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added TIFFRewriteField()

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This commit is contained in:
Frank Warmerdam 2007-12-31 21:55:07 +00:00
parent d0de6a396d
commit 2b64a8aac4
3 changed files with 370 additions and 3 deletions
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18
ChangeLog
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@ -1,3 +1,21 @@
2007-12-31 Frank Warmerdam <warmerdam@pobox.com>
* tif_dirwrite.c: Added TIFFRewriteField(). This new function
rewrites one field "on disk" updating an existing directory
entry. Lots of limitations still...
* tiffiop.h, tif_write.c, tif_dirread.c, tif_flush.c: Keep track of
TIFF_DIRTYSTRIP separately from TIFF_DIRTYDIRECT to indicate that
the strip offset/size values are dirty but nothing else about the
directory is dirty. In flush handle "just stripmaps dirty" as a
special case that just rewrites these values without otherwise
modifying the directory on disk using TIFFRewriteField().
We also modify logic so that in update mode the directory is not
marked dirty on read, but only when something is changed. This
means we need to keep track of updates to the stripmap stuff in
TIFFAppendToStrip().
2007-12-10 Frank Warmerdam <warmerdam@pobox.com>
* tif_jpeg.c: Improve ability to switch between encoding and decoding

349
libtiff/tif_dirwrite.c
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@ -1,4 +1,4 @@
/* $Id: tif_dirwrite.c,v 1.62 2007-11-23 20:49:43 fwarmerdam Exp $ */
/* $Id: tif_dirwrite.c,v 1.63 2007-12-31 21:55:07 fwarmerdam Exp $ */
/*
* Copyright (c) 1988-1997 Sam Leffler
@ -835,6 +835,7 @@ TIFFWriteDirectorySec(TIFF* tif, int isimage, int imagedone, uint64* pdiroff)
{
TIFFFreeDirectory(tif);
tif->tif_flags &= ~TIFF_DIRTYDIRECT;
tif->tif_flags &= ~TIFF_DIRTYSTRIP;
(*tif->tif_cleanup)(tif);
/*
* Reset directory-related state for subsequent
@ -2292,4 +2293,350 @@ TIFFLinkDirectory(TIFF* tif)
return (1);
}
/************************************************************************/
/* TIFFRewriteField() */
/* */
/* Rewrite a field in the directory on disk without regard to */
/* updating the TIFF directory structure in memory. Currently */
/* only supported for field that already exist in the on-disk */
/* directory. Mainly used for updating stripoffset / */
/* stripbytecount values after the directory is already on */
/* disk. */
/* */
/* Returns zero on failure, and one on success. */
/************************************************************************/
int
TIFFRewriteField(TIFF* tif, uint16 tag, TIFFDataType in_datatype,
uint32 count, void* data)
{
static const char module[] = "TIFFResetField";
const TIFFField* fip = NULL;
uint16 dircount;
uint32 dirsize;
uint8 direntry_raw[20];
uint16 entry_tag = 0;
uint16 entry_type = 0;
uint64 entry_count = 0;
uint64 entry_offset = 0;
int value_in_entry = 0;
uint32 i;
uint64 read_offset;
uint8 *buf_to_write = NULL;
TIFFDataType datatype;
/* -------------------------------------------------------------------- */
/* Find field definition. */
/* -------------------------------------------------------------------- */
fip = TIFFFindField(tif, tag, TIFF_ANY);
/* -------------------------------------------------------------------- */
/* Do some checking this is a straight forward case. */
/* -------------------------------------------------------------------- */
if( isMapped(tif) )
{
TIFFErrorExt( tif->tif_clientdata, module,
"Memory mapped files not currently supported for this operation." );
return 0;
}
if( tif->tif_diroff == 0 )
{
TIFFErrorExt( tif->tif_clientdata, module,
"Attempt to reset field on directory not already on disk." );
return 0;
}
/* -------------------------------------------------------------------- */
/* Read the directory entry count. */
/* -------------------------------------------------------------------- */
if (!SeekOK(tif, tif->tif_diroff)) {
TIFFErrorExt(tif->tif_clientdata, module,
"%s: Seek error accessing TIFF directory",
tif->tif_name);
return 0;
}
read_offset = tif->tif_diroff;
if (!(tif->tif_flags&TIFF_BIGTIFF))
{
if (!ReadOK(tif, &dircount, sizeof (uint16))) {
