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1 /* timepng.c
2  *
3  * Copyright (c) 2013,2016 John Cunningham Bowler
4  *
5  * Last changed in libpng 1.6.22 [May 26, 2016]
6  *
7  * This code is released under the libpng license.
8  * For conditions of distribution and use, see the disclaimer
9  * and license in png.h
10  *
11  * Load an arbitrary number of PNG files (from the command line, or, if there
12  * are no arguments on the command line, from stdin) then run a time test by
13  * reading each file by row or by image (possibly with transforms in the latter
14  * case).  The only output is a time as a floating point number of seconds with
15  * 9 decimal digits.
16  */
17 #define _POSIX_C_SOURCE 199309L /* for clock_gettime */
18 
19 #include <stdlib.h>
20 #include <stdio.h>
21 #include <string.h>
22 #include <errno.h>
23 #include <limits.h>
24 
25 #include <time.h>
26 
27 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
28 #  include <config.h>
29 #endif
30 
31 /* Define the following to use this test against your installed libpng, rather
32  * than the one being built here:
33  */
34 #ifdef PNG_FREESTANDING_TESTS
35 #  include <png.h>
36 #else
37 #  include "../../png.h"
38 #endif
39 
40 /* The following is to support direct compilation of this file as C++ */
41 #ifdef __cplusplus
42 #  define voidcast(type, value) static_cast<type>(value)
43 #else
44 #  define voidcast(type, value) (value)
45 #endif /* __cplusplus */
46 
47 /* 'CLOCK_PROCESS_CPUTIME_ID' is one of the clock timers for clock_gettime.  It
48  * need not be supported even when clock_gettime is available.  It returns the
49  * 'CPU' time the process has consumed.  'CPU' time is assumed to include time
50  * when the CPU is actually blocked by a pending cache fill but not time
51  * waiting for page faults.  The attempt is to get a measure of the actual time
52  * the implementation takes to read a PNG ignoring the potentially very large IO
53  * overhead.
54  */
55 #if defined (CLOCK_PROCESS_CPUTIME_ID) && defined(PNG_STDIO_SUPPORTED) &&\
56     defined(PNG_EASY_ACCESS_SUPPORTED) &&\
57     (PNG_LIBPNG_VER >= 10700 ? defined(PNG_READ_PNG_SUPPORTED) :\
58      defined (PNG_SEQUENTIAL_READ_SUPPORTED) &&\
59      defined(PNG_INFO_IMAGE_SUPPORTED))
60 
61 typedef struct
62 {
63    FILE *input;
64    FILE *output;
65 }  io_data;
66 
67 static PNG_CALLBACK(void, read_and_copy,
68       (png_structp png_ptr, png_bytep buffer, png_size_t cb))
69 {
70    io_data *io = (io_data*)png_get_io_ptr(png_ptr);
71 
72    if (fread(buffer, cb, 1, io->input) != 1)
73       png_error(png_ptr, strerror(errno));
74 
75    if (fwrite(buffer, cb, 1, io->output) != 1)
76    {
77       perror("temporary file");
78       fprintf(stderr, "temporary file PNG write failed\n");
79       exit(1);
80    }
81 }
82 
read_by_row(png_structp png_ptr,png_infop info_ptr,FILE * write_ptr,FILE * read_ptr)83 static void read_by_row(png_structp png_ptr, png_infop info_ptr,
84       FILE *write_ptr, FILE *read_ptr)
85 {
86    /* These don't get freed on error, this is fine; the program immediately
87     * exits.
88     */
89    png_bytep row = NULL, display = NULL;
90    io_data io_copy;
91 
92    if (write_ptr != NULL)
93    {
94       /* Set up for a copy to the temporary file: */
95       io_copy.input = read_ptr;
96       io_copy.output = write_ptr;
97       png_set_read_fn(png_ptr, &io_copy, read_and_copy);
98    }
99 
100    png_read_info(png_ptr, info_ptr);
101 
102    {
103       png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
104 
105       row = voidcast(png_bytep,malloc(rowbytes));
106       display = voidcast(png_bytep,malloc(rowbytes));
107 
108       if (row == NULL || display == NULL)
109          png_error(png_ptr, "OOM allocating row buffers");
110 
111       {
112          png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
113          int passes = png_set_interlace_handling(png_ptr);
114          int pass;
115 
116          png_start_read_image(png_ptr);
117 
118          for (pass = 0; pass < passes; ++pass)
119          {
120             png_uint_32 y = height;
121 
122             /* NOTE: this trashes the row each time; interlace handling won't
123              * work, but this avoids memory thrashing for speed testing and is
124              * somewhat representative of an application that works row-by-row.
