src/fccache.c

   1 /*
   2  * Copyright © 2000 Keith Packard
   3  * Copyright © 2005 Patrick Lam
   4  *
   5  * Permission to use, copy, modify, distribute, and sell this software and its
   6  * documentation for any purpose is hereby granted without fee, provided that
   7  * the above copyright notice appear in all copies and that both that
   8  * copyright notice and this permission notice appear in supporting
   9  * documentation, and that the name of Keith Packard not be used in
  10  * advertising or publicity pertaining to distribution of the software without
  11  * specific, written prior permission.  Keith Packard makes no
  12  * representations about the suitability of this software for any purpose.  It
  13  * is provided "as is" without express or implied warranty.
  14  *
  15  * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  16  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  17  * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  18  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  19  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  20  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  21  * PERFORMANCE OF THIS SOFTWARE.
  22  */
  23
  24 #include "fcint.h"
  25 #include "../fc-arch/fcarch.h"
  26 #include <stdio.h>
  27 #include <fcntl.h>
  28 #include <dirent.h>
  29 #include <string.h>
  30 #include <sys/types.h>
  31 #include <assert.h>
  32 #if defined(HAVE_MMAP) || defined(__CYGWIN__)
  33 #  include <unistd.h>
  34 #  include <sys/mman.h>
  35 #elif defined(_WIN32)
  36 #  include <windows.h>
  37 #endif
  38
  39 #ifndef O_BINARY
  40 #define O_BINARY 0
  41 #endif
  42
  43 struct MD5Context {
  44         FcChar32 buf[4];
  45         FcChar32 bits[2];
  46         unsigned char in[64];
  47 };
  48
  49 static void MD5Init(struct MD5Context *ctx);
  50 static void MD5Update(struct MD5Context *ctx, unsigned char *buf, unsigned len);
  51 static void MD5Final(unsigned char digest[16], struct MD5Context *ctx);
  52 static void MD5Transform(FcChar32 buf[4], FcChar32 in[16]);
  53
  54 #define CACHEBASE_LEN (1 + 32 + 1 + sizeof (FC_ARCHITECTURE) + sizeof (FC_CACHE_SUFFIX))
  55
  56 static const char bin2hex[] = { '0', '1', '2', '3',
  57                                 '4', '5', '6', '7',
  58                                 '8', '9', 'a', 'b',
  59                                 'c', 'd', 'e', 'f' };
  60
  61 static FcChar8 *
  62 FcDirCacheBasename (const FcChar8 * dir, FcChar8 cache_base[CACHEBASE_LEN])
  63 {
  64     unsigned char       hash[16];
  65     FcChar8             *hex_hash;
  66     int                 cnt;
  67     struct MD5Context   ctx;
  68
  69     MD5Init (&ctx);
  70     MD5Update (&ctx, (unsigned char *)dir, strlen ((char *) dir));
  71
  72     MD5Final (hash, &ctx);
  73
  74     cache_base[0] = '/';
  75     hex_hash = cache_base + 1;
  76     for (cnt = 0; cnt < 16; ++cnt)
  77     {
  78         hex_hash[2*cnt  ] = bin2hex[hash[cnt] >> 4];
  79         hex_hash[2*cnt+1] = bin2hex[hash[cnt] & 0xf];
  80     }
  81     hex_hash[2*cnt] = 0;
  82     strcat ((char *) cache_base, "-" FC_ARCHITECTURE FC_CACHE_SUFFIX);
  83
  84     return cache_base;
  85 }
  86
  87 FcBool
  88 FcDirCacheUnlink (const FcChar8 *dir, FcConfig *config)
  89 {
  90     FcChar8     *cache_hashed = NULL;
  91     FcChar8     cache_base[CACHEBASE_LEN];
  92     FcStrList   *list;
  93     FcChar8     *cache_dir;
  94
  95     FcDirCacheBasename (dir, cache_base);
  96
  97     list = FcStrListCreate (config->cacheDirs);
  98     if (!list)
  99         return FcFalse;
 100
 101     while ((cache_dir = FcStrListNext (list)))
 102     {
 103         cache_hashed = FcStrPlus (cache_dir, cache_base);
 104         if (!cache_hashed)
