lib-smtp: smtp-client-connection - Allow smtp_client_connection_connect() to be calle...

This change allows calling smtp_client_connection_connect() several times with
different login callbacks. If the connection is already available, the
provided login callback is called almost immediately from the ioloop. This way,
several parallel asynchronous activities using the same connection can wait for
its availability and don't need to check whether it is available already. This
is mostly useful to obtain the capabilities of the server.

diff --git a/src/lib-smtp/smtp-client-connection.c b/src/lib-smtp/smtp-client-connection.c
index c14ee644792b92be8f2ee71245468031b7a5aff5..297389cc12768acde4d2dcd3f5cb68b89803f46d 100644 (file)
--- a/src/lib-smtp/smtp-client-connection.c
+++ b/src/lib-smtp/smtp-client-connection.c
@@ -128,21 +128,29 @@ static void
 smtp_client_connection_login_callback(struct smtp_client_connection *conn,
                                      const struct smtp_reply *reply)
 {
-       smtp_client_command_callback_t *callback = conn->login_callback;
-       void *context = conn->login_context;
+       const struct smtp_client_login_callback *cb;
+       ARRAY(struct smtp_client_login_callback) login_cbs;
 
        if (conn->state_data.login_reply == NULL) {
                conn->state_data.login_reply =
                        smtp_reply_clone(conn->state_pool, reply);
        }
 
-       conn->login_callback = NULL;
-       conn->login_context = NULL;
-
-       if (conn->closed)
+       if (!array_is_created(&conn->login_callbacks) ||
+           array_count(&conn->login_callbacks) == 0)
                return;
-       if (callback != NULL)
-               callback(reply, context);
+
+       t_array_init(&login_cbs, array_count(&conn->login_callbacks));
+       array_copy(&login_cbs.arr, 0, &conn->login_callbacks.arr, 0,
+                  array_count(&conn->login_callbacks));
+       array_foreach(&login_cbs, cb) {
+               i_assert(cb->callback != NULL);
+               if (conn->closed)
+                       break;
+               if (cb->callback != NULL)
+                       cb->callback(reply, cb->context);
+       }
+       array_clear(&conn->login_callbacks);
 }
 
 static void
@@ -1660,17 +1668,72 @@ smtp_client_connection_lookup_ip(struct smtp_client_connection *conn)
        }
 }
 
+static void
+smtp_client_connection_already_connected(struct smtp_client_connection *conn)
+{
+       i_assert(conn->state_data.login_reply != NULL);
+
+       timeout_remove(&conn->to_connect);
+
+       e_debug(conn->event, "Already connected");
+
+       smtp_client_connection_login_callback(
+               conn, conn->state_data.login_reply);
+}
+
+static void
+smtp_client_connection_connect_more(struct smtp_client_connection *conn)
+{
+       if (!array_is_created(&conn->login_callbacks) ||
+           array_count(&conn->login_callbacks) == 0) {
+               /* No login callbacks required */
+               return;
+       }
+       if (conn->state < SMTP_CLIENT_CONNECTION_STATE_READY) {
+               /* Login callbacks will be called once the connection succeeds
+                  or fails. */
+               return;
+       }
+
+       if (array_count(&conn->login_callbacks) > 1) {
+               /* Another login callback is already pending */
+               i_assert(conn->to_connect != NULL);
+               return;
+       }
+
+       /* Schedule immediate login callback */
+       i_assert(conn->to_connect == NULL);
+       conn->to_connect = timeout_add(
+               0, smtp_client_connection_already_connected, conn);
+}
+
 void smtp_client_connection_connect(
        struct smtp_client_connection *conn,
        smtp_client_command_callback_t login_callback, void *login_context)
 {
-       if (conn->state != SMTP_CLIENT_CONNECTION_STATE_DISCONNECTED) {
-               i_assert(login_callback == NULL);
+       struct smtp_client_login_callback *login_cb;
+
+       if (conn->closed)
                return;
+
+       if (login_callback != NULL) {
+               if (!array_is_created(&conn->login_callbacks))
+                       i_array_init(&conn->login_callbacks, 4);
+
+               login_cb = array_append_space(&conn->login_callbacks);
+               login_cb->callback = login_callback;
+               login_cb->context = login_context;
        }
 
-       if (conn->closed || conn->failing)
+       if (conn->state != SMTP_CLIENT_CONNECTION_STATE_DISCONNECTED) {
+               /* Already connecting or connected */
+               smtp_client_connection_connect_more(conn);
                return;
+       }
+       if (conn->failing)
+               return;
+
+       e_debug(conn->event, "Disconnected");
 
        conn->xclient_replies_expected = 0;
        conn->authenticated = FALSE;
@@ -1681,10 +1744,6 @@ void smtp_client_connection_connect(
        conn->sent_quit = FALSE;
        conn->reset_needed = FALSE;
 
-       i_assert(conn->login_callback == NULL);
-       conn->login_callback = login_callback;
-       conn->login_context = login_context;
-
        smtp_client_connection_set_state(
                conn, SMTP_CLIENT_CONNECTION_STATE_CONNECTING);
 
@@ -1998,6 +2057,7 @@ void smtp_client_connection_unref(struct smtp_client_connection **_conn)
        connection_deinit(&conn->conn);
 
        i_free(conn->ips);
+       array_free(&conn->login_callbacks);
        pool_unref(&conn->cap_pool);
        pool_unref(&conn->state_pool);
        pool_unref(&conn->pool);

diff --git a/src/lib-smtp/smtp-client-private.h b/src/lib-smtp/smtp-client-private.h
index 67216c5ad9b634c3abc2977d50ca1186993e3660..d0b44875db0663b1db81f249d098771c6d85be43 100644 (file)
--- a/src/lib-smtp/smtp-client-private.h
+++ b/src/lib-smtp/smtp-client-private.h
@@ -152,6 +152,11 @@ struct smtp_client_transaction {
        bool submitted_data:1;
 };
 
+struct smtp_client_login_callback {
+       smtp_client_command_callback_t *callback;
+       void *context;
+};
+
 struct smtp_client_connection {
        struct connection conn;
        pool_t pool;
@@ -199,8 +204,7 @@ struct smtp_client_connection {
                struct smtp_reply *login_reply;
        } state_data;
 
-       smtp_client_command_callback_t *login_callback;
-       void *login_context;
+       ARRAY(struct smtp_client_login_callback) login_callbacks;
 
        /* commands pending in queue to be sent */
        struct smtp_client_command *cmd_send_queue_head, *cmd_send_queue_tail;