From cd3312496e1dbdc6cc39f838fec3cd46501f57ae Mon Sep 17 00:00:00 2001
From: Ian Barwick <ian@2ndquadrant.com>
Date: Wed, 6 Feb 2019 09:30:45 +0900
Subject: [PATCH] Rename functions which return an LSN for clarity

---
 dbutils.c               | 20 +++++++++++++++-----
 dbutils.h               |  4 ++--
 repmgr-action-standby.c |  4 ++--
 repmgr-client.c         |  2 +-
 repmgrd-physical.c      |  2 +-
 5 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/dbutils.c b/dbutils.c
index 20f71d55..e2da25de 100644
--- a/dbutils.c
+++ b/dbutils.c
@@ -4551,9 +4551,16 @@ reset_voting_status(PGconn *conn)
 /* replication status functions */
 /* ============================ */
 
-
+/*
+ * Returns the current LSN on the primary.
+ *
+ * This just executes "pg_current_wal_lsn()".
+ *
+ * Function "get_node_current_lsn()" below will return the latest
+ * LSN regardless of recovery state.
+ */
 XLogRecPtr
-get_current_wal_lsn(PGconn *conn)
+get_primary_current_lsn(PGconn *conn)
 {
 	PGresult   *res = NULL;
 	XLogRecPtr	ptr = InvalidXLogRecPtr;
@@ -4577,6 +4584,7 @@ get_current_wal_lsn(PGconn *conn)
 	return ptr;
 }
 
+
 XLogRecPtr
 get_last_wal_receive_location(PGconn *conn)
 {
@@ -4602,9 +4610,11 @@ get_last_wal_receive_location(PGconn *conn)
 	return ptr;
 }
 
-
+/*
+ * Returns the latest LSN for the node regardless of recovery state.
+ */
 XLogRecPtr
-get_current_lsn(PGconn *conn)
+get_node_current_lsn(PGconn *conn)
 {
 	PQExpBufferData query;
 	PGresult   *res = NULL;
@@ -4678,7 +4688,7 @@ get_current_lsn(PGconn *conn)
 
 	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
-		log_db_error(conn, query.data, _("unable to execute get_current_lsn()"));
+		log_db_error(conn, query.data, _("unable to execute get_node_current_lsn()"));
 	}
 	else if (!PQgetisnull(res, 0, 0))
 	{
diff --git a/dbutils.h b/dbutils.h
index 568ba9fa..43e193a9 100644
--- a/dbutils.h
+++ b/dbutils.h
@@ -538,9 +538,9 @@ bool		get_new_primary(PGconn *conn, int *primary_node_id);
 void		reset_voting_status(PGconn *conn);
 
 /* replication status functions */
-XLogRecPtr	get_current_wal_lsn(PGconn *conn);
+XLogRecPtr	get_primary_current_lsn(PGconn *conn);
+XLogRecPtr	get_node_current_lsn(PGconn *conn);
 XLogRecPtr	get_last_wal_receive_location(PGconn *conn);
-XLogRecPtr	get_current_lsn(PGconn *conn);
 void		init_replication_info(ReplInfo *replication_info);
 bool		get_replication_info(PGconn *conn, ReplInfo *replication_info);
 int			get_replication_lag_seconds(PGconn *conn);
diff --git a/repmgr-action-standby.c b/repmgr-action-standby.c
index bb499feb..020fdd8e 100644
--- a/repmgr-action-standby.c
+++ b/repmgr-action-standby.c
@@ -2532,7 +2532,7 @@ do_standby_follow(void)
 		t_system_identification local_identification = T_SYSTEM_IDENTIFICATION_INITIALIZER;
 
 		bool can_follow;
-		XLogRecPtr local_xlogpos = get_current_lsn(local_conn);
+		XLogRecPtr local_xlogpos = get_node_current_lsn(local_conn);
 
 		/* Check local replication connection - we want to execute IDENTIFY_SYSTEM
 		 * to get the current timeline ID, which might not yet be written to
@@ -3234,7 +3234,7 @@ do_standby_switchover(void)
 	 * to unexpected behaviour when the standby is promoted.
 	 *
 	 * For switchover we'll mandate that WAL replay *must not* be paused.
-	 * For a promote operation we can proceed if WAL replay is paused
+	 * For a promote operation we can proceed if WAL replay is paused and
 	 * there is no more available WAL to be replayed, as we can be sure the
 	 * primary is down already, but in a switchover context there's
 	 * potentially a window for more WAL to be received before we shut down
diff --git a/repmgr-client.c b/repmgr-client.c
index 08071101..0e9ac9c1 100644
--- a/repmgr-client.c
+++ b/repmgr-client.c
@@ -3321,7 +3321,7 @@ check_node_can_attach(TimeLineID local_tli, XLogRecPtr local_xlogpos, PGconn *fo
 
 	if (follow_target_identification.timeline == local_tli)
 	{
-		XLogRecPtr follow_target_xlogpos = get_current_lsn(follow_target_conn);
+		XLogRecPtr follow_target_xlogpos = get_node_current_lsn(follow_target_conn);
 
 		if (local_xlogpos == InvalidXLogRecPtr || follow_target_xlogpos == InvalidXLogRecPtr)
 		{
diff --git a/repmgrd-physical.c b/repmgrd-physical.c
index 4dc19b14..e09d1d54 100644
--- a/repmgrd-physical.c
+++ b/repmgrd-physical.c
@@ -2242,7 +2242,7 @@ update_monitoring_history(void)
 					local_node_info.node_id);
 	}
 
-	primary_last_wal_location = get_current_wal_lsn(primary_conn);
+	primary_last_wal_location = get_primary_current_lsn(primary_conn);
 
 	if (primary_last_wal_location == InvalidXLogRecPtr)
 	{