 105             break;
 106         (void) unlink ((char *) cache_hashed);
 107     }
 108     FcStrListDone (list);
 109     /* return FcFalse if something went wrong */
 110     if (cache_dir)
 111         return FcFalse;
 112     return FcTrue;
 113 }
 114
 115 static int
 116 FcDirCacheOpenFile (const FcChar8 *cache_file, struct stat *file_stat)
 117 {
 118     int fd;
 119
 120     fd = open((char *) cache_file, O_RDONLY | O_BINARY);
 121     if (fd < 0)
 122         return fd;
 123     if (fstat (fd, file_stat) < 0)
 124     {
 125         close (fd);
 126         return -1;
 127     }
 128     return fd;
 129 }
 130
 131 /*
 132  * Look for a cache file for the specified dir. Attempt
 133  * to use each one we find, stopping when the callback
 134  * indicates success
 135  */
 136 static FcBool
 137 FcDirCacheProcess (FcConfig *config, const FcChar8 *dir,
 138                    FcBool (*callback) (int fd, struct stat *stat, void *closure),
 139                    void *closure, FcChar8 **cache_file_ret)
 140 {
 141     int         fd = -1;
 142     FcChar8     cache_base[CACHEBASE_LEN];
 143     FcStrList   *list;
 144     FcChar8     *cache_dir;
 145     struct stat file_stat, dir_stat;
 146     FcBool      ret = FcFalse;
 147
 148     if (stat ((char *) dir, &dir_stat) < 0)
 149         return FcFalse;
 150
 151     FcDirCacheBasename (dir, cache_base);
 152
 153     list = FcStrListCreate (config->cacheDirs);
 154     if (!list)
 155         return FcFalse;
 156
 157     while ((cache_dir = FcStrListNext (list)))
 158     {
 159         FcChar8 *cache_hashed = FcStrPlus (cache_dir, cache_base);
 160         if (!cache_hashed)
 161             break;
 162         fd = FcDirCacheOpenFile (cache_hashed, &file_stat);
 163         if (fd >= 0) {
 164             if (dir_stat.st_mtime <= file_stat.st_mtime)
 165             {
 166                 ret = (*callback) (fd, &file_stat, closure);
 167                 if (ret)
 168                 {
 169                     if (cache_file_ret)
 170                         *cache_file_ret = cache_hashed;
 171                     else
 172                         FcStrFree (cache_hashed);
 173                     close (fd);
 174                     break;
 175                 }
 176             }
 177             close (fd);
 178         }
 179         FcStrFree (cache_hashed);
 180     }
 181     FcStrListDone (list);
 182
 183     return ret;
 184 }
 185
 186 #define FC_CACHE_MIN_MMAP   1024
 187
 188 /*
 189  * Skip list element, make sure the 'next' pointer is the last thing
 190  * in the structure, it will be allocated large enough to hold all
 191  * of the necessary pointers
 192  */
 193
 194 typedef struct _FcCacheSkip FcCacheSkip;
 195
 196 struct _FcCacheSkip {
 197     FcCache         *cache;
 198     int             ref;
 199     intptr_t        size;
 200     dev_t           cache_dev;
 201     ino_t           cache_ino;
 202     time_t          cache_mtime;
 203     FcCacheSkip     *next[1];
 204 };
 205
 206 /*
 207  * The head of the skip list; pointers for every possible level
 208  * in the skip list, plus the largest level in the list
 209  */
 210
 211 #define FC_CACHE_MAX_LEVEL  16
 212
 213 static FcCacheSkip      *fcCacheChains[FC_CACHE_MAX_LEVEL];
 214 static int              fcCacheMaxLevel;
 215
 216 /*
 217  * Generate a random level number, distributed
 218  * so that each level is 1/4 as likely as the one before
 219  *
 220  * Note that level numbers run 1 <= level <= MAX_LEVEL
 221  */
 222 static int
 223 random_level (void)
 224 {
 225     /* tricky bit -- each bit is '1' 75% of the time */
 226     long int    bits = random () | random ();
 227     int level = 0;
 228
 229     while (++level < FC_CACHE_MAX_LEVEL)