TIFFErrorExt(tif->tif_clientdata, module,
"%s: Can not read TIFF directory count",
tif->tif_name);
return 0;
}
if (tif->tif_flags & TIFF_SWAB)
TIFFSwabShort(&dircount);
dirsize = 12;
read_offset += 2;
} else {
uint64 dircount64;
if (!ReadOK(tif, &dircount64, sizeof (uint64))) {
TIFFErrorExt(tif->tif_clientdata, module,
"%s: Can not read TIFF directory count",
tif->tif_name);
return 0;
}
if (tif->tif_flags & TIFF_SWAB)
TIFFSwabLong8(&dircount64);
dircount = (uint16)dircount64;
dirsize = 20;
read_offset += 8;
}
/* -------------------------------------------------------------------- */
/* Read through directory to find target tag. */
/* -------------------------------------------------------------------- */
while( dircount > 0 )
{
if (!ReadOK(tif, direntry_raw, dirsize)) {
TIFFErrorExt(tif->tif_clientdata, module,
"%s: Can not read TIFF directory entry.",
tif->tif_name);
return 0;
}
memcpy( &entry_tag, direntry_raw + 0, sizeof(uint16) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabShort( &entry_tag );
if( entry_tag == tag )
break;
read_offset += dirsize;
}
if( entry_tag != tag )
{
TIFFErrorExt(tif->tif_clientdata, module,
"%s: Could not find tag %d.",
tif->tif_name, tag );
return 0;
}
/* -------------------------------------------------------------------- */
/* Extract the type, count and offset for this entry. */
/* -------------------------------------------------------------------- */
memcpy( &entry_type, direntry_raw + 2, sizeof(uint16) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabShort( &entry_type );
if (!(tif->tif_flags&TIFF_BIGTIFF))
{
uint32 value;
memcpy( &value, direntry_raw + 4, sizeof(uint32) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabLong( &value );
entry_count = value;
memcpy( &value, direntry_raw + 8, sizeof(uint32) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabLong( &value );
entry_offset = value;
}
else
{
memcpy( &entry_count, direntry_raw + 4, sizeof(uint64) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabLong8( &entry_count );
memcpy( &entry_offset, direntry_raw + 12, sizeof(uint64) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabLong8( &entry_offset );
}
/* -------------------------------------------------------------------- */
/* What data type do we want to write this as? */
/* -------------------------------------------------------------------- */
if( TIFFDataWidth(in_datatype) == 8 && !(tif->tif_flags&TIFF_BIGTIFF) )
{
if( in_datatype == TIFF_LONG8 )
datatype = TIFF_LONG;
else if( in_datatype == TIFF_SLONG8 )
datatype = TIFF_SLONG;
else if( in_datatype == TIFF_IFD8 )
datatype = TIFF_IFD;
else
datatype = in_datatype;
}
else
datatype = in_datatype;
/* -------------------------------------------------------------------- */
/* Prepare buffer of actual data to write. This includes */
/* swabbing as needed. */
/* -------------------------------------------------------------------- */
buf_to_write = (uint8 *) _TIFFmalloc(count * TIFFDataWidth(datatype));
if( buf_to_write == NULL )
{
TIFFErrorExt(tif->tif_clientdata,module,"Out of memory");
return 0;
}
if( datatype == in_datatype )
memcpy( buf_to_write, data, count * TIFFDataWidth(datatype) );
else if( datatype == TIFF_SLONG && in_datatype == TIFF_SLONG8 )
{
for( i = 0; i < count; i++ )
{
((int32 *) buf_to_write)[i] =
(int32) ((int64 *) data)[i];
if( (int64) ((int32 *) buf_to_write)[i] != ((int64 *) data)[i] )
{
_TIFFfree( buf_to_write );
TIFFErrorExt( tif->tif_clientdata, module,
"Value exceeds 32bit range of output type." );
return 0;
}
}
}
else if( (datatype == TIFF_LONG && in_datatype == TIFF_LONG8)
|| (datatype == TIFF_IFD && in_datatype == TIFF_IFD8) )
{
for( i = 0; i < count; i++ )
{
((uint32 *) buf_to_write)[i] =
(uint32) ((uint64 *) data)[i];
if( (uint64) ((uint32 *) buf_to_write)[i] != ((uint64 *) data)[i] )
{
_TIFFfree( buf_to_write );
TIFFErrorExt( tif->tif_clientdata, module,
"Value exceeds 32bit range of output type." );
return 0;
}
}
}
if( TIFFDataWidth(datatype) > 1 && (tif->tif_flags&TIFF_SWAB) )
{
if( TIFFDataWidth(datatype) == 2 )
TIFFSwabArrayOfShort( (uint16 *) buf_to_write, count );
else if( TIFFDataWidth(datatype) == 4 )
