void *mutt_hcache_fetch (void *db, const char *filename,
size_t (*keylen) (const char *fn));
int mutt_hcache_store (void *db, const char *filename, HEADER * h,
void *mutt_hcache_fetch (void *db, const char *filename,
size_t (*keylen) (const char *fn));
int mutt_hcache_store (void *db, const char *filename, HEADER * h,