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 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/html/imports/HTMLImport.h"
33
34#include "core/dom/Document.h"
35#include "core/html/imports/HTMLImportStateResolver.h"
36#include "wtf/Vector.h"
37
38namespace blink {
39
40HTMLImport* HTMLImport::root()
41{
42    HTMLImport* i = this;
43    while (i->parent())
44        i = i->parent();
45    return i;
46}
47
48bool HTMLImport::precedes(HTMLImport* import)
49{
50    for (HTMLImport* i = this; i; i = traverseNext(i)) {
51        if (i == import)
52            return true;
53    }
54
55    return false;
56}
57
58bool HTMLImport::formsCycle() const
59{
60    for (const HTMLImport* i = this->parent(); i; i = i->parent()) {
61        if (i->document() == this->document())
62            return true;
63    }
64
65    return false;
66
67}
68
69void HTMLImport::appendImport(HTMLImport* child)
70{
71    appendChild(child);
72
73    // This prevents HTML parser from going beyond the
74    // blockage line before the precise state is computed by recalcState().
75    if (child->isSync())
76        m_state = HTMLImportState::blockedState();
77
78    stateWillChange();
79}
80
81void HTMLImport::stateDidChange()
82{
83    if (!state().shouldBlockScriptExecution()) {
84        if (Document* document = this->document())
85            document->didLoadAllImports();
86    }
87}
88
89void HTMLImport::recalcTreeState(HTMLImport* root)
90{
91    WillBeHeapHashMap<RawPtrWillBeMember<HTMLImport>, HTMLImportState> snapshot;
92    WillBeHeapVector<RawPtrWillBeMember<HTMLImport> > updated;
93
94    for (HTMLImport* i = root; i; i = traverseNext(i)) {
95        snapshot.add(i, i->state());
96        i->m_state = HTMLImportState::invalidState();
97    }
98
99    // The post-visit DFS order matters here because
100    // HTMLImportStateResolver in recalcState() Depends on
101    // |m_state| of its children and precedents of ancestors.
102    // Accidental cycle dependency of state computation is prevented
103    // by invalidateCachedState() and isStateCacheValid() check.
104    for (HTMLImport* i = traverseFirstPostOrder(root); i; i = traverseNextPostOrder(i)) {
105        ASSERT(!i->m_state.isValid());
106        i->m_state = HTMLImportStateResolver(i).resolve();
107
108        HTMLImportState newState = i->state();
109        HTMLImportState oldState = snapshot.get(i);
110        // Once the state reaches Ready, it shouldn't go back.
111        ASSERT(!oldState.isReady() || oldState <= newState);
112        if (newState != oldState)
113            updated.append(i);
114    }
115
116    for (size_t i = 0; i < updated.size(); ++i)
117        updated[i]->stateDidChange();
118}
119
120#if !defined(NDEBUG)
121void HTMLImport::show()
122{
123    root()->showTree(this, 0);
124}
125
126void HTMLImport::showTree(HTMLImport* highlight, unsigned depth)
127{
128    for (unsigned i = 0; i < depth*4; ++i)
129        fprintf(stderr, " ");
130
131    fprintf(stderr, "%s", this == highlight ? "*" : " ");
132    showThis();
133    fprintf(stderr, "\n");
134    for (HTMLImport* child = firstChild(); child; child = child->next())
135        child->showTree(highlight, depth + 1);
136}
137
138void HTMLImport::showThis()
139{
140    fprintf(stderr, "%p state=%d", this, m_state.peekValueForDebug());
141}
142#endif
143
144} // namespace blink
145