Check if restore destination exists

Artur Zakirov · Artur Zakirov · commit 6485b9f64708 · 2017-02-20T13:39:51.000+03:00
diff --git a/dir.c b/dir.c
@@ -725,3 +725,41 @@ dir_copy_files(const char *from_root, const char *to_root)
 	parray_walk(files, pgFileFree);
 	parray_free(files);
 }
+
+/*
+ * Check if directory empty.
+ */
+bool
+dir_is_empty(const char *path)
+{
+	DIR		   *dir;
+	struct dirent *dir_ent;
+
+	dir = opendir(path);
+	if (dir == NULL)
+	{
+		/* Directory in path doesn't exist */
+		if (errno == ENOENT)
+			return true;
+		elog(ERROR, "cannot open directory \"%s\": %s", path, strerror(errno));
+	}
+
+	errno = 0;
+	while ((dir_ent = readdir(dir)))
+	{
+		/* Skip entries point current dir or parent dir */
+		if (strcmp(dir_ent->d_name, ".") == 0 ||
+			strcmp(dir_ent->d_name, "..") == 0)
+			continue;
+
+		/* Directory is not empty */
+		closedir(dir);
+		return false;
+	}
+	if (errno)
+		elog(ERROR, "cannot read directory \"%s\": %s", path, strerror(errno));
+
+	closedir(dir);
+
+	return true;
+}
diff --git a/pg_probackup.h b/pg_probackup.h
@@ -322,6 +322,7 @@ extern parray *dir_read_file_list(const char *root, const char *file_txt);
 
 extern int dir_create_dir(const char *path, mode_t mode);
 extern void dir_copy_files(const char *from_root, const char *to_root);
+extern bool dir_is_empty(const char *path);
 
 extern pgFile *pgFileNew(const char *path, bool omit_symlink);
 extern void pgFileDelete(pgFile *file);
diff --git a/restore.c b/restore.c
@@ -46,10 +46,8 @@ do_restore(time_t backup_id,
 	int			i;
 	int			base_index;				/* index of base (full) backup */
 	int			ret;
-	TimeLineID	cur_tli;
 	parray	   *backups;
 
-	parray	   *files;
 	parray	   *timelines;
 	pgBackup   *base_backup = NULL;
 	pgBackup   *dest_backup = NULL;
@@ -85,9 +83,6 @@ do_restore(time_t backup_id,
 	if (!backups)
 		elog(ERROR, "cannot process any more.");
 
-	cur_tli = get_current_timeline(true);
-	elog(LOG, "current instance timeline ID = %u", cur_tli);
-
 	if (target_tli)
 	{
 		elog(LOG, "target timeline ID = %u", target_tli);
@@ -148,27 +143,9 @@ do_restore(time_t backup_id,
 base_backup_found:
 	base_index = i;
 
-	/*
-	 * Clear restore destination, but don't remove $PGDATA.
-	 * To remove symbolic link, get file list with "omit_symlink = false".
-	 */
-	if (!check)
-	{
-		elog(LOG, "----------------------------------------");
-		elog(LOG, "clearing restore destination");
-
-		files = parray_new();
-		dir_list_file(files, pgdata, false, false, false);
-		parray_qsort(files, pgFileComparePathDesc);	/* delete from leaf */
-
-		for (i = 0; i < parray_num(files); i++)
-		{
-			pgFile *file = (pgFile *) parray_get(files, i);
-			pgFileDelete(file);
-		}
-		parray_walk(files, pgFileFree);
-		parray_free(files);
-	}
+	/* Check if restore destination empty */
+	if (!dir_is_empty(pgdata))
+		elog(ERROR, "restore destination is not empty");
 
 	print_backup_lsn(base_backup);
 
