LA_library/auxstorage.h
2009-11-12 21:01:19 +00:00

145 lines
4.7 KiB
C++

/*
LA: linear algebra C++ interface library
Copyright (C) 2008 Jiri Pittner <jiri.pittner@jh-inst.cas.cz> or <jiri@pittnerovi.com>
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, either version 3 of the License, or
(at your option) any later version.
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, see <http://www.gnu.org/licenses/>.
*/
#ifndef _AUXSTORAGE_H_
#define _AUXSTORAGE_H_
#include "vec.h"
#include "mat.h"
#include "smat.h"
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
namespace LA {
//CAUTION:
//it will not work if T is itself a class with dynamically allocated components
//it cannot be implemented for SparseMat, which lacks fixed record length
//for more complex I/O use put() and get() methods of the individual classes
template<typename T>
class AuxStorage
{
char filename[32];
int fd;
bool deleteme;
size_t recl;
public:
AuxStorage(void);
AuxStorage(const char *name);
~AuxStorage(void) {close(fd); if(deleteme) unlink(filename);};
void get(NRVec<T> &x, const int pos) const;
void put(const NRVec<T> &x, const int pos);
void get(NRMat<T> &x, const int pos) const;
void put(const NRMat<T> &x, const int pos);
void get(NRSMat<T> &x, const int pos) const;
void put(const NRSMat<T> &x, const int pos);
};
template<typename T>
AuxStorage<T>::AuxStorage(void)
{
//mkstemp probable does not support O_LARGEFILE?!
strcpy(filename,"AUX_XXXXXX");
mktemp(filename);
unlink(filename);
fd=open(filename,O_CREAT|O_LARGEFILE|O_RDWR,0777);
if(fd<0) {perror(""); laerror("open failed in AuxStorage");}
recl=0;
deleteme=1;
}
template<typename T>
AuxStorage<T>::AuxStorage(const char *name)
{
strcpy(filename,name);
unlink(filename);
fd=open(filename,O_CREAT|O_LARGEFILE|O_RDWR,0777);
if(fd<0) {perror(""); laerror("open failed in AuxStorage");}
recl=0;
deleteme=0;
}
//vectors
template<typename T>
void AuxStorage<T>::get(NRVec<T> &x, const int pos) const
{
if(recl==0) laerror("get from an empty file in AuxStorage");
if((off64_t)-1 == lseek64(fd,pos*((off64_t)recl),SEEK_SET)) {perror(""); laerror("seek failed in AuxStorage");}
x.copyonwrite();
if((ssize_t)recl!=read(fd,&x[0],recl)) {perror(""); laerror("read failed in AuxStorage");}
}
template<typename T>
void AuxStorage<T>::put(const NRVec<T> &x, const int pos)
{
if(recl) {if(recl!=x.size()*sizeof(T)) laerror("attempt to write objects of different size to one AuxStorage");}
else recl=x.size()*sizeof(T);
if((off64_t)-1 == lseek64(fd,pos*((off64_t)recl),SEEK_SET)) {perror(""); laerror("seek failed in AuxStorage");}
if(0>write(fd,&x[0],recl)) {perror(""); laerror("write failed in AuxStorage");}
}
//matrices
template<typename T>
void AuxStorage<T>::get(NRMat<T> &x, const int pos) const
{
if(recl==0) laerror("get from an empty file in AuxStorage");
if((off64_t)-1 == lseek64(fd,pos*((off64_t)recl),SEEK_SET)) {perror(""); laerror("seek failed in AuxStorage");}
x.copyonwrite();
if((ssize_t)recl!=read(fd,&x(0,0),recl)) {perror(""); laerror("read failed in AuxStorage");}
}
template<typename T>
void AuxStorage<T>::put(const NRMat<T> &x, const int pos)
{
if(recl) {if(recl!=x.nrows()*x.ncols()*sizeof(T)) laerror("attempt to write objects of different size to one AuxStorage");}
else recl=x.nrows()*x.ncols()*sizeof(T);
if((off64_t)-1 == lseek64(fd,pos*((off64_t)recl),SEEK_SET)) {perror(""); laerror("seek failed in AuxStorage");}
if(0>write(fd,&x(0,0),recl)) {perror(""); laerror("write failed in AuxStorage");}
}
//packed symmetric matrices
template<typename T>
void AuxStorage<T>::get(NRSMat<T> &x, const int pos) const
{
if(recl==0) laerror("get from an empty file in AuxStorage");
if((off64_t)-1 == lseek64(fd,pos*((off64_t)recl),SEEK_SET)) {perror(""); laerror("seek failed in AuxStorage");}
x.copyonwrite();
if((ssize_t)recl!=read(fd,&x(0,0),recl)) {perror(""); laerror("read failed in AuxStorage");}
}
template<typename T>
void AuxStorage<T>::put(const NRSMat<T> &x, const int pos)
{
if(recl) {if(recl!=x.nrows()*(x.nrows()+1)/2*sizeof(T)) laerror("attempt to write objects of different size to one AuxStorage");}
else recl=x.nrows()*(x.nrows()+1)/2*sizeof(T);
if((off64_t)-1 == lseek64(fd,pos*((off64_t)recl),SEEK_SET)) {perror(""); laerror("seek failed in AuxStorage");}
if(0>write(fd,&x(0,0),recl)) {perror(""); laerror("write failed in AuxStorage");}
}
}//namespace
#endif