/src/fontconfig/src/fccache.c

Source
/*
 * Copyright © 2000 Keith Packard
 * Copyright © 2005 Patrick Lam
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of the author(s) not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  The authors make no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * THE AUTHOR(S) DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */
#include "fcint.h"

#include "fcarch.h"
#include "fcmd5.h"

#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_DIRENT_H
#  include <dirent.h>
#endif
#include <inttypes.h>
#include <limits.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>

#ifndef _WIN32
#  include <sys/time.h>
#else
#  include <winsock2.h> /* for struct timeval */
#endif

#include <assert.h>
#if defined(HAVE_MMAP) || defined(__CYGWIN__)
#  include <sys/mman.h>
#  include <unistd.h>
#endif
#if defined(_WIN32)
#  include <sys/locking.h>
#endif

#ifndef O_BINARY
#  define O_BINARY 0
#endif

FcBool
FcDirCacheCreateUUID (FcChar8  *dir,
                      FcBool    force,
                      FcConfig *config)
{
    return FcTrue;
}

FcBool
FcDirCacheDeleteUUID (const FcChar8 *dir,
                      FcConfig      *config)
{
    FcBool ret = FcTrue;
#ifndef _WIN32
    const FcChar8 *sysroot;
    FcChar8       *target, *d;
    struct stat    statb;
    struct timeval times[2];

    config = FcConfigReference (config);
    if (!config)
  return FcFalse;
    sysroot = FcConfigGetSysRoot (config);
    if (sysroot)
  d = FcStrBuildFilename (sysroot, dir, NULL);
    else
  d = FcStrBuildFilename (dir, NULL);
    if (FcStat (d, &statb) != 0) {
  ret = FcFalse;
  goto bail;
    }
    target = FcStrBuildFilename (d, ".uuid", NULL);
    ret = unlink ((char *)target) == 0;
    if (ret) {
  times[0].tv_sec = statb.st_atime;
  times[1].tv_sec = statb.st_mtime;
#  ifdef HAVE_STRUCT_STAT_ST_MTIM
  times[0].tv_usec = statb.st_atim.tv_nsec / 1000;
  times[1].tv_usec = statb.st_mtim.tv_nsec / 1000;
#  else
  times[0].tv_usec = 0;
  times[1].tv_usec = 0;
#  endif
  if (utimes ((const char *)d, times) != 0) {
      fprintf (stderr, "Unable to revert mtime: %s\n", d);
  }
    }
    FcStrFree (target);
bail:
    FcStrFree (d);
    FcConfigDestroy (config);
#endif

    return ret;
}

#define CACHEBASE_LEN (1 + 36 + 1 + sizeof (FC_ARCHITECTURE) + sizeof (FC_CACHE_SUFFIX))

/* Rewrite the ".cache-<N>" suffix of a cache basename to a different
 * version.  Used both by the write side (to create compat symlinks)
 * and by the read side (to probe for caches written by older
 * fontconfig).  Independent of symlink support.
 */
static FcChar8 *
FcDirCacheReplaceVersion (const FcChar8 *cache_base,
                          FcChar8        compat_base[CACHEBASE_LEN],
                          int            version)
{
    const char *suffix = strstr ((const char *)cache_base, ".cache-");
    size_t      prefix_len;

    if (!suffix)
  return NULL;
    prefix_len = suffix - (const char *)cache_base;
    memcpy (compat_base, cache_base, prefix_len);
    sprintf ((char *)compat_base + prefix_len, ".cache-%d", version);
    return compat_base;
}

static FcBool
FcCacheIsMmapSafe (int fd)
{
    enum {
  MMAP_NOT_INITIALIZED = 0,
  MMAP_USE,
  MMAP_DONT_USE,
  MMAP_CHECK_FS,
    } status;
    static void *static_status;

    status = (intptr_t)fc_atomic_ptr_get (&static_status);

    if (status == MMAP_NOT_INITIALIZED) {
  const char *env = getenv ("FONTCONFIG_USE_MMAP");
  FcBool      use;
  if (env && FcNameBool ((const FcChar8 *)env, &use))
      status = use ? MMAP_USE : MMAP_DONT_USE;
  else
      status = MMAP_CHECK_FS;
  (void)fc_atomic_ptr_cmpexch (&static_status, NULL, (void *)(intptr_t)status);
    }

    if (status == MMAP_CHECK_FS)
  return FcIsFsMmapSafe (fd);
    else
  return status == MMAP_USE;
}

static const char bin2hex[] = { '0', '1', '2', '3',
                                '4', '5', '6', '7',
                                '8', '9', 'a', 'b',
                                'c', 'd', 'e', 'f' };

static FcChar8 *
FcDirCacheBasenameMD5 (FcConfig *config, const FcChar8 *dir, FcChar8 cache_base[CACHEBASE_LEN])
{
    FcChar8          *mapped_dir = NULL;
    unsigned char     hash[16];
    FcChar8          *hex_hash, *key = NULL;
    int               cnt;
    struct MD5Context ctx;
    const FcChar8    *salt, *orig_dir = NULL;

    salt = FcConfigMapSalt (config, dir);
    /* Obtain a path where "dir" is mapped to.
     * In case:
     * <remap-dir as-path="/usr/share/fonts">/run/host/fonts</remap-dir>
     *
     * FcConfigMapFontPath (config, "/run/host/fonts") will returns "/usr/share/fonts".
     */
    mapped_dir = FcConfigMapFontPath (config, dir);
    if (mapped_dir) {
  orig_dir = dir;
  dir = mapped_dir;
    }
    if (salt) {
  size_t dl = strlen ((const char *)dir);
  size_t sl = strlen ((const char *)salt);

  key = (FcChar8 *)malloc (dl + sl + 1);
  if (!key) {
      if (mapped_dir)
    FcStrFree (mapped_dir);
      return NULL;
  }
  memcpy (key, dir, dl);
  memcpy (key + dl, salt, sl + 1);
  key[dl + sl] = 0;
  if (!orig_dir)
      orig_dir = dir;
  dir = key;
    }
    MD5Init (&ctx);
    MD5Update (&ctx, (const unsigned char *)dir, strlen ((const char *)dir));

    MD5Final (hash, &ctx);

    if (key)
  FcStrFree (key);

    hex_hash = cache_base;
    for (cnt = 0; cnt < 16; ++cnt) {
  hex_hash[2 * cnt] = bin2hex[hash[cnt] >> 4];
  hex_hash[2 * cnt + 1] = bin2hex[hash[cnt] & 0xf];
    }
    hex_hash[2 * cnt] = 0;
    strcat ((char *)cache_base, "-" FC_ARCHITECTURE FC_CACHE_SUFFIX);
    if (FcDebug() & FC_DBG_CACHE) {
  printf ("cache: %s (dir: %s%s%s%s%s%s)\n", cache_base, orig_dir ? orig_dir : dir, mapped_dir ? " (mapped to " : "", mapped_dir ? (char *)mapped_dir : "", mapped_dir ? ")" : "", salt ? ", salt: " : "", salt ? (char *)salt : "");
    }

    if (mapped_dir)
  FcStrFree (mapped_dir);

    return cache_base;
}

#ifndef _WIN32
static FcChar8 *
FcDirCacheBasenameUUID (FcConfig *config, const FcChar8 *dir, FcChar8 cache_base[CACHEBASE_LEN])
{
    FcChar8       *target, *fuuid;
    const FcChar8 *sysroot = FcConfigGetSysRoot (config);
    int            fd;