 230     {
 231         if (bits & 1)
 232             break;
 233         bits >>= 1;
 234     }
 235     return level;
 236 }
 237
 238 /*
 239  * Insert cache into the list
 240  */
 241 static FcBool
 242 FcCacheInsert (FcCache *cache, struct stat *cache_stat)
 243 {
 244     FcCacheSkip    **update[FC_CACHE_MAX_LEVEL];
 245     FcCacheSkip    *s, **next;
 246     int             i, level;
 247
 248     /*
 249      * Find links along each chain
 250      */
 251     next = fcCacheChains;
 252     for (i = fcCacheMaxLevel; --i >= 0; )
 253     {
 254         for (; (s = next[i]); next = s->next)
 255             if (s->cache > cache)
 256                 break;
 257         update[i] = &next[i];
 258     }
 259
 260     /*
 261      * Create new list element
 262      */
 263     level = random_level ();
 264     if (level > fcCacheMaxLevel)
 265     {
 266         level = fcCacheMaxLevel + 1;
 267         update[fcCacheMaxLevel] = &fcCacheChains[fcCacheMaxLevel];
 268         fcCacheMaxLevel = level;
 269     }
 270
 271     s = malloc (sizeof (FcCacheSkip) + (level - 1) * sizeof (FcCacheSkip *));
 272     if (!s)
 273         return FcFalse;
 274
 275     s->cache = cache;
 276     s->size = cache->size;
 277     s->ref = 1;
 278     s->cache_dev = cache_stat->st_dev;
 279     s->cache_ino = cache_stat->st_ino;
 280     s->cache_mtime = cache_stat->st_mtime;
 281
 282     /*
 283      * Insert into all fcCacheChains
 284      */
 285     for (i = 0; i < level; i++)
 286     {
 287         s->next[i] = *update[i];
 288         *update[i] = s;
 289     }
 290     return FcTrue;
 291 }
 292
 293 static FcCacheSkip *
 294 FcCacheFindByAddr (void *object)
 295 {
 296     int     i;
 297     FcCacheSkip    **next = fcCacheChains;
 298     FcCacheSkip    *s;
 299
 300     /*
 301      * Walk chain pointers one level at a time
 302      */
 303     for (i = fcCacheMaxLevel; --i >= 0;)
 304         while (next[i] && (char *) object >= ((char *) next[i]->cache + next[i]->size))
 305             next = next[i]->next;
 306     /*
 307      * Here we are
 308      */
 309     s = next[0];
 310     if (s && (char *) object < ((char *) s->cache + s->size))
 311         return s;
 312     return NULL;
 313 }
 314
 315 static void
 316 FcCacheRemove (FcCache *cache)
 317 {
 318     FcCacheSkip     **update[FC_CACHE_MAX_LEVEL];
 319     FcCacheSkip     *s, **next;
 320     int             i;
 321
 322     /*
 323      * Find links along each chain
 324      */
 325     next = fcCacheChains;
 326     for (i = fcCacheMaxLevel; --i >= 0; )
 327     {
 328         for (; (s = next[i]); next = s->next)
 329             if (s->cache >= cache)
 330                 break;
 331         update[i] = &next[i];
 332     }
 333     s = next[0];
 334     assert (s->cache == cache);
 335     for (i = 0; i < fcCacheMaxLevel && *update[i] == s; i++)
 336         *update[i] = s->next[i];
 337     while (fcCacheMaxLevel > 0 && fcCacheChains[fcCacheMaxLevel - 1] == NULL)
 338         fcCacheMaxLevel--;
 339     free (s);
 340 }
 341
 342 static FcCache *
 343 FcCacheFindByStat (struct stat *cache_stat)
 344 {
 345     FcCacheSkip     *s;
 346
 347     for (s = fcCacheChains[0]; s; s = s->next[0])
 348         if (s->cache_dev == cache_stat->st_dev &&
 349             s->cache_ino == cache_stat->st_ino &&
 350             s->cache_mtime == cache_stat->st_mtime)
 351             return s->cache;
 352     return NULL;
 353 }
 354
 355 static void
 356 FcDirCacheDispose (FcCache *cache)
 357 {
 358     switch (cache->magic) {
 359     case FC_CACHE_MAGIC_ALLOC:
 360         free (cache);
 361         break;
 362     case FC_CACHE_MAGIC_MMAP:
 363 #if defined(HAVE_MMAP) || defined(__CYGWIN__)
