void *mutt_hcache_fetch(header_cache_t *h, const char *filename, size_t (*keylen)(const char *fn));
void *mutt_hcache_fetch_raw (header_cache_t *h, const char *filename,
size_t (*keylen)(const char *fn));
void *mutt_hcache_fetch(header_cache_t *h, const char *filename, size_t (*keylen)(const char *fn));
void *mutt_hcache_fetch_raw (header_cache_t *h, const char *filename,
size_t (*keylen)(const char *fn));
int mutt_hcache_store(header_cache_t *h, const char *filename, HEADER *header,
int mutt_hcache_store(header_cache_t *h, const char *filename, HEADER *header,
int mutt_hcache_store_raw (header_cache_t *h, const char* filename, void* data,
size_t dlen, size_t(*keylen) (const char* fn));
int mutt_hcache_delete(header_cache_t *h, const char *filename, size_t (*keylen)(const char *fn));
int mutt_hcache_store_raw (header_cache_t *h, const char* filename, void* data,
size_t dlen, size_t(*keylen) (const char* fn));
int mutt_hcache_delete(header_cache_t *h, const char *filename, size_t (*keylen)(const char *fn));