mirror of https://github.com/vitalif/zbackup
98 lines
2.0 KiB
C++
98 lines
2.0 KiB
C++
|
// Copyright (c) 2012-2013 Konstantin Isakov <ikm@zbackup.org>
|
||
|
// Part of ZBackup. Licensed under GNU GPLv2 or later
|
||
|
|
||
|
#define _LARGEFILE64_SOURCE
|
||
|
|
||
|
#include <fcntl.h>
|
||
|
#include <errno.h>
|
||
|
#include <fcntl.h>
|
||
|
#include <stdio.h>
|
||
|
#include <unistd.h>
|
||
|
|
||
|
#include "check.hh"
|
||
|
#include "unbuffered_file.hh"
|
||
|
|
||
|
UnbufferedFile::UnbufferedFile( char const * fileName, Mode mode )
|
||
|
throw( exCantOpen )
|
||
|
{
|
||
|
int flags = O_LARGEFILE |
|
||
|
( mode == WriteOnly ? ( O_WRONLY | O_CREAT | O_TRUNC ) :
|
||
|
O_RDONLY );
|
||
|
fd = open( fileName, flags, 0666 );
|
||
|
if ( fd < 0 )
|
||
|
throw exCantOpen( fileName );
|
||
|
}
|
||
|
|
||
|
size_t UnbufferedFile::read( void * buf, size_t size )
|
||
|
throw( exReadError )
|
||
|
{
|
||
|
char * next = ( char * ) buf;
|
||
|
size_t left = size;
|
||
|
|
||
|
while( left )
|
||
|
{
|
||
|
ssize_t rd = ::read( fd, next, left );
|
||
|
if ( rd < 0 )
|
||
|
{
|
||
|
if ( errno != EINTR )
|
||
|
throw exReadError();
|
||
|
}
|
||
|
else
|
||
|
if ( rd > 0 )
|
||
|
{
|
||
|
CHECK( ( size_t ) rd <= left, "read too many bytes from a file" );
|
||
|
next += rd;
|
||
|
left -= rd;
|
||
|
}
|
||
|
else
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
return size - left;
|
||
|
}
|
||
|
|
||
|
void UnbufferedFile::write( void const * buf, size_t size )
|
||
|
throw( exWriteError )
|
||
|
{
|
||
|
char const * next = ( char const * ) buf;
|
||
|
size_t left = size;
|
||
|
|
||
|
while( left )
|
||
|
{
|
||
|
ssize_t written = ::write( fd, next, left );
|
||
|
if ( written < 0 )
|
||
|
{
|
||
|
if ( errno != EINTR )
|
||
|
throw exWriteError();
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
CHECK( ( size_t ) written <= left, "wrote too many bytes to a file" );
|
||
|
next += written;
|
||
|
left -= written;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
UnbufferedFile::Offset UnbufferedFile::size() throw( exSeekError )
|
||
|
{
|
||
|
Offset cur = lseek64( fd, 0, SEEK_CUR );
|
||
|
if ( cur < 0 )
|
||
|
throw exSeekError();
|
||
|
Offset result = lseek64( fd, 0, SEEK_END );
|
||
|
if ( result < 0 || lseek64( fd, cur, SEEK_SET ) < 0 )
|
||
|
throw exSeekError();
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
void UnbufferedFile::seekCur( Offset offset ) throw( exSeekError )
|
||
|
{
|
||
|
if ( lseek64( fd, offset, SEEK_CUR ) < 0 )
|
||
|
throw exSeekError();
|
||
|
}
|
||
|
|
||
|
UnbufferedFile::~UnbufferedFile() throw()
|
||
|
{
|
||
|
close( fd );
|
||
|
}
|