libvips/libsrc/iofuncs/im_piocheck.c

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2007-08-29 18:23:50 +02:00
/* @(#) Function which checks the structures imagein and imageout and gets
* @(#) ready for partial input. If a function calls this in its setup stage,
* @(#) we assume it is partial-ready. If it calls im_iocheck(), we fall back
* @(#) to old-style behaviour.
* @(#)
* @(#) int
* @(#) im_piocheck( imagein, imageout )
* @(#) IMAGE *imagein, *imageout;
* @(#)
* @(#) int
* @(#) im_pincheck( imagein )
* @(#) IMAGE *imagein;
* @(#)
* @(#) int
* @(#) im_piocheck( imageout )
* @(#) IMAGE *imageout;
* @(#)
* @(#) Returns -1 on fail
* @(#)
*
* Copyright: Nicos Dessipris
* Written on: 12/02/1990
* Modified on :
* 15/4/93 J.Cupitt
* - im_incheck(), im_outcheck() added.
* - type field now checked.
* 10/6/93 J.Cupitt
* - im_iocheck() adapted to make im_piocheck()
* - auto-rewind feature added
* 27/10/95 JC
* - im_pincheck() on a setbuf now zaps generate function so as not to
* confuse any later calls to im_prepare() or im_prepare_inplace()
*/
/*
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
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#include <stdio.h>
#include <vips/vips.h>
#include <vips/internal.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
/* Check that an image is readable.
*/
int
im_pincheck( IMAGE *im )
{
if( im_image_sanity( im ) )
return( -1 );
#ifdef DEBUG_IO
printf( "im_pincheck: enabling partial input for %s\n", im->filename );
#endif /*DEBUG_IO*/
switch( im->dtype ) {
case IM_SETBUF:
case IM_SETBUF_FOREIGN:
/* Should have been written to.
*/
if( !im->data ) {
im_errormsg( "im_pincheck: no image data" );
return( -1 );
}
/* Should be no generate functions now.
*/
im->start = NULL;
im->generate = NULL;
im->stop = NULL;
break;
case IM_PARTIAL:
/* Should have had generate functions attached.
*/
if( !im->generate ) {
im_errormsg( "im_pincheck: no image data" );
return( -1 );
}
break;
case IM_MMAPIN:
case IM_MMAPINRW:
case IM_OPENIN:
break;
case IM_OPENOUT:
/* Close file down and reopen as im_mmapin.
*/
#ifdef DEBUG_IO
printf( "im_pincheck: auto-rewind of %s\n", im->filename );
#endif/*DEBUG_IO*/
if( im__close( im ) || im_openin( im ) ) {
im_errormsg( "im_pincheck: auto-rewind for %s failed",
im->filename );
return( -1 );
}
break;
default:
im_errormsg( "im_pincheck: image not readable" );
return( -1 );
}
return( 0 );
}
/* Check that an image is writeable.
*/
int
im_poutcheck( IMAGE *im )
{
if( !im ) {
im_errormsg( "im_poutcheck: null image descriptor" );
return( -1 );
}
#ifdef DEBUG_IO
printf( "im_pincheck: enabling partial output for %s\n", im->filename );
#endif /*DEBUG_IO*/
switch( im->dtype ) {
case IM_SETBUF:
/* Check that it has not been im_setupout().
*/
if( im->data ) {
im_errormsg( "im_poutcheck: image already written" );
return( -1 );
}
break;
case IM_PARTIAL:
/* Make sure nothing is attached.
*/
if( im->generate ) {
im_errormsg( "im_poutcheck: image already written" );
return( -1 );
}
break;
case IM_OPENOUT:
case IM_SETBUF_FOREIGN:
/* Okeydoke. Not much checking here.
*/
break;
default:
im_errormsg( "im_poutcheck: image not writeable" );
return( -1 );
}
return( 0 );
}
/* Check a pair of fds for IO.
*/
int
im_piocheck( IMAGE *in, IMAGE *out )
{
return( im_pincheck( in ) || im_poutcheck( out ) );
}