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Diffstat (limited to 'src/lib/parser/qmljsmemorypool_p.h')
-rw-r--r-- | src/lib/parser/qmljsmemorypool_p.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/src/lib/parser/qmljsmemorypool_p.h b/src/lib/parser/qmljsmemorypool_p.h new file mode 100644 index 000000000..458069282 --- /dev/null +++ b/src/lib/parser/qmljsmemorypool_p.h @@ -0,0 +1,124 @@ +/************************************************************************** +** +** This file is part of the Qt Build System +** +** Copyright (c) 2012 Nokia Corporation and/or its subsidiary(-ies). +** +** Contact: Nokia Corporation (info@qt.nokia.com) +** +** +** GNU Lesser General Public License Usage +** +** 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, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** Other Usage +** +** Alternatively, this file may be used in accordance with the terms and +** conditions contained in a signed written agreement between you and Nokia. +** +** If you have questions regarding the use of this file, please contact +** Nokia at info@qt.nokia.com. +** +**************************************************************************/ + +#ifndef QMLJSMEMORYPOOL_P_H +#define QMLJSMEMORYPOOL_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 "qmljsglobal_p.h" + +#include <QtCore/qglobal.h> +#include <QtCore/qshareddata.h> + +#include <string.h> + +QT_QML_BEGIN_NAMESPACE + +namespace QmlJS { + +class QML_PARSER_EXPORT MemoryPool : public QSharedData +{ +public: + enum { maxBlockCount = -1 }; + enum { defaultBlockSize = 1 << 12 }; + + MemoryPool() { + m_blockIndex = maxBlockCount; + m_currentIndex = 0; + m_storage = 0; + m_currentBlock = 0; + m_currentBlockSize = 0; + } + + virtual ~MemoryPool() { + for (int index = 0; index < m_blockIndex + 1; ++index) + qFree(m_storage[index]); + + qFree(m_storage); + } + + char *allocate(int bytes) { + bytes += (8 - bytes) & 7; // ensure multiple of 8 bytes (maintain alignment) + if (m_currentBlock == 0 || m_currentBlockSize < m_currentIndex + bytes) { + ++m_blockIndex; + m_currentBlockSize = defaultBlockSize << m_blockIndex; + + m_storage = reinterpret_cast<char**>(qRealloc(m_storage, sizeof(char*) * (1 + m_blockIndex))); + m_currentBlock = m_storage[m_blockIndex] = reinterpret_cast<char*>(qMalloc(m_currentBlockSize)); + ::memset(m_currentBlock, 0, m_currentBlockSize); + + m_currentIndex = (8 - quintptr(m_currentBlock)) & 7; // ensure first chunk is 64-bit aligned + Q_ASSERT(m_currentIndex + bytes <= m_currentBlockSize); + } + + char *p = reinterpret_cast<char *> + (m_currentBlock + m_currentIndex); + + m_currentIndex += bytes; + + return p; + } + + int bytesAllocated() const { + int bytes = 0; + for (int index = 0; index < m_blockIndex; ++index) + bytes += (defaultBlockSize << index); + bytes += m_currentIndex; + return bytes; + } + +private: + int m_blockIndex; + int m_currentIndex; + char *m_currentBlock; + int m_currentBlockSize; + char **m_storage; + +private: + Q_DISABLE_COPY(MemoryPool) +}; + +} // namespace QmlJS + +QT_QML_END_NAMESPACE + +#endif |