void *mutt_hcache_open(const char *path, const char *folder);
void mutt_hcache_close(void *db);
HEADER *mutt_hcache_restore(const unsigned char *d, HEADER **oh);
void *mutt_hcache_fetch(void *db, const char *filename,
void *mutt_hcache_open(const char *path, const char *folder);
void mutt_hcache_close(void *db);
HEADER *mutt_hcache_restore(const unsigned char *d, HEADER **oh);
void *mutt_hcache_fetch(void *db, const char *filename,