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Diffstat (limited to 'src/3rdparty/webkit/JavaScriptCore/wtf/StringHashFunctions.h')
-rw-r--r-- | src/3rdparty/webkit/JavaScriptCore/wtf/StringHashFunctions.h | 157 |
1 files changed, 0 insertions, 157 deletions
diff --git a/src/3rdparty/webkit/JavaScriptCore/wtf/StringHashFunctions.h b/src/3rdparty/webkit/JavaScriptCore/wtf/StringHashFunctions.h deleted file mode 100644 index 07f117f..0000000 --- a/src/3rdparty/webkit/JavaScriptCore/wtf/StringHashFunctions.h +++ /dev/null @@ -1,157 +0,0 @@ -/* - * Copyright (C) 2005, 2006, 2008, 2010 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_StringHashFunctions_h -#define WTF_StringHashFunctions_h - -#include <wtf/unicode/Unicode.h> - -namespace WTF { - -// Golden ratio - arbitrary start value to avoid mapping all 0's to all 0's -static const unsigned stringHashingStartValue = 0x9e3779b9U; - -// stringHash methods based on Paul Hsieh's SuperFastHash. -// http://www.azillionmonkeys.com/qed/hash.html -// char* data is interpreted as latin-encoded (zero extended to 16 bits). - -inline unsigned stringHash(const UChar* data, unsigned length) -{ - unsigned hash = WTF::stringHashingStartValue; - unsigned rem = length & 1; - length >>= 1; - - // Main loop - for (; length > 0; length--) { - hash += data[0]; - unsigned tmp = (data[1] << 11) ^ hash; - hash = (hash << 16) ^ tmp; - data += 2; - hash += hash >> 11; - } - - // Handle end case - if (rem) { - hash += data[0]; - hash ^= hash << 11; - hash += hash >> 17; - } - - // Force "avalanching" of final 127 bits - hash ^= hash << 3; - hash += hash >> 5; - hash ^= hash << 2; - hash += hash >> 15; - hash ^= hash << 10; - - hash &= 0x7fffffff; - - // this avoids ever returning a hash code of 0, since that is used to - // signal "hash not computed yet", using a value that is likely to be - // effectively the same as 0 when the low bits are masked - if (hash == 0) - hash = 0x40000000; - - return hash; -} - -inline unsigned stringHash(const char* data, unsigned length) -{ - unsigned hash = WTF::stringHashingStartValue; - unsigned rem = length & 1; - length >>= 1; - - // Main loop - for (; length > 0; length--) { - hash += static_cast<unsigned char>(data[0]); - unsigned tmp = (static_cast<unsigned char>(data[1]) << 11) ^ hash; - hash = (hash << 16) ^ tmp; - data += 2; - hash += hash >> 11; - } - - // Handle end case - if (rem) { - hash += static_cast<unsigned char>(data[0]); - hash ^= hash << 11; - hash += hash >> 17; - } - - // Force "avalanching" of final 127 bits - hash ^= hash << 3; - hash += hash >> 5; - hash ^= hash << 2; - hash += hash >> 15; - hash ^= hash << 10; - - hash &= 0x7fffffff; - - // this avoids ever returning a hash code of 0, since that is used to - // signal "hash not computed yet", using a value that is likely to be - // effectively the same as 0 when the low bits are masked - if (hash == 0) - hash = 0x40000000; - - return hash; -} - -inline unsigned stringHash(const char* data) -{ - unsigned hash = WTF::stringHashingStartValue; - - // Main loop - for (;;) { - unsigned char b0 = data[0]; - if (!b0) - break; - unsigned char b1 = data[1]; - if (!b1) { - hash += b0; - hash ^= hash << 11; - hash += hash >> 17; - break; - } - hash += b0; - unsigned tmp = (b1 << 11) ^ hash; - hash = (hash << 16) ^ tmp; - data += 2; - hash += hash >> 11; - } - - // Force "avalanching" of final 127 bits. - hash ^= hash << 3; - hash += hash >> 5; - hash ^= hash << 2; - hash += hash >> 15; - hash ^= hash << 10; - - hash &= 0x7fffffff; - - // This avoids ever returning a hash code of 0, since that is used to - // signal "hash not computed yet", using a value that is likely to be - // effectively the same as 0 when the low bits are masked. - if (hash == 0) - hash = 0x40000000; - - return hash; -} - -} // namespace WTF - -#endif // WTF_StringHashFunctions_h |