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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /layout/xul/tree/nsTreeStyleCache.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.tar.xz firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.zip |
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'layout/xul/tree/nsTreeStyleCache.h')
-rw-r--r-- | layout/xul/tree/nsTreeStyleCache.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/layout/xul/tree/nsTreeStyleCache.h b/layout/xul/tree/nsTreeStyleCache.h new file mode 100644 index 0000000000..b0c0e4d9dc --- /dev/null +++ b/layout/xul/tree/nsTreeStyleCache.h @@ -0,0 +1,82 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef nsTreeStyleCache_h__ +#define nsTreeStyleCache_h__ + +#include "mozilla/AtomArray.h" +#include "mozilla/Attributes.h" +#include "mozilla/UniquePtr.h" +#include "nsCOMArray.h" +#include "nsTHashMap.h" +#include "nsRefPtrHashtable.h" +#include "mozilla/ComputedStyle.h" + +class nsIContent; + +class nsTreeStyleCache { + public: + nsTreeStyleCache() : mNextState(0) {} + + ~nsTreeStyleCache() { Clear(); } + + void Clear() { + mTransitionTable = nullptr; + mCache = nullptr; + mNextState = 0; + } + + mozilla::ComputedStyle* GetComputedStyle( + nsPresContext* aPresContext, nsIContent* aContent, + mozilla::ComputedStyle* aStyle, + nsCSSAnonBoxPseudoStaticAtom* aPseudoElement, + const mozilla::AtomArray& aInputWord); + + protected: + typedef uint32_t DFAState; + + class Transition final { + public: + Transition(DFAState aState, nsAtom* aSymbol); + bool operator==(const Transition& aOther) const; + uint32_t Hash() const; + + private: + DFAState mState; + RefPtr<nsAtom> mInputSymbol; + }; + + typedef nsTHashMap<nsGenericHashKey<Transition>, DFAState> TransitionTable; + + // A transition table for a deterministic finite automaton. The DFA + // takes as its input a single pseudoelement and an ordered set of properties. + // It transitions on an input word that is the concatenation of the + // pseudoelement supplied with the properties in the array. + // + // It transitions from state to state by looking up entries in the transition + // table (which is a mapping from (S,i)->S', where S is the current state, i + // is the next property in the input word, and S' is the state to transition + // to. + // + // If S' is not found, it is constructed and entered into the hashtable + // under the key (S,i). + // + // Once the entire word has been consumed, the final state is used + // to reference the cache table to locate the ComputedStyle. + mozilla::UniquePtr<TransitionTable> mTransitionTable; + + // The cache of all active ComputedStyles. This is a hash from + // a final state in the DFA, Sf, to the resultant ComputedStyle. + typedef nsRefPtrHashtable<nsUint32HashKey, mozilla::ComputedStyle> + ComputedStyleCache; + mozilla::UniquePtr<ComputedStyleCache> mCache; + + // An integer counter that is used when we need to make new states in the + // DFA. + DFAState mNextState; +}; + +#endif // nsTreeStyleCache_h__ |