Split ImageResourceClient into ResourceClient and ImageResourceObserver [1/2]

third_party/WebKit/Source/core/fetch/ResourceClientWalker.h

-/*
-    Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
-    Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
-    Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Library General Public
-    License as published by the Free Software Foundation; either
-    version 2 of the License, or (at your option) any later version.
-
-    This library is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Library General Public License for more details.
-
-    You should have received a copy of the GNU Library General Public License
-    along with this library; see the file COPYING.LIB.  If not, write to
-    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-    Boston, MA 02110-1301, USA.
-
-    This class provides all functionality needed for loading images, style sheets and html
-    pages from the web. It has a memory cache for these objects.
-*/
-
-#ifndef ResourceClientWalker_h
-#define ResourceClientWalker_h
-
-#include "core/fetch/ResourceClient.h"
-#include "wtf/Allocator.h"
-#include "wtf/HashCountedSet.h"
-#include "wtf/Vector.h"
-
-namespace blink {
-
-// Call this "walker" instead of iterator so people won't expect Qt or STL-style iterator interface.
-// Just keep calling next() on this. It's safe from deletions of items.
-template<typename T> class ResourceClientWalker {
-    STACK_ALLOCATED();
-public:
-    ResourceClientWalker(const HashCountedSet<ResourceClient*>& set)
-        : m_clientSet(set), m_clientVector(set.size()), m_index(0)
-    {
-        size_t clientIndex = 0;
-        for (const auto& resourceClient : set)
-            m_clientVector[clientIndex++] = resourceClient.key;
-    }
-
-    T* next()
-    {
-        size_t size = m_clientVector.size();
-        while (m_index < size) {
-            ResourceClient* next = m_clientVector[m_index++];
-            if (m_clientSet.contains(next)) {
-                ASSERT(T::isExpectedType(next));
-                return static_cast<T*>(next);
-            }
-        }
-
-        return 0;
-    }
-private:
-    const HashCountedSet<ResourceClient*>& m_clientSet;
-    Vector<ResourceClient*> m_clientVector;
-    size_t m_index;
-};
-
-} // namespace blink
-
-#endif