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#include "config.h"
32#include "core/dom/shadow/SelectRuleFeatureSet.h"
33
34#include "core/css/CSSSelector.h"
35#include "core/css/CSSSelectorList.h"
36
37#include "wtf/BitVector.h"
38
39namespace blink {
40
41void SelectRuleFeatureSet::collectFeaturesFromSelector(const CSSSelector& selector)
42{
43    for (const CSSSelector* current = &selector; current; current = current->tagHistory()) {
44        if (invalidationSetForSelector(*current))
45            continue;
46
47        if (!current->selectorList())
48            continue;
49
50        for (const CSSSelector* selector = current->selectorList()->first(); selector; selector = CSSSelectorList::next(*selector))
51            collectFeaturesFromSelector(*selector);
52    }
53}
54
55bool SelectRuleFeatureSet::checkSelectorsForClassChange(const SpaceSplitString& changedClasses) const
56{
57    unsigned changedSize = changedClasses.size();
58    for (unsigned i = 0; i < changedSize; ++i) {
59        if (hasSelectorForClass(changedClasses[i]))
60            return true;
61    }
62    return false;
63}
64
65bool SelectRuleFeatureSet::checkSelectorsForClassChange(const SpaceSplitString& oldClasses, const SpaceSplitString& newClasses) const
66{
67    if (!oldClasses.size())
68        return checkSelectorsForClassChange(newClasses);
69
70    // Class vectors tend to be very short. This is faster than using a hash table.
71    BitVector remainingClassBits;
72    remainingClassBits.ensureSize(oldClasses.size());
73
74    for (unsigned i = 0; i < newClasses.size(); ++i) {
75        bool found = false;
76        for (unsigned j = 0; j < oldClasses.size(); ++j) {
77            if (newClasses[i] == oldClasses[j]) {
78                // Mark each class that is still in the newClasses so we can skip doing
79                // an n^2 search below when looking for removals. We can't break from
80                // this loop early since a class can appear more than once.
81                remainingClassBits.quickSet(j);
82                found = true;
83            }
84        }
85        // Class was added.
86        if (!found) {
87            if (hasSelectorForClass(newClasses[i]))
88                return true;
89        }
90    }
91
92    for (unsigned i = 0; i < oldClasses.size(); ++i) {
93        if (remainingClassBits.quickGet(i))
94            continue;
95
96        // Class was removed.
97        if (hasSelectorForClass(oldClasses[i]))
98            return true;
99    }
100    return false;
101}
102
103}
104
105