125              */
126             while (y-- > 0)
127                png_read_row(png_ptr, row, display);
128          }
129       }
130    }
131 
132    /* Make sure to read to the end of the file: */
133    png_read_end(png_ptr, info_ptr);
134 
135    /* Free this up: */
136    free(row);
137    free(display);
138 }
139 
140 static PNG_CALLBACK(void, no_warnings, (png_structp png_ptr,
141          png_const_charp warning))
142 {
143    (void)png_ptr;
144    (void)warning;
145 }
146 
read_png(FILE * fp,png_int_32 transforms,FILE * write_file)147 static int read_png(FILE *fp, png_int_32 transforms, FILE *write_file)
148 {
149    png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,
150          no_warnings);
151    png_infop info_ptr = NULL;
152 
153    if (png_ptr == NULL)
154       return 0;
155 
156    if (setjmp(png_jmpbuf(png_ptr)))
157    {
158       png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
159       return 0;
160    }
161 
162 #  ifdef PNG_BENIGN_ERRORS_SUPPORTED
163       png_set_benign_errors(png_ptr, 1/*allowed*/);
164 #  endif
165    png_init_io(png_ptr, fp);
166 
167    info_ptr = png_create_info_struct(png_ptr);
168 
169    if (info_ptr == NULL)
170       png_error(png_ptr, "OOM allocating info structure");
171 
172    if (transforms < 0)
173       read_by_row(png_ptr, info_ptr, write_file, fp);
174 
175    else
176       png_read_png(png_ptr, info_ptr, transforms, NULL/*params*/);
177 
178    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
179    return 1;
180 }
181 
mytime(struct timespec * t)182 static int mytime(struct timespec *t)
183 {
184    /* Do the timing using clock_gettime and the per-process timer. */
185    if (!clock_gettime(CLOCK_PROCESS_CPUTIME_ID, t))
186       return 1;
187 
188    perror("CLOCK_PROCESS_CPUTIME_ID");
189    fprintf(stderr, "timepng: could not get the time\n");
190    return 0;
191 }
192 
perform_one_test(FILE * fp,int nfiles,png_int_32 transforms)193 static int perform_one_test(FILE *fp, int nfiles, png_int_32 transforms)
194 {
195    int i;
196    struct timespec before, after;
197 
198    /* Clear out all errors: */
199    rewind(fp);
200 
201    if (mytime(&before))
202    {
203       for (i=0; i<nfiles; ++i)
204       {
205          if (read_png(fp, transforms, NULL/*write*/))
206          {
207             if (ferror(fp))
208             {
209                perror("temporary file");
210                fprintf(stderr, "file %d: error reading PNG data\n", i);
211                return 0;
212             }
213          }
214 
215          else
216          {
217             perror("temporary file");
218             fprintf(stderr, "file %d: error from libpng\n", i);
219             return 0;
220          }
221       }
222    }
223 
224    else
225       return 0;
226 
227    if (mytime(&after))
228    {
229       /* Work out the time difference and print it - this is the only output,
230        * so flush it immediately.
231        */
232       unsigned long s = after.tv_sec - before.tv_sec;
233       long ns = after.tv_nsec - before.tv_nsec;
234 
235       if (ns < 0)
236       {
237          --s;
238          ns += 1000000000;
239 
240          if (ns < 0)
241          {
242             fprintf(stderr, "timepng: bad clock from kernel\n");
243             return 0;
244          }
245       }
246 
247       printf("%lu.%.9ld\n", s, ns);
248       fflush(stdout);
249       if (ferror(stdout))
250       {
251          fprintf(stderr, "timepng: error writing output\n");
252          return 0;
253       }
254 
255       /* Successful return */
256       return 1;
257    }
258 
259    else
260       return 0;
261 }
262 
add_one_file(FILE * fp,char * name)263 static int add_one_file(FILE *fp, char *name)
264 {
265    FILE *ip = fopen(name, "rb");
266 
267    if (ip != NULL)
268    {
269       /* Read the file using libpng; this detects errors and also deals with
270        * files which contain data beyond the end of the file.
271        */
272       int ok = 0;
273       fpos_t pos;
274 
275       if (fgetpos(fp, &pos))
276       {
277          /* Fatal error reading the start: */
278          perror("temporary file");
279          fprintf(stderr, "temporary file fgetpos error\n");
280          exit(1);
281       }
282 
283       if (read_png(ip, -1/*by row*/, fp/*output*/))
284       {
285          if (ferror(ip))
286          {
287             perror(name);
288             fprintf(stderr, "%s: read error\n", name);
289          }
290 
291          else
292             ok = 1; /* read ok */
293       }
294 
295       else
296          fprintf(stderr, "%s: file not added\n", name);
297 
298       (void)fclose(ip);
299 
300       /* An error in the output is fatal; exit immediately: */
301       if (ferror(fp))
302       {
303          perror("temporary file");
304          fprintf(stderr, "temporary file write error\n");
305          exit(1);
306       }
307 
308       if (ok)
309          return 1;
310 
311       /* Did not read the file successfully, simply rewind the temporary
312        * file.  This must happen after the ferror check above to avoid clearing
313        * the error.
