Dominic Lachowicz <cinamod@hotmail.com>

[fontconfig.git] / src / fccache.c

/*
 * $RCSId: xc/lib/fontconfig/src/fccache.c,v 1.12 2002/08/22 07:36:44 keithp Exp $
 *
 * 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 Keith Packard not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  Keith Packard makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL KEITH PACKARD 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 <fcntl.h>
#include <dirent.h>
#include <string.h>
#include <sys/types.h>
#include "fcint.h"
#if defined(HAVE_MMAP) || defined(__CYGWIN__)
#  include <unistd.h>
#  include <sys/mman.h>
#elif defined(_WIN32)
#  include <windows.h>
#endif

#define ENDIAN_TEST 0x12345678
#define MACHINE_SIGNATURE_SIZE (9 + 5*20 + 1)
/* for when we don't have sysconf: */
#define FC_HARDCODED_PAGESIZE 8192 

#ifndef O_BINARY
#define O_BINARY 0
#endif

static int
FcDirCacheOpen (const FcChar8 * dir);

static char *
FcDirCacheHashName (char * cache_file, int collisions);

static off_t
FcCacheSkipToArch (int fd, const char * arch);

static FcBool 
FcCacheCopyOld (int fd, int fd_orig, off_t start);

static void *
FcDirCacheProduce (FcFontSet *set, FcCache * metadata);

static FcBool
FcDirCacheConsume (int fd, const char * dir, FcFontSet *set, FcConfig *config);

static int
FcCacheNextOffset(off_t w);

static char *
FcCacheMachineSignature (void);

static FcBool
FcCacheHaveBank (int bank);

static void
FcCacheAddBankDir (int bank, const char * dir);

struct MD5Context {
        FcChar32 buf[4];
        FcChar32 bits[2];
        unsigned char in[64];
};

static void MD5Init(struct MD5Context *ctx);
static void MD5Update(struct MD5Context *ctx, unsigned char *buf, unsigned len);
static void MD5Final(unsigned char digest[16], struct MD5Context *ctx);
static void MD5Transform(FcChar32 buf[4], FcChar32 in[16]);

#define FC_DBG_CACHE_REF    1024

static char *
FcCacheReadString (int fd, char *dest, int len)
{
    int    size;
    int    slen;

    if (len == 0)
        return 0;

    size = read (fd, dest, len-1);

    if (size > 0)
    {
        dest[size] = '\0';
        slen = strlen (dest);

        lseek (fd, slen - size + 1, SEEK_CUR);
        return slen < len ? dest : 0;
    }

    return 0;
}

static void
FcCacheSkipString (int fd)
{
    char buf[256];
    int  size;
    int  slen;

    while ( (size = read (fd, buf, sizeof (buf)-1)) > 0) 
    {
        buf [size] = '\0';
        slen = strlen (buf);
        if (slen < size) 
        {
            lseek (fd, slen - size + 1, SEEK_CUR);
            return;
        }
    }
}

static FcBool
FcCacheWriteString (int fd, const char *chars)
{
    if (write (fd, chars, strlen(chars)+1) != strlen(chars)+1)
        return FcFalse;
    return FcTrue;
}

static void
FcGlobalCacheDirDestroy (FcGlobalCacheDir *d)
{
    FcStrSetDestroy (d->subdirs);
    FcMemFree (FC_MEM_STRING, strlen (d->name)+1);
    free (d->name);
    FcMemFree (FC_MEM_CACHE, sizeof (FcGlobalCacheDir));
    free (d);
}

FcGlobalCache *
FcGlobalCacheCreate (void)
{
    FcGlobalCache   *cache;

    cache = malloc (sizeof (FcGlobalCache));
    if (!cache)
        return 0;
    FcMemAlloc (FC_MEM_CACHE, sizeof (FcGlobalCache));
    cache->dirs = 0;
    cache->updated = FcFalse;
    cache->fd = -1;
    return cache;
}

void
FcGlobalCacheDestroy (FcGlobalCache *cache)
{
    FcGlobalCacheDir    *d, *next;

    for (d = cache->dirs; d; d = next)
    {
        next = d->next;
        FcGlobalCacheDirDestroy (d);
    }
    FcMemFree (FC_MEM_CACHE, sizeof (FcGlobalCache));
    free (cache);
}

void
FcGlobalCacheLoad (FcGlobalCache    *cache,
                   FcStrSet         *staleDirs,
                   const FcChar8    *cache_file,
                   FcConfig         *config)
{
    char                name_buf[FC_MAX_FILE_LEN];
    FcGlobalCacheDir    *d, *next;
    FcFileTime          config_time = FcConfigModifiedTime (config);
    char                * current_arch_machine_name;
    char                candidate_arch_machine_name[MACHINE_SIGNATURE_SIZE + 9];
    off_t               current_arch_start;

    struct stat         cache_stat, dir_stat;
    char                subdirName[FC_MAX_FILE_LEN + 1 + 12 + 1];

    if (stat ((char *) cache_file, &cache_stat) < 0)
        return;

    cache->fd = open ((char *) cache_file, O_RDONLY | O_BINARY);
    if (cache->fd == -1)
        return;

    cache->updated = FcFalse;

    if (!FcCacheReadString (cache->fd, name_buf, sizeof (name_buf)))
        goto bail_and_destroy;
    if (strcmp (name_buf, FC_GLOBAL_MAGIC_COOKIE) != 0)
        goto bail_and_destroy;

    current_arch_machine_name = FcCacheMachineSignature ();
    current_arch_start = FcCacheSkipToArch(cache->fd, 
                                           current_arch_machine_name);
    if (current_arch_start < 0)
        goto bail1;

    lseek (cache->fd, current_arch_start, SEEK_SET);
    if (!FcCacheReadString (cache->fd, candidate_arch_machine_name, 
                            sizeof (candidate_arch_machine_name)))
        goto bail_and_destroy;
    if (strlen(candidate_arch_machine_name) == 0)
        goto bail_and_destroy;

    while (1) 
    {
        off_t targ;

        if (!FcCacheReadString (cache->fd, name_buf, sizeof (name_buf)) || 
            !strlen(name_buf))
            break;

        /* Directory must be older than the global cache file; also
           cache must be newer than the config file. */
        if (stat ((char *) name_buf, &dir_stat) < 0 || 
            dir_stat.st_mtime > cache_stat.st_mtime ||
            (config_time.set && cache_stat.st_mtime < config_time.time))
        {
            FcCache md;
            off_t off;