 364         munmap (cache, cache->size);
 365 #elif defined(_WIN32)
 366         UnmapViewOfFile (cache);
 367 #endif
 368         break;
 369     }
 370     FcCacheRemove (cache);
 371 }
 372
 373 void
 374 FcCacheObjectReference (void *object)
 375 {
 376     FcCacheSkip *skip = FcCacheFindByAddr (object);
 377
 378     if (skip)
 379         skip->ref++;
 380 }
 381
 382 void
 383 FcCacheObjectDereference (void *object)
 384 {
 385     FcCacheSkip *skip = FcCacheFindByAddr (object);
 386
 387     if (skip)
 388     {
 389         skip->ref--;
 390         if (skip->ref <= 0)
 391             FcDirCacheDispose (skip->cache);
 392     }
 393 }
 394
 395 void
 396 FcCacheFini (void)
 397 {
 398     int             i;
 399
 400     for (i = 0; i < FC_CACHE_MAX_LEVEL; i++)
 401         assert (fcCacheChains[i] == NULL);
 402     assert (fcCacheMaxLevel == 0);
 403 }
 404
 405 /*
 406  * Map a cache file into memory
 407  */
 408 static FcCache *
 409 FcDirCacheMapFd (int fd, struct stat *fd_stat)
 410 {
 411     FcCache     *cache;
 412     FcBool      allocated = FcFalse;
 413
 414     if (fd_stat->st_size < sizeof (FcCache))
 415         return NULL;
 416     cache = FcCacheFindByStat (fd_stat);
 417     if (cache)
 418         return cache;
 419     /*
 420      * For small cache files, just read them into memory
 421      */
 422     if (fd_stat->st_size >= FC_CACHE_MIN_MMAP)
 423     {
 424 #if defined(HAVE_MMAP) || defined(__CYGWIN__)
 425         cache = mmap (0, fd_stat->st_size, PROT_READ, MAP_SHARED, fd, 0);
 426 #elif defined(_WIN32)
 427         {
 428             HANDLE hFileMap;
 429
 430             cache = NULL;
 431             hFileMap = CreateFileMapping((HANDLE) _get_osfhandle(fd), NULL,
 432                                          PAGE_READONLY, 0, 0, NULL);
 433             if (hFileMap != NULL)
 434             {
 435                 cache = MapViewOfFile (hFileMap, FILE_MAP_READ, 0, 0, size);
 436                 CloseHandle (hFileMap);
 437             }
 438         }
 439 #endif
 440     }
 441     if (!cache)
 442     {
 443         cache = malloc (fd_stat->st_size);
 444         if (!cache)
 445             return NULL;
 446
 447         if (read (fd, cache, fd_stat->st_size) != fd_stat->st_size)
 448         {
 449             free (cache);
 450             return NULL;
 451         }
 452         allocated = FcTrue;
 453     }
 454     if (cache->magic != FC_CACHE_MAGIC_MMAP ||
 455         cache->version < FC_CACHE_CONTENT_VERSION ||
 456         cache->size != fd_stat->st_size ||
 457         !FcCacheInsert (cache, fd_stat))
 458     {
 459         if (allocated)
 460             free (cache);
 461         else
 462         {
 463 #if defined(HAVE_MMAP) || defined(__CYGWIN__)
 464             munmap (cache, fd_stat->st_size);
 465 #elif defined(_WIN32)
 466             UnmapViewOfFile (cache);
 467 #endif
 468         }
 469         return NULL;
 470     }
 471
 472     /* Mark allocated caches so they're freed rather than unmapped */
 473     if (allocated)
 474         cache->magic = FC_CACHE_MAGIC_ALLOC;
 475
 476     return cache;
 477 }
 478
 479 void
 480 FcDirCacheReference (FcCache *cache, int nref)
 481 {
 482     FcCacheSkip *skip = FcCacheFindByAddr (cache);
 483
 484     if (skip)
 485         skip->ref += nref;
 486 }
 487
 488 void
 489 FcDirCacheUnload (FcCache *cache)
 490 {
 491     FcCacheObjectDereference (cache);
 492 }
 493
 494 static FcBool
 495 FcDirCacheMapHelper (int fd, struct stat *fd_stat, void *closure)
 496 {
 497     FcCache *cache = FcDirCacheMapFd (fd, fd_stat);
 498
 499     if (!cache)
 500         return FcFalse;
 501     *((FcCache **) closure) = cache;
 502     return FcTrue;
 503 }
 504
 505 FcCache *
