mirror of https://github.com/vitalif/zbackup
113 lines
2.5 KiB
C++
113 lines
2.5 KiB
C++
// Copyright (c) 2012-2014 Konstantin Isakov <ikm@zbackup.org> and ZBackup contributors, see CONTRIBUTORS
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// Part of ZBackup. Licensed under GNU GPLv2 or later + OpenSSL, see LICENSE
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#define _LARGEFILE64_SOURCE
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#include <fcntl.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <unistd.h>
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#include "check.hh"
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#include "unbuffered_file.hh"
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#if defined( __APPLE__ ) || defined( __OpenBSD__ ) || defined(__FreeBSD__) || defined(__CYGWIN__)
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#define lseek64 lseek
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#endif
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UnbufferedFile::UnbufferedFile( char const * fileName, Mode mode )
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throw( exCantOpen )
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{
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int flags = ( mode == ReadWrite ? ( O_RDWR | O_CREAT ) :
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( mode == WriteOnly ? ( O_WRONLY | O_CREAT | O_TRUNC ) : O_RDONLY ) );
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#if !defined( __APPLE__ ) && !defined( __OpenBSD__ ) && !defined(__FreeBSD__) && !defined(__CYGWIN__)
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flags |= O_LARGEFILE;
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#endif
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fd = open( fileName, flags, 0666 );
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if ( fd < 0 )
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throw exCantOpen( fileName );
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}
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size_t UnbufferedFile::read( void * buf, size_t size )
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throw( exReadError )
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{
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char * next = ( char * ) buf;
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size_t left = size;
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while( left )
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{
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ssize_t rd = ::read( fd, next, left );
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if ( rd < 0 )
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{
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if ( errno != EINTR )
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throw exReadError();
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}
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else
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if ( rd > 0 )
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{
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CHECK( ( size_t ) rd <= left, "read too many bytes from a file" );
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next += rd;
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left -= rd;
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}
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else
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break;
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}
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return size - left;
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}
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void UnbufferedFile::write( void const * buf, size_t size )
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throw( exWriteError )
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{
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char const * next = ( char const * ) buf;
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size_t left = size;
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while( left )
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{
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ssize_t written = ::write( fd, next, left );
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if ( written < 0 )
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{
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if ( errno != EINTR )
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throw exWriteError();
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}
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else
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{
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CHECK( ( size_t ) written <= left, "wrote too many bytes to a file" );
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next += written;
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left -= written;
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}
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}
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}
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UnbufferedFile::Offset UnbufferedFile::size() throw( exSeekError )
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{
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Offset cur = lseek64( fd, 0, SEEK_CUR );
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if ( cur < 0 )
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throw exSeekError();
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Offset result = lseek64( fd, 0, SEEK_END );
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if ( result < 0 || lseek64( fd, cur, SEEK_SET ) < 0 )
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throw exSeekError();
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return result;
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}
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void UnbufferedFile::seekCur( Offset offset ) throw( exSeekError )
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{
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if ( lseek64( fd, offset, SEEK_CUR ) < 0 )
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throw exSeekError();
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}
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void UnbufferedFile::seek( Offset offset ) throw( exSeekError )
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{
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if ( lseek64( fd, offset, SEEK_SET ) < 0 )
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throw exSeekError();
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}
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UnbufferedFile::~UnbufferedFile() throw()
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{
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close( fd );
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}
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