            FcStrSetAdd (staleDirs, (FcChar8 *)name_buf);

            /* skip subdirs */
            while (FcCacheReadString (cache->fd, subdirName, 
                                      sizeof (subdirName)) &&
                   strlen (subdirName))
                ;

            if (read (cache->fd, &md, sizeof (FcCache)) != sizeof(FcCache)) 
            {
                perror ("read metadata");
                goto bail1;
            }
            off = FcCacheNextOffset (lseek(cache->fd, 0, SEEK_CUR)) + md.count;
            if (lseek (cache->fd, off, SEEK_SET) != off) 
            {
                perror ("lseek");
                goto bail1;
            }
            continue;
        }

        d = malloc (sizeof (FcGlobalCacheDir));
        if (!d)
            goto bail1;

        d->next = cache->dirs;
        cache->dirs = d;

        d->name = (char *)FcStrCopy ((FcChar8 *)name_buf);
        d->ent = 0;
        d->state = FcGCDirFileRead;

        d->subdirs = FcStrSetCreate();
        do
        {
            if (!FcCacheReadString (cache->fd, subdirName, 
                                    sizeof (subdirName)) ||
                !strlen (subdirName))
                break;
            FcStrSetAdd (d->subdirs, (FcChar8 *)subdirName);
        } while (1);

        d->offset = lseek (cache->fd, 0, SEEK_CUR);
        if (read (cache->fd, &d->metadata, sizeof (FcCache)) != sizeof (FcCache))
            goto bail1;
        targ = FcCacheNextOffset (lseek(cache->fd, 0, SEEK_CUR)) + d->metadata.count;
        if (lseek (cache->fd, targ, SEEK_SET) != targ)
            goto bail1;
    }
    return;

 bail1:
    for (d = cache->dirs; d; d = next)
    {
        next = d->next;
        free (d);
    }
    cache->dirs = 0;

    close (cache->fd);
    cache->fd = -1;
    return;

 bail_and_destroy:
    close (cache->fd);
    cache->fd = -1;

    if (stat ((char *) cache_file, &cache_stat) == 0)
        unlink ((char *)cache_file);

    return;

}

FcBool
FcGlobalCacheReadDir (FcFontSet *set, FcStrSet *dirs, FcGlobalCache * cache, const char *dir, FcConfig *config)
{
    FcGlobalCacheDir    *d;
    int                 i;

    if (cache->fd == -1)
        return FcFalse;

    if (config)
        if (!(dir = (char *)FcConfigNormalizeFontDir (config, (FcChar8 *)dir)))
            return FcFalse; /* non-existing directory */

    for (d = cache->dirs; d; d = d->next)
    {
        if (strcmp (d->name, dir) == 0)
        {
            if (d->state == FcGCDirDisabled)
                return FcFalse;

            if (d->state == FcGCDirFileRead) 
            {
                lseek (cache->fd, d->offset, SEEK_SET);
                if (!FcDirCacheConsume (cache->fd, d->name, set, config))
                    return FcFalse;

                for (i = 0; i < d->subdirs->num; i++)
                    FcStrSetAdd (dirs, (FcChar8 *)d->subdirs->strs[i]);

                d->state = FcGCDirConsumed;
            }
            return FcTrue;
        }
    }

    return FcFalse;
}

static FcGlobalCacheDir *
FcGlobalCacheDirFind (FcGlobalCache *cache, const char *name)
{
    FcGlobalCacheDir * d;

    if (!cache || !name)
        return NULL;

    for (d = cache->dirs; d; d = d->next)
        if (strcmp((const char *)d->name, (const char *)name) == 0)
            return d;

    return NULL;
 }

FcBool
FcGlobalCacheUpdate (FcGlobalCache  *cache,
                     FcStrSet       *dirs,
                     const char     *orig_name,
                     FcFontSet      *set,
                     FcConfig       *config)
{
    FcGlobalCacheDir    *d;
    int                 i;
    const char *name;

    name = (char *)FcConfigNormalizeFontDir (config, (FcChar8 *)orig_name);
    if (!name) 
    {
        fprintf(stderr, "Invalid directory name %s\n", orig_name);
        return FcFalse;
    }

    d = FcGlobalCacheDirFind (cache, name);

    if (!d)
    {
        d = malloc (sizeof (FcGlobalCacheDir));
        if (!d)
            return FcFalse;
        d->next = cache->dirs;
        cache->dirs = d;
    } else {
        /* free old resources */
        FcStrFree ((FcChar8 *)d->name);
        free (d->ent);
        FcStrSetDestroy (d->subdirs);
    }

    cache->updated = FcTrue;

    d->name = (char *)FcStrCopy ((FcChar8 *)name);
    d->ent = FcDirCacheProduce (set, &d->metadata);
    d->offset = 0;
    d->subdirs = FcStrSetCreate();
    d->state = FcGCDirUpdated;
    for (i = 0; i < dirs->num; i++)
        FcStrSetAdd (d->subdirs, dirs->strs[i]);
    return FcTrue;
}

FcBool
FcGlobalCacheSave (FcGlobalCache    *cache,
                   const FcChar8    *cache_file,
                   FcConfig         *config)
{
    int                 fd, fd_orig;
    FcGlobalCacheDir    *dir;
    FcAtomic            *atomic;
    off_t               current_arch_start = 0, truncate_to;
    char                * current_arch_machine_name, * header;

    if (!cache->updated)
        return FcTrue;
    
#if defined (HAVE_GETUID) && defined (HAVE_GETEUID)
    /* Set-UID programs can't safely update the cache */
    if (getuid () != geteuid ())
        return FcFalse;
#endif
    
    atomic = FcAtomicCreate (cache_file);
    if (!atomic)
        return FcFalse;

    if (!FcAtomicLock (atomic))
        goto bail1;
    fd = open ((char *) FcAtomicNewFile(atomic), O_RDWR | O_CREAT | O_BINARY, 
               S_IRUSR | S_IWUSR);
    if (fd == -1)
        goto bail2;
    FcCacheWriteString (fd, FC_GLOBAL_MAGIC_COOKIE);

    fd_orig = open ((char *) FcAtomicOrigFile(atomic), O_RDONLY | O_BINARY);

    current_arch_machine_name = FcCacheMachineSignature ();
    if (fd_orig == -1)
        current_arch_start = 0;
    else
        current_arch_start = FcCacheSkipToArch (fd_orig, 
                                                current_arch_machine_name);

