src/thumbnails.c

   1 /*
   2  * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
   3  *
   4  * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 /*
  23  * Large (and important) sections of this file were adapted from
  24  * ROX-Filer source code, Copyright (C) 2003, the ROX-Filer team,
  25  * originally licensed under the GPL v2 or greater (as above).
  26  *
  27  */
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include <stdlib.h>
  34 #ifdef HAVE_UNISTD_H
  35 #include <unistd.h>
  36 #endif
  37 #include <errno.h>
  38 #include <string.h>
  39 #include <glib.h>
  40 #include <glib/gstdio.h>
  41 #include "viking.h"
  42 #include "thumbnails.h"
  43 #include "icons/icons.h"
  44
  45 #ifdef __CYGWIN__
  46 #ifdef __CYGWIN_USE_BIG_TYPES__
  47 #define ST_SIZE_FMT "%lld"
  48 #else
  49 #define ST_SIZE_FMT "%ld"
  50 #endif
  51 #else
  52 /* FIXME -- on some systems this may need to me "lld", see ROX-Filer code */
  53 #define ST_SIZE_FMT "%ld"
  54 #endif
  55
  56 #undef MIN /* quit yer whining, gcc */
  57 #undef MAX
  58 #include <sys/param.h> /* for realpath() */
  59 #ifndef MAX
  60 /* We need MAX macro and some system does not offer it */
  61 #define MAX(a,b) (((a)>(b))?(a):(b))
  62 #endif
  63
  64 #define HOME_DIR g_get_home_dir()
  65
  66 #ifdef WINDOWS
  67 #define THUMB_DIR "\\THUMBNAILS\\" /* viking maps default viking\maps */
  68 #define THUMB_SUB_DIR "normal\\"
  69 #define realpath(X,Y) _fullpath(Y,X,MAX_PATH)
  70
  71 #else
  72 #define THUMB_DIR "/.thumbnails/"
  73 #define THUMB_SUB_DIR "normal/"
  74 #endif
  75
  76 #define PIXMAP_THUMB_SIZE  128
  77
  78 #ifndef MAXPATHLEN
  79 #define MAXPATHLEN 1024
  80 #endif
  81
  82 static char *md5_hash(const char *message);
  83 static char *pathdup(const char *path);
  84 static GdkPixbuf *save_thumbnail(const char *pathname, GdkPixbuf *full);
  85 static GdkPixbuf *child_create_thumbnail(const gchar *path);
  86
  87 gboolean a_thumbnails_exists ( const gchar *filename )
  88 {
  89   GdkPixbuf *pixbuf = a_thumbnails_get(filename);
  90   if ( pixbuf )
  91   {
  92     g_object_unref ( G_OBJECT ( pixbuf ) );
  93     return TRUE;
  94   }
  95   return FALSE;
  96 }
  97
  98 GdkPixbuf *a_thumbnails_get_default ()
  99 {
 100   return gdk_pixbuf_from_pixdata ( &thumbnails_pixbuf, FALSE, NULL );
 101 }
 102
 103 /* filename must be absolute. you could have a function to make sure it exists and absolutize it */
 104
 105 void a_thumbnails_create(const gchar *filename)
 106 {
 107   GdkPixbuf *pixbuf = a_thumbnails_get(filename);
 108
 109   if ( ! pixbuf )
 110     pixbuf = child_create_thumbnail(filename);
 111
 112   if ( pixbuf )
 113     g_object_unref (  G_OBJECT ( pixbuf ) );
 114 }
 115
 116 GdkPixbuf *a_thumbnails_scale_pixbuf(GdkPixbuf *src, int max_w, int max_h)
 117 {
 118         int     w, h;
 119
 120         w = gdk_pixbuf_get_width(src);
 121         h = gdk_pixbuf_get_height(src);
 122
 123         if (w <= max_w && h <= max_h)
 124         {
 125                 gdk_pixbuf_ref(src);
 126                 return src;
 127         }
 128         else
 129         {
 130                 float scale_x = ((float) w) / max_w;
 131                 float scale_y = ((float) h) / max_h;
