dovecot-2.1: imapc: Support retrying some IMAP commands if we ge...

dovecot at dovecot.org dovecot at dovecot.org
Sun Oct 9 20:29:51 EEST 2011


details:   http://hg.dovecot.org/dovecot-2.1/rev/c9594ff166a9
changeset: 13628:c9594ff166a9
user:      Timo Sirainen <tss at iki.fi>
date:      Sun Oct 09 20:38:11 2011 +0300
description:
imapc: Support retrying some IMAP commands if we get disconnected.

diffstat:

 src/lib-imap-client/imapc-client-private.h     |    1 +
 src/lib-imap-client/imapc-client.c             |   19 ++-
 src/lib-imap-client/imapc-connection.c         |  157 +++++++++++++++---------
 src/lib-imap-client/imapc-connection.h         |    1 +
 src/lib-storage/index/imapc/imapc-mail-fetch.c |    1 +
 src/lib-storage/index/imapc/imapc-storage.c    |    3 +
 src/lib-storage/index/imapc/imapc-storage.h    |    1 +
 src/lib-storage/index/imapc/imapc-sync.c       |   17 ++
 src/lib-storage/index/imapc/imapc-sync.h       |    1 +
 9 files changed, 142 insertions(+), 59 deletions(-)

diffs (truncated from 455 to 300 lines):

diff -r f63f2b2217c3 -r c9594ff166a9 src/lib-imap-client/imapc-client-private.h
--- a/src/lib-imap-client/imapc-client-private.h	Sun Oct 09 20:36:28 2011 +0300
+++ b/src/lib-imap-client/imapc-client-private.h	Sun Oct 09 20:38:11 2011 +0300
@@ -35,6 +35,7 @@
 	unsigned int pending_box_command_count;
 
 	bool reconnect_ok;
+	bool reconnecting;
 };
 
 void imapc_client_ref(struct imapc_client *client);
diff -r f63f2b2217c3 -r c9594ff166a9 src/lib-imap-client/imapc-client.c
--- a/src/lib-imap-client/imapc-client.c	Sun Oct 09 20:36:28 2011 +0300
+++ b/src/lib-imap-client/imapc-client.c	Sun Oct 09 20:38:11 2011 +0300
@@ -258,16 +258,27 @@
 {
 	struct imapc_client_mailbox *box = context;
 
+	i_assert(box->reconnecting);
+	box->reconnecting = FALSE;
+
 	if (reply->state == IMAPC_COMMAND_STATE_OK) {
 		/* reopen the mailbox */
 		box->reopen_callback(box->reopen_context);
+	} else {
+		imapc_connection_abort_commands(box->conn);
 	}
 }
 
 void imapc_client_mailbox_reconnect(struct imapc_client_mailbox *box)
 {
+	bool reconnect = box->reopen_callback != NULL && box->reconnect_ok;
+
+	if (reconnect) {
+		i_assert(!box->reconnecting);
+		box->reconnecting = TRUE;
+	}
 	imapc_connection_disconnect(box->conn);
-	if (box->reopen_callback != NULL && box->reconnect_ok) {
+	if (reconnect) {
 		imapc_connection_connect(box->conn,
 					 imapc_client_reconnect_cb, box);
 	}
@@ -282,6 +293,12 @@
 	/* cancel any pending commands */
 	imapc_connection_unselect(box);
 
+	if (box->reconnecting) {
+		/* need to abort the reconnection so it won't try to access
+		   the box */
+		imapc_connection_disconnect(box->conn);
+	}
+
 	/* set this only after unselect, which may cancel some commands that
 	   reference this box */
 	*_box = NULL;
diff -r f63f2b2217c3 -r c9594ff166a9 src/lib-imap-client/imapc-connection.c
--- a/src/lib-imap-client/imapc-connection.c	Sun Oct 09 20:36:28 2011 +0300
+++ b/src/lib-imap-client/imapc-connection.c	Sun Oct 09 20:38:11 2011 +0300
@@ -63,6 +63,7 @@
 	/* Waiting for '+' literal reply before we can continue */
 	unsigned int wait_for_literal:1;
 };
+ARRAY_DEFINE_TYPE(imapc_command, struct imapc_command *);
 
 struct imapc_connection_literal {
 	char *temp_path;
@@ -103,9 +104,9 @@
 	void *login_context;
 
