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author | The Android Open Source Project <initial-contribution@android.com> | 2008-12-17 18:05:15 -0800 |
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committer | The Android Open Source Project <initial-contribution@android.com> | 2008-12-17 18:05:15 -0800 |
commit | 1cbdecfa9fc428ac2d8aca0fa91c9580b3d57353 (patch) | |
tree | 4457a7306ea5acb43fe05bfe0973b1f7faf97ba2 /JavaScriptCore/wtf/HashFunctions.h | |
parent | 9364f22aed35e1a1e9d07c121510f80be3ab0502 (diff) | |
download | external_webkit-1cbdecfa9fc428ac2d8aca0fa91c9580b3d57353.zip external_webkit-1cbdecfa9fc428ac2d8aca0fa91c9580b3d57353.tar.gz external_webkit-1cbdecfa9fc428ac2d8aca0fa91c9580b3d57353.tar.bz2 |
Code drop from //branches/cupcake/...@124589
Diffstat (limited to 'JavaScriptCore/wtf/HashFunctions.h')
-rw-r--r-- | JavaScriptCore/wtf/HashFunctions.h | 70 |
1 files changed, 63 insertions, 7 deletions
diff --git a/JavaScriptCore/wtf/HashFunctions.h b/JavaScriptCore/wtf/HashFunctions.h index bf85dc0..2c66a2d 100644 --- a/JavaScriptCore/wtf/HashFunctions.h +++ b/JavaScriptCore/wtf/HashFunctions.h @@ -1,7 +1,5 @@ -// -*- mode: c++; c-basic-offset: 4 -*- /* - * This file is part of the KDE libraries - * Copyright (C) 2005, 2006 Apple Computer, Inc. + * Copyright (C) 2005, 2006, 2008 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 @@ -37,6 +35,32 @@ namespace WTF { // integer hash function // Thomas Wang's 32 Bit Mix Function: http://www.cris.com/~Ttwang/tech/inthash.htm + inline unsigned intHash(uint8_t key8) + { + unsigned key = key8; + key += ~(key << 15); + key ^= (key >> 10); + key += (key << 3); + key ^= (key >> 6); + key += ~(key << 11); + key ^= (key >> 16); + return key; + } + + // Thomas Wang's 32 Bit Mix Function: http://www.cris.com/~Ttwang/tech/inthash.htm + inline unsigned intHash(uint16_t key16) + { + unsigned key = key16; + key += ~(key << 15); + key ^= (key >> 10); + key += (key << 3); + key ^= (key >> 6); + key += ~(key << 11); + key ^= (key >> 16); + return key; + } + + // Thomas Wang's 32 Bit Mix Function: http://www.cris.com/~Ttwang/tech/inthash.htm inline unsigned intHash(uint32_t key) { key += ~(key << 15); @@ -69,7 +93,15 @@ namespace WTF { }; template<typename T> struct FloatHash { - static unsigned hash(T key) { return intHash(*reinterpret_cast<typename IntTypes<sizeof(T)>::UnsignedType*>(&key)); } + static unsigned hash(T key) + { + union { + T key; + typename IntTypes<sizeof(T)>::UnsignedType bits; + } u; + u.key = key; + return intHash(u.bits); + } static bool equal(T a, T b) { return a == b; } static const bool safeToCompareToEmptyOrDeleted = true; }; @@ -91,18 +123,36 @@ namespace WTF { static bool equal(T a, T b) { return a == b; } static const bool safeToCompareToEmptyOrDeleted = true; }; - template<typename P> struct PtrHash<RefPtr<P> > { - static unsigned hash(const RefPtr<P>& key) { return PtrHash<P*>::hash(key.get()); } + template<typename P> struct PtrHash<RefPtr<P> > : PtrHash<P*> { + using PtrHash<P*>::hash; + static unsigned hash(const RefPtr<P>& key) { return hash(key.get()); } + using PtrHash<P*>::equal; static bool equal(const RefPtr<P>& a, const RefPtr<P>& b) { return a == b; } - static const bool safeToCompareToEmptyOrDeleted = true; + static bool equal(P* a, const RefPtr<P>& b) { return a == b; } + static bool equal(const RefPtr<P>& a, P* b) { return a == b; } }; // default hash function for each type template<typename T> struct DefaultHash; + template<typename T, typename U> struct PairHash { + static unsigned hash(const std::pair<T, U>& p) + { + return intHash((static_cast<uint64_t>(DefaultHash<T>::Hash::hash(p.first)) << 32 | DefaultHash<U>::Hash::hash(p.second))); + } + static bool equal(const std::pair<T, U>& a, const std::pair<T, U>& b) + { + return DefaultHash<T>::Hash::equal(a.first, b.first) && DefaultHash<U>::Hash::equal(a.second, b.second); + } + static const bool safeToCompareToEmptyOrDeleted = DefaultHash<T>::Hash::safeToCompareToEmptyOrDeleted + && DefaultHash<U>::Hash::safeToCompareToEmptyOrDeleted; + }; + // make IntHash the default hash function for many integer types + template<> struct DefaultHash<short> { typedef IntHash<unsigned> Hash; }; + template<> struct DefaultHash<unsigned short> { typedef IntHash<unsigned> Hash; }; template<> struct DefaultHash<int> { typedef IntHash<unsigned> Hash; }; template<> struct DefaultHash<unsigned> { typedef IntHash<unsigned> Hash; }; template<> struct DefaultHash<long> { typedef IntHash<unsigned long> Hash; }; @@ -110,6 +160,10 @@ namespace WTF { template<> struct DefaultHash<long long> { typedef IntHash<unsigned long long> Hash; }; template<> struct DefaultHash<unsigned long long> { typedef IntHash<unsigned long long> Hash; }; +#if !COMPILER(MSVC) || defined(_NATIVE_WCHAR_T_DEFINED) + template<> struct DefaultHash<wchar_t> { typedef IntHash<wchar_t> Hash; }; +#endif + template<> struct DefaultHash<float> { typedef FloatHash<float> Hash; }; template<> struct DefaultHash<double> { typedef FloatHash<double> Hash; }; @@ -118,6 +172,8 @@ namespace WTF { template<typename P> struct DefaultHash<P*> { typedef PtrHash<P*> Hash; }; template<typename P> struct DefaultHash<RefPtr<P> > { typedef PtrHash<RefPtr<P> > Hash; }; + template<typename T, typename U> struct DefaultHash<std::pair<T, U> > { typedef PairHash<T, U> Hash; }; + } // namespace WTF using WTF::DefaultHash; |