 132                 float scale = MAX(scale_x, scale_y);
 133                 int dest_w = w / scale;
 134                 int dest_h = h / scale;
 135
 136                 return gdk_pixbuf_scale_simple(src,
 137                                                 MAX(dest_w, 1),
 138                                                 MAX(dest_h, 1),
 139                                                 GDK_INTERP_BILINEAR);
 140         }
 141 }
 142
 143 static GdkPixbuf *child_create_thumbnail(const gchar *path)
 144 {
 145         GdkPixbuf *image;
 146
 147         image = gdk_pixbuf_new_from_file(path, NULL);
 148
 149         if (image)
 150         {
 151                 GdkPixbuf *thumb = save_thumbnail(path, image);
 152                 gdk_pixbuf_unref ( image );
 153                 return thumb;
 154         }
 155
 156         return NULL;
 157 }
 158
 159 static GdkPixbuf *save_thumbnail(const char *pathname, GdkPixbuf *full)
 160 {
 161         struct stat info;
 162         gchar *path;
 163         int original_width, original_height;
 164         GString *to;
 165         char *md5, *swidth, *sheight, *ssize, *smtime, *uri;
 166         mode_t old_mask;
 167         int name_len;
 168         GdkPixbuf *thumb;
 169
 170         if (stat(pathname, &info) != 0)
 171                 return NULL;
 172
 173         thumb = a_thumbnails_scale_pixbuf(full, PIXMAP_THUMB_SIZE, PIXMAP_THUMB_SIZE);
 174
 175         original_width = gdk_pixbuf_get_width(full);
 176         original_height = gdk_pixbuf_get_height(full);
 177
 178
 179         swidth = g_strdup_printf("%d", original_width);
 180         sheight = g_strdup_printf("%d", original_height);
 181         ssize = g_strdup_printf(ST_SIZE_FMT, info.st_size);
 182         smtime = g_strdup_printf("%ld", (long) info.st_mtime);
 183
 184         path = pathdup(pathname);
 185         uri = g_strconcat("file://", path, NULL);
 186         md5 = md5_hash(uri);
 187         g_free(path);
 188
 189         to = g_string_new(HOME_DIR);
 190         g_string_append(to, THUMB_DIR);
 191         g_string_append(to, THUMB_SUB_DIR);
 192         g_mkdir_with_parents(to->str, 0700);
 193         g_string_append(to, md5);
 194         name_len = to->len + 4; /* Truncate to this length when renaming */
 195 #ifdef WINDOWS
 196         g_string_append_printf(to, ".png.Viking");
 197 #else
 198         g_string_append_printf(to, ".png.Viking-%ld", (long) getpid());
 199 #endif
 200
 201         g_free(md5);
 202
 203         old_mask = umask(0077);
 204         gdk_pixbuf_save(thumb, to->str, "png", NULL,
 205                         "tEXt::Thumb::Image::Width", swidth,
 206                         "tEXt::Thumb::Image::Height", sheight,
 207                         "tEXt::Thumb::Size", ssize,
 208                         "tEXt::Thumb::MTime", smtime,
 209                         "tEXt::Thumb::URI", uri,
 210                         "tEXt::Software", PROJECT,
 211                         NULL);
 212         umask(old_mask);
 213
 214         /* We create the file ###.png.ROX-Filer-PID and rename it to avoid
 215          * a race condition if two programs create the same thumb at
 216          * once.
