Vector<char> m_buffer;
99    OwnPtr<z_stream> m_stream;
100};
101
102}
103
104#endif // WebSocketDeflater_h
105