 	/* commands pending in queue to be sent */
-	ARRAY_DEFINE(cmd_send_queue, struct imapc_command *);
+	ARRAY_TYPE(imapc_command) cmd_send_queue;
 	/* commands that have been sent, waiting for their tagged reply */
-	ARRAY_DEFINE(cmd_wait_list, struct imapc_command *);
+	ARRAY_TYPE(imapc_command) cmd_wait_list;
 
 	unsigned int ips_count, prev_connect_idx;
 	struct ip_addr *ips;
@@ -209,29 +210,70 @@
 }
 
 static void
-imapc_connection_abort_pending_commands(struct imapc_connection *conn,
-					const struct imapc_command_reply *reply)
+imapc_connection_abort_commands_array(ARRAY_TYPE(imapc_command) *cmd_array,
+				      ARRAY_TYPE(imapc_command) *dest_array,
+				      bool keep_retriable)
 {
 	struct imapc_command *const *cmdp, *cmd;
+	unsigned int i;
 
-	while (array_count(&conn->cmd_wait_list) > 0) {
-		cmdp = array_idx(&conn->cmd_wait_list, 0);
+	for (i = 0; i < array_count(cmd_array); ) {
+		cmdp = array_idx(cmd_array, i);
 		cmd = *cmdp;
-		array_delete(&conn->cmd_wait_list, 0, 1);
 
-		if (cmd->callback != NULL)
-			cmd->callback(reply, cmd->context);
+		if (keep_retriable &&
+		    (cmd->flags & IMAPC_COMMAND_FLAG_RETRIABLE) != 0) {
+			cmd->send_pos = 0;
+			cmd->wait_for_literal = 0;
+			i++;
+		} else {
+			array_delete(cmd_array, i, 1);
+			array_append(dest_array, &cmd, 1);
+		}
+	}
+}
+
+static void
+imapc_connection_abort_commands_full(struct imapc_connection *conn,
+				     bool keep_retriable)
+{
+	struct imapc_command *const *cmdp, *cmd;
+	ARRAY_TYPE(imapc_command) tmp_array;
+	struct imapc_command_reply reply;
+
+	t_array_init(&tmp_array, 8);
+	imapc_connection_abort_commands_array(&conn->cmd_wait_list,
+					      &tmp_array, keep_retriable);
+	imapc_connection_abort_commands_array(&conn->cmd_send_queue,
+					      &tmp_array, keep_retriable);
+
+	if (array_count(&conn->cmd_wait_list) > 0) {
+		/* need to move all the waiting commands to send queue */
+		array_append_array(&conn->cmd_wait_list,
+				   &conn->cmd_send_queue);
+		array_clear(&conn->cmd_send_queue);
+		array_append_array(&conn->cmd_send_queue,
+				   &conn->cmd_wait_list);
+		array_clear(&conn->cmd_wait_list);
+	}
+
+	/* abort the commands. we'll do it here later so that if the
+	   callback recurses us back here we don't crash */
+	memset(&reply, 0, sizeof(reply));
+	reply.state = IMAPC_COMMAND_STATE_DISCONNECTED;
+	reply.text_without_resp = reply.text_full =
+		"Disconnected from server";
+	array_foreach(&tmp_array, cmdp) {
+		cmd = *cmdp;
+
+		cmd->callback(&reply, cmd->context);
 		imapc_command_free(cmd);
 	}
-	while (array_count(&conn->cmd_send_queue) > 0) {
-		cmdp = array_idx(&conn->cmd_send_queue, 0);
-		cmd = *cmdp;
-		array_delete(&conn->cmd_send_queue, 0, 1);
+}
 
-		if (cmd->callback != NULL)
-			cmd->callback(reply, cmd->context);
-		imapc_command_free(cmd);
-	}
+void imapc_connection_abort_commands(struct imapc_connection *conn)
+{
+	imapc_connection_abort_commands_full(conn, FALSE);
 }
 
 static void
@@ -262,7 +304,6 @@
 		reply.state = IMAPC_COMMAND_STATE_DISCONNECTED;
 		reply.text_without_resp = reply.text_full =
 			"Disconnected from server";
-		imapc_connection_abort_pending_commands(conn, &reply);
 		imapc_login_callback(conn, &reply);
 
 		conn->idling = FALSE;
@@ -272,9 +313,6 @@
 		conn->selecting_box = NULL;
 		conn->selected_box = NULL;
 		break;
-	case IMAPC_CONNECTION_STATE_DONE:
-		imapc_command_send_more(conn);
-		break;
 	default:
 		break;
 	}
@@ -306,6 +344,9 @@
 
 void imapc_connection_disconnect(struct imapc_connection *conn)
 {
+	bool reconnecting = conn->selected_box != NULL &&
+		conn->selected_box->reconnecting;
+
 	if (conn->fd == -1)
 		return;
 