    if (current_arch_start < 0)
    {
        off_t i = lseek(fd_orig, 0, SEEK_END);
        if (i < strlen (FC_GLOBAL_MAGIC_COOKIE)+1)
            i = strlen (FC_GLOBAL_MAGIC_COOKIE)+1;
        current_arch_start = FcCacheNextOffset (i);
    }

    if (!FcCacheCopyOld(fd, fd_orig, current_arch_start))
        goto bail3;

    current_arch_start = lseek(fd, 0, SEEK_CUR);
#if defined (HAVE_FTRUNCATE)
    if (ftruncate (fd, current_arch_start) == -1)
        goto bail3;
#else
#if defined (HAVE_CHSIZE)
    if (chsize (fd, current_arch_start) == -1)
        goto bail3;
#else
    goto bail3;
#endif
#endif

    header = malloc (10 + strlen (current_arch_machine_name));
    if (!header)
        goto bail3;

    truncate_to = current_arch_start + strlen(current_arch_machine_name) + 11;
    for (dir = cache->dirs; dir; dir = dir->next)
    {
        int i;

        if (dir->state == FcGCDirDisabled)
            continue;
        truncate_to += strlen(dir->name) + 1;
        truncate_to += sizeof (FcCache);
        truncate_to = FcCacheNextOffset (truncate_to);
        truncate_to += dir->metadata.count;

        for (i = 0; i < dir->subdirs->size; i++)
            truncate_to += strlen((char *)dir->subdirs->strs[i]) + 1;
        truncate_to ++;
    }
    truncate_to -= current_arch_start;

    sprintf (header, "%8x ", (int)truncate_to);
    strcat (header, current_arch_machine_name);
    if (!FcCacheWriteString (fd, header))
        goto bail4;

    free (header);

    for (dir = cache->dirs; dir; dir = dir->next)
    {
        int i;
        const char * d;
        off_t off;

        if (!dir->name || dir->state == FcGCDirDisabled)
            continue;
        d = (const char *)FcConfigNormalizeFontDir (config, (const FcChar8 *)dir->name);
        if (!d) 
            continue;
            
        if (dir->metadata.count && !dir->ent) 
        {
            if (dir->state == FcGCDirUpdated || fd_orig < 0) 
            {
                fprintf(stderr, "Invalid metadata entry for %s, skipping...\n", d);
                continue;
            }
            /* copy the old content */
            dir->ent = malloc (dir->metadata.count);
            if (!dir->ent) 
            {
                perror("malloc error");
                continue;
            }
            off = FcCacheNextOffset (dir->offset + sizeof(FcCache));
            if (lseek (fd_orig, off, SEEK_SET) != off) 
            {
                perror("lseek");
                free(dir->ent);
                continue;
            }
            if (read (fd_orig, dir->ent, dir->metadata.count)
                != dir->metadata.count) 
            {
                perror("read");
                free(dir->ent);
                continue;
            }
        }
        
        FcCacheWriteString (fd, d);

        for (i = 0; i < dir->subdirs->size; i++)
            FcCacheWriteString (fd, (char *)dir->subdirs->strs[i]);
        FcCacheWriteString (fd, "");
        
        if (write (fd, &dir->metadata, sizeof(FcCache)) != sizeof(FcCache))
        {
            perror ("write metadata");
            free (dir->ent);
            continue;
        }
        off = FcCacheNextOffset (lseek(fd, 0, SEEK_CUR));
        if (lseek (fd, off, SEEK_SET) != off)
        {
            perror ("lseek");
            free (dir->ent);
            continue;
        }
        if (dir->metadata.count)
        {
            if (write (fd, dir->ent, dir->metadata.count) != dir->metadata.count)
            {
                perror ("write dirent");
                free (dir->ent);
                continue;
            }
        }
        free (dir->ent);
    }
    FcCacheWriteString (fd, "");

    if (close (fd) == -1)
        goto bail25;

    close (fd_orig);
    fd_orig = -1;
    
    if (!FcAtomicReplaceOrig (atomic))
        goto bail25;
    
    FcAtomicUnlock (atomic);
    FcAtomicDestroy (atomic);

    cache->updated = FcFalse;
    return FcTrue;

 bail4:
    free (header);
 bail3:
    if (fd_orig != -1)
        close (fd_orig);

    close (fd);
 bail25:
    FcAtomicDeleteNew (atomic);
 bail2:
    FcAtomicUnlock (atomic);
 bail1:
    FcAtomicDestroy (atomic);
    return FcFalse;
}

/* 
 * Find the next presumably-mmapable offset after the supplied file
 * position.
 */
static int
FcCacheNextOffset(off_t w)
{
    static long pagesize = -1;

    if (w == -1)
        return w;

    if (pagesize == -1)
#if defined (HAVE_SYSCONF)
        pagesize = sysconf(_SC_PAGESIZE);
#else
        pagesize = FC_HARDCODED_PAGESIZE;
#endif
    if (w % pagesize == 0) 
        return w;
    else
        return ((w / pagesize)+1)*pagesize;
}

/* return the address of the segment for the provided arch,
 * or -1 if arch not found */
static off_t
FcCacheSkipToArch (int fd, const char * arch)
{
    char candidate_arch_machine_name_count[MACHINE_SIGNATURE_SIZE + 9];
    char * candidate_arch;
    off_t current_arch_start = 0;

    lseek (fd, 0, SEEK_SET);
    FcCacheSkipString (fd);
    current_arch_start = lseek (fd, 0, SEEK_CUR);

    /* skip arches that are not the current arch */
    while (1)
    {
        long bs;

        if (lseek (fd, current_arch_start, SEEK_SET) != current_arch_start)
            return -1;

        if (FcCacheReadString (fd, candidate_arch_machine_name_count, 
                                sizeof (candidate_arch_machine_name_count)) == 0)
            return -1;
        if (!strlen(candidate_arch_machine_name_count))
            return -1;
        bs = strtol(candidate_arch_machine_name_count, &candidate_arch, 16);

        /* count = 0 should probably be distinguished from the !bs condition */
        if (!bs || bs < strlen (candidate_arch_machine_name_count))
            return -1;

        candidate_arch++; /* skip leading space */

        if (strcmp (candidate_arch, arch)==0)
            return current_arch_start;
        current_arch_start += bs;
        current_arch_start = FcCacheNextOffset (current_arch_start);
    }
}

