/* * Copyright (C) 2019 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. AND ITS CONTRIBUTORS ``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 ITS 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. */ #pragma once #include "ElementRuleCollector.h" #include "RenderStyle.h" #include "Timer.h" namespace WebCore { namespace Style { class MatchedDeclarationsCache { WTF_MAKE_FAST_ALLOCATED; public: MatchedDeclarationsCache(); ~MatchedDeclarationsCache(); static bool isCacheable(const Element&, const RenderStyle&, const RenderStyle& parentStyle); static unsigned computeHash(const MatchResult&); struct Entry { MatchResult matchResult; std::unique_ptr<const RenderStyle> renderStyle; std::unique_ptr<const RenderStyle> parentRenderStyle; bool isUsableAfterHighPriorityProperties(const RenderStyle&) const; }; const Entry* find(unsigned hash, const MatchResult&); void add(const RenderStyle&, const RenderStyle& parentStyle, unsigned hash, const MatchResult&); // Every N additions to the matched declaration cache trigger a sweep where entries holding // the last reference to a style declaration are garbage collected. void invalidate(); void clearEntriesAffectedByViewportUnits(); private: void sweep(); HashMap<unsigned, Entry> m_entries; Timer m_sweepTimer; unsigned m_additionsSinceLastSweep { 0 }; }; } }