    /* We don't need to apply remapping here. because .uuid was created at that very directory
     * to determine the cache name no matter where it was mapped to.
     */
    cache_base[0] = 0;
    if (sysroot)
  target = FcStrBuildFilename (sysroot, dir, NULL);
    else
  target = FcStrCopy (dir);
    fuuid = FcStrBuildFilename (target, ".uuid", NULL);
    if ((fd = FcOpen ((char *)fuuid, O_RDONLY)) != -1) {
  char    suuid[37];
  ssize_t len;

  memset (suuid, 0, sizeof (suuid));
  len = read (fd, suuid, 36);
  suuid[36] = 0;
  close (fd);
  if (len < 0)
      goto bail;
  cache_base[0] = '/';
  strcpy ((char *)&cache_base[1], suuid);
  strcat ((char *)cache_base, "-" FC_ARCHITECTURE FC_CACHE_SUFFIX);
  if (FcDebug() & FC_DBG_CACHE) {
      printf ("cache fallbacks to: %s (dir: %s)\n", cache_base, dir);
  }
    }
bail:
    FcStrFree (fuuid);
    FcStrFree (target);

    return cache_base;
}
#endif

FcBool
FcDirCacheUnlink (const FcChar8 *dir, FcConfig *config)
{
    FcChar8 *cache_hashed = NULL;
    FcChar8  cache_base[CACHEBASE_LEN];
#ifndef _WIN32
    FcChar8 uuid_cache_base[CACHEBASE_LEN];
#endif
    FcStrList     *list;
    FcChar8       *cache_dir;
    const FcChar8 *sysroot;
    FcBool         ret = FcTrue;

    config = FcConfigReference (config);
    if (!config)
  return FcFalse;
    sysroot = FcConfigGetSysRoot (config);

    if (!FcDirCacheBasenameMD5 (config, dir, cache_base)) {
  ret = FcFalse;
  goto bail;
    }
#ifndef _WIN32
    FcDirCacheBasenameUUID (config, dir, uuid_cache_base);
#endif

    list = FcStrListCreate (config->cacheDirs);
    if (!list) {
  ret = FcFalse;
  goto bail;
    }

    while ((cache_dir = FcStrListNext (list))) {
  if (sysroot)
      cache_hashed = FcStrBuildFilename (sysroot, cache_dir, cache_base, NULL);
  else
      cache_hashed = FcStrBuildFilename (cache_dir, cache_base, NULL);
  if (!cache_hashed)
      break;
  (void)unlink ((char *)cache_hashed);
  FcStrFree (cache_hashed);
#ifndef _WIN32
  if (uuid_cache_base[0] != 0) {
      if (sysroot)
    cache_hashed = FcStrBuildFilename (sysroot, cache_dir, uuid_cache_base, NULL);
      else
    cache_hashed = FcStrBuildFilename (cache_dir, uuid_cache_base, NULL);
      if (!cache_hashed)
    break;
      (void)unlink ((char *)cache_hashed);
      FcStrFree (cache_hashed);
  }
#endif
    }
    FcStrListDone (list);
    FcDirCacheDeleteUUID (dir, config);
    /* return FcFalse if something went wrong */
    if (cache_dir)
  ret = FcFalse;
bail:
    FcConfigDestroy (config);

    return ret;
}

static int
FcDirCacheOpenFile (const FcChar8 *cache_file, struct stat *file_stat)
{
    int fd;

#ifdef _WIN32
    if (FcStat (cache_file, file_stat) < 0)
  return -1;
#endif
    fd = FcOpen ((char *)cache_file, O_RDONLY | O_BINARY);
    if (fd < 0)
  return fd;
#ifndef _WIN32
    if (fstat (fd, file_stat) < 0) {
  close (fd);
  return -1;
    }
#endif
    return fd;
}

/*
 * Open a single cache file, run the callback, and take over ownership of
 * *cache_hashed* (either stored into *cache_file_ret* on success, or freed).
 * Returns FcTrue if the file existed and the callback accepted it.
 */
static FcBool
FcDirCacheProcessFile (FcConfig *config, FcChar8 *cache_hashed,
                       FcBool (*callback) (FcConfig *config, int fd, struct stat *fd_stat,
                                           struct stat *dir_stat, struct timeval *cache_mtime, void *closure),
                       void *closure, FcChar8 **cache_file_ret,
                       struct timeval *latest_mtime, struct stat *dir_stat)
{
    struct stat file_stat;
    int         fd;
    FcBool      ret = FcFalse;

    fd = FcDirCacheOpenFile (cache_hashed, &file_stat);
    if (fd < 0) {
  FcStrFree (cache_hashed);
  return FcFalse;
    }
    ret = (*callback) (config, fd, &file_stat, dir_stat, latest_mtime, closure);
    close (fd);
    if (ret && cache_file_ret) {
  if (*cache_file_ret)
      FcStrFree (*cache_file_ret);
  *cache_file_ret = cache_hashed;
    } else
  FcStrFree (cache_hashed);

    return ret;
}

/*
 * Look for a cache file for the specified dir. Attempt
 * to use each one we find, stopping when the callback
 * indicates success
 */
static FcBool
FcDirCacheProcess (FcConfig *config, const FcChar8 *dir,
                   FcBool (*callback) (FcConfig *config, int fd, struct stat *fd_stat,
                                       struct stat *dir_stat, struct timeval *cache_mtime, void *closure),
                   void *closure, FcChar8 **cache_file_ret)
{
    FcChar8        cache_base[CACHEBASE_LEN];
    FcStrList     *list;
    FcChar8       *cache_dir, *d;
    struct stat    dir_stat;
    FcBool         ret = FcFalse;
    const FcChar8 *sysroot = FcConfigGetSysRoot (config);
    struct timeval latest_mtime = (struct timeval){ 0 };

    if (sysroot)
  d = FcStrBuildFilename (sysroot, dir, NULL);
    else
  d = FcStrCopy (dir);
    if (FcStatChecksum (d, &dir_stat) < 0) {
  FcStrFree (d);
  return FcFalse;
    }
    FcStrFree (d);

    if (!FcDirCacheBasenameMD5 (config, dir, cache_base))
  return FcFalse;

    list = FcStrListCreate (config->cacheDirs);
    if (!list)
  return FcFalse;

    while ((cache_dir = FcStrListNext (list))) {
  FcChar8 *cache_hashed;
  FcBool   found;

  if (sysroot)
      cache_hashed = FcStrBuildFilename (sysroot, cache_dir, cache_base, NULL);
  else
      cache_hashed = FcStrBuildFilename (cache_dir, cache_base, NULL);
  if (!cache_hashed)
      break;
  found = FcDirCacheProcessFile (config, cache_hashed, callback, closure,
                                 cache_file_ret, &latest_mtime, &dir_stat);
  if (found)
      ret = FcTrue;

  /*
   * The current-version cache was not found in this cache directory.
   * Probe for caches written by older fontconfig (down to the minimum
   * compatible version) in the SAME directory before moving on, so a
   * cache written by an older reader (e.g. a Flatpak host's fonts,
   * issue #562) is discovered instead of being shadowed by a stale
   * current-version cache elsewhere.
   */
  if (!found && FC_CACHE_MIN_COMPAT_VERSION < FC_CACHE_VERSION_NUMBER) {
      int v;

      for (v = FC_CACHE_VERSION_NUMBER - 1; v >= FC_CACHE_MIN_COMPAT_VERSION; v--) {
    FcChar8  compat_base[CACHEBASE_LEN];
    FcChar8 *compat_hashed;

    if (!FcDirCacheReplaceVersion (cache_base, compat_base, v))
        break;
    if (sysroot)
        compat_hashed = FcStrBuildFilename (sysroot, cache_dir, compat_base, NULL);
    else
        compat_hashed = FcStrBuildFilename (cache_dir, compat_base, NULL);
    if (!compat_hashed)
        break;
    if (FcDirCacheProcessFile (config, compat_hashed, callback, closure,
                               cache_file_ret, &latest_mtime, &dir_stat)) {
        ret = FcTrue;
        found = FcTrue;
        break;
    }
      }
  }
#ifndef _WIN32
  if (!found) {
      FcChar8 uuid_cache_base[CACHEBASE_LEN];

      FcDirCacheBasenameUUID (config, dir, uuid_cache_base);
      if (uuid_cache_base[0] != 0) {
    FcChar8 *uuid_hashed;

    if (sysroot)
        uuid_hashed = FcStrBuildFilename (sysroot, cache_dir, uuid_cache_base, NULL);
    else
        uuid_hashed = FcStrBuildFilename (cache_dir, uuid_cache_base, NULL);
    if (uuid_hashed &&
        FcDirCacheProcessFile (config, uuid_hashed, callback, closure,
                               cache_file_ret, &latest_mtime, &dir_stat))
        ret = FcTrue;
      }
  }
#endif
    }
    FcStrListDone (list);

    if (closure)
  return !!(*((FcCache **)closure) != NULL);
    return ret;
}

#define FC_CACHE_MIN_MMAP 1024

/*
 * Skip list element, make sure the 'next' pointer is the last thing
 * in the structure, it will be allocated large enough to hold all
 * of the necessary pointers
 */

typedef struct _FcCacheSkip FcCacheSkip;

struct _FcCacheSkip {
    FcCache     *cache;
    FcRef        ref;
    intptr_t     size;
    void        *allocated;
    dev_t        cache_dev;
    ino_t        cache_ino;
    time_t       cache_mtime;
    long         cache_mtime_nano;
    FcCacheSkip *next[1];
};

/*
 * The head of the skip list; pointers for every possible level
 * in the skip list, plus the largest level in the list
 */