/* Cuts out the segment at the file pointer (moves everything else
 * down to cover it), and leaves the file pointer at the end of the
 * file. */
static FcBool 
FcCacheCopyOld (int fd, int fd_orig, off_t start)
{
    char * buf = malloc (8192);
    char candidate_arch_machine_name[MACHINE_SIGNATURE_SIZE + 9];
    long bs;
    int c, bytes_skipped;
    off_t loc;

    if (!buf)
        return FcFalse;

    loc = 0;
    lseek (fd, 0, SEEK_SET); lseek (fd_orig, 0, SEEK_SET);
    FcCacheSkipString (fd); FcCacheSkipString (fd_orig);
    do
    {
        int b = 8192;
        if (loc + b > start)
            b = start - loc;

        if ((c = read (fd_orig, buf, b)) <= 0)
            break;
        if (write (fd, buf, c) < 0)
            goto bail;

        loc += c;
    }
    while (c > 0);

    lseek (fd, start, SEEK_SET);
    if (FcCacheReadString (fd, candidate_arch_machine_name, 
                           sizeof (candidate_arch_machine_name)) == 0)
        goto done;
    if (!strlen(candidate_arch_machine_name))
        goto done;

    bs = strtol(candidate_arch_machine_name, 0, 16);
    if (bs == 0)
        goto done;

    bytes_skipped = 0;
    do
    {
        lseek (fd, start+bs+bytes_skipped, SEEK_SET);
        if ((c = read (fd, buf, 8192)) <= 0)
            break;
        lseek (fd, start+bytes_skipped, SEEK_SET);
        if (write (fd, buf, c) < 0)
            goto bail;
        bytes_skipped += c;
    }
    while (c > 0);
    lseek (fd, start+bytes_skipped, SEEK_SET);

 done:
    free (buf);
    return FcTrue;

 bail:
    free (buf);
    return FcFalse;
}

/* Does not check that the cache has the appropriate arch section. */
/* Also, this can be fooled if the original location has a stale
 * cache, and the hashed location has an up-to-date cache.  Oh well,
 * sucks to be you in that case! */
FcBool
FcDirCacheValid (const FcChar8 *dir)
{
    struct stat file_stat, dir_stat;
    int         fd;

    if (stat ((char *) dir, &dir_stat) < 0)
        return FcFalse;

    fd = FcDirCacheOpen (dir);

    if (fd < 0)
        return FcFalse;
    if (fstat (fd, &file_stat) < 0)
        goto bail;

    close (fd);

    /*
     * If the directory has been modified more recently than
     * the cache file, the cache is not valid
     */
    if (dir_stat.st_mtime > file_stat.st_mtime)
        return FcFalse;

    return FcTrue;

 bail:
    close (fd);
    return FcFalse;
}

/* Assumes that the cache file in 'dir' exists.
 * Checks that the cache has the appropriate arch section. */
FcBool
FcDirCacheHasCurrentArch (const FcChar8 *dir)
{
    int         fd;
    off_t       current_arch_start;
    char        *current_arch_machine_name;
    FcCache     metadata;
    char        subdirName[FC_MAX_FILE_LEN + 1 + 12 + 1];

    fd = FcDirCacheOpen (dir);
    if (fd < 0)
        goto bail;

    current_arch_machine_name = FcCacheMachineSignature();
    current_arch_start = FcCacheSkipToArch(fd, current_arch_machine_name);

    if (current_arch_start >= 0)
    {
        if (lseek (fd, current_arch_start, SEEK_SET) != current_arch_start)
            goto bail1;

        FcCacheSkipString (fd);

        while (FcCacheReadString (fd, subdirName, sizeof (subdirName)) && strlen (subdirName) > 0)
            ;

        if (read(fd, &metadata, sizeof(FcCache)) != sizeof(FcCache))
            goto bail1;

        if (metadata.magic != FC_CACHE_MAGIC)
            goto bail1;
    }

    close (fd);

    if (current_arch_start < 0)
        return FcFalse;
    
    return FcTrue;

 bail1:
    close (fd);
 bail:
    return FcFalse;
}

FcBool
FcDirCacheUnlink (const FcChar8 *dir, FcConfig *config)
{
    char        *cache_file;
    char        *cache_hashed = 0;
    int         fd, collisions;
    struct stat cache_stat;
    char        name_buf[FC_MAX_FILE_LEN];

    dir = FcConfigNormalizeFontDir (config, dir);
    cache_file = (char *)FcStrPlus (dir, (FcChar8 *) "/" FC_DIR_CACHE_FILE);
    if (!cache_file)
        return FcFalse;

    /* First remove normal cache file. */
    if (stat ((char *) cache_file, &cache_stat) == 0)
        unlink ((char *)cache_file);

    /* Next remove any applicable hashed files. */
    fd = -1; collisions = 0;
    do
    {
        if (cache_hashed)
            FcStrFree ((FcChar8 *)cache_hashed);

        cache_hashed = FcDirCacheHashName (cache_file, collisions++);
        if (!cache_hashed)
            goto bail;

        if (fd > 0)
            close (fd);
        fd = open(cache_hashed, O_RDONLY | O_BINARY);
        if (fd == -1)
        {
            FcStrFree ((FcChar8 *)cache_hashed);
            FcStrFree ((FcChar8 *)cache_file);
            return FcTrue;
        }

        if (!FcCacheReadString (fd, name_buf, sizeof (name_buf)) || !strlen(name_buf))
        {
            FcStrFree ((FcChar8 *)cache_hashed);
            goto bail;
        }
    } while (strcmp (name_buf, cache_file) != 0);

    close (fd);

    if (stat ((char *) cache_hashed, &cache_stat) == 0 &&
        unlink ((char *)cache_hashed) != 0)
    {
        FcStrFree ((FcChar8 *)cache_hashed);
        goto bail;
    }

    FcStrFree ((FcChar8 *)cache_file);
    FcStrFree ((FcChar8 *)cache_hashed);
    return FcTrue;

 bail:
    FcStrFree ((FcChar8 *)cache_file);
    return FcFalse;
}

static int
FcCacheReadDirs (FcConfig * config, FcGlobalCache * cache, 
                 FcStrList *list, FcFontSet * set, FcStrSet *processed_dirs)
{
    int                 ret = 0;
    FcChar8             *dir;
    FcStrSet            *subdirs;
    FcStrList           *sublist;
    struct stat         statb;
    FcGlobalCacheDir   *d;

    /*
     * Read in the results from 'list'.
     */
    while ((dir = FcStrListNext (list)))
    {
        if (!FcConfigAcceptFilename (config, dir))
            continue;

