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      1 /*
      2     Copyright (C) 1998 Lars Knoll (knoll (at) mpi-hd.mpg.de)
      3     Copyright (C) 2001 Dirk Mueller <mueller (at) kde.org>
      4     Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
      5 
      6     This library is free software; you can redistribute it and/or
      7     modify it under the terms of the GNU Library General Public
      8     License as published by the Free Software Foundation; either
      9     version 2 of the License, or (at your option) any later version.
     10 
     11     This library is distributed in the hope that it will be useful,
     12     but WITHOUT ANY WARRANTY; without even the implied warranty of
     13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14     Library General Public License for more details.
     15 
     16     You should have received a copy of the GNU Library General Public License
     17     along with this library; see the file COPYING.LIB.  If not, write to
     18     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     19     Boston, MA 02110-1301, USA.
     20 
     21     This class provides all functionality needed for loading images, style sheets and html
     22     pages from the web. It has a memory cache for these objects.
     23 */
     24 
     25 #ifndef ResourceClientWalker_h
     26 #define ResourceClientWalker_h
     27 
     28 #include "core/fetch/ResourceClient.h"
     29 #include "wtf/HashCountedSet.h"
     30 #include "wtf/Vector.h"
     31 
     32 namespace WebCore {
     33 
     34 // Call this "walker" instead of iterator so people won't expect Qt or STL-style iterator interface.
     35 // Just keep calling next() on this. It's safe from deletions of items.
     36 template<typename T> class ResourceClientWalker {
     37 public:
     38     ResourceClientWalker(const HashCountedSet<ResourceClient*>& set)
     39         : m_clientSet(set), m_clientVector(set.size()), m_index(0)
     40     {
     41         typedef HashCountedSet<ResourceClient*>::const_iterator Iterator;
     42         Iterator end = set.end();
     43         size_t clientIndex = 0;
     44         for (Iterator current = set.begin(); current != end; ++current)
     45             m_clientVector[clientIndex++] = current->key;
     46     }
     47 
     48     T* next()
     49     {
     50         size_t size = m_clientVector.size();
     51         while (m_index < size) {
     52             ResourceClient* next = m_clientVector[m_index++];
     53             if (m_clientSet.contains(next)) {
     54                 ASSERT(T::expectedType() == ResourceClient::expectedType() || next->resourceClientType() == T::expectedType());
     55                 return static_cast<T*>(next);
     56             }
     57         }
     58 
     59         return 0;
     60     }
     61 private:
     62     const HashCountedSet<ResourceClient*>& m_clientSet;
     63     Vector<ResourceClient*> m_clientVector;
     64     size_t m_index;
     65 };
     66 
     67 }
     68 
     69 #endif
     70