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author | The Android Open Source Project <initial-contribution@android.com> | 2009-03-03 18:28:41 -0800 |
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committer | The Android Open Source Project <initial-contribution@android.com> | 2009-03-03 18:28:41 -0800 |
commit | 648161bb0edfc3d43db63caed5cc5213bc6cb78f (patch) | |
tree | 4b825dc642cb6eb9a060e54bf8d69288fbee4904 /JavaScriptCore/wtf/HashFunctions.h | |
parent | a65af38181ac7d34544586bdb5cd004de93897ad (diff) | |
download | external_webkit-648161bb0edfc3d43db63caed5cc5213bc6cb78f.zip external_webkit-648161bb0edfc3d43db63caed5cc5213bc6cb78f.tar.gz external_webkit-648161bb0edfc3d43db63caed5cc5213bc6cb78f.tar.bz2 |
auto import from //depot/cupcake/@135843
Diffstat (limited to 'JavaScriptCore/wtf/HashFunctions.h')
-rw-r--r-- | JavaScriptCore/wtf/HashFunctions.h | 183 |
1 files changed, 0 insertions, 183 deletions
diff --git a/JavaScriptCore/wtf/HashFunctions.h b/JavaScriptCore/wtf/HashFunctions.h deleted file mode 100644 index 2c66a2d..0000000 --- a/JavaScriptCore/wtf/HashFunctions.h +++ /dev/null @@ -1,183 +0,0 @@ -/* - * 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 - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Library General Public License for more details. - * - * You should have received a copy of the GNU Library General Public License - * along with this library; see the file COPYING.LIB. If not, write to - * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, - * Boston, MA 02110-1301, USA. - * - */ - -#ifndef WTF_HashFunctions_h -#define WTF_HashFunctions_h - -#include "RefPtr.h" -#include <stdint.h> - -namespace WTF { - - template<size_t size> struct IntTypes; - template<> struct IntTypes<1> { typedef int8_t SignedType; typedef uint8_t UnsignedType; }; - template<> struct IntTypes<2> { typedef int16_t SignedType; typedef uint16_t UnsignedType; }; - template<> struct IntTypes<4> { typedef int32_t SignedType; typedef uint32_t UnsignedType; }; - template<> struct IntTypes<8> { typedef int64_t SignedType; typedef uint64_t UnsignedType; }; - - // 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); - key ^= (key >> 10); - key += (key << 3); - key ^= (key >> 6); - key += ~(key << 11); - key ^= (key >> 16); - return key; - } - - // Thomas Wang's 64 bit Mix Function: http://www.cris.com/~Ttwang/tech/inthash.htm - inline unsigned intHash(uint64_t key) - { - key += ~(key << 32); - key ^= (key >> 22); - key += ~(key << 13); - key ^= (key >> 8); - key += (key << 3); - key ^= (key >> 15); - key += ~(key << 27); - key ^= (key >> 31); - return static_cast<unsigned>(key); - } - - template<typename T> struct IntHash { - static unsigned hash(T key) { return intHash(static_cast<typename IntTypes<sizeof(T)>::UnsignedType>(key)); } - static bool equal(T a, T b) { return a == b; } - static const bool safeToCompareToEmptyOrDeleted = true; - }; - - template<typename T> struct FloatHash { - 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; - }; - - // pointer identity hash function - - template<typename T> struct PtrHash { - static unsigned hash(T key) - { -#if COMPILER(MSVC) -#pragma warning(push) -#pragma warning(disable: 4244) // work around what seems to be a bug in MSVC's conversion warnings -#endif - return IntHash<uintptr_t>::hash(reinterpret_cast<uintptr_t>(key)); -#if COMPILER(MSVC) -#pragma warning(pop) -#endif - } - static bool equal(T a, T b) { return a == b; } - static const bool safeToCompareToEmptyOrDeleted = true; - }; - 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 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; }; - template<> struct DefaultHash<unsigned long> { typedef IntHash<unsigned long> Hash; }; - 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; }; - - // make PtrHash the default hash function for pointer types that don't specialize - - 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; -using WTF::IntHash; -using WTF::PtrHash; - -#endif // WTF_HashFunctions_h |