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 "web/ContextFeaturesClientImpl.h"
33
34#include "core/dom/Document.h"
35#include "platform/weborigin/SecurityOrigin.h"
36#include "public/web/WebDocument.h"
37#include "public/web/WebPermissionClient.h"
38#include "web/WebLocalFrameImpl.h"
39
40namespace blink {
41
42class ContextFeaturesCache FINAL : public NoBaseWillBeGarbageCollectedFinalized<ContextFeaturesCache>, public DocumentSupplement {
43    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(ContextFeaturesCache);
44public:
45    class Entry {
46    public:
47        enum Value {
48            IsEnabled,
49            IsDisabled,
50            NeedsRefresh
51        };
52
53        Entry()
54            : m_value(NeedsRefresh)
55            , m_defaultValue(false)
56        { }
57
58        bool isEnabled() const
59        {
60            ASSERT(m_value != NeedsRefresh);
61            return m_value == IsEnabled;
62        }
63
64        void set(bool value, bool defaultValue)
65        {
66            m_value = value ? IsEnabled : IsDisabled;
67            m_defaultValue = defaultValue;
68        }
69
70        bool needsRefresh(bool defaultValue) const
71        {
72            return m_value == NeedsRefresh || m_defaultValue != defaultValue;
73        }
74
75    private:
76        Value m_value;
77        bool m_defaultValue; // Needs to be traked as a part of the signature since it can be changed dynamically.
78    };
79
80    static const char* supplementName();
81    static ContextFeaturesCache& from(Document&);
82
83    Entry& entryFor(ContextFeatures::FeatureType type)
84    {
85        size_t index = static_cast<size_t>(type);
86        ASSERT_WITH_SECURITY_IMPLICATION(index < ContextFeatures::FeatureTypeSize);
87        return m_entries[index];
88    }
89
90    void validateAgainst(Document*);
91
92private:
93    String m_domain;
94    Entry m_entries[ContextFeatures::FeatureTypeSize];
95};
96
97const char* ContextFeaturesCache::supplementName()
98{
99    return "ContextFeaturesCache";
100}
101
102ContextFeaturesCache& ContextFeaturesCache::from(Document& document)
103{
104    ContextFeaturesCache* cache = static_cast<ContextFeaturesCache*>(DocumentSupplement::from(document, supplementName()));
105    if (!cache) {
106        cache = new ContextFeaturesCache();
107        DocumentSupplement::provideTo(document, supplementName(), adoptPtrWillBeNoop(cache));
108    }
109
110    return *cache;
111}
112
113void ContextFeaturesCache::validateAgainst(Document* document)
114{
115    String currentDomain = document->securityOrigin()->domain();
116    if (currentDomain == m_domain)
117        return;
118    m_domain = currentDomain;
119    for (size_t i = 0; i < ContextFeatures::FeatureTypeSize; ++i)
120        m_entries[i] = Entry();
121}
122
123bool ContextFeaturesClientImpl::isEnabled(Document* document, ContextFeatures::FeatureType type, bool defaultValue)
124{
125    ASSERT(document);
126    ContextFeaturesCache::Entry& cache = ContextFeaturesCache::from(*document).entryFor(type);
127    if (cache.needsRefresh(defaultValue))
128        cache.set(askIfIsEnabled(document, type, defaultValue), defaultValue);
129    return cache.isEnabled();
130}
131
132void ContextFeaturesClientImpl::urlDidChange(Document* document)
133{
134    ASSERT(document);
135    ContextFeaturesCache::from(*document).validateAgainst(document);
136}
137
138bool ContextFeaturesClientImpl::askIfIsEnabled(Document* document, ContextFeatures::FeatureType type, bool defaultValue)
139{
140    WebLocalFrameImpl* frame = WebLocalFrameImpl::fromFrame(document->frame());
141    if (!frame || !frame->permissionClient())
142        return defaultValue;
143
144    switch (type) {
145    case ContextFeatures::MutationEvents:
146        return frame->permissionClient()->allowMutationEvents(defaultValue);
147    case ContextFeatures::PushState:
148        return frame->permissionClient()->allowPushState();
149    default:
150        return defaultValue;
151    }
152}
153
154} // namespace blink
155