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DEFINITIONS
This source file includes following definitions.
- read_png
- mytime
- perform_one_test
- add_one_file
- main
/* timepng.c
*
* Copyright (c) 2013 John Cunningham Bowler
*
* Last changed in libpng 1.6.1 [March 28, 2013]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
* Load an arbitrary number of PNG files (from the command line, or, if there
* are no arguments on the command line, from stdin) then run a time test by
* reading each file by row. The test does nothing with the read result and
* does no transforms. The only output is a time as a floating point number of
* seconds with 9 decimal digits.
*/
#define _POSIX_C_SOURCE 199309L /* for clock_gettime */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
# include <config.h>
#endif
/* Define the following to use this test against your installed libpng, rather
* than the one being built here:
*/
#ifdef PNG_FREESTANDING_TESTS
# include <png.h>
#else
# include "../../png.h"
#endif
static int read_png(FILE *fp)
{
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
png_infop info_ptr = NULL;
png_bytep row = NULL, display = NULL;
if (png_ptr == NULL)
return 0;
if (setjmp(png_jmpbuf(png_ptr)))
{
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
if (row != NULL) free(row);
if (display != NULL) free(display);
return 0;
}
png_init_io(png_ptr, fp);
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL)
png_error(png_ptr, "OOM allocating info structure");
png_read_info(png_ptr, info_ptr);
{
png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
row = malloc(rowbytes);
display = malloc(rowbytes);
if (row == NULL || display == NULL)
png_error(png_ptr, "OOM allocating row buffers");
{
png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
int passes = png_set_interlace_handling(png_ptr);
int pass;
png_start_read_image(png_ptr);
for (pass = 0; pass < passes; ++pass)
{
png_uint_32 y = height;
/* NOTE: this trashes the row each time; interlace handling won't
* work, but this avoids memory thrashing for speed testing.
*/
while (y-- > 0)
png_read_row(png_ptr, row, display);
}
}
}
/* Make sure to read to the end of the file: */
png_read_end(png_ptr, info_ptr);
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
free(row);
free(display);
return 1;
}
static int mytime(struct timespec *t)
{
/* Do the timing using clock_gettime and the per-process timer. */
if (!clock_gettime(CLOCK_PROCESS_CPUTIME_ID, t))
return 1;
perror("CLOCK_PROCESS_CPUTIME_ID");
fprintf(stderr, "timepng: could not get the time\n");
return 0;
}
static int perform_one_test(FILE *fp, int nfiles)
{
int i;
struct timespec before, after;
/* Clear out all errors: */
rewind(fp);
if (mytime(&before))
{
for (i=0; i<nfiles; ++i)
{
if (read_png(fp))
{
if (ferror(fp))
{
perror("temporary file");
fprintf(stderr, "file %d: error reading PNG data\n", i);
return 0;
}
}
else
{
perror("temporary file");
fprintf(stderr, "file %d: error from libpng\n", i);
return 0;
}
}
}
else
return 0;
if (mytime(&after))
{
/* Work out the time difference and print it - this is the only output,
* so flush it immediately.
*/
unsigned long s = after.tv_sec - before.tv_sec;
long ns = after.tv_nsec - before.tv_nsec;
if (ns < 0)
{
--s;
ns += 1000000000;
if (ns < 0)
{
fprintf(stderr, "timepng: bad clock from kernel\n");
return 0;
}
}
printf("%lu.%.9ld\n", s, ns);
fflush(stdout);
if (ferror(stdout))
{
fprintf(stderr, "timepng: error writing output\n");
return 0;
}
/* Successful return */
return 1;
}
else
return 0;
}
static int add_one_file(FILE *fp, char *name)
{
FILE *ip = fopen(name, "rb");
if (ip != NULL)
{
int ch;
for (;;)
{
ch = getc(ip);
if (ch == EOF) break;
putc(ch, fp);
}
if (ferror(ip))
{
perror(name);
fprintf(stderr, "%s: read error\n", name);
return 0;
}
(void)fclose(ip);
if (ferror(fp))
{
perror("temporary file");
fprintf(stderr, "temporary file write error\n");
return 0;
}
}
else
{
perror(name);
fprintf(stderr, "%s: open failed\n", name);
return 0;
}
return 1;
}
int main(int argc, char **argv)
{
int ok = 0;
FILE *fp = tmpfile();
if (fp != NULL)
{
int err = 0;
int nfiles = 0;
if (argc > 1)
{
int i;
for (i=1; i<argc; ++i)
{
if (add_one_file(fp, argv[i]))
++nfiles;
else
{
err = 1;
break;
}
}
}
else
{
char filename[FILENAME_MAX+1];
while (fgets(filename, FILENAME_MAX+1, stdin))
{
size_t len = strlen(filename);
if (filename[len-1] == '\n')
{
filename[len-1] = 0;
if (add_one_file(fp, filename))
++nfiles;
else
{
err = 1;
break;
}
}
else
{
fprintf(stderr, "timepng: truncated file name ...%s\n",
filename+len-32);
err = 1;
break;
}
}
if (ferror(stdin))
{
fprintf(stderr, "timepng: stdin: read error\n");
err = 1;
}
}
if (!err)
{
if (nfiles > 0)
ok = perform_one_test(fp, nfiles);
else
fprintf(stderr, "usage: timepng {files} or ls files | timepng\n");
}
(void)fclose(fp);
}
else
fprintf(stderr, "timepng: could not open temporary file\n");
/* Exit code 0 on success. */
return ok == 0;
}