PageCache.h revision ab9e7a118cf1ea2e3a93dce683b2ded3e7291ddb
1/* 2 * Copyright (C) 2007 Apple 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 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#ifndef PageCache_h 27#define PageCache_h 28 29#include "HistoryItem.h" 30#include "Timer.h" 31#include <wtf/Forward.h> 32#include <wtf/HashSet.h> 33#include <wtf/Noncopyable.h> 34 35namespace WebCore { 36 37 class CachedPage; 38 class Frame; 39 class HistoryItem; 40 class Page; 41 42 class PageCache { 43 WTF_MAKE_NONCOPYABLE(PageCache); WTF_MAKE_FAST_ALLOCATED; 44 public: 45 friend PageCache* pageCache(); 46 47 static bool canCache(Page*); 48 49 void setCapacity(int); // number of pages to cache 50 int capacity() { return m_capacity; } 51 52 void add(PassRefPtr<HistoryItem>, Page*); // Prunes if capacity() is exceeded. 53 void remove(HistoryItem*); 54 CachedPage* get(HistoryItem* item); 55 56 void releaseAutoreleasedPagesNow(); 57 58 int pageCount() const { return m_size; } 59 int frameCount() const; 60 int autoreleasedPageCount() const; 61 62 private: 63 typedef HashSet<RefPtr<CachedPage> > CachedPageSet; 64 65 PageCache(); // Use pageCache() instead. 66 ~PageCache(); // Not implemented to make sure nobody accidentally calls delete -- WebCore does not delete singletons. 67 68 static bool canCachePageContainingThisFrame(Frame*); 69 70 void addToLRUList(HistoryItem*); // Adds to the head of the list. 71 void removeFromLRUList(HistoryItem*); 72 73 void prune(); 74 75 void autorelease(PassRefPtr<CachedPage>); 76 void releaseAutoreleasedPagesNowOrReschedule(Timer<PageCache>*); 77 78 int m_capacity; 79 int m_size; 80 81 // LRU List 82 HistoryItem* m_head; 83 HistoryItem* m_tail; 84 85 Timer<PageCache> m_autoreleaseTimer; 86 CachedPageSet m_autoreleaseSet; 87 }; 88 89 // Function to obtain the global page cache. 90 PageCache* pageCache(); 91 92} // namespace WebCore 93 94#endif // PageCache_h 95