 217          */
 218         {
 219                 gchar *final;
 220
 221                 final = g_strndup(to->str, name_len);
 222                 if (rename(to->str, final))
 223                 {
 224                         g_warning("Failed to rename '%s' to '%s': %s",
 225                                   to->str, final, g_strerror(errno));
 226                         g_object_unref ( G_OBJECT(thumb) );
 227                         thumb = NULL; /* return NULL */
 228                 }
 229
 230                 g_free(final);
 231         }
 232
 233         g_string_free(to, TRUE);
 234         g_free(swidth);
 235         g_free(sheight);
 236         g_free(ssize);
 237         g_free(smtime);
 238         g_free(uri);
 239
 240         return thumb;
 241 }
 242
 243
 244 GdkPixbuf *a_thumbnails_get(const gchar *pathname)
 245 {
 246         GdkPixbuf *thumb = NULL;
 247         char *thumb_path, *md5, *uri, *path;
 248         const char *ssize, *smtime;
 249         struct stat info;
 250
 251         path = pathdup(pathname);
 252         uri = g_strconcat("file://", path, NULL);
 253         md5 = md5_hash(uri);
 254         g_free(uri);
 255
 256         thumb_path = g_strdup_printf("%s%s%s%s.png", HOME_DIR, THUMB_DIR, THUMB_SUB_DIR, md5);
 257
 258         g_free(md5);
 259
 260         thumb = gdk_pixbuf_new_from_file(thumb_path, NULL);
 261         if (!thumb)
 262                 goto err;
 263
 264         /* Note that these don't need freeing... */
 265         ssize = gdk_pixbuf_get_option(thumb, "tEXt::Thumb::Size");
 266         if (!ssize)
 267                 goto err;
 268
 269         smtime = gdk_pixbuf_get_option(thumb, "tEXt::Thumb::MTime");
 270         if (!smtime)
 271                 goto err;
 272
 273         if (stat(path, &info) != 0)
 274                 goto err;
 275
 276         if (info.st_mtime != atol(smtime) || info.st_size != atol(ssize))
 277                 goto err;
 278
 279         goto out;
 280 err:
 281         if (thumb)
 282                 gdk_pixbuf_unref(thumb);
 283         thumb = NULL;
 284 out:
 285         g_free(path);
 286         g_free(thumb_path);
 287         return thumb;
 288 }
 289
 290 /* pathdup() stuff */
 291
 292 static char *pathdup(const char *path)
 293 {
 294         char real[MAXPATHLEN];
 295
 296         g_return_val_if_fail(path != NULL, NULL);
 297
 298         if (realpath(path, real))
 299                 return g_strdup(real);
 300
 301         return g_strdup(path);
 302 }
 303
 304 /*
 305  * This code implements the MD5 message-digest algorithm.
 306  * The algorithm is due to Ron Rivest. The original code was
 307  * written by Colin Plumb in 1993, and put in the public domain.
 308  *
 309  * Modified to use glib datatypes. Put under GPL to simplify
 310  * licensing for ROX-Filer. Taken from Debian's dpkg package.
 311  *
 312  */
 313
 314 #define md5byte unsigned char
 315
 316 typedef struct _MD5Context MD5Context;
 317
 318 struct _MD5Context {
 319         guint32 buf[4];
 320         guint32 bytes[2];
 321         guint32 in[16];
 322 };
 323
 324 static void MD5Init(MD5Context *ctx);
 325 static void MD5Update(MD5Context *ctx, md5byte const *buf, unsigned len);
 326 static char *MD5Final(MD5Context *ctx);
 327 static void MD5Transform(guint32 buf[4], guint32 const in[16]);
 328
 329 #if G_BYTE_ORDER == G_BIG_ENDIAN
 330 static void byteSwap(guint32 *buf, unsigned words)
 331 {
 332         md5byte *p = (md5byte *)buf;
 333
 334         do {
 335                 *buf++ = (guint32)((unsigned)p[3] << 8 | p[2]) << 16 |
 336                         ((unsigned)p[1] << 8 | p[0]);
 337                 p += 4;
 338         } while (--words);
 339 }
 340 #else
 341 #define byteSwap(buf,words)
 342 #endif
 343
 344 /*
 345  * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
 346  * initialization constants.
 347  */
 348 static void MD5Init(MD5Context *ctx)
 349 {
 350         ctx->buf[0] = 0x67452301;
 351         ctx->buf[1] = 0xefcdab89;
 352         ctx->buf[2] = 0x98badcfe;
 353         ctx->buf[3] = 0x10325476;
 354
 355         ctx->bytes[0] = 0;
 356         ctx->bytes[1] = 0;
 357 }
 358
 359 /*
 360  * Update context to reflect the concatenation of another buffer full
 361  * of bytes.
 362  */
 363 static void MD5Update(MD5Context *ctx, md5byte const *buf, unsigned len)
 364 {
 365         guint32 t;
 366
 367         /* Update byte count */
 368
 369         t = ctx->bytes[0];
 370         if ((ctx->bytes[0] = t + len) < t)
 371                 ctx->bytes[1]++;        /* Carry from low to high */
 372
 373         t = 64 - (t & 0x3f);    /* Space available in ctx->in (at least 1) */
 374         if (t > len) {
 375                 memcpy((md5byte *)ctx->in + 64 - t, buf, len);
 376                 return;
 377         }
 378         /* First chunk is an odd size */
 379         memcpy((md5byte *)ctx->in + 64 - t, buf, t);
 380         byteSwap(ctx->in, 16);
 381         MD5Transform(ctx->buf, ctx->in);
 382         buf += t;
 383         len -= t;
 384
 385         /* Process data in 64-byte chunks */
 386         while (len >= 64) {
 387                 memcpy(ctx->in, buf, 64);
 388                 byteSwap(ctx->in, 16);
 389                 MD5Transform(ctx->buf, ctx->in);
 390                 buf += 64;
 391                 len -= 64;
 392         }
 393
 394         /* Handle any remaining bytes of data. */
 395         memcpy(ctx->in, buf, len);
 396 }
 397
 398 /*
 399  * Final wrapup - pad to 64-byte boundary with the bit pattern
 400  * 1 0* (64-bit count of bits processed, MSB-first)
 401  * Returns the newly allocated string of the hash.