#define FC_CACHE_MAX_LEVEL 16

/* Protected by cache_lock below */
static FcCacheSkip *fcCacheChains[FC_CACHE_MAX_LEVEL];
static int          fcCacheMaxLevel;

static FcMutex *cache_lock;

static void
lock_cache (void)
{
    FcMutex *lock;
retry:
    lock = fc_atomic_ptr_get (&cache_lock);
    if (!lock) {
  lock = (FcMutex *)malloc (sizeof (FcMutex));
  FcMutexInit (lock);
  if (!fc_atomic_ptr_cmpexch (&cache_lock, NULL, lock)) {
      FcMutexFinish (lock);
      free (lock);
      goto retry;
  }

  FcMutexLock (lock);
  /* Initialize random state */
  FcRandom();
  return;
    }
    FcMutexLock (lock);
}

static void
unlock_cache (void)
{
    FcMutex *lock;
    lock = fc_atomic_ptr_get (&cache_lock);
    FcMutexUnlock (lock);
}

static void
free_lock (void)
{
    FcMutex *lock;
    lock = fc_atomic_ptr_get (&cache_lock);
    if (lock && fc_atomic_ptr_cmpexch (&cache_lock, lock, NULL)) {
  FcMutexFinish (lock);
  free (lock);
    }
}

/*
 * Generate a random level number, distributed
 * so that each level is 1/4 as likely as the one before
 *
 * Note that level numbers run 1 <= level <= MAX_LEVEL
 */
static int
random_level (void)
{
    /* tricky bit -- each bit is '1' 75% of the time */
    long int bits = FcRandom() | FcRandom();
    int      level = 0;

    while (++level < FC_CACHE_MAX_LEVEL) {
  if (bits & 1)
      break;
  bits >>= 1;
    }
    return level;
}

/*
 * Insert cache into the list
 */
static FcBool
FcCacheInsert (FcCache *cache, struct stat *cache_stat)
{
    FcCacheSkip **update[FC_CACHE_MAX_LEVEL];
    FcCacheSkip  *s, **next;
    int           i, level;

    lock_cache();

    /*
     * Find links along each chain
     */
    next = fcCacheChains;
    for (i = fcCacheMaxLevel; --i >= 0;) {
  for (; (s = next[i]); next = s->next)
      if (s->cache > cache)
    break;
  update[i] = &next[i];
    }

    /*
     * Create new list element
     */
    level = random_level();
    if (level > fcCacheMaxLevel) {
  level = fcCacheMaxLevel + 1;
  update[fcCacheMaxLevel] = &fcCacheChains[fcCacheMaxLevel];
  fcCacheMaxLevel = level;
    }

    s = malloc (sizeof (FcCacheSkip) + (level - 1) * sizeof (FcCacheSkip *));
    if (!s) {
  unlock_cache();
  return FcFalse;
    }

    s->cache = cache;
    s->size = cache->size;
    s->allocated = NULL;
    FcRefInit (&s->ref, 1);
    if (cache_stat) {
  s->cache_dev = cache_stat->st_dev;
  s->cache_ino = cache_stat->st_ino;
  s->cache_mtime = cache_stat->st_mtime;
#ifdef HAVE_STRUCT_STAT_ST_MTIM
  s->cache_mtime_nano = cache_stat->st_mtim.tv_nsec;
#else
  s->cache_mtime_nano = 0;
#endif
    } else {
  s->cache_dev = 0;
  s->cache_ino = 0;
  s->cache_mtime = 0;
  s->cache_mtime_nano = 0;
    }

    /*
     * Insert into all fcCacheChains
     */
    for (i = 0; i < level; i++) {
  s->next[i] = *update[i];
  *update[i] = s;
    }

    unlock_cache();
    return FcTrue;
}

static FcCacheSkip *
FcCacheFindByAddrUnlocked (void *object)
{
    int           i;
    FcCacheSkip **next = fcCacheChains;
    FcCacheSkip  *s;

    if (!object)
  return NULL;

    /*
     * Walk chain pointers one level at a time
     */
    for (i = fcCacheMaxLevel; --i >= 0;)
  while (next[i] && (char *)object >= ((char *)next[i]->cache + next[i]->size))
      next = next[i]->next;
    /*
     * Here we are
     */
    s = next[0];
    if (s && (char *)object < ((char *)s->cache + s->size))
  return s;
    return NULL;
}

static FcCacheSkip *
FcCacheFindByAddr (void *object)
{
    FcCacheSkip *ret;
    lock_cache();
    ret = FcCacheFindByAddrUnlocked (object);
    unlock_cache();
    return ret;
}

static void
FcCacheRemoveUnlocked (FcCache *cache)
{
    FcCacheSkip **update[FC_CACHE_MAX_LEVEL];
    FcCacheSkip  *s, **next;
    int           i;
    void         *allocated;

    /*
     * Find links along each chain
     */
    next = fcCacheChains;
    for (i = fcCacheMaxLevel; --i >= 0;) {
  for (; (s = next[i]); next = s->next)
      if (s->cache >= cache)
    break;
  update[i] = &next[i];
    }
    s = next[0];
    for (i = 0; i < fcCacheMaxLevel && *update[i] == s; i++)
  *update[i] = s->next[i];
    while (fcCacheMaxLevel > 0 && fcCacheChains[fcCacheMaxLevel - 1] == NULL)
  fcCacheMaxLevel--;

    if (s) {
  allocated = s->allocated;
  while (allocated) {
      /* First element in allocated chunk is the free list */
      next = *(void **)allocated;
      free (allocated);
      allocated = next;
  }
  free (s);
    }
}

static FcCache *
FcCacheFindByStat (struct stat *cache_stat)
{
    FcCacheSkip *s;

    lock_cache();
    for (s = fcCacheChains[0]; s; s = s->next[0])
  if (s->cache_dev == cache_stat->st_dev &&
      s->cache_ino == cache_stat->st_ino &&
      s->cache_mtime == cache_stat->st_mtime) {
#ifdef HAVE_STRUCT_STAT_ST_MTIM
      if (s->cache_mtime_nano != cache_stat->st_mtim.tv_nsec)
    continue;
#endif
      FcRefInc (&s->ref);
      unlock_cache();
      return s->cache;
  }
    unlock_cache();
    return NULL;
}

static void
FcDirCacheDisposeUnlocked (FcCache *cache)
{
    FcCacheRemoveUnlocked (cache);

    switch (cache->magic) {
    case FC_CACHE_MAGIC_ALLOC:
  free (cache);
  break;
    case FC_CACHE_MAGIC_MMAP:
#if defined(HAVE_MMAP) || defined(__CYGWIN__)
  munmap (cache, cache->size);
#elif defined(_WIN32)
  UnmapViewOfFile (cache);
#endif
  break;
    }
}

void
FcCacheObjectReference (void *object)
{
    FcCacheSkip *skip = FcCacheFindByAddr (object);

    if (skip)
  FcRefInc (&skip->ref);
}

void
FcCacheObjectDereference (void *object)
{
    FcCacheSkip *skip;

    lock_cache();
    skip = FcCacheFindByAddrUnlocked (object);
    if (skip) {
  if (FcRefDec (&skip->ref) == 1)
      FcDirCacheDisposeUnlocked (skip->cache);
    }
    unlock_cache();
}

void *
FcCacheAllocate (FcCache *cache, size_t len)
{
    FcCacheSkip *skip;
    void        *allocated = NULL;

    lock_cache();
    skip = FcCacheFindByAddrUnlocked (cache);
    if (skip) {
  void *chunk = malloc (sizeof (void *) + len);
  if (chunk) {
      /* First element in allocated chunk is the free list */
      *(void **)chunk = skip->allocated;
      skip->allocated = chunk;
      /* Return the rest */
      allocated = ((FcChar8 *)chunk) + sizeof (void *);
  }
    }
    unlock_cache();
    return allocated;
}

void
FcCacheFini (void)
{
    int    i;
    FcBool res = FcTrue;

    for (i = 0; i < FC_CACHE_MAX_LEVEL; i++) {
  if (fcCacheChains[i] != NULL) {
      res = FcFalse;
      if (FcDebug() & FC_DBG_CACHE) {
    FcCacheSkip *s = fcCacheChains[i];
    fprintf (stderr, "Fontconfig error: not freed %p (dir: %s, refcount %" FC_ATOMIC_INT_FORMAT ")\n", s->cache, FcCacheDir (s->cache), s->ref.count);
      }
  }
    }
    if (res)
  free_lock();
}

static FcBool
FcCacheIsNewVersion (FcConfig *config, FcCache *cache)
{
    int64_t       version = (FC_VERSION_MAJOR << 24) +
                            (FC_VERSION_MINOR << 12) +
                            FC_VERSION_MICRO;
    enum {
  CHECK_NOT_INITIALIZED = 0,
  CHECK_ENABLED,
  CHECK_DISABLED,
    } status;
    static void           *static_status;
    static fc_atomic_int_t warned = 0;