        /* Skip this directory if already updated
         * to avoid the looped directories via symlinks
         * Clearly a dir not in fonts.conf shouldn't be globally cached.
         */
        dir = (FcChar8 *)FcConfigNormalizeFontDir (config, dir);
        if (!dir)
            continue;

        if (FcStrSetMember (processed_dirs, dir))
            continue;
        if (!FcStrSetAdd (processed_dirs, dir))
            continue;

        subdirs = FcStrSetCreate ();
        if (!subdirs)
        {
            fprintf (stderr, "Can't create directory set\n");
            ret++;
            continue;
        }
        
        if (access ((char *) dir, X_OK) < 0)
        {
            switch (errno) {
            case ENOENT:
            case ENOTDIR:
            case EACCES:
                break;
            default:
                fprintf (stderr, "\"%s\": ", dir);
                perror ("");
                ret++;
            }
            FcStrSetDestroy (subdirs);
            continue;
        }
        if (stat ((char *) dir, &statb) == -1)
        {
            fprintf (stderr, "\"%s\": ", dir);
            perror ("");
            FcStrSetDestroy (subdirs);
            ret++;
            continue;
        }
        if (!S_ISDIR (statb.st_mode))
        {
            fprintf (stderr, "\"%s\": not a directory, skipping\n", dir);
            FcStrSetDestroy (subdirs);
            continue;
        }
        if (FcDirCacheValid (dir) && 
            FcDirCacheHasCurrentArch (dir) && 
            FcDirCacheRead (set, subdirs, dir, config))
        {
            /* if an old entry is found in the global cache, disable it */
            if ((d = FcGlobalCacheDirFind (cache, (const char *)dir)) != NULL)
            {
                d->state = FcGCDirDisabled;
                /* save the updated config later without this entry */
                cache->updated = FcTrue;
            }
        }
        else
        {
            if (FcDebug () & FC_DBG_FONTSET)
                printf ("cache scan dir %s\n", dir);

            FcDirScanConfig (set, subdirs, cache, 
                             config->blanks, dir, FcFalse, config);
        }
        sublist = FcStrListCreate (subdirs);
        FcStrSetDestroy (subdirs);
        if (!sublist)
        {
            fprintf (stderr, "Can't create subdir list in \"%s\"\n", dir);
            ret++;
            continue;
        }
        ret += FcCacheReadDirs (config, cache, sublist, set, processed_dirs);
    }
    FcStrListDone (list);
    return ret;
}

FcFontSet *
FcCacheRead (FcConfig *config, FcGlobalCache * cache)
{
    FcFontSet   *s = FcFontSetCreate();
    FcStrSet    *processed_dirs;

    if (!s) 
        return 0;

    processed_dirs = FcStrSetCreate();
    if (!processed_dirs)
        goto bail;

    if (FcCacheReadDirs (config, cache, FcConfigGetConfigDirs (config), s, processed_dirs))
        goto bail1;

    FcStrSetDestroy (processed_dirs);
    return s;

 bail1:
    FcStrSetDestroy (processed_dirs);
 bail:
    FcFontSetDestroy (s);
    return 0;
}

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

static char *
FcDirCacheHashName (char * cache_file, int collisions)
{
    unsigned char       hash[16], hex_hash[33];
    char                *cache_hashed;
    unsigned char       uscore = '_';
    int                 cnt, i;
    FcChar8             *tmp;
    struct MD5Context   ctx;

    MD5Init (&ctx);
    MD5Update (&ctx, (unsigned char *)cache_file, strlen (cache_file));

    for (i = 0; i < collisions; i++)
        MD5Update (&ctx, &uscore, 1);

    MD5Final (hash, &ctx);

    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[32] = 0;

    tmp = FcStrPlus ((FcChar8 *)hex_hash, (FcChar8 *)FC_CACHE_SUFFIX);
    if (!tmp)
        return 0;

    cache_hashed = (char *)FcStrPlus ((FcChar8 *)PKGCACHEDIR"/", tmp);
    free (tmp);

    return cache_hashed;
}

/* Opens the hashed name for cache_file.
 * This would fail in the unlikely event of a collision and subsequent
 * removal of the file which originally caused the collision. */
static int
FcDirCacheOpen (const FcChar8 *dir)
{
    FcBool      found;
    int         fd = -1, collisions = 0;
    char        *cache_file, *cache_hashed;
    char        name_buf[FC_MAX_FILE_LEN];
    struct stat dir_stat;

    if (stat ((char *)dir, &dir_stat) == -1)
        return -1;

    cache_file = (char *)FcStrPlus (dir, (FcChar8 *) "/" FC_DIR_CACHE_FILE);
    if (!cache_file)
        return -1;

    found = FcFalse;
    do
    {
        struct stat     c;
        FcChar8         *name_buf_dir;

        if (fd >= 0)
            close (fd);

        cache_hashed = FcDirCacheHashName (cache_file, collisions++);
        if (!cache_hashed)
        {
            FcStrFree ((FcChar8 *)cache_file);
            return -1;
        }

        fd = open(cache_hashed, O_RDONLY | O_BINARY);
        FcStrFree ((FcChar8 *)cache_hashed);

        if (fd == -1)
            break;
        if (!FcCacheReadString (fd, name_buf, sizeof (name_buf)) || 
            !strlen(name_buf))
            break;

        name_buf_dir = FcStrDirname ((FcChar8 *)name_buf);
        if (stat ((char *)name_buf_dir, &c) == -1)
        {
            FcStrFree (name_buf_dir);
            continue;
        }
        FcStrFree (name_buf_dir);
        found = (c.st_ino == dir_stat.st_ino) && (c.st_dev == dir_stat.st_dev);
    } while (!found);

    if (!found || fd < 0) 
    {
        if (fd >= 0)
            close (fd);
        fd = open(cache_file, O_RDONLY | O_BINARY);
    }

