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Diffstat (limited to 'storage/ndb/src/common/transporter/SHM_Buffer.hpp')
| -rw-r--r-- | storage/ndb/src/common/transporter/SHM_Buffer.hpp | 233 |
1 files changed, 0 insertions, 233 deletions
diff --git a/storage/ndb/src/common/transporter/SHM_Buffer.hpp b/storage/ndb/src/common/transporter/SHM_Buffer.hpp deleted file mode 100644 index 5e900170318..00000000000 --- a/storage/ndb/src/common/transporter/SHM_Buffer.hpp +++ /dev/null @@ -1,233 +0,0 @@ -/* Copyright (c) 2003-2005 MySQL AB - Use is subject to license terms - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; version 2 of the License. - - This program 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 General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */ - -#ifndef SHM_BUFFER_HPP -#define SHM_BUFFER_HPP - -#include <ndb_global.h> - -#include <NdbSleep.h> - -/** - * These classes implement a circular buffer - * - * One reader and one writer - */ - -/** - * SHM_Reader - * - * Use as follows: - * getReadPtr(ptr, sz); - * for(int i = 0; i<sz; i++) - * printf("%c\n", ptr[i]); - * updateReadPtr(sz); - */ -class SHM_Reader { -public: - SHM_Reader(char * const _startOfBuffer, - Uint32 _sizeOfBuffer, - Uint32 _slack, - Uint32 * _readIndex, - Uint32 * _writeIndex) : - m_startOfBuffer(_startOfBuffer), - m_totalBufferSize(_sizeOfBuffer), - m_bufferSize(_sizeOfBuffer - _slack), - m_sharedReadIndex(_readIndex), - m_sharedWriteIndex(_writeIndex) - { - } - - void clear() { - m_readIndex = 0; - } - - /** - * - */ - inline bool empty() const; - - /** - * Get read pointer - * - * returns ptr - where to start reading - * sz - how much can I read - */ - inline void getReadPtr(Uint32 * & ptr, Uint32 * & eod); - - /** - * Update read ptr - */ - inline void updateReadPtr(Uint32 *ptr); - -private: - char * const m_startOfBuffer; - Uint32 m_totalBufferSize; - Uint32 m_bufferSize; - Uint32 m_readIndex; - - Uint32 * m_sharedReadIndex; - Uint32 * m_sharedWriteIndex; -}; - -inline -bool -SHM_Reader::empty() const{ - bool ret = (m_readIndex == * m_sharedWriteIndex); - return ret; -} - -/** - * Get read pointer - * - * returns ptr - where to start reading - * sz - how much can I read - */ -inline -void -SHM_Reader::getReadPtr(Uint32 * & ptr, Uint32 * & eod) -{ - Uint32 tReadIndex = m_readIndex; - Uint32 tWriteIndex = * m_sharedWriteIndex; - - ptr = (Uint32*)&m_startOfBuffer[tReadIndex]; - - if(tReadIndex <= tWriteIndex){ - eod = (Uint32*)&m_startOfBuffer[tWriteIndex]; - } else { - eod = (Uint32*)&m_startOfBuffer[m_bufferSize]; - } -} - -/** - * Update read ptr - */ -inline -void -SHM_Reader::updateReadPtr(Uint32 *ptr) -{ - Uint32 tReadIndex = ((char*)ptr) - m_startOfBuffer; - - assert(tReadIndex < m_totalBufferSize); - - if(tReadIndex >= m_bufferSize){ - tReadIndex = 0; - } - - m_readIndex = tReadIndex; - * m_sharedReadIndex = tReadIndex; -} - -#define WRITER_SLACK 4 - -class SHM_Writer { -public: - SHM_Writer(char * const _startOfBuffer, - Uint32 _sizeOfBuffer, - Uint32 _slack, - Uint32 * _readIndex, - Uint32 * _writeIndex) : - m_startOfBuffer(_startOfBuffer), - m_totalBufferSize(_sizeOfBuffer), - m_bufferSize(_sizeOfBuffer - _slack), - m_sharedReadIndex(_readIndex), - m_sharedWriteIndex(_writeIndex) - { - } - - void clear() { - m_writeIndex = 0; - } - - inline char * getWritePtr(Uint32 sz); - inline void updateWritePtr(Uint32 sz); - - inline Uint32 getWriteIndex() const { return m_writeIndex;} - inline Uint32 getBufferSize() const { return m_bufferSize;} - inline Uint32 get_free_buffer() const; - - inline void copyIndexes(SHM_Writer * standbyWriter); - -private: - char * const m_startOfBuffer; - Uint32 m_totalBufferSize; - Uint32 m_bufferSize; - - Uint32 m_writeIndex; - - Uint32 * m_sharedReadIndex; - Uint32 * m_sharedWriteIndex; -}; - -inline -char * -SHM_Writer::getWritePtr(Uint32 sz){ - Uint32 tReadIndex = * m_sharedReadIndex; - Uint32 tWriteIndex = m_writeIndex; - - char * ptr = &m_startOfBuffer[tWriteIndex]; - - Uint32 free; - if(tReadIndex <= tWriteIndex){ - free = m_bufferSize + tReadIndex - tWriteIndex; - } else { - free = tReadIndex - tWriteIndex; - } - - sz += 4; - if(sz < free){ - return ptr; - } - - return 0; -} - -inline -void -SHM_Writer::updateWritePtr(Uint32 sz){ - - assert(m_writeIndex == * m_sharedWriteIndex); - - Uint32 tWriteIndex = m_writeIndex; - tWriteIndex += sz; - - assert(tWriteIndex < m_totalBufferSize); - - if(tWriteIndex >= m_bufferSize){ - tWriteIndex = 0; - } - - m_writeIndex = tWriteIndex; - * m_sharedWriteIndex = tWriteIndex; -} - -inline -Uint32 -SHM_Writer::get_free_buffer() const -{ - Uint32 tReadIndex = * m_sharedReadIndex; - Uint32 tWriteIndex = m_writeIndex; - - Uint32 free; - if(tReadIndex <= tWriteIndex){ - free = m_bufferSize + tReadIndex - tWriteIndex; - } else { - free = tReadIndex - tWriteIndex; - } - return free; -} - -#endif |