82 lines
2.3 KiB
C++
82 lines
2.3 KiB
C++
/*
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* ZoneMinder flexible memory class implementation, $Date$, $Revision$
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* Copyright (C) 2001-2008 Philip Coombes
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <string.h>
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#include <fcntl.h>
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#include "zm.h"
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#include "zm_buffer.h"
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unsigned int Buffer::assign( const unsigned char *pStorage, unsigned int pSize )
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{
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if ( mAllocation < pSize )
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{
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delete[] mStorage;
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mAllocation = pSize;
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mHead = mStorage = new unsigned char[pSize];
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}
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mSize = pSize;
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memcpy( mStorage, pStorage, mSize );
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mHead = mStorage;
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mTail = mHead + mSize;
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return( mSize );
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}
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unsigned int Buffer::expand( unsigned int count )
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{
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int spare = mAllocation - mSize;
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int headSpace = mHead - mStorage;
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int tailSpace = spare - headSpace;
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int width = mTail - mHead;
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if ( spare > (int)count )
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{
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if ( tailSpace < (int)count )
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{
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memmove( mStorage, mHead, mSize );
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mHead = mStorage;
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mTail = mHead + width;
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}
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}
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else
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{
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mAllocation += count;
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unsigned char *newStorage = new unsigned char[mAllocation];
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if ( mStorage )
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{
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memcpy( newStorage, mHead, mSize );
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delete[] mStorage;
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}
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mStorage = newStorage;
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mHead = mStorage;
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mTail = mHead + width;
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}
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return( mSize );
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}
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int Buffer::read_into( int sd, unsigned int bytes ) {
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// Make sure there is enough space
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this->expand(bytes);
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int bytes_read = read( sd, mTail, bytes );
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if ( bytes_read > 0 ) {
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mTail += bytes_read;
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mSize += bytes_read;
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}
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return bytes_read;
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}
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