    FcStrFree ((FcChar8 *)cache_file);
    return fd;
}

/* read serialized state from the cache file */
FcBool
FcDirCacheRead (FcFontSet * set, FcStrSet * dirs, const FcChar8 *dir, FcConfig *config)
{
    int         fd;
    char        *current_arch_machine_name;
    char        candidate_arch_machine_name[9+MACHINE_SIGNATURE_SIZE];
    off_t       current_arch_start = 0;
    char        subdirName[FC_MAX_FILE_LEN + 1 + 12 + 1];

    fd = FcDirCacheOpen (dir);
    if (fd < 0)
        goto bail;

    current_arch_machine_name = FcCacheMachineSignature();
    current_arch_start = FcCacheSkipToArch(fd, 
                                           current_arch_machine_name);
    if (current_arch_start < 0)
        goto bail1;

    lseek (fd, current_arch_start, SEEK_SET);
    if (FcCacheReadString (fd, candidate_arch_machine_name, 
                           sizeof (candidate_arch_machine_name)) == 0)
        goto bail1;

    while (FcCacheReadString (fd, subdirName, sizeof (subdirName)) && strlen (subdirName) > 0)
        FcStrSetAdd (dirs, (FcChar8 *)subdirName);

    if (!FcDirCacheConsume (fd, (const char *)dir, set, config))
        goto bail1;
        
    close(fd);
    return FcTrue;

 bail1:
    close (fd);
 bail:
    return FcFalse;
}

static FcBool
FcDirCacheConsume (int fd, const char * dir, FcFontSet *set, FcConfig *config)
{
    FcCache metadata;
    void * current_dir_block;
    off_t pos, endpos;

    if (read(fd, &metadata, sizeof(FcCache)) != sizeof(FcCache))
        return FcFalse;
    if (metadata.magic != FC_CACHE_MAGIC)
        return FcFalse;

    if (!metadata.count)
    {
        pos = FcCacheNextOffset (lseek(fd, 0, SEEK_CUR));
        lseek (fd, pos, SEEK_SET);
        if (config)
            FcConfigAddFontDir (config, (FcChar8 *)dir);
        return FcTrue;
    }

    pos = FcCacheNextOffset (lseek(fd, 0, SEEK_CUR));

    /* This is not failsafe (multi-arches can break it),
     * but fd has got to have at least as many bytes as
     * metadata.count, or something's going to go horribly wrong. */
    if (pos == (off_t)-1)
        return FcFalse;

    endpos = lseek (fd, 0, SEEK_END);
    if (endpos == (off_t)-1 || endpos - pos < metadata.count)
        return FcFalse;
    if (lseek (fd, pos, SEEK_SET) == -1)
        return FcFalse;

#if defined(HAVE_MMAP) || defined(__CYGWIN__)
    current_dir_block = mmap (0, metadata.count, 
                              PROT_READ, MAP_SHARED, fd, pos);
    if (current_dir_block == MAP_FAILED)
        return FcFalse;
#elif defined(_WIN32)
        {
                HANDLE hFileMap;

                hFileMap = CreateFileMapping((HANDLE) _get_osfhandle(fd), NULL, PAGE_READONLY, 0, 0, NULL);
                if (hFileMap == NULL)
                        return FcFalse;

                current_dir_block = MapViewOfFile (hFileMap, FILE_MAP_READ, 0, 0, metadata.count + pos);
                if (current_dir_block == NULL)
                {
                        CloseHandle (hFileMap);
                        return FcFalse;
                }

                current_dir_block = (void *)((char *)current_dir_block + pos);
        }
#else
    current_dir_block = malloc (metadata.count);
    if (!current_dir_block)
        return FcFalse;

    /* could also use CreateMappedViewOfFile under MinGW... */
    if (read (fd, current_dir_block, metadata.count) != metadata.count)
        goto bail;
#endif
    lseek (fd, pos+metadata.count, SEEK_SET);

    FcCacheAddBankDir (metadata.bank, dir);
    if (config)
        FcConfigAddFontDir (config, (FcChar8 *)dir);

    if (!FcFontSetUnserialize (&metadata, set, current_dir_block))
        goto bail;

    return FcTrue;
 bail:
#if !(defined(HAVE_MMAP) || defined(__CYGWIN__))
    free (current_dir_block);
#endif
    return FcFalse;
}

static void *
FcDirCacheProduce (FcFontSet *set, FcCache *metadata)
{
    void * current_dir_block, * final_dir_block;
    static unsigned int rand_state = 0;
    int bank, needed_bytes_no_align;

#if defined (HAVE_RAND_R)
    if (!rand_state) 
        rand_state = time(0L);
    bank = rand_r(&rand_state);

    while (FcCacheHaveBank(bank))
        bank = rand_r(&rand_state);
#else
    if (!rand_state)
    {
        rand_state = 1;
        srand (time (0L));
    }
    bank = rand();

    while (FcCacheHaveBank(bank))
        bank = rand();
#endif

    memset (metadata, 0, sizeof(FcCache));
    FcFontSetNewBank();
    needed_bytes_no_align = FcFontSetNeededBytes (set);
    metadata->count = needed_bytes_no_align + 
        FcFontSetNeededBytesAlign ();
    metadata->magic = FC_CACHE_MAGIC;
    metadata->bank = bank;

    if (!needed_bytes_no_align) /* not a failure, no fonts to write */
    {
        /* no, you don't really need to write any bytes at all. */
        metadata->count = 0;
        return 0;
    }

    current_dir_block = malloc (metadata->count);
    if (!current_dir_block)
        goto bail;
    /* shut up valgrind */
    memset (current_dir_block, 0, metadata->count);
    final_dir_block = FcFontSetDistributeBytes (metadata, current_dir_block);

    if ((void *)((char *)current_dir_block+metadata->count) < final_dir_block)
        goto bail;
                              
    if (!FcFontSetSerialize (bank, set))
        goto bail;

    return current_dir_block;

 bail:
    free (current_dir_block);
    return 0;
}

/* write serialized state to the cache file */
FcBool
FcDirCacheWrite (FcFontSet *set, FcStrSet *dirs, const FcChar8 *dir)
{
    char            *cache_file;
    char            *cache_hashed;
    int             fd, fd_orig, i, dirs_count;
    FcAtomic        *atomic;
    FcCache         metadata;
    off_t           current_arch_start = 0, truncate_to;
    char            name_buf[FC_MAX_FILE_LEN];
    int             collisions;

    char            *current_arch_machine_name, * header;
    void            *current_dir_block = 0;

    dir = FcConfigNormalizeFontDir (FcConfigGetCurrent(), dir);
    if (!dir)
        return FcFalse;

    cache_file = (char *)FcStrPlus (dir, (FcChar8 *) "/" FC_DIR_CACHE_FILE);
    if (!cache_file)
        goto bail;

