refactoring to use common logic when getting standby.signal file (#172)

* refactoring to use common logic when getting standby.signal file

* move common functions for backup.c and restore.c to data.c

backup.c

@@ -860,9 +860,7 @@ do_backup(pgBackupOption bkupopt)
 	 * (ie, $PGDATA has recovery.conf or standby.signal),
 	 * check required parameters (ie, standby connection info).
 	 */
-	snprintf(path, lengthof(path), "%s/standby.signal", pgdata);
-	make_native_path(path);
-	if (fileExists(path))
+	if (get_standby_signal_filepath(path, sizeof(path)))
 	{
 		if (!bkupopt.standby_host || !bkupopt.standby_port)
 			ereport(ERROR,
@@ -1351,22 +1349,6 @@ get_xid(PGresult *res, uint32 *xid)
 	elog(DEBUG, "current XID is %s", PQgetvalue(res, 0, 0));
 }
 
-/*
- * Return true if the path is a existing regular file.
- */
-bool
-fileExists(const char *path)
-{
-	struct stat buf;
-
-	if (stat(path, &buf) == -1 && errno == ENOENT)
-		return false;
-	else if (!S_ISREG(buf.st_mode))
-		return false;
-	else
-		return true;
-}
-
 /*
  * Return true if the path is a existing directory.
  */

data.c

@@ -1276,3 +1276,31 @@ figure_out_segno(char *filepath)
 
 	return segno;
 }
+
+/*
+ * Return true if the path is a existing regular file.
+ */
+bool
+fileExists(const char *path)
+{
+	struct stat buf;
+
+	if (stat(path, &buf) == -1 && errno == ENOENT)
+		return false;
+	else if (!S_ISREG(buf.st_mode))
+		return false;
+	else
+		return true;
+}
+
+/*
+ * Return true if standby.signal file exists and
+ * store the file path to the "path"
+ */
+bool
+get_standby_signal_filepath(char *path, size_t size)
+{
+	snprintf(path, size, "%s/standby.signal", pgdata);
+	make_native_path(path);
+	return fileExists(path);
+}

expected/backup_from_standby.out

@@ -35,3 +35,5 @@
  streaming
 (1 row)
 
+###### BACKUP COMMAND FROM STANDBY SERVER TEST-0005 ######
+ERROR: please specify both standby host and port

pg_rman.h

@@ -258,7 +258,6 @@ extern bool data_checksum_enabled;
 /* in backup.c */
 extern int do_backup(pgBackupOption bkupopt);
 extern BackupMode parse_backup_mode(const char *value, int elevel);
-extern bool fileExists(const char *path);
 
 /* in restore.c */
 extern int do_restore(const char *target_time,
@@ -340,6 +339,8 @@ extern void restore_data_file(const char *from_root, const char *to_root,
 extern bool copy_file(const char *from_root, const char *to_root,
 					  pgFile *file, CompressionMode compress);
 extern pgFile *write_stop_backup_file(pgBackup *backup, const char *buf, int len, const char *file_name);
+extern bool fileExists(const char *path);
+extern bool get_standby_signal_filepath(char *path, size_t size);
 
 /* in util.c */
 extern void time2iso(char *buf, size_t len, time_t time);

restore.c

@@ -809,7 +809,6 @@ create_recovery_signal(void)
 static void
 remove_standby_signal(void)
 {
-	struct stat stat_buf;
 	char path[MAXPGPATH];
 
 	if (verbose && !check)
@@ -819,9 +818,7 @@ remove_standby_signal(void)
 
 	if (!check)
 	{
-		snprintf(path, lengthof(path), "%s/standby.signal", pgdata);
-
-		if (stat(path, &stat_buf) == 0)
+		if (get_standby_signal_filepath(path, sizeof(path)))
 		{
 			if (remove(path))
 			{

sql/backup_from_standby.sh

@@ -273,6 +273,13 @@ psql -p ${TEST_SBYPGPORT} --no-psqlrc -d pgbench -c "SELECT status FROM pg_stat_
 get_database_data_from_standby > ${TEST_BASE}/TEST-0004-after.out
 diff ${TEST_BASE}/TEST-0004-before.out ${TEST_BASE}/TEST-0004-after.out
 
+# check to fail if "--standby-host" and "--standby-port" are not specified
+init_backup
+setup_standby
+init_catalog
+echo '###### BACKUP COMMAND FROM STANDBY SERVER TEST-0005 ######'
+pg_rman backup -B ${BACKUP_PATH} -b full -Z -p ${TEST_PGPORT} -d postgres -D ${SBYDATA_PATH}
+
 # clean up the temporal test data
 pg_ctl stop -m immediate -D ${PGDATA_PATH} > /dev/null 2>&1
 pg_ctl stop -m immediate -D ${SBYDATA_PATH} > /dev/null 2>&1