    /* To revert the behavior for some emergency. This will be removed in the future */
    status = (intptr_t)fc_atomic_ptr_get (&static_status);
    if (status == CHECK_NOT_INITIALIZED) {
  const char *env = getenv ("FONTCONFIG_NO_CHECK_CACHE_VERSION");
  FcBool      flag = FcFalse;

  if (env)
      FcNameBool ((const FcChar8 *)env, &flag);
  status = flag ? CHECK_DISABLED : CHECK_ENABLED;
  (void)fc_atomic_ptr_cmpexch (&static_status, NULL, (void *)(intptr_t)status);
    }
    if (status == CHECK_DISABLED)
  return FcFalse;
    /* The fc_version field does not exist before cache version 10; in an
     * older cache those bytes are payload and must not be interpreted.
     */
    if (cache->version < 10)
  return FcFalse;
    if (cache->fc_version > version && fc_atomic_int_add (warned, 1) == 0) {
  fprintf (stderr, "Fontconfig warning: We will not regenerate the cache because some cache files were generated by a newer version (0x%" PRIx64 ") of Fontconfig. Please regenerate the cache with the latest version of Fontconfig to avoid any unexpected behavior. (current version: 0x%" PRIx64 ")\n", cache->fc_version, version);
    }

    return cache->fc_version > version;
}

static int64_t FcDirMtime (struct stat *statb);
static int64_t FcCacheGetChecksum (FcCache *cache);

static FcBool
FcCacheTimeValid (FcConfig *config, FcCache *cache, struct stat *dir_stat)
{
    struct stat dir_static;
    FcBool      fnano = FcTrue;

    if (!dir_stat) {
  const FcChar8 *sysroot = FcConfigGetSysRoot (config);
  FcChar8       *d;

  if (sysroot)
      d = FcStrBuildFilename (sysroot, FcCacheDir (cache), NULL);
  else
      d = FcStrCopy (FcCacheDir (cache));
  if (FcStatChecksum (d, &dir_static) < 0) {
      FcStrFree (d);
      return FcFalse;
  }
  FcStrFree (d);
  dir_stat = &dir_static;
    }
#ifdef HAVE_STRUCT_STAT_ST_MTIM
    fnano = (cache->checksum_nano == dir_stat->st_mtim.tv_nsec);
    if (FcDebug() & FC_DBG_CACHE)
  printf ("FcCacheTimeValid dir \"%s\" cache checksum %" PRIi64 ".%ld dir checksum %" PRIi64 ".%ld\n",
          FcCacheDir (cache),
          FcCacheGetChecksum (cache),
          (long)cache->checksum_nano,
          (int64_t)dir_stat->st_mtime, dir_stat->st_mtim.tv_nsec);
#else
    if (FcDebug() & FC_DBG_CACHE)
  printf ("FcCacheTimeValid dir \"%s\" cache checksum %" PRIi64 " dir checksum %" PRIi64 "\n",
          FcCacheDir (cache),
          FcCacheGetChecksum (cache),
          (int64_t)dir_stat->st_mtime);
#endif
    {
  int64_t cache_mtime = FcCacheGetChecksum (cache);
  return dir_stat->st_mtime == 0 || (cache_mtime == (int64_t)dir_stat->st_mtime && fnano);
    }
}

static FcBool
FcCacheOffsetsValid (FcCache *cache)
{
    char      *base = (char *)cache;
    char      *end = base + cache->size;
    intptr_t  *dirs;
    FcFontSet *fs;
    int        i, j;

    if (cache->dir < 0 || cache->dir > cache->size - sizeof (intptr_t) ||
        memchr (base + cache->dir, '\0', cache->size - cache->dir) == NULL)
  return FcFalse;

    if (cache->dirs < 0 || cache->dirs >= cache->size ||
        cache->dirs_count < 0 ||
        cache->dirs_count > (cache->size - cache->dirs) / sizeof (intptr_t))
  return FcFalse;

    dirs = FcCacheDirs (cache);
    if (dirs) {
  for (i = 0; i < cache->dirs_count; i++) {
      FcChar8 *dir;

      if (dirs[i] < 0 ||
          dirs[i] > end - (char *)dirs - sizeof (intptr_t))
    return FcFalse;

      dir = FcOffsetToPtr (dirs, dirs[i], FcChar8);
      if (memchr (dir, '\0', end - (char *)dir) == NULL)
    return FcFalse;
  }
    }

    if (cache->set < 0 || cache->set > cache->size - sizeof (FcFontSet))
  return FcFalse;

    fs = FcCacheSet (cache);
    if (fs) {
  if (fs->nfont > (end - (char *)fs) / sizeof (FcPattern))
      return FcFalse;

  if (!FcIsEncodedOffset (fs->fonts))
      return FcFalse;

  for (i = 0; i < fs->nfont; i++) {
      FcPattern       *font = FcFontSetFont (fs, i);
      FcPatternElt    *e;
      FcValueListPtr   l;
      char            *last_offset;
      const FcLangSet *ls;
      const FcRange   *r;
      const FcChar8   *s;

      if ((char *)font < base ||
          (char *)font > end - sizeof (FcFontSet) ||
          font->elts_offset < 0 ||
          font->elts_offset > end - (char *)font ||
          font->num > (end - (char *)font - font->elts_offset) / sizeof (FcPatternElt) ||
          !FcRefIsConst (&font->ref))
    return FcFalse;

      e = FcPatternElts (font);
      if (e->values != 0 && !FcIsEncodedOffset (e->values))
    return FcFalse;

      for (j = 0; j < font->num; j++) {
    last_offset = (char *)font + font->elts_offset;
    for (l = FcPatternEltValues (&e[j]); l; l = FcValueListNext (l)) {
        if ((char *)l < last_offset || (char *)l > end - sizeof (*l) ||
            (l->next != NULL && !FcIsEncodedOffset (l->next)))
      return FcFalse;
        /* The checks below are driven by the type stored in the
         * value, whereas the users of a pattern pick the accessor
         * for a value by the object it belongs to. Reject values
         * whose type doesn't match the type registered for the
         * object, otherwise e.g. an integer stored for FC_FAMILY
         * would be accepted here without validating the union,
         * but dereferenced as a string later on.
         */
        if (!FcObjectValidType (e[j].object, l->value.type)) {
      if (FcDebug() & FC_DBG_CACHE) {
          fprintf (stderr, "Fontconfig warning: invalid cache: value of type %d doesn't match the type of object %d\n",
                   l->value.type, e[j].object);
      }
      return FcFalse;
        }
        switch (l->value.type) {
        case FcTypeVoid:
        case FcTypeInteger:
        case FcTypeDouble:
        case FcTypeBool:
        case FcTypeMatrix:
        case FcTypeFTFace:
      break; /* nop */
        case FcTypeString:
      s = FcValueString (&l->value);
      if ((intptr_t)s < (intptr_t)&e[j] ||
          (intptr_t)&l->value > (intptr_t)end - sizeof (*l) ||
          !FcIsEncodedOffset (l->value.u.s)) {
          if (FcDebug() & FC_DBG_CACHE) {
        fprintf (stderr, "Fontconfig warning: invalid cache: broken string pointer\n");
          }
          return FcFalse;
      }
      break;
        case FcTypeCharSet:
      /* FcCharSet might be re-used by FcCharSetFindFrozen
       * which would means a pointer might be out of Elts
       */
      if ((intptr_t)&l->value > (intptr_t)end - sizeof (*l) ||
          !FcIsEncodedOffset (l->value.u.c)) {
          if (FcDebug() & FC_DBG_CACHE) {
        fprintf (stderr, "Fontconfig warning: invalid cache: broken charset\n");
          }
          return FcFalse;
      }
      {
          const FcCharSet *cs = FcValueCharSet (&l->value);
          intptr_t *leaves;
          int k;