    /* Ensure that we're not trampling a cache for some other dir. */
    /* This is slightly different from FcDirCacheOpen, since it 
     * needs the filename, not the file descriptor. */
    fd = -1; collisions = 0;
    do
    {
        cache_hashed = FcDirCacheHashName (cache_file, collisions++);
        if (!cache_hashed)
            goto bail0;

        if (fd > 0)
            close (fd);
        fd = open(cache_hashed, O_RDONLY | O_BINARY);
        if (fd == -1)
            break;
        if(!FcCacheReadString (fd, name_buf, sizeof (name_buf)) || !strlen(name_buf))
        {
            close (fd);
            FcStrFree ((FcChar8 *)cache_hashed);
            continue;
        }
        close (fd);

        if (strcmp (name_buf, cache_file) != 0) 
        {
            FcStrFree ((FcChar8 *)cache_hashed);
            continue;
        }

        break;
    } while (1);

    current_dir_block = FcDirCacheProduce (set, &metadata);

    if (metadata.count && !current_dir_block)
        goto bail1;

    if (FcDebug () & FC_DBG_CACHE)
        printf ("FcDirCacheWriteDir cache_file \"%s\"\n", cache_file);

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

    if (!FcAtomicLock (atomic))
    {
        /* Now try rewriting the original version of the file. */
        FcAtomicDestroy (atomic);

        atomic = FcAtomicCreate ((FcChar8 *)cache_file);
        fd_orig = open (cache_file, O_RDONLY | O_BINARY);
        if (fd_orig == -1)
            fd_orig = open((char *)FcAtomicOrigFile (atomic), O_RDONLY | O_BINARY);

        fd = open((char *)FcAtomicNewFile (atomic), O_RDWR | O_CREAT | O_BINARY, 0666);
        if (fd == -1)
            goto bail2;
    }

    /* In all cases, try opening the real location of the cache file first. */
    /* (even if that's not atomic.) */
    fd_orig = open (cache_file, O_RDONLY | O_BINARY);
    if (fd_orig == -1)
        fd_orig = open((char *)FcAtomicOrigFile (atomic), O_RDONLY | O_BINARY);

    fd = open((char *)FcAtomicNewFile (atomic), O_RDWR | O_CREAT | O_BINARY, 0666);
    if (fd == -1)
        goto bail3;

    FcCacheWriteString (fd, cache_file);

    current_arch_machine_name = FcCacheMachineSignature ();
    current_arch_start = 0;

    if (fd_orig != -1)
        current_arch_start = 
            FcCacheSkipToArch(fd_orig, current_arch_machine_name);

    if (current_arch_start < 0)
    {
        off_t offset = lseek(fd_orig, 0, SEEK_END);
        current_arch_start = FcCacheNextOffset (offset);
    }

    if (fd_orig != -1 && !FcCacheCopyOld(fd, fd_orig, current_arch_start))
        goto bail4;

    if (fd_orig != -1)
        close (fd_orig);

    current_arch_start = lseek(fd, 0, SEEK_CUR);
#if defined (HAVE_FTRUNCATE)
    if (ftruncate (fd, current_arch_start) == -1)
        goto bail4;
#else
#if defined (HAVE_CHSIZE)
    if (chsize (fd, current_arch_start) == -1)
        goto bail4;
#else
    goto bail4;
#endif
#endif

    /* allocate space for subdir names in this block */
    dirs_count = 0;
    for (i = 0; i < dirs->size; i++)
        dirs_count += strlen((char *)dirs->strs[i]) + 1;
    dirs_count ++;

    /* now write the address of the next offset */
    truncate_to = FcCacheNextOffset (FcCacheNextOffset (current_arch_start + sizeof (FcCache) + dirs_count) + metadata.count) - current_arch_start;
    header = malloc (10 + strlen (current_arch_machine_name));
    if (!header)
        goto bail4;
    sprintf (header, "%8x ", (int)truncate_to);
    strcat (header, current_arch_machine_name);
    if (!FcCacheWriteString (fd, header))
        goto bail5;

    for (i = 0; i < dirs->size; i++)
        FcCacheWriteString (fd, (char *)dirs->strs[i]);
    FcCacheWriteString (fd, "");

    if (write (fd, &metadata, sizeof(FcCache)) != sizeof(FcCache)) 
    {
        perror("write metadata");
        goto bail5;
    }
    if (metadata.count)
    {
        off_t off = FcCacheNextOffset (lseek(fd, 0, SEEK_END));
        if (lseek (fd, off, SEEK_SET) != off)
            perror("lseek");
        else if (write (fd, current_dir_block, metadata.count) !=
                 metadata.count)
            perror("write current_dir_block");
        free (current_dir_block);
        current_dir_block = 0;
    }

    /* this actually serves to pad out the cache file, if needed */
#if defined (HAVE_FTRUNCATE)
    if (ftruncate (fd, current_arch_start + truncate_to) == -1)
        goto bail5;
#else
#if defined (HAVE_CHSIZE)
    if (chsize (fd, current_arch_start + truncate_to) == -1)
        goto bail5;
#else
    goto bail5;
#endif
#endif

    free (header);
    close(fd);
    if (!FcAtomicReplaceOrig(atomic))
        goto bail3;
    FcStrFree ((FcChar8 *)cache_hashed);
    FcStrFree ((FcChar8 *)cache_file);
    FcAtomicUnlock (atomic);
    FcAtomicDestroy (atomic);
    return FcTrue;

 bail5:
    free (header);
 bail4:
    close (fd);
 bail3:
    FcAtomicUnlock (atomic);
 bail2:
    FcAtomicDestroy (atomic);
 bail1:
    FcStrFree ((FcChar8 *)cache_hashed);
 bail0:
    unlink ((char *)cache_file);
    FcStrFree ((FcChar8 *)cache_file);
    if (current_dir_block)
        free (current_dir_block);
 bail:
    return FcFalse;
}

static char *
FcCacheMachineSignature ()
{
    static char buf[MACHINE_SIGNATURE_SIZE];
    int32_t magic = ENDIAN_TEST;
    char * m = (char *)&magic;

    sprintf (buf, "%2x%2x%2x%2x "
             "%4x %4x %4x %4x %4x %4x %4x %4x %4x %4x %4x %4x "
             "%4x %4x %4x %4x %4x %4x %4x %4x\n", 
             m[0], m[1], m[2], m[3],
             (unsigned int)sizeof (char),
             (unsigned int)sizeof (char *),
             (unsigned int)sizeof (int),
             (unsigned int)sizeof (FcPattern),
             (unsigned int)sizeof (FcPatternEltPtr),
             (unsigned int)sizeof (struct _FcPatternElt *),
             (unsigned int)sizeof (FcPatternElt),
             (unsigned int)sizeof (FcObjectPtr),
             (unsigned int)sizeof (FcValueListPtr),
             (unsigned int)sizeof (FcValue),
             (unsigned int)sizeof (FcValueBinding),
             (unsigned int)sizeof (struct _FcValueList *),
             (unsigned int)sizeof (FcCharSet),
             (unsigned int)sizeof (FcCharLeaf **),
             (unsigned int)sizeof (FcChar16 *),
             (unsigned int)sizeof (FcChar16),
             (unsigned int)sizeof (FcCharLeaf),
             (unsigned int)sizeof (FcChar32),
             (unsigned int)sizeof (FcCache),
#if defined (HAVE_SYSCONF)
             (unsigned int)sysconf(_SC_PAGESIZE));
#else
             (unsigned int)FC_HARDCODED_PAGESIZE);
#endif

