/* * Copyright (C) 2007, 2015 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef PageCache_h #define PageCache_h #include "HistoryItem.h" #include "Timer.h" #include <wtf/Forward.h> #include <wtf/ListHashSet.h> #include <wtf/Noncopyable.h> namespace WebCore { class CachedPage; class Frame; class Page; enum class PruningReason { None, ProcessSuspended, MemoryPressure, ReachedMaxSize }; class PageCache { WTF_MAKE_NONCOPYABLE(PageCache); WTF_MAKE_FAST_ALLOCATED; public: // Function to obtain the global page cache. WEBCORE_EXPORT static PageCache& singleton(); bool canCache(Page&) const; // Used when memory is low to prune some cached pages. WEBCORE_EXPORT void pruneToSizeNow(unsigned maxSize, PruningReason); WEBCORE_EXPORT void setMaxSize(unsigned); // number of pages to cache. unsigned maxSize() const { return m_maxSize; } void addIfCacheable(HistoryItem&, Page*); // Prunes if maxSize() is exceeded. WEBCORE_EXPORT void remove(HistoryItem&); CachedPage* get(HistoryItem&, Page*); std::unique_ptr<CachedPage> take(HistoryItem&, Page*); unsigned pageCount() const { return m_items.size(); } WEBCORE_EXPORT unsigned frameCount() const; WEBCORE_EXPORT void markPagesForVisitedLinkStyleRecalc(); // Will mark all cached pages associated with the given page as needing style recalc. void markPagesForFullStyleRecalc(Page&); void markPagesForDeviceOrPageScaleChanged(Page&); void markPagesForContentsSizeChanged(Page&); #if ENABLE(VIDEO_TRACK) void markPagesForCaptionPreferencesChanged(); #endif bool shouldClearBackingStores() const { return m_shouldClearBackingStores; } void setShouldClearBackingStores(bool flag) { m_shouldClearBackingStores = flag; } private: PageCache() = default; // Use singleton() instead. ~PageCache() = delete; // Make sure nobody accidentally calls delete -- WebCore does not delete singletons. static bool canCachePageContainingThisFrame(Frame&); void prune(PruningReason); ListHashSet<RefPtr<HistoryItem>> m_items; unsigned m_maxSize {0}; bool m_shouldClearBackingStores {false}; friend class WTF::NeverDestroyed<PageCache>; }; } // namespace WebCore #endif // PageCache_h