Changed HFS back-end to prefer look up by identifier (#657)

dfvfs/vfs/apfs_file_system.py

@@ -89,8 +89,8 @@ def FileEntryExistsByPathSpec(self, path_spec):
     Raises:
       BackEndError: if the file entry cannot be opened.
     """
-    # Opening a file by identifier by location will ensure added time is
-    # provided when available.
+    # Opening a file by location will ensure added time is provided when
+    # available.
     fsapfs_file_entry = None
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
@@ -119,8 +119,8 @@ def GetFileEntryByPathSpec(self, path_spec):
     Raises:
       BackEndError: if the file entry cannot be opened.
     """
-    # Opening a file by identifier by location will ensure added time is
-    # provided when available.
+    # Opening a file by location will ensure added time is provided when
+    # available.
     fsapfs_file_entry = None
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
@@ -162,8 +162,8 @@ def GetAPFSFileEntryByPathSpec(self, path_spec):
       PathSpecError: if the path specification is missing location and
           identifier.
     """
-    # Opening a file by identifier by location will ensure added time is
-    # provided when available.
+    # Opening a file by location will ensure added time is provided when
+    # available.
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
 

dfvfs/vfs/hfs_file_system.py

@@ -75,17 +75,17 @@ def FileEntryExistsByPathSpec(self, path_spec):
     Raises:
       BackEndError: if the file entry cannot be opened.
     """
-    # Opening a file by location is faster than opening a file by identifier.
+    # Opening a file by identifier is faster than opening a file by location.
     fshfs_file_entry = None
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
 
     try:
-      if location is not None:
-        fshfs_file_entry = self._fshfs_volume.get_file_entry_by_path(location)
-      elif identifier is not None:
+      if identifier is not None:
         fshfs_file_entry = self._fshfs_volume.get_file_entry_by_identifier(
             identifier)
+      elif location is not None:
+        fshfs_file_entry = self._fshfs_volume.get_file_entry_by_path(location)
 
     except IOError as exception:
       raise errors.BackEndError(exception)
@@ -104,7 +104,7 @@ def GetFileEntryByPathSpec(self, path_spec):
     Raises:
       BackEndError: if the file entry cannot be opened.
     """
-    # Opening a file by location is faster than opening a file by identifier.
+    # Opening a file by identifier is faster than opening a file by location.
     fshfs_file_entry = None
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
@@ -117,11 +117,11 @@ def GetFileEntryByPathSpec(self, path_spec):
           fshfs_file_entry=fshfs_file_entry, is_root=True)
 
     try:
-      if location is not None:
-        fshfs_file_entry = self._fshfs_volume.get_file_entry_by_path(location)
-      elif identifier is not None:
+      if identifier is not None:
         fshfs_file_entry = self._fshfs_volume.get_file_entry_by_identifier(
             identifier)
+      elif location is not None:
+        fshfs_file_entry = self._fshfs_volume.get_file_entry_by_path(location)
 
     except IOError as exception:
       raise errors.BackEndError(exception)
@@ -146,15 +146,15 @@ def GetHFSFileEntryByPathSpec(self, path_spec):
       PathSpecError: if the path specification is missing location and
           identifier.
     """
-    # Opening a file by location is faster than opening a file by identifier.
+    # Opening a file by identifier is faster than opening a file by location.
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
 
-    if location is not None:
-      fshfs_file_entry = self._fshfs_volume.get_file_entry_by_path(location)
-    elif identifier is not None:
+    if identifier is not None:
       fshfs_file_entry = self._fshfs_volume.get_file_entry_by_identifier(
           identifier)
+    elif location is not None:
+      fshfs_file_entry = self._fshfs_volume.get_file_entry_by_path(location)
     else:
       raise errors.PathSpecError(
           'Path specification missing location and identifier.')