extend tarfile API for rescue mode

[python-delta-tar] / deltatar / deltatar.py

diff --git a/deltatar/deltatar.py b/deltatar/deltatar.py
index 55a1905..b1b8ccc 100644 (file)
--- a/deltatar/deltatar.py
+++ b/deltatar/deltatar.py
@@ -1296,7 +1296,7 @@ class DeltaTar(object):
 
     def restore_backup(self, target_path, backup_indexes_paths=[],
                        backup_tar_path=None, restore_callback=None,
-                       disaster=False):
+                       disaster=tarfile.TOLERANCE_STRICT):
         '''
         Restores a backup.
 
@@ -1386,7 +1386,8 @@ class DeltaTar(object):
             helper = RestoreHelper(self, cwd, backup_path=backup_tar_path,
                                    tarobj=index_it.tar_obj)
         elif mode == "diff":
-            helper = RestoreHelper(self, cwd, backup_indexes_paths, disaster=disaster)
+            helper = RestoreHelper(self, cwd, backup_indexes_paths,
+                                   disaster=disaster)
             try:
                 # get iterator from newest index at _data[0]
                 index1 = helper._data[0]["path"]
@@ -1439,7 +1440,7 @@ class DeltaTar(object):
                     iipath = ipath.get ("path", "")
                     self.logger.error("FAILED to restore: {} ({})"
                                       .format(iipath, e))
-                    if disaster is True:
+                    if disaster != tarfile.TOLERANCE_STRICT:
                         failed.append ((iipath, e))
                 continue
 
@@ -1459,7 +1460,7 @@ class DeltaTar(object):
                 try:
                     helper.restore(ipath, l_no, restore_callback)
                 except Exception as e:
-                    if disaster is False:
+                    if disaster == tarfile.TOLERANCE_STRICT:
                         raise
                     failed.append ((ipath.get ("path", ""), e))
                     continue
@@ -1486,7 +1487,19 @@ class DeltaTar(object):
         """
         return self.restore_backup(target_path,
                                    backup_indexes_paths=backup_indexes_paths,
-                                   disaster=True)
+                                   disaster=tarfile.TOLERANCE_RECOVER)
+
+
+    def rescue_backup(self, target_path, backup_indexes_paths=[],
+                      restore_callback=None):
+        """
+        More aggressive “unfsck” mode: do not rely on the index data as the
+        files may be corrupt; skim files for header-like information and
+        attempt to retrieve the data.
+        """
+        return self.restore_backup(target_path,
+                                   backup_indexes_paths=backup_indexes_paths,
+                                   disaster=tarfile.TOLERANCE_RESCUE)
 
 
     def _parse_json_line(self, f, l_no):
@@ -1529,10 +1542,10 @@ class RestoreHelper(object):
     # tarfile.extractall for details.
     _directories = []
 
-    _disaster = False
+    _disaster = tarfile.TOLERANCE_STRICT
 
     def __init__(self, deltatar, cwd, index_list=None, backup_path=False,
-                 tarobj=None, disaster=False):
+                 tarobj=None, disaster=tarfile.TOLERANCE_STRICT):
         '''
         Constructor opens the tars and init the data structures.
 
@@ -1878,7 +1891,7 @@ class RestoreHelper(object):
                     encryption=index_data["decryptor"],
                     new_volume_handler=index_data['new_volume_handler'],
                     save_to_members=False,
-                    tolerant=self._disaster)
+                    tolerance=self._disaster)
 
                 member = index_data['tarobj'].__iter__().__next__()