 506 FcDirCacheLoad (const FcChar8 *dir, FcConfig *config, FcChar8 **cache_file)
 507 {
 508     FcCache *cache = NULL;
 509
 510     if (!FcDirCacheProcess (config, dir,
 511                             FcDirCacheMapHelper,
 512                             &cache, cache_file))
 513         return NULL;
 514     return cache;
 515 }
 516
 517 FcCache *
 518 FcDirCacheLoadFile (const FcChar8 *cache_file, struct stat *file_stat)
 519 {
 520     int fd;
 521     FcCache *cache;
 522
 523     fd = FcDirCacheOpenFile (cache_file, file_stat);
 524     if (fd < 0)
 525         return NULL;
 526     cache = FcDirCacheMapFd (fd, file_stat);
 527     close (fd);
 528     return cache;
 529 }
 530
 531 /*
 532  * Validate a cache file by reading the header and checking
 533  * the magic number and the size field
 534  */
 535 static FcBool
 536 FcDirCacheValidateHelper (int fd, struct stat *fd_stat, void *closure)
 537 {
 538     FcBool  ret = FcTrue;
 539     FcCache     c;
 540
 541     if (read (fd, &c, sizeof (FcCache)) != sizeof (FcCache))
 542         ret = FcFalse;
 543     else if (c.magic != FC_CACHE_MAGIC_MMAP)
 544         ret = FcFalse;
 545     else if (c.version < FC_CACHE_CONTENT_VERSION)
 546         ret = FcFalse;
 547     else if (fd_stat->st_size != c.size)
 548         ret = FcFalse;
 549     return ret;
 550 }
 551
 552 static FcBool
 553 FcDirCacheValidConfig (const FcChar8 *dir, FcConfig *config)
 554 {
 555     return FcDirCacheProcess (config, dir,
 556                               FcDirCacheValidateHelper,
 557                               NULL, NULL);
 558 }
 559
 560 FcBool
 561 FcDirCacheValid (const FcChar8 *dir)
 562 {
 563     FcConfig    *config;
 564
 565     config = FcConfigGetCurrent ();
 566     if (!config)
 567         return FcFalse;
 568
 569     return FcDirCacheValidConfig (dir, config);
 570 }
 571
 572 /*
 573  * Build a cache structure from the given contents
 574  */
 575 FcCache *
 576 FcDirCacheBuild (FcFontSet *set, const FcChar8 *dir, FcStrSet *dirs)
 577 {
 578     FcSerialize *serialize = FcSerializeCreate ();
 579     FcCache *cache;
 580     int i;
 581     intptr_t    cache_offset;
 582     intptr_t    dirs_offset;
 583     FcChar8     *dir_serialize;
 584     intptr_t    *dirs_serialize;
 585     FcFontSet   *set_serialize;
 586
 587     if (!serialize)
 588         return NULL;
 589     /*
 590      * Space for cache structure
 591      */
 592     cache_offset = FcSerializeReserve (serialize, sizeof (FcCache));
 593     /*
 594      * Directory name
 595      */
 596     if (!FcStrSerializeAlloc (serialize, dir))
 597         goto bail1;
 598     /*
 599      * Subdirs
 600      */
 601     dirs_offset = FcSerializeAlloc (serialize, dirs, dirs->num * sizeof (FcChar8 *));
 602     for (i = 0; i < dirs->num; i++)
 603         if (!FcStrSerializeAlloc (serialize, dirs->strs[i]))
 604             goto bail1;
 605
 606     /*
 607      * Patterns
 608      */
 609     if (!FcFontSetSerializeAlloc (serialize, set))
 610         goto bail1;
 611
 612     /* Serialize layout complete. Now allocate space and fill it */
 613     cache = malloc (serialize->size);
 614     if (!cache)
 615         goto bail1;
 616     /* shut up valgrind */
 617     memset (cache, 0, serialize->size);
 618
 619     serialize->linear = cache;
 620
 621     cache->magic = FC_CACHE_MAGIC_ALLOC;
 622     cache->version = FC_CACHE_CONTENT_VERSION;
 623     cache->size = serialize->size;
 624
 625     /*
 626      * Serialize directory name
 627      */
 628     dir_serialize = FcStrSerialize (serialize, dir);
 629     if (!dir_serialize)
 630         goto bail2;
 631     cache->dir = FcPtrToOffset (cache, dir_serialize);
 632
 633     /*
 634      * Serialize sub dirs
 635      */
