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/**************************************************************************/
/* */
/* Copyright (c) 2001, 2011 NoMachine (http://www.nomachine.com) */
/* Copyright (c) 2008-2017 Oleksandr Shneyder <o.shneyder@phoca-gmbh.de> */
/* Copyright (c) 2014-2022 Ulrich Sibiller <uli42@gmx.de> */
/* Copyright (c) 2014-2019 Mihai Moldovan <ionic@ionic.de> */
/* Copyright (c) 2011-2022 Mike Gabriel <mike.gabriel@das-netzwerkteam.de>*/
/* Copyright (c) 2015-2016 Qindel Group (http://www.qindel.com) */
/* */
/* NXCOMP, NX protocol compression and NX extensions to this software */
/* are copyright of the aforementioned persons and companies. */
/* */
/* Redistribution and use of the present software is allowed according */
/* to terms specified in the file LICENSE.nxcomp which comes in the */
/* source distribution. */
/* */
/* All rights reserved. */
/* */
/* NOTE: This software has received contributions from various other */
/* contributors, only the core maintainers and supporters are listed as */
/* copyright holders. Please contact us, if you feel you should be listed */
/* as copyright holder, as well. */
/* */
/**************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "BlockCache.h"
int BlockCache::compare(unsigned int size, const unsigned char *data,
int overwrite)
{
int match = 0;
if (size == size_)
{
match = 1;
for (unsigned int i = 0; i < size_; i++)
if (data[i] != buffer_[i])
{
match = 0;
break;
}
}
if (!match && overwrite)
set(size, data);
return match;
}
void BlockCache::set(unsigned int size, const unsigned char *data)
{
if (size_ < size)
{
delete[]buffer_;
buffer_ = new unsigned char[size];
}
size_ = size;
memcpy(buffer_, data, size);
checksum_ = checksum(size, data);
}
unsigned int BlockCache::checksum(unsigned int size, const unsigned char *data)
{
unsigned int sum = 0;
unsigned int shift = 0;
const unsigned char *next = data;
for (unsigned int i = 0; i < size; i++)
{
unsigned int value = (unsigned int) *next++;
sum += (value << shift);
shift++;
if (shift == 8)
shift = 0;
}
return sum;
}
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