/* timepng.c
*
* Copyright (c) 2013,2016 John Cunningham Bowler
*
* Last changed in libpng 1.6.22 [May 26, 2016]
*
* 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 or by image (possibly with transforms in the latter
* case). 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 <errno.h>
#include <limits.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
/* The following is to support direct compilation of this file as C++ */
#ifdef __cplusplus
# define voidcast(type, value) static_cast<type>(value)
#else
# define voidcast(type, value) (value)
#endif /* __cplusplus */
/* 'CLOCK_PROCESS_CPUTIME_ID' is one of the clock timers for clock_gettime. It
* need not be supported even when clock_gettime is available. It returns the
* 'CPU' time the process has consumed. 'CPU' time is assumed to include time
* when the CPU is actually blocked by a pending cache fill but not time
* waiting for page faults. The attempt is to get a measure of the actual time
* the implementation takes to read a PNG ignoring the potentially very large IO
* overhead.
*/
#if defined (CLOCK_PROCESS_CPUTIME_ID) && defined(PNG_STDIO_SUPPORTED) &&\
defined(PNG_EASY_ACCESS_SUPPORTED) &&\
(PNG_LIBPNG_VER >= 10700 ? defined(PNG_READ_PNG_SUPPORTED) :\
defined (PNG_SEQUENTIAL_READ_SUPPORTED) &&\
defined(PNG_INFO_IMAGE_SUPPORTED))
typedef struct
{
FILE *input;
FILE *output;
} io_data;
static PNG_CALLBACK(void, read_and_copy,
(png_structp png_ptr, png_bytep buffer, png_size_t cb))
{
io_data *io = (io_data*)png_get_io_ptr(png_ptr);
if (fread(buffer, cb, 1, io->input) != 1)
png_error(png_ptr, strerror(errno));
if (fwrite(buffer, cb, 1, io->output) != 1)
{
perror("temporary file");
fprintf(stderr, "temporary file PNG write failed\n");
exit(1);
}
}
static void read_by_row(png_structp png_ptr, png_infop info_ptr,
FILE *write_ptr, FILE *read_ptr)
{
/* These don't get freed on error, this is fine; the program immediately
* exits.
*/
png_bytep row = NULL, display = NULL;
io_data io_copy;
if (write_ptr != NULL)
{
/* Set up for a copy to the temporary file: */
io_copy.input = read_ptr;
io_copy.output = write_ptr;
png_set_read_fn(png_ptr, &io_copy, read_and_copy);
}
png_read_info(png_ptr, info_ptr);
{
png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
row = voidcast(png_bytep,malloc(rowbytes));
display = voidcast(png_bytep,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 and is
* somewhat representative of an application that works row-by-row.
*/
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);
/* Free this up: */
free(row);
free(display);
}
static PNG_CALLBACK(void, no_warnings, (png_structp png_ptr,
png_const_charp warning))
{
(void)png_ptr;
(void)warning;
}
static int read_png(FILE *fp, png_int_32 transforms, FILE *write_file)
{
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,
no_warnings);
png_infop info_ptr = NULL;
if (png_ptr == NULL)
return 0;
if (setjmp(png_jmpbuf(png_ptr)))
{
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return 0;
}
# ifdef PNG_BENIGN_ERRORS_SUPPORTED
png_set_benign_errors(png_ptr, 1/*allowed*/);
# endif
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");
if (transforms < 0)
read_by_row(png_ptr, info_ptr, write_file, fp);
else
png_read_png(png_ptr, info_ptr, transforms, NULL/*params*/);
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
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, png_int_32 transforms)
{
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, transforms, NULL/*write*/))
{
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)
{
/* Read the file using libpng; this detects errors and also deals with
* files which contain data beyond the end of the file.
*/
int ok = 0;
fpos_t pos;
if (fgetpos(fp, &pos))
{
/* Fatal error reading the start: */
perror("temporary file");
fprintf(stderr, "temporary file fgetpos error\n");
exit(1);
}
if (read_png(ip, -1/*by row*/, fp/*output*/))
{
if (ferror(ip))
{
perror(name);
fprintf(stderr, "%s: read error\n", name);
}
else
ok = 1; /* read ok */
}
else
fprintf(stderr, "%s: file not added\n", name);
(void)fclose(ip);
/* An error in the output is fatal; exit immediately: */
if (ferror(fp))
{
perror("temporary file");
fprintf(stderr, "temporary file write error\n");
exit(1);
}
if (ok)
return 1;
/* Did not read the file successfully, simply rewind the temporary
* file. This must happen after the ferror check above to avoid clearing
* the error.
