libtiff/test/defer_strile_loading.c
Even Rouault 371ad2658c
Make defer strile offset/bytecount loading available at runtime
... and add per-strile offset/bytecount loading capabilities.

Part of this commit makes the behaviour that was previously met when
libtiff was compiled with -DDEFER_STRILE_LOAD available for default builds
when specifying the new 'D' (Deferred) TIFFOpen() flag. In that mode, the [Tile/Strip][ByteCounts/Offsets]
arrays are only loaded when first accessed. This can speed-up the opening
of files stored on the network when just metadata retrieval is needed.
This mode has been used for years by the GDAL library when compiled with
its embeded libtiff copy.

To avoid potential out-of-tree code (typically codecs) that would use
the td_stripbytecount and td_stripoffset array inconditionnaly assuming they
have been loaded, those have been suffixed with _p (for protected). The
use of the new functions mentionned below is then recommended.

Another addition of this commit is the capability of loading only the
values of the offset/bytecount of the strile of interest instead of the
whole array. This is enabled with the new 'O' (Ondemand) flag of TIFFOpen()
(which implies 'D'). That behaviour has also been used by GDAL, which hacked
into the td_stripoffset/td_stripbytecount arrays directly. The new code
added in the _TIFFFetchStrileValue() and _TIFFPartialReadStripArray() internal
functions is mostly a port of what was in GDAL GTiff driver previously.

Related to that, the public TIFFGetStrileOffset[WithErr]() and TIFFGetStrileByteCount[WithErr]()
functions have been added to API. They are of particular interest when
using sparse files (with offset == bytecount == 0) and you want to detect
if a strile is present or not without decompressing the data, or updating
an existing sparse file.
They will also be used to enable a future enhancement where client code can entirely
skip bytecount loading in some situtations

A new test/defer_strile_loading.c test has been added to test the above
capabilities.
2019-05-10 14:46:45 +02:00