 636     dirs_serialize = FcSerializePtr (serialize, dirs);
 637     if (!dirs_serialize)
 638         goto bail2;
 639     cache->dirs = FcPtrToOffset (cache, dirs_serialize);
 640     cache->dirs_count = dirs->num;
 641     for (i = 0; i < dirs->num; i++)
 642     {
 643         FcChar8 *d_serialize = FcStrSerialize (serialize, dirs->strs[i]);
 644         if (!d_serialize)
 645             goto bail2;
 646         dirs_serialize[i] = FcPtrToOffset (dirs_serialize, d_serialize);
 647     }
 648
 649     /*
 650      * Serialize font set
 651      */
 652     set_serialize = FcFontSetSerialize (serialize, set);
 653     if (!set_serialize)
 654         goto bail2;
 655     cache->set = FcPtrToOffset (cache, set_serialize);
 656
 657     FcSerializeDestroy (serialize);
 658
 659     return cache;
 660
 661 bail2:
 662     free (cache);
 663 bail1:
 664     FcSerializeDestroy (serialize);
 665     return NULL;
 666 }
 667
 668 static FcBool
 669 FcMakeDirectory (const FcChar8 *dir)
 670 {
 671     FcChar8 *parent;
 672     FcBool  ret;
 673
 674     if (strlen ((char *) dir) == 0)
 675         return FcFalse;
 676
 677     parent = FcStrDirname (dir);
 678     if (!parent)
 679         return FcFalse;
 680     if (access ((char *) parent, W_OK|X_OK) == 0)
 681         ret = mkdir ((char *) dir, 0777) == 0;
 682     else if (access ((char *) parent, F_OK) == -1)
 683         ret = FcMakeDirectory (parent) && (mkdir ((char *) dir, 0777) == 0);
 684     else
 685         ret = FcFalse;
 686     FcStrFree (parent);
 687     return ret;
 688 }
 689
 690 /* write serialized state to the cache file */
 691 FcBool
 692 FcDirCacheWrite (FcCache *cache, FcConfig *config)
 693 {
 694     FcChar8         *dir = FcCacheDir (cache);
 695     FcChar8         cache_base[CACHEBASE_LEN];
 696     FcChar8         *cache_hashed;
 697     int             fd;
 698     FcAtomic        *atomic;
 699     FcStrList       *list;
 700     FcChar8         *cache_dir = NULL;
 701     FcChar8         *test_dir;
 702     int             magic;
 703     int             written;
 704
 705     /*
 706      * Write it to the first directory in the list which is writable
 707      */
 708
 709     list = FcStrListCreate (config->cacheDirs);
 710     if (!list)
 711         return FcFalse;
 712     while ((test_dir = FcStrListNext (list))) {
 713         if (access ((char *) test_dir, W_OK|X_OK) == 0)
 714         {
 715             cache_dir = test_dir;
 716             break;
 717         }
 718         else
 719         {
 720             /*
 721              * If the directory doesn't exist, try to create it
 722              */
 723             if (access ((char *) test_dir, F_OK) == -1) {
 724                 if (FcMakeDirectory (test_dir))
 725                 {
 726                     cache_dir = test_dir;
 727                     break;
 728                 }
 729             }
 730         }
 731     }
 732     FcStrListDone (list);
 733     if (!cache_dir)
 734         return FcFalse;
 735
 736     FcDirCacheBasename (dir, cache_base);
 737     cache_hashed = FcStrPlus (cache_dir, cache_base);
 738     if (!cache_hashed)
 739         return FcFalse;
 740
 741     if (FcDebug () & FC_DBG_CACHE)
 742         printf ("FcDirCacheWriteDir dir \"%s\" file \"%s\"\n",
 743                 dir, cache_hashed);
 744
 745     atomic = FcAtomicCreate ((FcChar8 *)cache_hashed);
 746     if (!atomic)
 747         goto bail1;
 748
 749     if (!FcAtomicLock (atomic))
 750         goto bail3;
 751
 752     fd = open((char *)FcAtomicNewFile (atomic), O_RDWR | O_CREAT | O_BINARY, 0666);
 753     if (fd == -1)
 754         goto bail4;
 755
 756     /* Temporarily switch magic to MMAP while writing to file */
 757     magic = cache->magic;
