libvips/libsrc/iofuncs/im_mapfile.c

358 lines
8.0 KiB
C
Raw Normal View History

2007-08-29 18:23:50 +02:00
/* @(#) Function which returns a char pointer at the beginning of the file
* @(#) corresponding to fd.
* @(#)
* @(#) int
* @(#) im_mapfile( im )
* @(#) IMAGE im;
* @(#)
* @(#) As above, but map read-write.
* @(#)
* @(#) int
* @(#) im_mapfilerw( im )
* @(#) IMAGE im;
* @(#)
* @(#) Return -1 on error, 0 for success.
*
* Copyright: Nicos Dessipris
* Wriiten on: 13/02/1990
* Updated on:
* 10/5/93 J.Cupitt
* - im_mapfilerw() added
* 13/12/94 JC
* - ANSIfied
* 5/7/99 JC
* - better error if unable to map rw
* 31/3/02 JC
* - better mmap() fails error
* 19/9/02 JC
* - added im__mmap()/im__munmap() with windows versions
* 5/1/04 Lev Serebryakov
* - patched for freebsd compatibility
* 5/2/04 JC
* - now records length as well as base, so we unmap the right amount of
* memory even if files change behind our back
*/
/*
This file is part of VIPS.
VIPS 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 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
/*
#define DEBUG
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <sys/types.h>
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif /*HAVE_SYS_MMAN_H*/
#ifdef HAVE_SYS_FILE_H
#include <sys/file.h>
#endif /*HAVE_SYS_FILE_H*/
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif /*HAVE_UNISTD_H*/
#ifdef OS_WIN32
#ifndef S_ISREG
#define S_ISREG(m) (!!(m & _S_IFREG))
#endif
#endif /*OS_WIN32*/
#include <vips/vips.h>
#ifdef OS_WIN32
#include <windows.h>
#endif /*OS_WIN32*/
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
void *
im__mmap( int fd, int writeable, size_t length, gint64 offset )
{
void *baseaddr;
#ifdef DEBUG
printf( "im__mmap: length = %d, offset = %lld\n", length, offset );
#endif /*DEBUG*/
#ifdef OS_WIN32
{
HANDLE hFile = (HANDLE) _get_osfhandle( fd );
HANDLE hMMFile;
DWORD flProtect;
DWORD dwDesiredAccess;
DWORD dwFileOffsetHigh;
DWORD dwFileOffsetLow;
/* woah, slightly gross
*/
int dws = sizeof( DWORD );
int shift = 8 * dws;
gint64 mask = ((gint64) -1) >> shift;
if( writeable ) {
flProtect = PAGE_READWRITE;
dwDesiredAccess = FILE_MAP_WRITE;
}
else {
flProtect = PAGE_READONLY;
dwDesiredAccess = FILE_MAP_READ;
}
if( !(hMMFile = CreateFileMapping( hFile,
NULL, flProtect, 0, 0, NULL )) ) {
im_error_system( GetLastError(), "im_mapfile",
2008-11-02 23:11:01 +01:00
"%s", _( "unable to CreateFileMapping" ) );
2007-08-29 18:23:50 +02:00
return( NULL );
}
dwFileOffsetHigh = (offset >> shift) & mask;
dwFileOffsetLow = offset & mask;
if( !(baseaddr = (char *)MapViewOfFile( hMMFile, dwDesiredAccess,
dwFileOffsetHigh, dwFileOffsetLow, length )) ) {
im_error_system( GetLastError(), "im_mapfile",
2008-11-02 23:11:01 +01:00
"%s", _( "unable to MapViewOfFile" ) );
2007-08-29 18:23:50 +02:00
CloseHandle( hMMFile );
return( NULL );
}
/* Can close mapping now ... view stays until UnmapViewOfFile().
FIXME ... is this a performance problem?
*/
CloseHandle( hMMFile );
}
#else /*!OS_WIN32*/
{
int prot;
if( writeable )
prot = PROT_WRITE;
else
prot = PROT_READ;
/* Casting gint64 to off_t should be safe, even on *nixes without
* LARGEFILE.