257 lines
7.7 KiB
C

/*
* Copyright (c) 2019, Even Rouault <even.rouault at spatialys.com>
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that (i) the above copyright notices and this permission notice appear in
* all copies of the software and related documentation, and (ii) the names of
* Sam Leffler and Silicon Graphics may not be used in any advertising or
* publicity relating to the software without the specific, prior written
* permission of Sam Leffler and Silicon Graphics.
*
* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
/*
* TIFF Library
*
* Module to test 'D' and 'O' open flags
*/
#include "tif_config.h"
#include <assert.h>
#include <stdio.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include "tiffio.h"
#include "tifftest.h"
int test(int classictif, int height, int tiled)
{
const char* filename = "defer_strile_loading.tif";
TIFF* tif;
int i;
int ret;
tif = TIFFOpen(filename, classictif ? "wDO" : "w8DO"); /* O should be ignored in write mode */
if(!tif)
{
fprintf(stderr, "cannot create %s\n", filename);
return 1;
}
ret = TIFFSetField(tif, TIFFTAG_COMPRESSION, COMPRESSION_NONE);
assert(ret);
ret = TIFFSetField(tif, TIFFTAG_IMAGEWIDTH, 1);
assert(ret);
ret = TIFFSetField(tif, TIFFTAG_IMAGELENGTH, height);
assert(ret);
ret = TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 8);
assert(ret);
ret = TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 1);
assert(ret);
ret = TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
assert(ret);
if( tiled )
{
int j;
ret = TIFFSetField(tif, TIFFTAG_TILEWIDTH, 16);
assert( ret );
ret = TIFFSetField(tif, TIFFTAG_TILELENGTH, 16);
assert( ret );
for( j = 0; j < (height+15) / 16; j++ )
{
unsigned char tilebuffer[256];
memset(tilebuffer, (unsigned char)j, 256);
ret = TIFFWriteEncodedTile( tif, j, tilebuffer, 256 );
assert(ret == 256);
}
}
else
{
ret = TIFFSetField(tif, TIFFTAG_ROWSPERSTRIP, 1);
assert(ret);
for( i = 0; i < height; i++ )
{
unsigned char c = (unsigned char)i;
ret = TIFFWriteEncodedStrip( tif, i, &c, 1 );
assert(ret == 1);
if( i == 1 && height > 100000 )
i = height - 2;
}
}
TIFFClose(tif);
for( i = 0; i < 2; i++ )
{
tif = TIFFOpen(filename, i == 0 ? "rD" : "rO");
if(!tif)
{
fprintf(stderr, "cannot open %s\n", filename);
return 1;
}
if( tiled )
{
int j;
for( j = 0; j < (height+15) / 16; j++ )
{
int retry;
for( retry = 0; retry < 2; retry++ )
{
unsigned char tilebuffer[256];
unsigned char expected_c = (unsigned char)j;
memset(tilebuffer,0, 256);
ret = TIFFReadEncodedTile( tif, j, tilebuffer, 256 );
assert(ret == 256);
if( tilebuffer[0] != expected_c ||
tilebuffer[255] != expected_c )
{
fprintf(stderr, "unexpected value at tile %d: %d %d\n",
j, tilebuffer[0], tilebuffer[255]);
TIFFClose(tif);
return 1;
}
}
{
int err = 0;
ret = TIFFGetStrileOffsetWithErr(tif, j, &err);
assert(ret != 0);
assert(err == 0);
ret = TIFFGetStrileByteCountWithErr(tif, j, &err);
assert(ret == 256);
assert(err == 0);
}
}
}
else
{
int j;
for( j = 0; j < height; j++ )
{
int retry;
for( retry = 0; retry < 2; retry++ )
{
unsigned char c = 0;
unsigned char expected_c = (unsigned char)j;
ret = TIFFReadEncodedStrip( tif, j, &c, 1 );
assert(ret == 1);
if( c != expected_c )
{
fprintf(stderr, "unexpected value at line %d: %d\n",
j, c);
TIFFClose(tif);
return 1;
}
}
{
int err = 0;
ret = TIFFGetStrileOffsetWithErr(tif, j, &err);
assert(ret != 0);
assert(err == 0);
ret = TIFFGetStrileByteCountWithErr(tif, j, &err);
assert(ret == 1);
assert(err == 0);
}
if( j == 1 && height > 100000 )
j = height - 2;
}
if( height > 100000 )
{
/* Missing strip */
int err = 0;
ret = TIFFGetStrileOffsetWithErr(tif, 2, &err);
assert(ret == 0);
assert(err == 0);
ret = TIFFGetStrileByteCountWithErr(tif, 2, &err);
assert(ret == 0);
assert(err == 0);
}
}
{
int err = 0;
ret = TIFFGetStrileOffsetWithErr(tif, 0xFFFFFFFFU, &err);
assert(ret == 0);
assert(err == 1);
ret = TIFFGetStrileByteCountWithErr(tif, 0xFFFFFFFFU, &err);
assert(ret == 0);
assert(err == 1);
}
{
toff_t* offsets = NULL;
toff_t* bytecounts = NULL;
ret = TIFFGetField( tif,
tiled ? TIFFTAG_TILEOFFSETS : TIFFTAG_STRIPOFFSETS, &offsets );
assert(ret);
assert(offsets);
ret = TIFFGetField( tif,
tiled ? TIFFTAG_TILEBYTECOUNTS : TIFFTAG_STRIPBYTECOUNTS, &bytecounts );
assert(ret);
assert(bytecounts);
if( tiled )
{
assert(bytecounts[0] == 256);
}
else
{
assert(bytecounts[0] == 1);
if( height > 1 && height <= 100000)
{
assert(offsets[1] == offsets[0] + 1);
assert(offsets[height - 1] == offsets[0] + height - 1);
}
assert(bytecounts[height - 1] == 1);
}
}
TIFFClose(tif);
}
unlink(filename);
return 0;
}
int
main()
{
int is_classic;
for( is_classic = 1; is_classic >= 0; is_classic-- )
{
int tiled;
for( tiled = 0; tiled <= 1; tiled ++ )
{
if( test(is_classic, 1, tiled) )
return 1;
if( test(is_classic, 8192, tiled) )
return 1;
}
if( test(is_classic, 2000000, 0) )
return 1;
}
return 0;
}