summaryrefslogtreecommitdiff
path: root/chromium/third_party/WebKit/Source/core/html/parser/HTMLEntitySearch.cpp
blob: c4ef2b0c92f2bae7693be9036ab8a0693367824e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
/*
 * Copyright (C) 2010 Google, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "core/html/parser/HTMLEntitySearch.h"

#include "core/html/parser/HTMLEntityTable.h"

namespace WebCore {

static const HTMLEntityTableEntry* halfway(const HTMLEntityTableEntry* left, const HTMLEntityTableEntry* right)
{
    return &left[(right - left) / 2];
}

HTMLEntitySearch::HTMLEntitySearch()
    : m_currentLength(0)
    , m_mostRecentMatch(0)
    , m_first(HTMLEntityTable::firstEntry())
    , m_last(HTMLEntityTable::lastEntry())
{
}

HTMLEntitySearch::CompareResult HTMLEntitySearch::compare(const HTMLEntityTableEntry* entry, UChar nextCharacter) const
{
    if (entry->length < m_currentLength + 1)
        return Before;
    UChar entryNextCharacter = entry->entity[m_currentLength];
    if (entryNextCharacter == nextCharacter)
        return Prefix;
    return entryNextCharacter < nextCharacter ? Before : After;
}

const HTMLEntityTableEntry* HTMLEntitySearch::findFirst(UChar nextCharacter) const
{
    const HTMLEntityTableEntry* left = m_first;
    const HTMLEntityTableEntry* right = m_last;
    if (left == right)
        return left;
    CompareResult result = compare(left, nextCharacter);
    if (result == Prefix)
        return left;
    if (result == After)
        return right;
    while (left + 1 < right) {
        const HTMLEntityTableEntry* probe = halfway(left, right);
        result = compare(probe, nextCharacter);
        if (result == Before)
            left = probe;
        else {
            ASSERT(result == After || result == Prefix);
            right = probe;
        }
    }
    ASSERT(left + 1 == right);
    return right;
}

const HTMLEntityTableEntry* HTMLEntitySearch::findLast(UChar nextCharacter) const
{
    const HTMLEntityTableEntry* left = m_first;
    const HTMLEntityTableEntry* right = m_last;
    if (left == right)
        return right;
    CompareResult result = compare(right, nextCharacter);
    if (result == Prefix)
        return right;
    if (result == Before)
        return left;
    while (left + 1 < right) {
        const HTMLEntityTableEntry* probe = halfway(left, right);
        result = compare(probe, nextCharacter);
        if (result == After)
            right = probe;
        else {
            ASSERT(result == Before || result == Prefix);
            left = probe;
        }
    }
    ASSERT(left + 1 == right);
    return left;
}

void HTMLEntitySearch::advance(UChar nextCharacter)
{
    ASSERT(isEntityPrefix());
    if (!m_currentLength) {
        m_first = HTMLEntityTable::firstEntryStartingWith(nextCharacter);
        m_last = HTMLEntityTable::lastEntryStartingWith(nextCharacter);
        if (!m_first || !m_last)
            return fail();
    } else {
        m_first = findFirst(nextCharacter);
        m_last = findLast(nextCharacter);
        if (m_first == m_last && compare(m_first, nextCharacter) != Prefix)
            return fail();
    }
    ++m_currentLength;
    if (m_first->length != m_currentLength) {
        return;
    }
    m_mostRecentMatch = m_first;
}

}