1 files changed, 113 insertions, 0 deletions
diff --git a/src/lib-ldap/ldap-connection-pool.c b/src/lib-ldap/ldap-connection-pool.c
new file mode 100644
index 0000000..7635ce0
--- /dev/null
+++ b/src/lib-ldap/ldap-connection-pool.c
@@ -0,0 +1,113 @@
+/* Copyright (c) 2016-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "llist.h"
+#include "ldap-private.h"
+#include "ldap-connection-pool.h"
+
+struct ldap_connection_pool {
+	struct ldap_connection_list *conn_list;
+	unsigned int conn_count;
+
+	unsigned int max_connections;
+};
+
+static void ldap_connection_list_remove(struct ldap_connection_pool *pool,
+					struct ldap_connection_list *list)
+{
+	DLLIST_REMOVE(&pool->conn_list, list);
+	pool->conn_count--;
+
+	ldap_connection_deinit(&list->conn);
+	i_free(list);
+}
+
+static void
+ldap_connection_pool_shrink_to(struct ldap_connection_pool *pool,
+			       unsigned int max_count)
+{
+	struct ldap_connection_list *list, *next;
+
+	list = pool->conn_list;
+	for (; list != NULL && pool->conn_count > max_count; list = next) {
+		next = list->next;
+		if (list->refcount == 0)
+			ldap_connection_list_remove(pool, list);
+	}
+}
+
+struct ldap_connection_pool *
+ldap_connection_pool_init(unsigned int max_connections)
+{
+	struct ldap_connection_pool *pool;
+
+	pool = i_new(struct ldap_connection_pool, 1);
+	pool->max_connections = max_connections;
+	return pool;
+}
+
+void ldap_connection_pool_deinit(struct ldap_connection_pool **_pool)
+{
+	struct ldap_connection_pool *pool = *_pool;
+
+	*_pool = NULL;
+
+	ldap_connection_pool_shrink_to(pool, 0);
+	i_assert(pool->conn_list == NULL);
+	i_free(pool);
+}
+
+int ldap_connection_pool_get(struct ldap_connection_pool *pool,
+			     struct ldap_client *client,
+			     const struct ldap_client_settings *set,
+			     struct ldap_connection_list **list_r,
+			     const char **error_r)
+{
+	struct ldap_connection_list *list;
+	struct ldap_connection *conn;
+
+	for (list = pool->conn_list; list != NULL; list = list->next) {
+		if (ldap_connection_have_settings(list->conn, set)) {
+			list->refcount++;
+			*list_r = list;
+			return 0;
+		}
+	}
+	if (ldap_connection_init(client, set, &conn, error_r) < 0)
+		return -1;
+
+	list = i_new(struct ldap_connection_list, 1);
+	list->conn = conn;
+	list->refcount++;
+
+	DLLIST_PREPEND(&pool->conn_list, list);
+	pool->conn_count++;
+
+	ldap_connection_pool_shrink_to(pool, pool->max_connections);
+	*list_r = list;
+	return 0;
+}
+
+void ldap_connection_pool_unref(struct ldap_connection_pool *pool,
+				struct ldap_connection_list **_list)
+{
+	struct ldap_connection_list *list = *_list;
+
+	*_list = NULL;
+
+	i_assert(list->refcount > 0);
+
+	if (--list->refcount == 0)
+		ldap_connection_pool_shrink_to(pool, pool->max_connections);
+}
+
+bool ldap_connection_pool_have_references(struct ldap_connection_pool *pool)
+{
+	struct ldap_connection_list *list;
+
+	for (list = pool->conn_list; list != NULL; list = list->next) {
+		if (list->refcount > 0)
+			return TRUE;
+	}
+	return FALSE;
+}