Factoring out switchover sanity checks

We refactor switchover sanity checks into a separate function, using a
dedicated structure to pass variables across.

Signed-off-by: Gianni Ciolli <gianni.ciolli@enterprisedb.com>

repmgr-action-standby.h

@@ -19,6 +19,77 @@
 #ifndef _REPMGR_ACTION_STANDBY_H_
 #define _REPMGR_ACTION_STANDBY_H_
 
+
+typedef struct
+{
+	int			reachable_sibling_node_count;
+	int			reachable_sibling_nodes_with_slot_count;
+	int			unreachable_sibling_node_count;
+	int			min_required_wal_senders;
+	int			min_required_free_slots;
+} SiblingNodeStats;
+
+#define T_SIBLING_NODES_STATS_INITIALIZER { \
+	0, \
+	0, \
+	0, \
+	0, \
+	0 \
+}
+
+typedef struct
+{
+	RepmgrdInfo **repmgrd_info;
+	int			repmgrd_running_count;
+
+	bool		dry_run_success;
+
+	/* store list of configuration files on the demotion candidate */
+	KeyValueList remote_config_files;
+
+	/* used for handling repmgrd pause/unpause */
+	NodeInfoList all_nodes;
+
+	NodeInfoList sibling_nodes;
+	SiblingNodeStats sibling_nodes_stats;
+
+	t_event_info event_info;
+	int remote_node_id;
+	t_node_info remote_node_record;
+	t_node_info local_node_record;
+	char remote_conninfo[MAXCONNINFO];
+	bool	switchover_success;
+	RecoveryType recovery_type;
+	PGconn	*superuser_conn;
+
+	/* the remote server is the primary to be demoted */
+	char		remote_host[MAXLEN];
+	int 		remote_repmgr_version;
+	PGconn	*remote_conn;
+	PGconn	*local_conn;
+} t_standby_switchover_rec;
+
+#define T_STANDBY_SWITCHOVER_INITIALIZER { \
+	NULL, \
+	true, \
+	{NULL, NULL}, \
+	T_NODE_INFO_LIST_INITIALIZER, \
+	T_NODE_INFO_LIST_INITIALIZER, \
+	T_SIBLING_NODES_STATS_INITIALIZER, \
+	T_EVENT_INFO_INITIALIZER, \
+	UNKNOWN_NODE_ID, \
+	T_NODE_INFO_INITIALIZER, \
+	T_NODE_INFO_INITIALIZER, \
+	"", \
+	true, \
+	RECTYPE_UNKNOWN, \
+	NULL, \
+	"", \
+	UNKNOWN_REPMGR_VERSION_NUM, \
+	NULL, \
+	NULL \
+}
+
 extern void do_standby_clone(void);
 extern void do_standby_register(void);
 extern void do_standby_unregister(void);