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