*/
baseaddr = mmap( 0, length, prot, MAP_SHARED, fd, (off_t) offset );
if( baseaddr == MAP_FAILED ) {
2008-11-02 23:11:01 +01:00
im_error_system( errno, "im_mapfile",
"%s", _( "unable to mmap" ) );
2007-08-29 18:23:50 +02:00
im_warn( "im_mapfile", _( "map failed (%s), "
"running very low on system resources, "
"expect a crash soon" ), strerror( errno ) );
return( NULL );
}
}
#endif /*OS_WIN32*/
return( baseaddr );
}
int
im__munmap( void *start, size_t length )
{
#ifdef OS_WIN32
if( !UnmapViewOfFile( start ) ) {
im_error_system( GetLastError(), "im_mapfile",
2008-11-02 23:11:01 +01:00
"%s", _( "unable to UnmapViewOfFile" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
#else /*!OS_WIN32*/
if( munmap( start, length ) < 0 ) {
im_error_system( errno, "im_mapfile",
2008-11-02 23:11:01 +01:00
"%s", _( "unable to munmap file" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
#endif /*OS_WIN32*/
return( 0 );
}
int
im_mapfile( IMAGE *im )
{
gint64 length;
struct stat st;
mode_t m;
assert( !im->baseaddr );
/* Check the size of the file; if it is less than 64 bytes, then flag
* an error.
*/
if( (length = im_file_length( im->fd )) == -1 )
return( -1 );
if( fstat( im->fd, &st ) == -1 ) {
2008-11-02 23:11:01 +01:00
im_error( "im_mapfile",
"%s", _( "unable to get file status" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
m = (mode_t) st.st_mode;
if( length < 64 ) {
2008-11-02 23:11:01 +01:00
im_error( "im_mapfile",
"%s", _( "file is less than 64 bytes" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
if( !S_ISREG( m ) ) {
2008-11-02 23:11:01 +01:00
im_error( "im_mapfile",
"%s", _( "not a regular file" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
if( !(im->baseaddr = im__mmap( im->fd, 0, length, 0 )) )
return( -1 );
/* im__mmap() will fail for >2GB, so this is safe even for large
* files.
*/
im->length = length;
return( 0 );
}
/* As above, but map read/write.
*/
int
im_mapfilerw( IMAGE *im )
{
gint64 length;
struct stat st;
mode_t m;
assert( !im->baseaddr );
/* Check the size of the file if it is less than 64 bytes return
* make also sure that it is a regular file
*/
if( (length = im_file_length( im->fd )) == -1 )
return( -1 );
if( fstat( im->fd, &st ) == -1 ) {
2008-11-02 23:11:01 +01:00
im_error( "im_mapfilerw",
"%s", _( "unable to get file status" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
m = (mode_t) st.st_mode;
if( length < 64 || !S_ISREG( m ) ) {
2008-11-02 23:11:01 +01:00
im_error( "im_mapfile",
"%s", _( "unable to read data" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
if( !(im->baseaddr = im__mmap( im->fd, 1, length, 0 )) )
return( -1 );
/* im__mmap() will fail for >2GB, so this is safe even for large
* files.
*/
im->length = length;
return( 0 );
}
/* From im_rwcheck() ... image needs to be a completely mapped read-only file,
* we try to remap it read-write.
*/
int
im_remapfilerw( IMAGE *image )
{
void *baseaddr;
#ifdef OS_WIN32
{
HANDLE hFile = (HANDLE) _get_osfhandle( image->fd );
HANDLE hMMFile;
if( !(hMMFile = CreateFileMapping( hFile,
NULL, PAGE_READWRITE, 0, 0, NULL )) ) {
im_error_system( GetLastError(), "im_mapfile",
2008-11-02 23:11:01 +01:00
"%s", _( "unable to CreateFileMapping" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
if( !UnmapViewOfFile( image->baseaddr ) ) {
im_error_system( GetLastError(), "im_mapfile",
2008-11-02 23:11:01 +01:00
"%s", _( "unable to UnmapViewOfFile" ) );
2007-08-29 18:23:50 +02:00
return( -1 );
}
if( !(baseaddr = (char *)MapViewOfFileEx( hMMFile, FILE_MAP_WRITE,
0, 0, 0, image->baseaddr )) ) {
im_error_system( GetLastError(), "im_mapfile",
2008-11-02 23:11:01 +01:00
"%s", _( "unable to MapViewOfFile" ) );
2007-08-29 18:23:50 +02:00
CloseHandle( hMMFile );
return( -1 );
}
/* Can close mapping now ... view stays until UnmapViewOfFile().
FIXME ... is this a performance problem?
*/
CloseHandle( hMMFile );
}
#else /*!OS_WIN32*/
{
assert( image->dtype == IM_MMAPIN );
baseaddr = mmap( image->baseaddr, image->length,
PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED,
image->fd, 0 );
if( baseaddr == (void *)-1 ) {
im_error( "im_mapfile", _( "unable to mmap: \"%s\" - %s" ),
image->filename, strerror( errno ) );
return( -1 );
}
}
#endif /*OS_WIN32*/
image->dtype = IM_MMAPINRW;
if( baseaddr != image->baseaddr ) {
im_error( "im_mapfile", _( "unable to mmap \"%s\" to same "
"address" ), image->filename );
image->baseaddr = baseaddr;
return( -1 );
}
return( 0 );
}