314        */
315       if (fsetpos(fp, &pos))
316       {
317          perror("temporary file");
318          fprintf(stderr, "temporary file fsetpos error\n");
319          exit(1);
320       }
321    }
322 
323    else
324    {
325       /* file open error: */
326       perror(name);
327       fprintf(stderr, "%s: open failed\n", name);
328    }
329 
330    return 0; /* file not added */
331 }
332 
333 static void
usage(FILE * fp)334 usage(FILE *fp)
335 {
336    if (fp != NULL) fclose(fp);
337 
338    fprintf(stderr,
339 "Usage:\n"
340 " timepng --assemble <assembly> {files}\n"
341 "  Read the files into <assembly>, output the count.  Options are ignored.\n"
342 " timepng --dissemble <assembly> <count> [options]\n"
343 "  Time <count> files from <assembly>, additional files may not be given.\n"
344 " Otherwise:\n"
345 "  Read the files into a temporary file and time the decode\n"
346 "Transforms:\n"
347 "  --by-image: read by image with png_read_png\n"
348 "  --<transform>: implies by-image, use PNG_TRANSFORM_<transform>\n"
349 "  Otherwise: read by row using png_read_row (to a single row buffer)\n"
350    /* ISO C90 string length max 509 */);fprintf(stderr,
351 "{files}:\n"
352 "  PNG files to copy into the assembly and time.  Invalid files are skipped\n"
353 "  with appropriate error messages.  If no files are given the list of files\n"
354 "  is read from stdin with each file name terminated by a newline\n"
355 "Output:\n"
356 "  For --assemble the output is the name of the assembly file followed by the\n"
357 "  count of the files it contains; the arguments for --dissemble.  Otherwise\n"
358 "  the output is the total decode time in seconds.\n");
359 
360    exit(99);
361 }
362 
main(int argc,char ** argv)363 int main(int argc, char **argv)
364 {
365    int ok = 0;
366    int err = 0;
367    int nfiles = 0;
368    int transforms = -1; /* by row */
369    const char *assembly = NULL;
370    FILE *fp;
371 
372    if (argc > 2 && strcmp(argv[1], "--assemble") == 0)
373    {
374       /* Just build the test file, argv[2] is the file name. */
375       assembly = argv[2];
376       fp = fopen(assembly, "wb");
377       if (fp == NULL)
378       {
379          perror(assembly);
380          fprintf(stderr, "timepng --assemble %s: could not open for write\n",
381                assembly);
382          usage(NULL);
383       }
384 
385       argv += 2;
386       argc -= 2;
387    }
388 
389    else if (argc > 3 && strcmp(argv[1], "--dissemble") == 0)
390    {
391       fp = fopen(argv[2], "rb");
392 
393       if (fp == NULL)
394       {
395          perror(argv[2]);
396          fprintf(stderr, "timepng --dissemble %s: could not open for read\n",
397                argv[2]);
398          usage(NULL);
399       }
400 
401       nfiles = atoi(argv[3]);
402       if (nfiles <= 0)
403       {
404          fprintf(stderr,
405                "timepng --dissemble <file> <count>: %s is not a count\n",
406                argv[3]);
407          exit(99);
408       }
409 #ifdef __COVERITY__
410       else
411       {
412          nfiles &= PNG_UINT_31_MAX;
413       }
414 #endif
415 
416       argv += 3;
417       argc -= 3;
418    }
419 
420    else /* Else use a temporary file */
421    {
422 #ifndef __COVERITY__
423       fp = tmpfile();
424 #else
425       /* Experimental. Coverity says tmpfile() is insecure because it
426        * generates predictable names.
427        *
428        * It is possible to satisfy Coverity by using mkstemp(); however,
429        * any platform supporting mkstemp() undoubtedly has a secure tmpfile()
430        * implementation as well, and doesn't need the fix.  Note that
431        * the fix won't work on platforms that don't support mkstemp().
432        *
433        * https://www.securecoding.cert.org/confluence/display/c/
434        * FIO21-C.+Do+not+create+temporary+files+in+shared+directories
435        * says that most historic implementations of tmpfile() provide
436        * only a limited number of possible temporary file names
437        * (usually 26) before file names are recycled. That article also
438        * provides a secure solution that unfortunately depends upon mkstemp().
