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