TIFFSwabArrayOfLong( (uint32 *) buf_to_write, count );
else if( TIFFDataWidth(datatype) == 8 )
TIFFSwabArrayOfLong8( (uint64 *) buf_to_write, count );
}
/* -------------------------------------------------------------------- */
/* Is this a value that fits into the directory entry? */
/* -------------------------------------------------------------------- */
if (!(tif->tif_flags&TIFF_BIGTIFF))
{
if( TIFFDataWidth(datatype) * count <= 4 )
{
entry_offset = read_offset + 8;
value_in_entry = 1;
}
}
else
{
if( TIFFDataWidth(datatype) * count <= 8 )
{
entry_offset = read_offset + 12;
value_in_entry = 1;
}
}
/* -------------------------------------------------------------------- */
/* If the tag type, and count match, then we just write it out */
/* over the old values without altering the directory entry at */
/* all. */
/* -------------------------------------------------------------------- */
if( entry_count == count && entry_type == (uint16) datatype )
{
if (!SeekOK(tif, entry_offset)) {
_TIFFfree( buf_to_write );
TIFFErrorExt(tif->tif_clientdata, module,
"%s: Seek error accessing TIFF directory",
tif->tif_name);
return 0;
}
if (!WriteOK(tif, buf_to_write, count*TIFFDataWidth(datatype))) {
_TIFFfree( buf_to_write );
TIFFErrorExt(tif->tif_clientdata, module,
"Error writing directory link");
return (0);
}
_TIFFfree( buf_to_write );
return 1;
}
/* -------------------------------------------------------------------- */
/* Otherwise, we write the new tag data at the end of the file. */
/* -------------------------------------------------------------------- */
if( !value_in_entry )
{
entry_offset = TIFFSeekFile(tif,0,SEEK_END);
if (!WriteOK(tif, buf_to_write, count*TIFFDataWidth(datatype))) {
_TIFFfree( buf_to_write );
TIFFErrorExt(tif->tif_clientdata, module,
"Error writing directory link");
return (0);
}
_TIFFfree( buf_to_write );
}
else
{
memcpy( &entry_offset, buf_to_write, count*TIFFDataWidth(datatype));
}
/* -------------------------------------------------------------------- */
/* Adjust the directory entry. */
/* -------------------------------------------------------------------- */
entry_type = datatype;
memcpy( direntry_raw + 2, &entry_type, sizeof(uint16) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabShort( direntry_raw + 2 );
if (!(tif->tif_flags&TIFF_BIGTIFF))
{
uint32 value;
value = entry_count;
memcpy( direntry_raw + 4, &value, sizeof(uint32) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabLong( direntry_raw + 4 );
value = entry_offset;
memcpy( direntry_raw + 8, &value, sizeof(uint32) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabLong( direntry_raw + 8 );
}
else
{
memcpy( direntry_raw + 4, &entry_count, sizeof(uint64) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabLong8( direntry_raw + 4 );
memcpy( direntry_raw + 12, &entry_offset, sizeof(uint64) );
if (tif->tif_flags&TIFF_SWAB)
TIFFSwabLong8( direntry_raw + 12 );
}
/* -------------------------------------------------------------------- */
/* Write the directory entry out to disk. */
/* -------------------------------------------------------------------- */
if (!SeekOK(tif, read_offset )) {
TIFFErrorExt(tif->tif_clientdata, module,
"%s: Seek error accessing TIFF directory",
tif->tif_name);
return 0;
}
if (!WriteOK(tif, direntry_raw,dirsize))
{
TIFFErrorExt(tif->tif_clientdata, module,
"%s: Can not write TIFF directory entry.",
tif->tif_name);
return 0;
}
return 1;
}
/* vim: set ts=8 sts=8 sw=8 noet: */

4
libtiff/tiffio.h
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@ -1,4 +1,4 @@
/* $Id: tiffio.h,v 1.79 2007-08-10 10:19:57 joris Exp $ */
/* $Id: tiffio.h,v 1.80 2007-12-31 21:55:07 fwarmerdam Exp $ */
/*
* Copyright (c) 1988-1997 Sam Leffler
@ -392,6 +392,8 @@ extern int TIFFSetSubDirectory(TIFF*, uint64);
extern int TIFFUnlinkDirectory(TIFF*, uint16);
extern int TIFFSetField(TIFF*, uint32, ...);
extern int TIFFVSetField(TIFF*, uint32, va_list);
extern int TIFFRewriteField(TIFF *tif , uint16 tag, TIFFDataType type,
uint32 count, void *data );
extern int TIFFWriteDirectory(TIFF *);
extern int TIFFCheckpointDirectory(TIFF *);
extern int TIFFRewriteDirectory(TIFF *);