@@ -327,6 +368,13 @@
 	net_disconnect(conn->fd);
 	conn->fd = -1;
 
+	imapc_connection_abort_commands_full(conn, reconnecting);
+	imapc_connection_set_state(conn, IMAPC_CONNECTION_STATE_DISCONNECTED);
+}
+
+static void imapc_connection_set_disconnected(struct imapc_connection *conn)
+{
+	imapc_connection_abort_commands(conn);
 	imapc_connection_set_state(conn, IMAPC_CONNECTION_STATE_DISCONNECTED);
 }
 
@@ -794,6 +842,7 @@
 {
 	const struct imap_arg *imap_args;
 	const char *name, *value;
+	struct imap_parser *parser;
 	struct imapc_untagged_reply reply;
 	int ret;
 
@@ -854,7 +903,12 @@
 		reply.untagged_box_context =
 			conn->selected_box->untagged_box_context;
 	}
+
+	/* the callback may disconnect and destroy the parser */
+	parser = conn->parser;
+	imap_parser_ref(parser);
 	conn->client->untagged_callback(&reply, conn->client->untagged_context);
+	imap_parser_unref(&parser);
 	imapc_connection_input_reset(conn);
 	return 1;
 }
@@ -893,8 +947,7 @@
 imapc_command_reply_free(struct imapc_command *cmd,
 			 const struct imapc_command_reply *reply)
 {
-	if (cmd->callback != NULL)
-		cmd->callback(reply, cmd->context);
+	cmd->callback(reply, cmd->context);
 	imapc_command_free(cmd);
 }
 
@@ -904,6 +957,7 @@
 	unsigned int i, count;
 	char *line, *linep;
 	const char *p;
+	struct imap_parser *parser;
 	struct imapc_command_reply reply;
 
 	line = i_stream_next_line(conn->input);
@@ -985,7 +1039,13 @@
 	}
 
 	imapc_connection_input_reset(conn);
+
+	parser = conn->parser;
+	imap_parser_ref(parser);
 	imapc_command_reply_free(cmd, &reply);
+	imap_parser_unref(&parser);
+
+	imapc_command_send_more(conn);
 	return 1;
 }
 
@@ -1215,8 +1275,7 @@
 	ip = &conn->ips[conn->prev_connect_idx];
 	fd = net_connect_ip(ip, conn->client->set.port, NULL);
 	if (fd == -1) {
-		imapc_connection_set_state(conn,
-			IMAPC_CONNECTION_STATE_DISCONNECTED);
+		imapc_connection_set_disconnected(conn);
 		return;
 	}
 	conn->fd = fd;
@@ -1252,8 +1311,7 @@
 	if (result->ret != 0) {
 		i_error("imapc(%s): dns_lookup(%s) failed: %s",
 			conn->name, conn->client->set.host, result->error);
-		imapc_connection_set_state(conn,
-			IMAPC_CONNECTION_STATE_DISCONNECTED);
+		imapc_connection_set_disconnected(conn);
 		return;
 	}
 
@@ -1483,10 +1541,14 @@
 		/* SELECT/EXAMINE command */
 		imapc_connection_set_selecting(cmd->box);
 	} else if (!imapc_client_mailbox_is_opened(cmd->box)) {
+		if (cmd->box->reconnecting) {
+			/* wait for SELECT/EXAMINE */
+			return;
+		}
 		/* shouldn't normally happen */
 		memset(&reply, 0, sizeof(reply));
 		reply.text_without_resp = reply.text_full = "Mailbox not open";
-		reply.state = IMAPC_COMMAND_STATE_BAD;
+		reply.state = IMAPC_COMMAND_STATE_DISCONNECTED;
 
 		array_delete(&conn->cmd_send_queue, 0, 1);
 		imapc_command_reply_free(cmd, &reply);
@@ -1577,7 +1639,14 @@
 					       imapc_command_timeout, conn);
 		}
 	}


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