          if ((char *)cs < base || (char *)cs > end - sizeof (FcCharSet) ||
              !FcRefIsConst (&cs->ref)) {
        if (FcDebug() & FC_DBG_CACHE) {
            fprintf (stderr, "Fontconfig warning: invalid cache: non-constant or out-of-bounds charset\n");
        }
        return FcFalse;
          }
          if (cs->num < 0)
        return FcFalse;
          if (cs->num > 0) {
        if (cs->leaves_offset < 0 ||
            cs->leaves_offset > end - (char *)cs ||
            cs->num > (end - (char *)cs - cs->leaves_offset) / sizeof (intptr_t)) {
            if (FcDebug() & FC_DBG_CACHE) {
          fprintf (stderr, "Fontconfig warning: invalid cache: broken charset leaves offset\n");
            }
            return FcFalse;
        }
        if (cs->numbers_offset < 0 ||
            cs->numbers_offset > end - (char *)cs ||
            cs->num > (end - (char *)cs - cs->numbers_offset) / sizeof (FcChar16)) {
            if (FcDebug() & FC_DBG_CACHE) {
          fprintf (stderr, "Fontconfig warning: invalid cache: broken charset numbers offset\n");
            }
            return FcFalse;
        }
        leaves = FcCharSetLeaves (cs);
        for (k = 0; k < cs->num; k++) {
            if (leaves[k] < -((char *)leaves - base) ||
                leaves[k] > end - (char *)leaves - (ptrdiff_t) sizeof (FcCharLeaf)) {
          if (FcDebug() & FC_DBG_CACHE) {
              fprintf (stderr, "Fontconfig warning: invalid cache: broken charset leaf offset\n");
          }
          return FcFalse;
            }
        }
          }
      }
      break;
        case FcTypeLangSet:
      ls = FcValueLangSet (&l->value);
      if ((intptr_t)ls < (intptr_t)&e[j] ||
          (intptr_t)&l->value > (intptr_t)end - sizeof (*l) ||
          !FcIsEncodedOffset (l->value.u.l)) {
          if (FcDebug() & FC_DBG_CACHE) {
        fprintf (stderr, "Fontconfig warning: invalid cache: broken langset\n");
          }
          return FcFalse;
      }
      /* ls->extra isn't serialized. it must be null */
      if (ls->extra != NULL) {
          if (FcDebug() & FC_DBG_CACHE) {
        fprintf (stderr, "Fontconfig warning: invalid cache: broken langset\n");
          }
          return FcFalse;
      }
      break;
        case FcTypeRange:
      r = FcValueRange (&l->value);
      if ((intptr_t)r < (intptr_t)&e[j] ||
          (intptr_t)&l->value > (intptr_t)end - sizeof (*l) ||
          !FcIsEncodedOffset (l->value.u.r)) {
          if (FcDebug() & FC_DBG_CACHE) {
        fprintf (stderr, "Fontconfig warning: invalid cache: broken range\n");
          }
          return FcFalse;
      }
      break;
        default:
      /* just ignore unknown object type for upper-compatible in the future */
      if (FcDebug() & FC_DBG_CACHEV) {
          fprintf (stderr, "Fontconfig warning: invalid cache: unknown object type in pattern: %d\n", l->value.type);
      }
      break;
        }
        last_offset = (char *)l + 1;
    }
      }
  }
    }

    return FcTrue;
}

/*
 * Map a cache file into memory
 */
static FcCache *
FcDirCacheMapFd (FcConfig *config, int fd, struct stat *fd_stat, struct stat *dir_stat)
{
    FcCache *cache;
    FcBool   allocated = FcFalse;

    if (fd_stat->st_size > INTPTR_MAX ||
        fd_stat->st_size < (int)sizeof (FcCache))
  return NULL;
    cache = FcCacheFindByStat (fd_stat);
    if (cache) {
  if (FcCacheTimeValid (config, cache, dir_stat))
      return cache;
  else if (FcCacheIsNewVersion (config, cache)) {
      /* Re-use if cache was generated by newer version of fontconfig
       * Do not trigger regenerating
       */
      return cache;
  }
  FcDirCacheUnload (cache);
  cache = NULL;
    }

    /*
     * Large cache files are mmap'ed, smaller cache files are read. This
     * balances the system cost of mmap against per-process memory usage.
     */
    if (FcCacheIsMmapSafe (fd) && fd_stat->st_size >= FC_CACHE_MIN_MMAP) {
#if defined(HAVE_MMAP) || defined(__CYGWIN__)
  cache = mmap (0, fd_stat->st_size, PROT_READ, MAP_SHARED, fd, 0);
#  if defined(HAVE_POSIX_FADVISE) && defined(POSIX_FADV_WILLNEED)
  posix_fadvise (fd, 0, fd_stat->st_size, POSIX_FADV_WILLNEED);
#  endif
  if (cache == MAP_FAILED)
      cache = NULL;
#elif defined(_WIN32)
  {
      HANDLE hFileMap;

      cache = NULL;
      hFileMap = CreateFileMapping ((HANDLE)_get_osfhandle (fd), NULL,
                                    PAGE_READONLY, 0, 0, NULL);
      if (hFileMap != NULL) {
    cache = MapViewOfFile (hFileMap, FILE_MAP_READ, 0, 0,
                           fd_stat->st_size);
    CloseHandle (hFileMap);
      }
  }
#endif
    }
    if (!cache) {
  cache = malloc (fd_stat->st_size);
  if (!cache)
      return NULL;

  if (read (fd, cache, fd_stat->st_size) != fd_stat->st_size) {
      free (cache);
      return NULL;
  }
  allocated = FcTrue;
    }
    if (cache->magic != FC_CACHE_MAGIC_MMAP ||
        cache->version < FC_CACHE_MIN_COMPAT_VERSION ||
        cache->size != (intptr_t)fd_stat->st_size ||
        !FcCacheOffsetsValid (cache) ||
        (!FcCacheTimeValid (config, cache, dir_stat) &&
         !FcCacheIsNewVersion (config, cache)) ||
        !FcCacheInsert (cache, fd_stat)) {
  if (allocated)
      free (cache);
  else {
#if defined(HAVE_MMAP) || defined(__CYGWIN__)
      munmap (cache, fd_stat->st_size);
#elif defined(_WIN32)
      UnmapViewOfFile (cache);
#endif
  }
  return NULL;
    }

    /* Mark allocated caches so they're freed rather than unmapped */
    if (allocated)
  cache->magic = FC_CACHE_MAGIC_ALLOC;

    return cache;
}

void
FcDirCacheReference (FcCache *cache, int nref)
{
    FcCacheSkip *skip = FcCacheFindByAddr (cache);

    if (skip)
  FcRefAdd (&skip->ref, nref);
}

void
FcDirCacheUnload (FcCache *cache)
{
    FcCacheObjectDereference (cache);
}

static FcBool
FcDirCacheMapHelper (FcConfig *config, int fd, struct stat *fd_stat, struct stat *dir_stat, struct timeval *latest_cache_mtime, void *closure)
{
    FcCache       *cache = FcDirCacheMapFd (config, fd, fd_stat, dir_stat);
    struct timeval cache_mtime, zero_mtime = { 0, 0 }, dir_mtime;

    if (!cache)
  return FcFalse;
    cache_mtime.tv_sec = fd_stat->st_mtime;
    dir_mtime.tv_sec = dir_stat->st_mtime;
#ifdef HAVE_STRUCT_STAT_ST_MTIM
    cache_mtime.tv_usec = fd_stat->st_mtim.tv_nsec / 1000;
    dir_mtime.tv_usec = dir_stat->st_mtim.tv_nsec / 1000;
#else
    cache_mtime.tv_usec = 0;
    dir_mtime.tv_usec = 0;
#endif
    /* special take care of OSTree */
    if (!timercmp (&zero_mtime, &dir_mtime, !=)) {
  if (!timercmp (&zero_mtime, &cache_mtime, !=)) {
      if (*((FcCache **)closure))
    FcDirCacheUnload (*((FcCache **)closure));
  } else if (*((FcCache **)closure) && !timercmp (&zero_mtime, latest_cache_mtime, !=)) {
      FcDirCacheUnload (cache);
      return FcFalse;
  } else if (timercmp (latest_cache_mtime, &cache_mtime, <)) {
      if (*((FcCache **)closure))
    FcDirCacheUnload (*((FcCache **)closure));
  }
    } else if (timercmp (latest_cache_mtime, &cache_mtime, <)) {
  if (*((FcCache **)closure))
      FcDirCacheUnload (*((FcCache **)closure));
    } else {
  FcDirCacheUnload (cache);
  return FcFalse;
    }
    latest_cache_mtime->tv_sec = cache_mtime.tv_sec;
    latest_cache_mtime->tv_usec = cache_mtime.tv_usec;
    *((FcCache **)closure) = cache;
    return FcTrue;
}

FcCache *
FcDirCacheLoad (const FcChar8 *dir, FcConfig *config, FcChar8 **cache_file)
{
    FcCache *cache = NULL;

    config = FcConfigReference (config);
    if (!config)
  return NULL;
    if (!FcDirCacheProcess (config, dir,
                            FcDirCacheMapHelper,
                            &cache, cache_file))
  cache = NULL;

