status fix

Author: Vladimir Ershov

src/pgpro_scheduler.c

@@ -615,6 +615,8 @@ int _find_stat_database(scheduler_stat_t *list, char *dbname)
 {
 	int i;
 
+	if(list->num_db == 0) return -1;
+
 	for(i=0; i < list->num_db; i++)
 	{
 		if(strcmp(list->dats[i]->name, dbname) == 0) return i;	
@@ -1132,7 +1134,7 @@ scheduler_status(PG_FUNCTION_ARGS)
 		current = (char *)GetConfigOption("schedule.database", false, true);
 		in_use = _split_string_to_char_array(current, true);
 
-		list.super_pid = InvalidPid;
+		list.super_pid = 0;
 		list.super_datname[0] = 0;
 		list.num_db = in_use ? in_use->n: 0;
 		if(list.num_db)
@@ -1146,13 +1148,17 @@ scheduler_status(PG_FUNCTION_ARGS)
 				if(!list.dats[i])
 					elog(ERROR, "cannot alloc memory for pgpro_scheduler database stat");
 				snprintf(list.dats[i]->name, NAMEDATALEN, "%s", in_use->data[i]);
-				list.dats[i]->manager_pid = InvalidPid;
+				list.dats[i]->manager_pid = 0;
 				list.dats[i]->nexecs = 0;
 				list.dats[i]->execs = palloc(sizeof(pid_t)*max_worker_processes);
 				list.dats[i]->natexecs = 0;
 				list.dats[i]->atexecs = palloc(sizeof(pid_t)*max_worker_processes);
 			}
 		}
+		else
+		{
+			list.dats = NULL;
+		}
 
 		num_backends = pgstat_fetch_stat_numbackends();
 		for(i = 1; i <= num_backends; i++)
@@ -1205,53 +1211,57 @@ scheduler_status(PG_FUNCTION_ARGS)
 		{
 			if(list.dats[i]->manager_pid == 0) nrecords++;
 		}
-	
-		records = palloc(sizeof(scheduler_stat_record_t) * nrecords);
-		if(list.super_pid)
+
+		if(nrecords == 0)
 		{
-			records[nr].pid = list.super_pid;
-			records[nr].datname = list.super_datname;
-			records[nr].name = names[0];
-			nr++;
+			funcctx->max_calls = 0;
+			funcctx->user_fctx = NULL;
 		}
-		for(i = 0; i < list.num_db; i++)
+		else
 		{
-			if(list.dats[i]->manager_pid)
+			records = palloc(sizeof(scheduler_stat_record_t) * nrecords);
+			if(list.super_pid)
 			{
-				records[nr].pid = list.dats[i]->manager_pid;
-				records[nr].datname = list.dats[i]->name;
-				records[nr++].name = names[1];
-				if(list.dats[i]->nexecs)
+				records[nr].pid = list.super_pid;
+				records[nr].datname = list.super_datname;
+				records[nr++].name = names[0];
+			}
+			for(i = 0; i < list.num_db; i++)
+			{
+				if(list.dats[i]->manager_pid)
 				{
-					for(j=0; j < list.dats[i]->nexecs; j++)
+					records[nr].pid = list.dats[i]->manager_pid;
+					records[nr].datname = list.dats[i]->name;
+					records[nr++].name = names[1];
+					if(list.dats[i]->nexecs)
 					{
-						records[nr].pid = list.dats[i]->execs[j];
-						records[nr].datname = list.dats[i]->name;
-						records[nr++].name = names[2];
+						for(j=0; j < list.dats[i]->nexecs; j++)
+						{
+							records[nr].pid = list.dats[i]->execs[j];
+							records[nr].datname = list.dats[i]->name;
+							records[nr++].name = names[2];
+						}
 					}
-				}
-				if(list.dats[i]->natexecs)
-				{
-					for(j=0; j < list.dats[i]->natexecs; j++)
+					if(list.dats[i]->natexecs)
 					{
-						records[nr].pid = list.dats[i]->atexecs[j];
-						records[nr].datname = list.dats[i]->name;
-						records[nr++].name = names[3];
+						for(j=0; j < list.dats[i]->natexecs; j++)
+						{
+							records[nr].pid = list.dats[i]->atexecs[j];
+							records[nr].datname = list.dats[i]->name;
+							records[nr++].name = names[3];
+						}
 					}
 				}
+				else
+				{
+					records[nr].pid = 0;
+					records[nr].datname = list.dats[i]->name;
+					records[nr++].name = names[1];
+				}
 			}
+			funcctx->max_calls = nrecords;
+			funcctx->user_fctx = (void *)records;
 		}
-		for(i=0; i < list.num_db; i++)
-		{
-			if(list.dats[i]->manager_pid == 0) 
-			{
-				records[nr].pid = 0;
-				records[nr].datname = list.dats[i]->name;
-				records[nr++].name = names[1];
-			}
-		}
-		funcctx->max_calls = nrecords;
-		funcctx->user_fctx = (void *)records;
 		MemoryContextSwitchTo(old_ctx);
 	}
 	funcctx = SRF_PERCALL_SETUP();
@@ -1260,6 +1270,8 @@ scheduler_status(PG_FUNCTION_ARGS)
 	tupdesc = funcctx->tuple_desc;
 	nrecords = funcctx->max_calls;
 
+	if(nrecords == 0) SRF_RETURN_DONE(funcctx);
+
 	records = (scheduler_stat_record_t *)funcctx->user_fctx;
 	if(nr < nrecords)
 	{