1 files changed, 120 insertions, 0 deletions
diff --git a/src/lib-storage/mailbox-guid-cache.c b/src/lib-storage/mailbox-guid-cache.c
new file mode 100644
index 0000000..e35a358
--- /dev/null
+++ b/src/lib-storage/mailbox-guid-cache.c
@@ -0,0 +1,120 @@
+/* Copyright (c) 2005-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "ioloop.h"
+#include "hash.h"
+#include "mail-storage-private.h"
+#include "mailbox-list-private.h"
+#include "mailbox-guid-cache.h"
+
+struct mailbox_guid_cache_rec {
+	guid_128_t guid;
+	const char *vname;
+};
+
+int mailbox_guid_cache_find(struct mailbox_list *list,
+			    const guid_128_t guid, const char **vname_r)
+{
+	const struct mailbox_guid_cache_rec *rec;
+	const uint8_t *guid_p = guid;
+
+	if (!hash_table_is_created(list->guid_cache) ||
+	    list->guid_cache_invalidated) {
+		mailbox_guid_cache_refresh(list);
+		rec = hash_table_lookup(list->guid_cache, guid_p);
+	} else {
+		rec = hash_table_lookup(list->guid_cache, guid_p);
+		if (rec == NULL && list->guid_cache_updated) {
+			mailbox_guid_cache_refresh(list);
+			rec = hash_table_lookup(list->guid_cache, guid_p);
+		}
+	}
+	if (rec == NULL) {
+		*vname_r = NULL;
+		return list->guid_cache_errors ? -1 : 0;
+	}
+	*vname_r = rec->vname;
+	return 0;
+}
+
+static void mailbox_guid_cache_add_mailbox(struct mailbox_list *list,
+					   const struct mailbox_info *info)
+{
+	struct mailbox *box;
+	struct mailbox_metadata metadata;
+	struct mailbox_guid_cache_rec *rec;
+	uint8_t *guid_p;
+
+	box = mailbox_alloc(list, info->vname, 0);
+	if (mailbox_get_metadata(box, MAILBOX_METADATA_GUID,
+				 &metadata) < 0) {
+		e_error(box->event, "Couldn't get mailbox GUID: %s",
+			mailbox_get_last_internal_error(box, NULL));
+		list->guid_cache_errors = TRUE;
+	} else if ((rec = hash_table_lookup(list->guid_cache,
+			(const uint8_t *)metadata.guid)) != NULL) {
+		e_warning(list->ns->user->event,
+			  "Mailbox %s has duplicate GUID with %s: %s",
+			  info->vname, rec->vname,
+			  guid_128_to_string(metadata.guid));
+	} else {
+		rec = p_new(list->guid_cache_pool,
+			    struct mailbox_guid_cache_rec, 1);
+		memcpy(rec->guid, metadata.guid, sizeof(rec->guid));
+		rec->vname = p_strdup(list->guid_cache_pool, info->vname);
+		guid_p = rec->guid;
+		hash_table_insert(list->guid_cache, guid_p, rec);
+	}
+	mailbox_free(&box);
+}
+
+void mailbox_guid_cache_refresh(struct mailbox_list *list)
+{
+	struct mailbox_list_iterate_context *ctx;
+	const struct mailbox_info *info;
+
+	if (!hash_table_is_created(list->guid_cache)) {
+		list->guid_cache_pool =
+			pool_alloconly_create("guid cache", 1024*16);
+		hash_table_create(&list->guid_cache, list->guid_cache_pool, 0,
+				  guid_128_hash, guid_128_cmp);
+	} else {
+		hash_table_clear(list->guid_cache, TRUE);
+		p_clear(list->guid_cache_pool);
+	}
+	list->guid_cache_invalidated = FALSE;
+	list->guid_cache_updated = FALSE;
+	list->guid_cache_errors = FALSE;
+
+	ctx = mailbox_list_iter_init(list, "*",
+				     MAILBOX_LIST_ITER_SKIP_ALIASES |
+				     MAILBOX_LIST_ITER_NO_AUTO_BOXES);
+	while ((info = mailbox_list_iter_next(ctx)) != NULL) {
+		if ((info->flags &
+		     (MAILBOX_NOSELECT | MAILBOX_NONEXISTENT)) != 0)
+			continue;
+		T_BEGIN {
+			mailbox_guid_cache_add_mailbox(list, info);
+		} T_END;
+	}
+	if ((list->ns->prefix_len > 0) && !mail_namespace_prefix_is_inbox(list->ns)) {
+		/* Also check if namespace prefix is a selectable mailbox
+		   and add it to cache. Does not need to include INBOX since
+		   it is added separately by mailbox_list_iter_init above. */
+		const char *ns_vname = t_strndup(list->ns->prefix,
+					         list->ns->prefix_len-1);
+		const struct mailbox_info ns_info = {
+			.vname = ns_vname,
+			.ns = list->ns,
+		};
+		struct mailbox *box = mailbox_alloc(list, ns_vname, 0);
+		enum mailbox_existence existence;
+		if (mailbox_exists(box, FALSE, &existence) == 0 &&
+		    existence == MAILBOX_EXISTENCE_SELECT)
+			mailbox_guid_cache_add_mailbox(list, &ns_info);
+		mailbox_free(&box);
+	}
+
+	if (mailbox_list_iter_deinit(&ctx) < 0)
+		list->guid_cache_errors = TRUE;
+}