    FcConfigDestroy (config);

    return cache;
}

FcCache *
FcDirCacheLoadFile (const FcChar8 *cache_file, struct stat *file_stat)
{
    int         fd;
    FcCache    *cache = NULL;
    struct stat my_file_stat;
    FcConfig   *config;

    if (!file_stat)
  file_stat = &my_file_stat;
    config = FcConfigReference (NULL);
    if (!config)
  return NULL;
    fd = FcDirCacheOpenFile (cache_file, file_stat);
    if (fd >= 0) {
  cache = FcDirCacheMapFd (config, fd, file_stat, NULL);
  close (fd);
    }
    FcConfigDestroy (config);

    return cache;
}

static int64_t
FcDirMtime (struct stat *statb)
{
    int64_t   ret = (int64_t)statb->st_mtime;
    char     *endptr;
    char     *source_date_epoch;
    uintmax_t epoch;

    source_date_epoch = getenv ("SOURCE_DATE_EPOCH");
    if (source_date_epoch) {
  errno = 0;
  epoch = strtoumax (source_date_epoch, &endptr, 10);

  if (endptr == source_date_epoch)
      fprintf (stderr,
               "Fontconfig: SOURCE_DATE_EPOCH invalid\n");
  else if ((errno == ERANGE && (epoch == UINTMAX_MAX || epoch == 0)) || (errno != 0 && epoch == 0))
      fprintf (stderr,
               "Fontconfig: SOURCE_DATE_EPOCH: strtoumax: %s: %" PRIuMAX "\n",
               strerror (errno), epoch);
  else if (*endptr != '\0')
      fprintf (stderr,
               "Fontconfig: SOURCE_DATE_EPOCH has trailing garbage\n");
  else if (epoch > INT64_MAX)
      fprintf (stderr,
               "Fontconfig: SOURCE_DATE_EPOCH must be <= %" PRIi64 " but saw: %" PRIuMAX "\n",
               INT64_MAX, epoch);
  else if ((int64_t)epoch < ret) {
      /* Only override if directory is newer */
      ret = (int64_t)epoch;
  }
    }

    return ret;
}

static uint32_t
FcDirChecksum (struct stat *statb)
{
    return (uint32_t)(FcDirMtime (statb) & 0xFFFFFFFF);
}

static uint32_t
FcDirChecksumHigh (struct stat *statb)
{
    return (uint32_t)(FcDirMtime (statb) >> 32);
}

static int64_t
FcCacheGetChecksum (FcCache *cache)
{
    return ((int64_t)cache->checksum_hi << 32) | cache->checksum;
}

static int64_t
FcDirChecksumNano (struct stat *statb)
{
#ifdef HAVE_STRUCT_STAT_ST_MTIM
    /* No nanosecond component to parse */
    if (getenv ("SOURCE_DATE_EPOCH"))
  return 0;
    return statb->st_mtim.tv_nsec;
#else
    return 0;
#endif
}

/*
 * Validate a cache file by reading the header and checking
 * the magic number and the size field
 */
static FcBool
FcDirCacheValidateHelper (FcConfig *config, int fd, struct stat *fd_stat, struct stat *dir_stat, struct timeval *latest_cache_mtime, void *closure FC_UNUSED)
{
    FcBool  ret = FcTrue;
    FcCache c;

    if (read (fd, &c, sizeof (FcCache)) != sizeof (FcCache))
  ret = FcFalse;
    else if (c.magic != FC_CACHE_MAGIC_MMAP)
  ret = FcFalse;
    else if (c.version < FC_CACHE_MIN_COMPAT_VERSION)
  ret = FcFalse;
    else if (fd_stat->st_size != c.size)
  ret = FcFalse;
    else if (FcCacheGetChecksum (&c) != FcDirMtime (dir_stat))
  ret = FcFalse;
#ifdef HAVE_STRUCT_STAT_ST_MTIM
    else if (c.checksum_nano != FcDirChecksumNano (dir_stat))
  ret = FcFalse;
#endif
    return ret;
}

static FcBool
FcDirCacheValidConfig (const FcChar8 *dir, FcConfig *config)
{
    return FcDirCacheProcess (config, dir,
                              FcDirCacheValidateHelper,
                              NULL, NULL);
}

FcBool
FcDirCacheValid (const FcChar8 *dir)
{
    FcConfig *config;
    FcBool    ret;

    config = FcConfigReference (NULL);
    if (!config)
  return FcFalse;

    ret = FcDirCacheValidConfig (dir, config);
    FcConfigDestroy (config);

    return ret;
}

/*
 * Build a cache structure from the given contents
 */
FcCache *
FcDirCacheBuild (FcFontSet *set, const FcChar8 *dir, struct stat *dir_stat, FcStrSet *dirs)
{
    FcSerialize *serialize = FcSerializeCreate();
    FcCache     *cache;
    int          i;
    FcChar8     *dir_serialize;
    intptr_t    *dirs_serialize;
    FcFontSet   *set_serialize;

    if (!serialize)
  return NULL;
    /*
     * Space for cache structure
     */
    FcSerializeReserve (serialize, sizeof (FcCache));
    /*
     * Directory name
     */
    if (!FcStrSerializeAlloc (serialize, dir))
  goto bail1;
    /*
     * Subdirs
     */
    FcSerializeAlloc (serialize, dirs, dirs->num * sizeof (FcChar8 *));
    for (i = 0; i < dirs->num; i++)
  if (!FcStrSerializeAlloc (serialize, dirs->strs[i]))
      goto bail1;

    /*
     * Patterns
     */
    if (!FcFontSetSerializeAlloc (serialize, set))
  goto bail1;

    /* Serialize layout complete. Now allocate space and fill it */
    cache = malloc (serialize->size);
    if (!cache)
  goto bail1;
    /* shut up valgrind */
    memset (cache, 0, serialize->size);

    serialize->linear = cache;

    cache->magic = FC_CACHE_MAGIC_ALLOC;
    cache->version = FC_CACHE_VERSION_NUMBER;
    cache->size = serialize->size;
    cache->checksum = FcDirChecksum (dir_stat);
    cache->checksum_hi = FcDirChecksumHigh (dir_stat);
    cache->checksum_nano = FcDirChecksumNano (dir_stat);
    cache->fc_version = (FC_VERSION_MAJOR << 24) +
                        (FC_VERSION_MINOR << 12) +
                        FC_VERSION_MICRO;

    /*
     * Serialize directory name
     */
    dir_serialize = FcStrSerialize (serialize, dir);
    if (!dir_serialize)
  goto bail2;
    cache->dir = FcPtrToOffset (cache, dir_serialize);

    /*
     * Serialize sub dirs
     */
    dirs_serialize = FcSerializePtr (serialize, dirs);
    if (!dirs_serialize)
  goto bail2;
    cache->dirs = FcPtrToOffset (cache, dirs_serialize);
    cache->dirs_count = dirs->num;
    for (i = 0; i < dirs->num; i++) {
  FcChar8 *d_serialize = FcStrSerialize (serialize, dirs->strs[i]);
  if (!d_serialize)
      goto bail2;
  dirs_serialize[i] = FcPtrToOffset (dirs_serialize, d_serialize);
    }

    /*
     * Serialize font set
     */
    set_serialize = FcFontSetSerialize (serialize, set);
    if (!set_serialize)
  goto bail2;
    cache->set = FcPtrToOffset (cache, set_serialize);

    FcSerializeDestroy (serialize);

    FcCacheInsert (cache, NULL);

    return cache;

bail2:
    free (cache);
bail1:
    FcSerializeDestroy (serialize);
    return NULL;
}

FcCache *
FcDirCacheRebuild (FcCache *cache, struct stat *dir_stat, FcStrSet *dirs)
{
    FcCache       *newp;
    FcFontSet     *set = FcFontSetDeserialize (FcCacheSet (cache));
    const FcChar8 *dir = FcCacheDir (cache);

    newp = FcDirCacheBuild (set, dir, dir_stat, dirs);
    FcFontSetDestroy (set);

    return newp;
}

/* write serialized state to the cache file */
FcBool
FcDirCacheWrite (FcCache *cache, FcConfig *config)
{
    FcChar8       *dir = FcCacheDir (cache);
    FcChar8        cache_base[CACHEBASE_LEN];
    FcChar8       *cache_hashed;
    int            fd;
    FcAtomic      *atomic;
    FcStrList     *list;
    FcChar8       *cache_dir = NULL;
    FcChar8       *test_dir, *d = NULL;
    FcCacheSkip   *skip;
    struct stat    cache_stat;
    unsigned int   magic;
    int            written;
    const FcChar8 *sysroot = FcConfigGetSysRoot (config);
    FcStrSet      *cpath;