 402  */
 403 static char *MD5Final(MD5Context *ctx)
 404 {
 405         char *retval;
 406         int i;
 407         int count = ctx->bytes[0] & 0x3f;       /* Number of bytes in ctx->in */
 408         md5byte *p = (md5byte *)ctx->in + count;
 409         guint8  *bytes;
 410
 411         /* Set the first char of padding to 0x80.  There is always room. */
 412         *p++ = 0x80;
 413
 414         /* Bytes of padding needed to make 56 bytes (-8..55) */
 415         count = 56 - 1 - count;
 416
 417         if (count < 0) {        /* Padding forces an extra block */
 418                 memset(p, 0, count + 8);
 419                 byteSwap(ctx->in, 16);
 420                 MD5Transform(ctx->buf, ctx->in);
 421                 p = (md5byte *)ctx->in;
 422                 count = 56;
 423         }
 424         memset(p, 0, count);
 425         byteSwap(ctx->in, 14);
 426
 427         /* Append length in bits and transform */
 428         ctx->in[14] = ctx->bytes[0] << 3;
 429         ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
 430         MD5Transform(ctx->buf, ctx->in);
 431
 432         byteSwap(ctx->buf, 4);
 433
 434         retval = g_malloc(33);
 435         bytes = (guint8 *) ctx->buf;
 436         for (i = 0; i < 16; i++)
 437                 sprintf(retval + (i * 2), "%02x", bytes[i]);
 438         retval[32] = '\0';
 439
 440         return retval;
 441 }
 442
 443 # ifndef ASM_MD5
 444
 445 /* The four core functions - F1 is optimized somewhat */
 446
 447 /* #define F1(x, y, z) (x & y | ~x & z) */
 448 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 449 #define F2(x, y, z) F1(z, x, y)
 450 #define F3(x, y, z) (x ^ y ^ z)
 451 #define F4(x, y, z) (y ^ (x | ~z))
 452
 453 /* This is the central step in the MD5 algorithm. */
 454 #define MD5STEP(f,w,x,y,z,in,s) \
 455          (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
 456
 457 /*
 458  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 459  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 460  * the data and converts bytes into longwords for this routine.
 461  */
 462 static void MD5Transform(guint32 buf[4], guint32 const in[16])
 463 {
 464         register guint32 a, b, c, d;
 465
 466         a = buf[0];
 467         b = buf[1];
 468         c = buf[2];
 469         d = buf[3];
 470
 471         MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 472         MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 473         MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 474         MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 475         MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 476         MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 477         MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 478         MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 479         MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 480         MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 481         MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 482         MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 483         MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 484         MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 485         MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 486         MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 487
 488         MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 489         MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 490         MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 491         MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 492         MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 493         MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 494         MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 495         MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 496         MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 497         MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 498         MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 499         MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 500         MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 501         MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 502         MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 503         MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 504
 505         MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 506         MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 507         MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 508         MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 509         MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 510         MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 511         MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 512         MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 513         MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 514         MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 515         MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 516         MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 517         MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 518         MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 519         MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 520         MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 521
 522         MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 523         MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 524         MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 525         MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 526         MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 527         MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 528         MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 529         MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 530         MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 531         MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 532         MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 533         MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 534         MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 535         MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 536         MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 537         MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 538
 539         buf[0] += a;
 540         buf[1] += b;
 541         buf[2] += c;
 542         buf[3] += d;
 543 }
 544
 545 # endif /* ASM_MD5 */
 546
 547 static char *md5_hash(const char *message)
 548 {
 549         MD5Context ctx;
 550
 551         MD5Init(&ctx);
 552         MD5Update(&ctx, message, strlen(message));
 553         return MD5Final(&ctx);
 554 }