Support adding new node

Author: knizhnik

multimaster--1.0.sql

@@ -13,10 +13,9 @@ CREATE FUNCTION mtm.drop_node(node integer, drop_slot bool default false) RETURN
 AS 'MODULE_PATHNAME','mtm_drop_node'
 LANGUAGE C;
 
--- -- XXX: cstring as an argument breaks sanity check
--- CREATE FUNCTION mtm.add_node(conn_str cstring) RETURNS void
--- AS 'MODULE_PATHNAME','mtm_add_node'
--- LANGUAGE C;
+CREATE FUNCTION mtm.add_node(conn_str cstring) RETURNS void
+AS 'MODULE_PATHNAME','mtm_add_node'
+LANGUAGE C;
 
 -- Create replication slot for the node which was previously dropped together with it's slot 
 CREATE FUNCTION mtm.recover_node(node integer) RETURNS void

multimaster.c

@@ -1932,7 +1932,7 @@ static void MtmCheckControlFile(void)
 		if (f == NULL) { 
 			elog(FATAL, "Failed to create mmts_control file: %m");
 		}
-		Mtm->donorNodeId = -1;
+		Mtm->donorNodeId = MtmNodeId;
 		fprintf(f, "%s:%d\n", MtmClusterName, Mtm->donorNodeId);
 		fclose(f);
 	}
@@ -2706,7 +2706,7 @@ MtmReplicationMode MtmGetReplicationMode(int nodeId, sig_atomic_t volatile* shut
 		MtmLock(LW_EXCLUSIVE);
 		if (Mtm->status == MTM_RECOVERY) { 
 			recovery = true;
-			if ((Mtm->recoverySlot == 0 && (Mtm->donorNodeId < 0 || Mtm->donorNodeId == nodeId))
+			if ((Mtm->recoverySlot == 0 && (Mtm->donorNodeId == MtmNodeId || Mtm->donorNodeId == nodeId))
 				|| Mtm->recoverySlot == nodeId) 
 			{ 
 				/* Choose for recovery first available slot or slot of donor node (if any) */
@@ -2819,7 +2819,7 @@ MtmReplicationStartupHook(struct PGLogicalStartupHookArgs* args)
 			}				
 		} else if (strcmp("mtm_restart_pos", elem->defname) == 0) { 
 			if (elem->arg != NULL && strVal(elem->arg) != NULL) {
-				recoveryStartPos = intVal(elem->arg);
+				sscanf(strVal(elem->arg), "%lx", &recoveryStartPos);
 			} else { 
 				elog(ERROR, "Restart position is not specified");
 			}