*/
if (fsetpos(fp, &pos))
{
perror("temporary file");
fprintf(stderr, "temporary file fsetpos error\n");
exit(1);
}
}
else
{
/* file open error: */
perror(name);
fprintf(stderr, "%s: open failed\n", name);
}
return 0; /* file not added */
}
static void
usage(FILE *fp)
{
if (fp != NULL) fclose(fp);
fprintf(stderr,
"Usage:\n"
" timepng --assemble <assembly> {files}\n"
" Read the files into <assembly>, output the count. Options are ignored.\n"
" timepng --dissemble <assembly> <count> [options]\n"
" Time <count> files from <assembly>, additional files may not be given.\n"
" Otherwise:\n"
" Read the files into a temporary file and time the decode\n"
"Transforms:\n"
" --by-image: read by image with png_read_png\n"
" --<transform>: implies by-image, use PNG_TRANSFORM_<transform>\n"
" Otherwise: read by row using png_read_row (to a single row buffer)\n"
/* ISO C90 string length max 509 */);fprintf(stderr,
"{files}:\n"
" PNG files to copy into the assembly and time. Invalid files are skipped\n"
" with appropriate error messages. If no files are given the list of files\n"
" is read from stdin with each file name terminated by a newline\n"
"Output:\n"
" For --assemble the output is the name of the assembly file followed by the\n"
" count of the files it contains; the arguments for --dissemble. Otherwise\n"
" the output is the total decode time in seconds.\n");
exit(99);
}
int main(int argc, char **argv)
{
int ok = 0;
int err = 0;
int nfiles = 0;
int transforms = -1; /* by row */
const char *assembly = NULL;
FILE *fp;
if (argc > 2 && strcmp(argv[1], "--assemble") == 0)
{
/* Just build the test file, argv[2] is the file name. */
assembly = argv[2];
fp = fopen(assembly, "wb");
if (fp == NULL)
{
perror(assembly);
fprintf(stderr, "timepng --assemble %s: could not open for write\n",
assembly);
usage(NULL);
}
argv += 2;
argc -= 2;
}
else if (argc > 3 && strcmp(argv[1], "--dissemble") == 0)
{
fp = fopen(argv[2], "rb");
if (fp == NULL)
{
perror(argv[2]);
fprintf(stderr, "timepng --dissemble %s: could not open for read\n",
argv[2]);
usage(NULL);
}
nfiles = atoi(argv[3]);
if (nfiles <= 0)
{
fprintf(stderr,
"timepng --dissemble <file> <count>: %s is not a count\n",
argv[3]);
exit(99);
}
#ifdef __COVERITY__
else
{
nfiles &= PNG_UINT_31_MAX;
}
#endif
argv += 3;
argc -= 3;
}
else /* Else use a temporary file */
{
#ifndef __COVERITY__
fp = tmpfile();
#else
/* Experimental. Coverity says tmpfile() is insecure because it
* generates predictable names.
*
* It is possible to satisfy Coverity by using mkstemp(); however,
* any platform supporting mkstemp() undoubtedly has a secure tmpfile()
* implementation as well, and doesn't need the fix. Note that
* the fix won't work on platforms that don't support mkstemp().
*
* https://www.securecoding.cert.org/confluence/display/c/
* FIO21-C.+Do+not+create+temporary+files+in+shared+directories
* says that most historic implementations of tmpfile() provide
* only a limited number of possible temporary file names
* (usually 26) before file names are recycled. That article also
* provides a secure solution that unfortunately depends upon mkstemp().
*/
char tmpfile[] = "timepng-XXXXXX";
int filedes;
umask(0177);
filedes = mkstemp(tmpfile);
if (filedes < 0)
fp = NULL;
else
{
fp = fdopen(filedes,"w+");
/* Hide the filename immediately and ensure that the file does
* not exist after the program ends
*/
(void) unlink(tmpfile);
}
#endif
if (fp == NULL)
{
perror("tmpfile");
fprintf(stderr, "timepng: could not open the temporary file\n");
exit(1); /* not a user error */
}
}
/* Handle the transforms: */
while (argc > 1 && argv[1][0] == '-' && argv[1][1] == '-')
{
const char *opt = *++argv + 2;
--argc;
/* Transforms turn on the by-image processing and maybe set some
* transforms:
*/
if (transforms == -1)
transforms = PNG_TRANSFORM_IDENTITY;
if (strcmp(opt, "by-image") == 0)
{
/* handled above */
}
# define OPT(name) else if (strcmp(opt, #name) == 0)\
transforms |= PNG_TRANSFORM_ ## name
OPT(STRIP_16);
OPT(STRIP_ALPHA);
OPT(PACKING);
OPT(PACKSWAP);
OPT(EXPAND);
OPT(INVERT_MONO);
OPT(SHIFT);
OPT(BGR);
OPT(SWAP_ALPHA);
OPT(SWAP_ENDIAN);
OPT(INVERT_ALPHA);
OPT(STRIP_FILLER);
OPT(STRIP_FILLER_BEFORE);
OPT(STRIP_FILLER_AFTER);
OPT(GRAY_TO_RGB);
OPT(EXPAND_16);
OPT(SCALE_16);
else
{
fprintf(stderr, "timepng %s: unrecognized transform\n", opt);
usage(fp);
}
}
/* Handle the files: */
if (argc > 1 && nfiles > 0)
usage(fp); /* Additional files not valid with --dissemble */
else if (argc > 1)
{
int i;
for (i=1; i<argc; ++i)
{
if (nfiles == INT_MAX)
{
fprintf(stderr, "%s: skipped, too many files\n", argv[i]);
break;
}
else if (add_one_file(fp, argv[i]))
++nfiles;
}
}
else if (nfiles == 0) /* Read from stdin withoout --dissemble */
{
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 (nfiles == INT_MAX)
{
fprintf(stderr, "%s: skipped, too many files\n", filename);
break;
}
else if (add_one_file(fp, filename))
++nfiles;
}
else
{
fprintf(stderr, "timepng: file name too long: ...%s\n",
filename+len-32);
err = 1;
break;
}
}
if (ferror(stdin))
{
fprintf(stderr, "timepng: stdin: read error\n");
err = 1;
}
}
/* Perform the test, or produce the --assemble output: */
if (!err)
{
if (nfiles > 0)
{
if (assembly != NULL)
{
if (fflush(fp) && !ferror(fp) && fclose(fp))
{
perror(assembly);
fprintf(stderr, "%s: close failed\n", assembly);
}
else
{
printf("%s %d\n", assembly, nfiles);
fflush(stdout);
ok = !ferror(stdout);
}
}
else
{
ok = perform_one_test(fp, nfiles, transforms);
(void)fclose(fp);
}
}
else
usage(fp);
}
else
(void)fclose(fp);
/* Exit code 0 on success. */
return ok == 0;
}
#else /* !sufficient support */
int main(void) { return 77; }
#endif /* !sufficient support */