+#if HAVE_QDBM
+void *
+mutt_hcache_open(const char *path, const char *folder)
+{
+ struct header_cache *h = p_new(HEADER_CACHE, 1);
+ int flags = VL_OWRITER | VL_OCREAT;
+ h->db = NULL;
+ h->folder = m_strdup(folder);
+ h->crc = generate_crc32();
+
+ if (!path || path[0] == '\0')
+ {
+ p_delete(&h->folder);
+ p_delete(&h);
+ return NULL;
+ }
+
+ path = mutt_hcache_per_folder(path, folder);
+
+ if (option(OPTHCACHECOMPRESS))
+ flags |= VL_OZCOMP;
+
+ h->db = vlopen(path, flags, VL_CMPLEX);
+ if (h->db)
+ return h;
+ else
+ {
+ p_delete(&h->folder);
+ p_delete(&h);
+
+ return NULL;
+ }
+}
+
+void
+mutt_hcache_close(void *db)
+{
+ struct header_cache *h = db;
+
+ if (!h)
+ return;
+
+ vlclose(h->db);
+ p_delete(&h->folder);
+ p_delete(&h);
+}
+
+void *
+mutt_hcache_fetch(void *db, const char *filename,
+ size_t(*keylen) (const char *fn))
+{
+ struct header_cache *h = db;
+ char path[_POSIX_PATH_MAX];
+ int ksize, len;
+ char *data = NULL;
+
+ if (!h)
+ return NULL;
+
+ m_strcpy(path, sizeof(path), h->folder);
+ m_strcat(path, sizeof(path), filename);
+
+ ksize = strlen(h->folder) + keylen(path + strlen(h->folder));
+
+ data = vlget(h->db, path, ksize, NULL);
+
+ if (!crc32_matches(data, h->crc))
+ {
+ p_delete(&data);
+ return NULL;
+ }
+
+ return data;
+}
+
+int
+mutt_hcache_store(void *db, const char *filename, HEADER * header,
+ unsigned long uid_validity,
+ size_t(*keylen) (const char *fn))
+{
+ struct header_cache *h = db;
+ char path[_POSIX_PATH_MAX];
+ int ret;
+ int ksize, dsize;
+ char *data = NULL;
+
+ if (!h)
+ return -1;
+
+ m_strcpy(path, sizeof(path), h->folder);
+ m_strcat(path, sizeof(path), filename);
+
+ ksize = strlen(h->folder) + keylen(path + strlen(h->folder));
+
+ data = mutt_hcache_dump(db, header, &dsize, uid_validity);
+
+ ret = vlput(h->db, path, ksize, data, dsize, VL_DOVER);
+
+ p_delete(&data);
+
+ return ret;
+}
+
+int
+mutt_hcache_delete(void *db, const char *filename,
+ size_t(*keylen) (const char *fn))
+{
+ struct header_cache *h = db;
+ char path[_POSIX_PATH_MAX];
+ int ksize;
+
+ if (!h)
+ return -1;
+
+ m_strcpy(path, sizeof(path), h->folder);
+ m_strcat(path, sizeof(path), filename);
+
+ ksize = strlen(h->folder) + keylen(path + strlen(h->folder));
+
+ return vlout(h->db, path, ksize);
+}
+
+#elif HAVE_GDBM