    /*
     * Write it to the first directory in the list which is writable
     */

    cpath = FcStrSetCreateEx (FCSS_GROW_BY_64);
    if (!cpath)
  return FcFalse;
    list = FcStrListCreate (config->cacheDirs);
    if (!list) {
  FcStrSetDestroy (cpath);
  return FcFalse;
    }
    while ((test_dir = FcStrListNext (list))) {
  if (d)
      FcStrFree (d);
  if (sysroot)
      d = FcStrBuildFilename (sysroot, test_dir, NULL);
  else
      d = FcStrCopyFilename (test_dir);

  if (access ((char *)d, W_OK) == 0) {
      cache_dir = FcStrCopyFilename (d);
      break;
  } else {
      /*
       * If the directory doesn't exist, try to create it
       */
      if (access ((char *)d, F_OK) == -1) {
    if (FcMakeDirectory (d)) {
        cache_dir = FcStrCopyFilename (d);
        /* Create CACHEDIR.TAG */
        FcDirCacheCreateTagFile (d);
        break;
    }
      }
      /*
       * Otherwise, try making it writable
       */
      else if (chmod ((char *)d, 0755) == 0) {
    cache_dir = FcStrCopyFilename (d);
    /* Try to create CACHEDIR.TAG too */
    FcDirCacheCreateTagFile (d);
    break;
      }
      /* Record a path that was supposed to be a cache directory */
      FcStrSetAdd (cpath, d);
  }
    }
    if (!test_dir) {
  FcStrList *l;
  FcChar8   *s;

  l = FcStrListCreate (cpath);
  fprintf (stderr, "\nFontconfig error: No writable cache directories\n");
  while ((s = FcStrListNext (l))) {
      fprintf (stderr, "\t%s\n", s);
  }
  FcStrListDone (l);
    }
    if (d)
  FcStrFree (d);
    FcStrSetDestroy (cpath);
    FcStrListDone (list);
    if (!cache_dir)
  return FcFalse;

    if (!FcDirCacheBasenameMD5 (config, dir, cache_base)) {
  FcStrFree (cache_dir);
  return FcFalse;
    }
    cache_hashed = FcStrBuildFilename (cache_dir, cache_base, NULL);
    if (!cache_hashed) {
  FcStrFree (cache_dir);
  return FcFalse;
    }

    if (FcDebug() & FC_DBG_CACHE)
  printf ("FcDirCacheWriteDir dir \"%s\" file \"%s\"\n",
          dir, cache_hashed);

    atomic = FcAtomicCreate ((FcChar8 *)cache_hashed);
    if (!atomic)
  goto bail1;

    if (!FcAtomicLock (atomic))
  goto bail3;

    fd = FcOpen ((char *)FcAtomicNewFile (atomic), O_RDWR | O_CREAT | O_BINARY, 0666);
    if (fd == -1)
  goto bail4;

    /* Temporarily switch magic to MMAP while writing to file */
    magic = cache->magic;
    if (magic != FC_CACHE_MAGIC_MMAP)
  cache->magic = FC_CACHE_MAGIC_MMAP;

    /*
     * Write cache contents to file
     */
    written = write (fd, cache, cache->size);

    /* Switch magic back */
    if (magic != FC_CACHE_MAGIC_MMAP)
  cache->magic = magic;

    if (written != cache->size) {
  perror ("write cache");
  goto bail5;
    }

    close (fd);
    if (!FcAtomicReplaceOrig (atomic))
  goto bail4;

    /* If the file is small, update the cache chain entry such that the
     * new cache file is not read again.  If it's large, we don't do that
     * such that we reload it, using mmap, which is shared across processes.
     */
    if (cache->size < FC_CACHE_MIN_MMAP && FcStat (cache_hashed, &cache_stat)) {
  lock_cache();
  if ((skip = FcCacheFindByAddrUnlocked (cache))) {
      skip->cache_dev = cache_stat.st_dev;
      skip->cache_ino = cache_stat.st_ino;
      skip->cache_mtime = cache_stat.st_mtime;
#ifdef HAVE_STRUCT_STAT_ST_MTIM
      skip->cache_mtime_nano = cache_stat.st_mtim.tv_nsec;
#else
      skip->cache_mtime_nano = 0;
#endif
  }
  unlock_cache();
    }

#ifdef HAVE_SYMLINK
    if (FC_CACHE_MIN_COMPAT_VERSION < FC_CACHE_VERSION_NUMBER) {
  int v;

  for (v = FC_CACHE_MIN_COMPAT_VERSION; v < FC_CACHE_VERSION_NUMBER; v++) {
      FcChar8  compat_base[CACHEBASE_LEN];
      FcChar8 *compat_path;
      int      compat_fd;

      if (!FcDirCacheReplaceVersion (cache_base, compat_base, v))
    continue;
      compat_path = FcStrBuildFilename (cache_dir, compat_base, NULL);
      if (!compat_path)
    continue;
      /*
       * Only (re)create the compat link when it is missing or stale.
       * A compat file that already represents the same directory state
       * as the cache we just wrote -- whether it is our own symlink or
       * a real cache file written by another fontconfig -- must be left
       * alone.  Otherwise a newer library embedded in an application
       * (e.g. a browser) would clobber the host's valid cache whenever
       * it writes its own, which is what triggered the cache-9/12
       * breakage.  We compare against the just-written cache's own
       * checksum, which already encodes the current directory state, so
       * matching checksums mean the compat file is up to date.
       */
      compat_fd = FcOpen ((char *)compat_path, O_RDONLY | O_BINARY);
      if (compat_fd >= 0) {
    FcCache c;
    FcBool  up_to_date;

    up_to_date = (read (compat_fd, &c, sizeof (c)) == sizeof (c) &&
                  c.magic == FC_CACHE_MAGIC_MMAP &&
                  c.version >= FC_CACHE_MIN_COMPAT_VERSION &&
                  FcCacheGetChecksum (&c) == FcCacheGetChecksum (cache) &&
                  c.checksum_nano == cache->checksum_nano);
    close (compat_fd);
    if (up_to_date) {
        FcStrFree (compat_path);
        continue;
    }
      }
      (void)unlink ((char *)compat_path);
      if (symlink ((char *)cache_base, (char *)compat_path) < 0) {
    if (FcDebug() & FC_DBG_CACHE)
        printf ("FcDirCacheWrite: symlink %s -> %s failed\n",
                compat_path, cache_base);
      }
      FcStrFree (compat_path);
  }
    }
#endif

    FcStrFree (cache_dir);
    FcStrFree (cache_hashed);
    FcAtomicUnlock (atomic);
    FcAtomicDestroy (atomic);
    return FcTrue;

bail5:
    close (fd);
bail4:
    FcAtomicUnlock (atomic);
bail3:
    FcAtomicDestroy (atomic);
bail1:
    FcStrFree (cache_dir);
    FcStrFree (cache_hashed);
    return FcFalse;
}

static int
FcCacheFileVersion (const char *name)
{
    const char *arch_suffix = "-" FC_ARCHITECTURE ".cache-";
    size_t      arch_suffix_len = strlen (arch_suffix);
    const char *version_str;
    char       *end;
    long        version;

    if (strlen (name) < 32 + arch_suffix_len + 1)
  return -1;
    if (strncmp (name + 32, arch_suffix, arch_suffix_len) != 0)
  return -1;
    version_str = name + 32 + arch_suffix_len;
    version = strtol (version_str, &end, 10);
    if (*end != '\0' || version <= 0)
  return -1;
    return (int)version;
}

