1/*
2 * Copyright (C) 2013 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 GOOGLE 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 GOOGLE 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 BackgroundHTMLInputStream_h
27#define BackgroundHTMLInputStream_h
28
29#if ENABLE(THREADED_HTML_PARSER)
30
31#include "SegmentedString.h"
32#include <wtf/Vector.h>
33#include <wtf/text/WTFString.h>
34
35namespace WebCore {
36
37typedef size_t HTMLInputCheckpoint;
38
39class BackgroundHTMLInputStream {
40    WTF_MAKE_NONCOPYABLE(BackgroundHTMLInputStream);
41public:
42    BackgroundHTMLInputStream();
43
44    void append(const String&);
45    void close();
46
47    SegmentedString& current() { return m_current; }
48
49    // An HTMLInputCheckpoint is valid until the next call to rewindTo, at which
50    // point all outstanding checkpoints are invalidated.
51    HTMLInputCheckpoint createCheckpoint();
52    void rewindTo(HTMLInputCheckpoint, const String& unparsedInput);
53    void invalidateCheckpointsBefore(HTMLInputCheckpoint);
54
55    size_t outstandingCheckpointCount() const { return m_checkpoints.size() - m_firstValidCheckpointIndex; }
56
57private:
58    struct Checkpoint {
59        Checkpoint(const SegmentedString& i, size_t n) : input(i), numberOfSegmentsAlreadyAppended(n) { }
60
61        SegmentedString input;
62        size_t numberOfSegmentsAlreadyAppended;
63
64#ifndef NDEBUG
65        bool isNull() const { return input.isEmpty() && !numberOfSegmentsAlreadyAppended; }
66#endif
67        void clear() { input.clear(); numberOfSegmentsAlreadyAppended = 0; }
68    };
69
70    SegmentedString m_current;
71    Vector<String> m_segments;
72    Vector<Checkpoint> m_checkpoints;
73
74    // Note: These indicies may === vector.size(), in which case there are no valid checkpoints/segments at this time.
75    size_t m_firstValidCheckpointIndex;
76    size_t m_firstValidSegmentIndex;
77};
78
79}
80
81#endif // ENABLE(THREADED_HTML_PARSER)
82
83#endif
84