/* 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></stdlib.h>

#include <stdio.h></stdio.h>

#include <string.h></string.h>

#include <time.h></time.h>

#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)

#  include <config.h></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></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

      {

         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

         {

            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;

}