    return buf;
}

static int banks_ptr = 0, banks_alloc = 0;
int * _fcBankId = 0, * _fcBankIdx = 0;
static const char ** bankDirs = 0;

static FcBool
FcCacheHaveBank (int bank)
{
    int i;

    if (bank < FC_BANK_FIRST)
        return FcTrue;

    for (i = 0; i < banks_ptr; i++)
        if (_fcBankId[i] == bank)
            return FcTrue;

    return FcFalse;
}

int
FcCacheBankToIndexMTF (int bank)
{
    int i, j;

    for (i = 0; i < banks_ptr; i++)
        if (_fcBankId[_fcBankIdx[i]] == bank)
        {
            int t = _fcBankIdx[i];

            for (j = i; j > 0; j--)
                _fcBankIdx[j] = _fcBankIdx[j-1];
            _fcBankIdx[0] = t;
            return t;
        }

    if (banks_ptr >= banks_alloc)
    {
        int * b, * bidx;
        const char ** bds;

        b = realloc (_fcBankId, (banks_alloc + 4) * sizeof(int));
        if (!b)
            return -1;
        _fcBankId = b;

        bidx = realloc (_fcBankIdx, (banks_alloc + 4) * sizeof(int));
        if (!bidx)
            return -1;
        _fcBankIdx = bidx;

        bds = realloc (bankDirs, (banks_alloc + 4) * sizeof (char *));
        if (!bds)
            return -1;
        bankDirs = bds;

        banks_alloc += 4;
    }

    i = banks_ptr++;
    _fcBankId[i] = bank;
    _fcBankIdx[i] = i;
    return i;
}

static void
FcCacheAddBankDir (int bank, const char * dir)
{
    int bi = FcCacheBankToIndexMTF (bank);

    if (bi < 0)
        return;

    bankDirs[bi] = (const char *)FcStrCopy ((FcChar8 *)dir);
}

const char *
FcCacheFindBankDir (int bank)
{
    int bi = FcCacheBankToIndex (bank);
    return bankDirs[bi];
}

/*
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 */

#ifndef HIGHFIRST
#define byteReverse(buf, len)   /* Nothing */
#else
/*
 * Note: this code is harmless on little-endian machines.
 */
void byteReverse(unsigned char *buf, unsigned longs)
{
    FcChar32 t;
    do {
        t = (FcChar32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
            ((unsigned) buf[1] << 8 | buf[0]);
        *(FcChar32 *) buf = t;
        buf += 4;
    } while (--longs);
}
#endif

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
static void MD5Init(struct MD5Context *ctx)
{
    ctx->buf[0] = 0x67452301;
    ctx->buf[1] = 0xefcdab89;
    ctx->buf[2] = 0x98badcfe;
    ctx->buf[3] = 0x10325476;

    ctx->bits[0] = 0;
    ctx->bits[1] = 0;
}

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
static void MD5Update(struct MD5Context *ctx, unsigned char *buf, unsigned len)
{
    FcChar32 t;

    /* Update bitcount */

    t = ctx->bits[0];
    if ((ctx->bits[0] = t + ((FcChar32) len << 3)) < t)
        ctx->bits[1]++;         /* Carry from low to high */
    ctx->bits[1] += len >> 29;

    t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */

    /* Handle any leading odd-sized chunks */

    if (t) {
        unsigned char *p = (unsigned char *) ctx->in + t;

        t = 64 - t;
        if (len < t) {
            memcpy(p, buf, len);
            return;
        }
        memcpy(p, buf, t);
        byteReverse(ctx->in, 16);
        MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
        buf += t;
        len -= t;
    }
    /* Process data in 64-byte chunks */

    while (len >= 64) {
        memcpy(ctx->in, buf, 64);
        byteReverse(ctx->in, 16);
        MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
        buf += 64;
        len -= 64;
    }

    /* Handle any remaining bytes of data. */

    memcpy(ctx->in, buf, len);
}

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern 
 * 1 0* (64-bit count of bits processed, MSB-first)
 */
static void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
{
    unsigned count;
    unsigned char *p;

    /* Compute number of bytes mod 64 */
    count = (ctx->bits[0] >> 3) & 0x3F;

    /* Set the first char of padding to 0x80.  This is safe since there is
       always at least one byte free */
    p = ctx->in + count;
    *p++ = 0x80;

    /* Bytes of padding needed to make 64 bytes */
    count = 64 - 1 - count;

    /* Pad out to 56 mod 64 */
    if (count < 8) {
        /* Two lots of padding:  Pad the first block to 64 bytes */
        memset(p, 0, count);
        byteReverse(ctx->in, 16);
        MD5Transform(ctx->buf, (FcChar32 *) ctx->in);

        /* Now fill the next block with 56 bytes */
        memset(ctx->in, 0, 56);
    } else {
        /* Pad block to 56 bytes */
        memset(p, 0, count - 8);
    }
    byteReverse(ctx->in, 14);

    /* Append length in bits and transform */
    ((FcChar32 *) ctx->in)[14] = ctx->bits[0];
    ((FcChar32 *) ctx->in)[15] = ctx->bits[1];

    MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
    byteReverse((unsigned char *) ctx->buf, 4);
    memcpy(digest, ctx->buf, 16);
    memset(ctx, 0, sizeof(ctx));        /* In case it's sensitive */
}


/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) \
        ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

/*
 * The core of the MD5 algorithm, this alters an existing MD5 hash to
 * reflect the addition of 16 longwords of new data.  MD5Update blocks
 * the data and converts bytes into longwords for this routine.
 */
static void MD5Transform(FcChar32 buf[4], FcChar32 in[16])
{
    register FcChar32 a, b, c, d;

    a = buf[0];
    b = buf[1];
    c = buf[2];
    d = buf[3];

    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);

    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);

    buf[0] += a;
    buf[1] += b;
    buf[2] += c;
    buf[3] += d;
}