 758     if (magic != FC_CACHE_MAGIC_MMAP)
 759         cache->magic = FC_CACHE_MAGIC_MMAP;
 760
 761     /*
 762      * Write cache contents to file
 763      */
 764     written = write (fd, cache, cache->size);
 765
 766     /* Switch magic back */
 767     if (magic != FC_CACHE_MAGIC_MMAP)
 768         cache->magic = magic;
 769
 770     if (written != cache->size)
 771     {
 772         perror ("write cache");
 773         goto bail5;
 774     }
 775
 776     close(fd);
 777     if (!FcAtomicReplaceOrig(atomic))
 778         goto bail4;
 779     FcStrFree (cache_hashed);
 780     FcAtomicUnlock (atomic);
 781     FcAtomicDestroy (atomic);
 782     return FcTrue;
 783
 784  bail5:
 785     close (fd);
 786  bail4:
 787     FcAtomicUnlock (atomic);
 788  bail3:
 789     FcAtomicDestroy (atomic);
 790  bail1:
 791     FcStrFree (cache_hashed);
 792     return FcFalse;
 793 }
 794
 795 /*
 796  * Hokey little macro trick to permit the definitions of C functions
 797  * with the same name as CPP macros
 798  */
 799 #define args(x...)          (x)
 800
 801 const FcChar8 *
 802 FcCacheDir args(const FcCache *c)
 803 {
 804     return FcCacheDir (c);
 805 }
 806
 807 FcFontSet *
 808 FcCacheCopySet args(const FcCache *c)
 809 {
 810     FcFontSet   *old = FcCacheSet (c);
 811     FcFontSet   *new = FcFontSetCreate ();
 812     int         i;
 813
 814     if (!new)
 815         return NULL;
 816     for (i = 0; i < old->nfont; i++)
 817         if (!FcFontSetAdd (new, FcFontSetFont (old, i)))
 818         {
 819             FcFontSetDestroy (new);
 820             return NULL;
 821         }
 822     return new;
 823 }
 824
 825 const FcChar8 *
 826 FcCacheSubdir args(const FcCache *c, int i)
 827 {
 828     return FcCacheSubdir (c, i);
 829 }
 830
 831 int
 832 FcCacheNumSubdir args(const FcCache *c)
 833 {
 834     return c->dirs_count;
 835 }
 836
 837 int
 838 FcCacheNumFont args(const FcCache *c)
 839 {
 840     return FcCacheSet(c)->nfont;
 841 }
 842
 843 /*
 844  * This code implements the MD5 message-digest algorithm.
 845  * The algorithm is due to Ron Rivest.  This code was
 846  * written by Colin Plumb in 1993, no copyright is claimed.
 847  * This code is in the public domain; do with it what you wish.
 848  *
 849  * Equivalent code is available from RSA Data Security, Inc.
 850  * This code has been tested against that, and is equivalent,
 851  * except that you don't need to include two pages of legalese
 852  * with every copy.
 853  *
 854  * To compute the message digest of a chunk of bytes, declare an
 855  * MD5Context structure, pass it to MD5Init, call MD5Update as
 856  * needed on buffers full of bytes, and then call MD5Final, which
 857  * will fill a supplied 16-byte array with the digest.
 858  */
 859
 860 #ifndef HIGHFIRST
 861 #define byteReverse(buf, len)   /* Nothing */
 862 #else
 863 /*
 864  * Note: this code is harmless on little-endian machines.
 865  */
 866 void byteReverse(unsigned char *buf, unsigned longs)
 867 {
 868     FcChar32 t;
 869     do {
 870         t = (FcChar32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
 871             ((unsigned) buf[1] << 8 | buf[0]);
 872         *(FcChar32 *) buf = t;
 873         buf += 4;
 874     } while (--longs);
 875 }
 876 #endif
 877
 878 /*
 879  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 880  * initialization constants.
 881  */
 882 static void MD5Init(struct MD5Context *ctx)
 883 {
 884     ctx->buf[0] = 0x67452301;
 885     ctx->buf[1] = 0xefcdab89;
 886     ctx->buf[2] = 0x98badcfe;
 887     ctx->buf[3] = 0x10325476;
 888
 889     ctx->bits[0] = 0;
 890     ctx->bits[1] = 0;
 891 }
 892
 893 /*
 894  * Update context to reflect the concatenation of another buffer full
 895  * of bytes.
