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/*
* This file is part of rsyncrypto - rsync friendly encryption
* Copyright (C) 2005 Shachar Shemesh for Lingnu Open Source Consulting (http://www.lignu.com)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _AUTOMMAP_H
#define _AUTOMMAP_H
#include <errno.h>
// automap will auto-release mmaped areas
class autommap {
void *ptr;
size_t size;
// Disable default copy constructor
autommap( const autommap & );
public:
autommap() : ptr(reinterpret_cast<void *>(-1l)), size(0)
{
}
autommap(void *start, size_t length, int prot, int flags, int fd, off_t offset ) :
ptr(mmap(start, length, prot, flags, fd, offset)), size(length)
{
if( ptr==reinterpret_cast<void *>(-1l) ) {
size=0;
#if defined(EXCEPT_CLASS)
throw EXCEPT_CLASS("mmap failed", errno);
#endif
}
}
// Map an entire file into memory
autommap(file_t fd, int prot) : ptr(reinterpret_cast<void *>(-1l)), size(0)
{
struct stat filestat;
if( fstat(fd, &filestat)==0 ) {
// Do nothing without an error if file is empty
if( filestat.st_size!=0 ) {
autommap that(NULL, filestat.st_size, prot, MAP_SHARED, fd, 0);
*this=that;
}
}
#if defined(EXCEPT_CLASS)
else
throw EXCEPT_CLASS("file mmap failed", errno);
#endif
}
~autommap()
{
clear();
}
void *get() const
{
return ptr;
}
unsigned char *get_uc() const
{
return static_cast<unsigned char *>(ptr);
}
autommap &operator=( autommap &that )
{
clear();
ptr=that.ptr;
size=that.size;
that.ptr=reinterpret_cast<void *>(-1l);
that.size=0;
return *this;
}
void clear()
{
if( ptr!=reinterpret_cast<void *>(-1l) ) {
munmap( ptr, size );
}
ptr=reinterpret_cast<void *>(-1l);
size=0;
}
size_t getsize() const {
return size;
}
};
#endif // _AUTOMMAP_H
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