FcBool
FcDirCacheClean (const FcChar8 *cache_dir, FcBool verbose)
{
    DIR           *d;
    struct dirent *ent;
    FcChar8       *dir;
    FcBool         ret = FcTrue;
    FcBool         remove;
    FcCache       *cache;
    struct stat    target_stat;
    const FcChar8 *sysroot;
    FcConfig      *config;

    config = FcConfigReference (NULL);
    if (!config)
  return FcFalse;
    /* FIXME: this API needs to support non-current FcConfig */
    sysroot = FcConfigGetSysRoot (config);
    if (sysroot)
  dir = FcStrBuildFilename (sysroot, cache_dir, NULL);
    else
  dir = FcStrCopyFilename (cache_dir);
    if (!dir) {
  fprintf (stderr, "Fontconfig error: %s: out of memory\n", cache_dir);
  ret = FcFalse;
  goto bail;
    }
    if (access ((char *)dir, W_OK) != 0) {
  if (verbose || FcDebug() & FC_DBG_CACHE)
      printf ("%s: not cleaning %s cache directory\n", dir,
              access ((char *)dir, F_OK) == 0 ? "unwritable" : "non-existent");
  goto bail0;
    }
    if (verbose || FcDebug() & FC_DBG_CACHE)
  printf ("%s: cleaning cache directory\n", dir);
    d = opendir ((char *)dir);
    if (!d) {
  perror ((char *)dir);
  ret = FcFalse;
  goto bail0;
    }
    while ((ent = readdir (d))) {
  FcChar8       *file_name;
  const FcChar8 *target_dir;
  int            file_version;

  if (ent->d_name[0] == '.')
      continue;
  file_version = FcCacheFileVersion (ent->d_name);
  if (file_version < FC_CACHE_MIN_COMPAT_VERSION ||
      file_version > FC_CACHE_VERSION_NUMBER)
      continue;

  file_name = FcStrBuildFilename (dir, (FcChar8 *)ent->d_name, NULL);
  if (!file_name) {
      fprintf (stderr, "Fontconfig error: %s: allocation failure\n", dir);
      ret = FcFalse;
      break;
  }
  remove = FcFalse;
  cache = FcDirCacheLoadFile (file_name, NULL);
  if (!cache) {
      if (verbose || FcDebug() & FC_DBG_CACHE)
    printf ("%s: invalid cache file: %s\n", dir, ent->d_name);
      remove = FcTrue;
  } else {
      FcChar8 *s;

      target_dir = FcCacheDir (cache);
      if (sysroot)
    s = FcStrBuildFilename (sysroot, target_dir, NULL);
      else
    s = FcStrCopy (target_dir);
      if (!s) {
    fprintf (stderr, "Fontconfig error: %s: allocation failure\n", dir);
    ret = FcFalse;
    FcDirCacheUnload (cache);
    FcStrFree (file_name);
    break;
      }
      if (stat ((char *)s, &target_stat) < 0) {
    if (verbose || FcDebug() & FC_DBG_CACHE)
        printf ("%s: %s: missing directory: %s \n",
                dir, ent->d_name, s);
    remove = FcTrue;
      }
      FcDirCacheUnload (cache);
      FcStrFree (s);
  }
  if (remove) {
      if (unlink ((char *)file_name) < 0) {
    perror ((char *)file_name);
    ret = FcFalse;
      }
  }
  FcStrFree (file_name);
    }

    closedir (d);
bail0:
    FcStrFree (dir);
bail:
    FcConfigDestroy (config);

    return ret;
}

int
FcDirCacheLock (const FcChar8 *dir,
                FcConfig      *config)
{
    FcChar8       *cache_hashed = NULL;
    FcChar8        cache_base[CACHEBASE_LEN];
    FcStrList     *list;
    FcChar8       *cache_dir;
    const FcChar8 *sysroot = FcConfigGetSysRoot (config);
    int            fd = -1;

    if (!FcDirCacheBasenameMD5 (config, dir, cache_base))
  return -1;
    list = FcStrListCreate (config->cacheDirs);
    if (!list)
  return -1;

    while ((cache_dir = FcStrListNext (list))) {
  if (sysroot)
      cache_hashed = FcStrBuildFilename (sysroot, cache_dir, cache_base, NULL);
  else
      cache_hashed = FcStrBuildFilename (cache_dir, cache_base, NULL);
  if (!cache_hashed)
      break;
  fd = FcOpen ((const char *)cache_hashed, O_RDWR);
  FcStrFree (cache_hashed);
  /* No caches in that directory. simply retry with another one */
  if (fd != -1) {
#if defined(_WIN32)
      if (_locking (fd, _LK_LOCK, 1) == -1)
    goto bail;
#else
      struct flock fl;

      fl.l_type = F_WRLCK;
      fl.l_whence = SEEK_SET;
      fl.l_start = 0;
      fl.l_len = 0;
      fl.l_pid = getpid();
      if (fcntl (fd, F_SETLKW, &fl) == -1)
    goto bail;
#endif
      break;
  }
    }
    FcStrListDone (list);
    return fd;
bail:
    FcStrListDone (list);
    if (fd != -1)
  close (fd);
    return -1;
}

void
FcDirCacheUnlock (int fd)
{
    if (fd != -1) {
#if defined(_WIN32)
  _locking (fd, _LK_UNLCK, 1);
#else
  struct flock fl;

  fl.l_type = F_UNLCK;
  fl.l_whence = SEEK_SET;
  fl.l_start = 0;
  fl.l_len = 0;
  fl.l_pid = getpid();
  fcntl (fd, F_SETLK, &fl);
#endif
  close (fd);
    }
}

/*
 * Hokey little macro trick to permit the definitions of C functions
 * with the same name as CPP macros
 */
#define args1(x)    (x)
#define args2(x, y) (x, y)

const FcChar8 *
FcCacheDir args1 (const FcCache *c)
{
    return FcCacheDir (c);
}

FcFontSet *
FcCacheCopySet args1 (const FcCache *c)
{
    FcFontSet *old = FcCacheSet (c);
    FcFontSet *newp = FcFontSetCreate();
    int        i;

    if (!newp)
  return NULL;
    for (i = 0; i < old->nfont; i++) {
  FcPattern *font = FcFontSetFont (old, i);

  FcPatternReference (font);
  if (!FcFontSetAdd (newp, font)) {
      FcFontSetDestroy (newp);
      return NULL;
  }
    }
    return newp;
}

const FcChar8 *
FcCacheSubdir args2 (const FcCache *c, int i)
{
    return FcCacheSubdir (c, i);
}

int
FcCacheNumSubdir args1 (const FcCache *c)
{
    return c->dirs_count;
}

int
FcCacheNumFont args1 (const FcCache *c)
{
    return FcCacheSet (c)->nfont;
}

FcBool
FcDirCacheCreateTagFile (const FcChar8 *cache_dir)
{
    FcChar8             *cache_tag;
    int                  fd;
    FILE                *fp;
    FcAtomic            *atomic;
    static const FcChar8 cache_tag_contents[] =
  "Signature: 8a477f597d28d172789f06886806bc55\n"
  "# This file is a cache directory tag created by fontconfig.\n"
  "# For information about cache directory tags, see:\n"
  "#       http://www.brynosaurus.com/cachedir/\n";
    static size_t cache_tag_contents_size = sizeof (cache_tag_contents) - 1;
    FcBool        ret = FcFalse;

    if (!cache_dir)
  return FcFalse;

    if (access ((char *)cache_dir, W_OK) == 0) {
  /* Create CACHEDIR.TAG */
  cache_tag = FcStrBuildFilename (cache_dir, "CACHEDIR.TAG", NULL);
  if (!cache_tag)
      return FcFalse;
  atomic = FcAtomicCreate ((FcChar8 *)cache_tag);
  if (!atomic)
      goto bail1;
  if (!FcAtomicLock (atomic))
      goto bail2;
  fd = FcOpen ((char *)FcAtomicNewFile (atomic), O_RDWR | O_CREAT, 0644);
  if (fd == -1)
      goto bail3;
  fp = fdopen (fd, "wb");
  if (fp == NULL)
      goto bail3;

  fwrite (cache_tag_contents, cache_tag_contents_size, sizeof (FcChar8), fp);
  fclose (fp);

  if (!FcAtomicReplaceOrig (atomic))
      goto bail3;

  ret = FcTrue;
    bail3:
  FcAtomicUnlock (atomic);
    bail2:
  FcAtomicDestroy (atomic);
    bail1:
  FcStrFree (cache_tag);
    }

    if (FcDebug() & FC_DBG_CACHE) {
  if (ret)
      printf ("Created CACHEDIR.TAG at %s\n", cache_dir);
  else
      printf ("Unable to create CACHEDIR.TAG at %s\n", cache_dir);
    }

    return ret;
}

void
FcCacheCreateTagFile (FcConfig *config)
{
    FcChar8       *cache_dir = NULL, *d = NULL;
    FcStrList     *list;
    const FcChar8 *sysroot;

    config = FcConfigReference (config);
    if (!config)
  return;
    sysroot = FcConfigGetSysRoot (config);

    list = FcConfigGetCacheDirs (config);
    if (!list)
  goto bail;

    while ((cache_dir = FcStrListNext (list))) {
  if (d)
      FcStrFree (d);
  if (sysroot)
      d = FcStrBuildFilename (sysroot, cache_dir, NULL);
  else
      d = FcStrCopyFilename (cache_dir);
  if (FcDirCacheCreateTagFile (d))
      break;
    }
    if (d)
  FcStrFree (d);
    FcStrListDone (list);
bail:
    FcConfigDestroy (config);
}

#define __fccache__
#include "fcaliastail.h"
#undef __fccache__

Coverage Report

Created: 2026-10-28 07:09