diff options
Diffstat (limited to 'src/v8/qcalculatehash_p.h')
| -rw-r--r-- | src/v8/qcalculatehash_p.h | 140 |
1 files changed, 0 insertions, 140 deletions
diff --git a/src/v8/qcalculatehash_p.h b/src/v8/qcalculatehash_p.h deleted file mode 100644 index 7076b48..0000000 --- a/src/v8/qcalculatehash_p.h +++ /dev/null @@ -1,140 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). -** Contact: http://www.qt-project.org/legal -** -** This file is part of the QtV8 module of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:LGPL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and Digia. For licensing terms and -** conditions see http://qt.digia.com/licensing. For further information -** use the contact form at http://qt.digia.com/contact-us. -** -** GNU Lesser General Public License Usage -** Alternatively, this file may be used under the terms of the GNU Lesser -** General Public License version 2.1 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 2.1 requirements -** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. -** -** In addition, as a special exception, Digia gives you certain additional -** rights. These rights are described in the Digia Qt LGPL Exception -** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. -** -** GNU General Public License Usage -** Alternatively, this file may be used under the terms of the GNU -** General Public License version 3.0 as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL included in the -** packaging of this file. Please review the following information to -** ensure the GNU General Public License version 3.0 requirements will be -** met: http://www.gnu.org/copyleft/gpl.html. -** -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -#ifndef CALCULATEHASH_P_H -#define CALCULATEHASH_P_H - -// -// W A R N I N G -// ------------- -// -// This file is not part of the Qt API. It exists purely as an -// implementation detail. This header file may change from version to -// version without notice, or even be removed. -// -// We mean it. -// - -#include <QtCore/qglobal.h> -#include <QtCore/qstring.h> - -QT_BEGIN_NAMESPACE - -// This is a reimplementation of V8's string hash algorithm. It is significantly -// faster to do it here than call into V8, but it adds the maintenance burden of -// ensuring that the two hashes are identical. We Q_ASSERT() that the two return -// the same value. If these asserts start to fail, the hash code needs to be -// synced with V8. -namespace HashedString { - static const int kMaxArrayIndexSize = 10; - static const int kMaxHashCalcLength = 16383; - static const int kNofHashBitFields = 2; - static const int kHashShift = kNofHashBitFields; - static const int kIsNotArrayIndexMask = 1 << 1; - static const int kArrayIndexValueBits = 24; - static const int kArrayIndexHashLengthShift = kArrayIndexValueBits + kNofHashBitFields; - static const int kMaxCachedArrayIndexLength = 7; -}; - -template <typename schar> -uint32_t calculateHash(const schar* chars, int length) { - if (length > HashedString::kMaxHashCalcLength) { - // V8 trivial hash - return (length << HashedString::kHashShift) | HashedString::kIsNotArrayIndexMask; - } - - uint32_t raw_running_hash = 0; - uint32_t array_index = 0; - bool is_array_index = (0 < length && length <= HashedString::kMaxArrayIndexSize); - bool is_first_char = true; - - int ii = 0; - for (;is_array_index && ii < length; ++ii) { - quint32 c = *chars++; - - raw_running_hash += c; - raw_running_hash += (raw_running_hash << 10); - raw_running_hash ^= (raw_running_hash >> 6); - - if (c < '0' || c > '9') { - is_array_index = false; - } else { - int d = c - '0'; - if (is_first_char) { - is_first_char = false; - if (c == '0' && length > 1) { - is_array_index = false; - continue; - } - } - if (array_index > 429496729U - ((d + 2) >> 3)) { - is_array_index = false; - } else { - array_index = array_index * 10 + d; - } - } - } - - for (;ii < length; ++ii) { - raw_running_hash += *chars++; - raw_running_hash += (raw_running_hash << 10); - raw_running_hash ^= (raw_running_hash >> 6); - } - - if (is_array_index) { - array_index <<= HashedString::kHashShift; - array_index |= length << HashedString::kArrayIndexHashLengthShift; - return array_index; - } else { - raw_running_hash += (raw_running_hash << 3); - raw_running_hash ^= (raw_running_hash >> 11); - raw_running_hash += (raw_running_hash << 15); - if (raw_running_hash == 0) { - raw_running_hash = 27; - } - - return (raw_running_hash << HashedString::kHashShift) | HashedString::kIsNotArrayIndexMask; - } -} - -QT_END_NAMESPACE - -#endif // CALCULATEHASH_P_H |