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// Copyright (c) 2012-2014 Konstantin Isakov <ikm@zbackup.org> and ZBackup contributors, see CONTRIBUTORS
// Part of ZBackup. Licensed under GNU GPLv2 or later + OpenSSL, see LICENSE
#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"
#if defined( __APPLE__ ) || defined( __OpenBSD__ ) || defined(__FreeBSD__) || defined(__CYGWIN__)
#define lseek64 lseek
#endif
UnbufferedFile::UnbufferedFile( char const * fileName, Mode mode )
{
int flags = ( mode == ReadWrite ? ( O_RDWR | O_CREAT ) :
( mode == WriteOnly ? ( O_WRONLY | O_CREAT | O_TRUNC ) : O_RDONLY ) );
#if !defined( __APPLE__ ) && !defined( __OpenBSD__ ) && !defined(__FreeBSD__) && !defined(__CYGWIN__)
flags |= O_LARGEFILE;
#endif
fd = open( fileName, flags, 0666 );
if ( fd < 0 )
throw exCantOpen( fileName );
}
size_t UnbufferedFile::read( void * buf, size_t size )
{
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 )
{
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()
{
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 )
{
if ( lseek64( fd, offset, SEEK_CUR ) < 0 )
throw exSeekError();
}
void UnbufferedFile::seek( Offset offset )
{
if ( lseek64( fd, offset, SEEK_SET ) < 0 )
throw exSeekError();
}
UnbufferedFile::~UnbufferedFile()
{
close( fd );
}
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