439        */
440       char tmpfile[] = "timepng-XXXXXX";
441       int filedes;
442       umask(0177);
443       filedes = mkstemp(tmpfile);
444       if (filedes < 0)
445         fp = NULL;
446       else
447       {
448         fp = fdopen(filedes,"w+");
449         /* Hide the filename immediately and ensure that the file does
450          * not exist after the program ends
451          */
452         (void) unlink(tmpfile);
453       }
454 #endif
455 
456       if (fp == NULL)
457       {
458          perror("tmpfile");
459          fprintf(stderr, "timepng: could not open the temporary file\n");
460          exit(1); /* not a user error */
461       }
462    }
463 
464    /* Handle the transforms: */
465    while (argc > 1 && argv[1][0] == '-' && argv[1][1] == '-')
466    {
467       const char *opt = *++argv + 2;
468 
469       --argc;
470 
471       /* Transforms turn on the by-image processing and maybe set some
472        * transforms:
473        */
474       if (transforms == -1)
475          transforms = PNG_TRANSFORM_IDENTITY;
476 
477       if (strcmp(opt, "by-image") == 0)
478       {
479          /* handled above */
480       }
481 
482 #        define OPT(name) else if (strcmp(opt, #name) == 0)\
483          transforms |= PNG_TRANSFORM_ ## name
484 
485       OPT(STRIP_16);
486       OPT(STRIP_ALPHA);
487       OPT(PACKING);
488       OPT(PACKSWAP);
489       OPT(EXPAND);
490       OPT(INVERT_MONO);
491       OPT(SHIFT);
492       OPT(BGR);
493       OPT(SWAP_ALPHA);
494       OPT(SWAP_ENDIAN);
495       OPT(INVERT_ALPHA);
496       OPT(STRIP_FILLER);
497       OPT(STRIP_FILLER_BEFORE);
498       OPT(STRIP_FILLER_AFTER);
499       OPT(GRAY_TO_RGB);
500       OPT(EXPAND_16);
501       OPT(SCALE_16);
502 
503       else
504       {
505          fprintf(stderr, "timepng %s: unrecognized transform\n", opt);
506          usage(fp);
507       }
508    }
509 
510    /* Handle the files: */
511    if (argc > 1 && nfiles > 0)
512       usage(fp); /* Additional files not valid with --dissemble */
513 
514    else if (argc > 1)
515    {
516       int i;
517 
518       for (i=1; i<argc; ++i)
519       {
520          if (nfiles == INT_MAX)
521          {
522             fprintf(stderr, "%s: skipped, too many files\n", argv[i]);
523             break;
524          }
525 
526          else if (add_one_file(fp, argv[i]))
527             ++nfiles;
528       }
529    }
530 
531    else if (nfiles == 0) /* Read from stdin withoout --dissemble */
532    {
533       char filename[FILENAME_MAX+1];
534 
535       while (fgets(filename, FILENAME_MAX+1, stdin))
536       {
537          size_t len = strlen(filename);
538 
539          if (filename[len-1] == '\n')
540          {
541             filename[len-1] = 0;
542             if (nfiles == INT_MAX)
543             {
544                fprintf(stderr, "%s: skipped, too many files\n", filename);
545                break;
546             }
547 
548             else if (add_one_file(fp, filename))
549                ++nfiles;
550          }
551 
552          else
553          {
554             fprintf(stderr, "timepng: file name too long: ...%s\n",
555                filename+len-32);
556             err = 1;
557             break;
558          }
559       }
560 
561       if (ferror(stdin))
562       {
563          fprintf(stderr, "timepng: stdin: read error\n");
564          err = 1;
565       }
566    }
567 
568    /* Perform the test, or produce the --assemble output: */
569    if (!err)
570    {
571       if (nfiles > 0)
572       {
573          if (assembly != NULL)
574          {
575             if (fflush(fp) && !ferror(fp) && fclose(fp))
576             {
577                perror(assembly);
578                fprintf(stderr, "%s: close failed\n", assembly);
579             }
580 
581             else
582             {
583                printf("%s %d\n", assembly, nfiles);
584                fflush(stdout);
585                ok = !ferror(stdout);
586             }
587          }
588 
589          else
590          {
591             ok = perform_one_test(fp, nfiles, transforms);
592             (void)fclose(fp);
593          }
594       }
595 
596       else
597          usage(fp);
598    }
599 
600    else
601       (void)fclose(fp);
602 
603    /* Exit code 0 on success. */
604    return ok == 0;
605 }
606 #else /* !sufficient support */
main(void)607 int main(void) { return 77; }
608 #endif /* !sufficient support */
609