 896  */
 897 static void MD5Update(struct MD5Context *ctx, unsigned char *buf, unsigned len)
 898 {
 899     FcChar32 t;
 900
 901     /* Update bitcount */
 902
 903     t = ctx->bits[0];
 904     if ((ctx->bits[0] = t + ((FcChar32) len << 3)) < t)
 905         ctx->bits[1]++;         /* Carry from low to high */
 906     ctx->bits[1] += len >> 29;
 907
 908     t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
 909
 910     /* Handle any leading odd-sized chunks */
 911
 912     if (t) {
 913         unsigned char *p = (unsigned char *) ctx->in + t;
 914
 915         t = 64 - t;
 916         if (len < t) {
 917             memcpy(p, buf, len);
 918             return;
 919         }
 920         memcpy(p, buf, t);
 921         byteReverse(ctx->in, 16);
 922         MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
 923         buf += t;
 924         len -= t;
 925     }
 926     /* Process data in 64-byte chunks */
 927
 928     while (len >= 64) {
 929         memcpy(ctx->in, buf, 64);
 930         byteReverse(ctx->in, 16);
 931         MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
 932         buf += 64;
 933         len -= 64;
 934     }
 935
 936     /* Handle any remaining bytes of data. */
 937
 938     memcpy(ctx->in, buf, len);
 939 }
 940
 941 /*
 942  * Final wrapup - pad to 64-byte boundary with the bit pattern
 943  * 1 0* (64-bit count of bits processed, MSB-first)
 944  */
 945 static void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
 946 {
 947     unsigned count;
 948     unsigned char *p;
 949
 950     /* Compute number of bytes mod 64 */
 951     count = (ctx->bits[0] >> 3) & 0x3F;
 952
 953     /* Set the first char of padding to 0x80.  This is safe since there is
 954        always at least one byte free */
 955     p = ctx->in + count;
 956     *p++ = 0x80;
 957
 958     /* Bytes of padding needed to make 64 bytes */
 959     count = 64 - 1 - count;
 960
 961     /* Pad out to 56 mod 64 */
 962     if (count < 8) {
 963         /* Two lots of padding:  Pad the first block to 64 bytes */
 964         memset(p, 0, count);
 965         byteReverse(ctx->in, 16);
 966         MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
 967
 968         /* Now fill the next block with 56 bytes */
 969         memset(ctx->in, 0, 56);
 970     } else {
 971         /* Pad block to 56 bytes */
 972         memset(p, 0, count - 8);
 973     }
 974     byteReverse(ctx->in, 14);
 975
 976     /* Append length in bits and transform */
 977     ((FcChar32 *) ctx->in)[14] = ctx->bits[0];
 978     ((FcChar32 *) ctx->in)[15] = ctx->bits[1];
 979
 980     MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
 981     byteReverse((unsigned char *) ctx->buf, 4);
 982     memcpy(digest, ctx->buf, 16);
 983     memset(ctx, 0, sizeof(ctx));        /* In case it's sensitive */
 984 }
 985
 986
 987 /* The four core functions - F1 is optimized somewhat */
 988
 989 /* #define F1(x, y, z) (x & y | ~x & z) */
 990 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 991 #define F2(x, y, z) F1(z, x, y)
 992 #define F3(x, y, z) (x ^ y ^ z)
 993 #define F4(x, y, z) (y ^ (x | ~z))
 994
 995 /* This is the central step in the MD5 algorithm. */
 996 #define MD5STEP(f, w, x, y, z, data, s) \
 997         ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
 998
 999 /*
1000  * The core of the MD5 algorithm, this alters an existing MD5 hash to
1001  * reflect the addition of 16 longwords of new data.  MD5Update blocks
1002  * the data and converts bytes into longwords for this routine.
1003  */
1004 static void MD5Transform(FcChar32 buf[4], FcChar32 in[16])
1005 {
1006     register FcChar32 a, b, c, d;
1007
1008     a = buf[0];
1009     b = buf[1];
1010     c = buf[2];
1011     d = buf[3];
1012
1013     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
1014     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
1015     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
1016     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
1017     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
1018     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
1019     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
1020     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
1021     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
1022     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
1023     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
1024     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
1025     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
1026     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
1027     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
1028     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
1029
1030     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
1031     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
1032     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
1033     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
1034     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
1035     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
1036     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
1037     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
1038     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
1039     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
1040     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
1041     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
1042     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
1043     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
1044     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
1045     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
1046
1047     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
1048     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
1049     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
1050     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
1051     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
1052     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
1053     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
1054     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
1055     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
1056     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
1057     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
1058     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
1059     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
1060     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
1061     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
1062     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
1063
1064     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
1065     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
1066     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
1067     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
1068     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
1069     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
1070     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
1071     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
1072     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
1073     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
1074     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
1075     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
1076     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
1077     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
1078     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
1079     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
1080
1081     buf[0] += a;
1082     buf[1] += b;
1083     buf[2] += c;
1084     buf[3] += d;
1085 }