From: Craig Ringer <craig@2ndquadrant.com>
Date: Fri, 6 Feb 2015 11:31:19 +0000 (+1300)
Subject: bdr: add bdr_test_replication_connection(...)
X-Git-Tag: bdr-plugin/0.9.0~81
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=eb5cb8bd15e77a138d37e4e77717077ce8504be7;p=2ndquadrant_bdr.git

bdr: add bdr_test_replication_connection(...)
---

diff --git a/bdr_remotecalls.c b/bdr_remotecalls.c
index 108cd0a739..d0557f65a8 100644
--- a/bdr_remotecalls.c
+++ b/bdr_remotecalls.c
@@ -45,8 +45,10 @@
 #include "utils/syscache.h"
 
 PGDLLEXPORT Datum bdr_get_remote_nodeinfo(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum bdr_test_replication_connection(PG_FUNCTION_ARGS);
 
 PG_FUNCTION_INFO_V1(bdr_get_remote_nodeinfo);
+PG_FUNCTION_INFO_V1(bdr_test_replication_connection);
 
 /*
  * Make standard postgres connection, ERROR on failure.
@@ -288,3 +290,50 @@ bdr_get_remote_nodeinfo(PG_FUNCTION_ARGS)
 
 	PG_RETURN_DATUM(HeapTupleGetDatum(returnTuple));
 }
+
+/*
+ * Test a given dsn as a replication connection, appending the replication
+ * parameter.
+ *
+ * If non-null, the node identity information arguments will be checked
+ * against the identity reported by the connection.
+ *
+ * This can be used safely against the local_dsn, as it does not enforce
+ * that the local node ID differ from the identity on the other end.
+ */
+Datum
+bdr_test_replication_connection(PG_FUNCTION_ARGS)
+{
+	const char	*conninfo = text_to_cstring(PG_GETARG_TEXT_P(0));
+	TupleDesc	tupleDesc;
+	HeapTuple	returnTuple;
+	PGconn		*conn;
+	NameData	appname;
+	uint64		remote_sysid;
+	TimeLineID	remote_tlid;
+	Oid			remote_dboid;
+	Datum		values[3];
+	bool		isnull[3] = {false, false, false};
+	char		sysid_str[33];
+
+	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	strncpy(NameStr(appname), "BDR test connection", NAMEDATALEN);
+
+	conn = bdr_connect(conninfo, &appname, &remote_sysid, &remote_tlid,
+					   &remote_dboid);
+
+	snprintf(sysid_str, sizeof(sysid_str), UINT64_FORMAT, remote_sysid);
+	sysid_str[sizeof(sysid_str)-1] = '\0';
+
+	values[0] = CStringGetTextDatum(sysid_str);
+	values[1] = ObjectIdGetDatum(remote_tlid);
+	values[2] = ObjectIdGetDatum(remote_dboid);
+
+	returnTuple = heap_form_tuple(tupleDesc, values, isnull);
+
+	PQfinish(conn);
+
+	PG_RETURN_DATUM(HeapTupleGetDatum(returnTuple));
+}
diff --git a/expected/identifier.out b/expected/identifier.out
index 1564cddd82..c0322129cd 100644
--- a/expected/identifier.out
+++ b/expected/identifier.out
@@ -39,3 +39,25 @@ FROM bdr.bdr_get_remote_nodeinfo('dbname='||current_database()) r;
  t
 (1 row)
 
+-- Test probing for replication connection
+SELECT
+	r.sysid = l.sysid,
+	r.timeline = l.timeline,
+	r.dboid = (SELECT oid FROM pg_database WHERE datname = 'postgres')
+FROM bdr.bdr_test_replication_connection('dbname=postgres') r,
+     bdr.bdr_get_local_nodeid() l;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+-- Probing replication connection for the local dsn will work too
+-- even though the identifier is the same.
+SELECT
+	r.dboid = (SELECT oid FROM pg_database WHERE datname = current_database())
+FROM bdr.bdr_test_replication_connection('dbname='||current_database()) r;
+ ?column? 
+----------
+ t
+(1 row)
+
diff --git a/extsql/bdr--0.8.0.7--0.9.0.0.sql b/extsql/bdr--0.8.0.7--0.9.0.0.sql
index 4feaf86e97..6843d0db48 100644
--- a/extsql/bdr--0.8.0.7--0.9.0.0.sql
+++ b/extsql/bdr--0.8.0.7--0.9.0.0.sql
@@ -13,6 +13,14 @@ REVOKE ALL ON FUNCTION bdr_get_remote_nodeinfo(text) FROM public;
 
 COMMENT ON FUNCTION bdr_get_remote_nodeinfo(text) IS 'Get node identity and BDR info from a remote server by dsn';
 
+CREATE FUNCTION bdr_test_replication_connection(dsn text, sysid OUT text, timeline OUT oid, dboid OUT oid)
+RETURNS record LANGUAGE c AS 'MODULE_PATHNAME';
+
+REVOKE ALL ON FUNCTION bdr_test_replication_connection(text) FROM public;
+
+COMMENT ON FUNCTION bdr_test_replication_connection(text)
+IS 'Make a replication-mode connection to the specified DSN and get its node identity.';
+
 RESET bdr.permit_unsafe_ddl_commands;
 RESET bdr.skip_ddl_replication;
 RESET search_path;
diff --git a/sql/identifier.sql b/sql/identifier.sql
index 3627694745..58a3a8f206 100644
--- a/sql/identifier.sql
+++ b/sql/identifier.sql
@@ -22,3 +22,17 @@ FROM bdr.bdr_get_remote_nodeinfo('dbname=postgres') r,
 SELECT
     r.dboid = (SELECT oid FROM pg_database WHERE datname = current_database())
 FROM bdr.bdr_get_remote_nodeinfo('dbname='||current_database()) r;
+
+-- Test probing for replication connection
+SELECT
+	r.sysid = l.sysid,
+	r.timeline = l.timeline,
+	r.dboid = (SELECT oid FROM pg_database WHERE datname = 'postgres')
+FROM bdr.bdr_test_replication_connection('dbname=postgres') r,
+     bdr.bdr_get_local_nodeid() l;
+
+-- Probing replication connection for the local dsn will work too
+-- even though the identifier is the same.
+SELECT
+	r.dboid = (SELECT oid FROM pg_database WHERE datname = current_database())
+FROM bdr.bdr_test_replication_connection('dbname='||current_database()) r;