add support for modifying metadata/extended attributes

1 files changed, 32 insertions, 0 deletions

diff --git a/datastore-fuse.py b/datastore-fuse.py
index ee32aad..de0f215 100755
--- a/datastore-fuse.py
+++ b/datastore-fuse.py
@@ -43,6 +43,9 @@ DS_DBUS_SERVICE = "org.laptop.sugar.DataStore"
 DS_DBUS_INTERFACE = "org.laptop.sugar.DataStore"
 DS_DBUS_PATH = "/org/laptop/sugar/DataStore"
 
+XATTR_CREATE = 1
+XATTR_REPLACE = 2
+
 
 class DataStoreObjectStat(fuse.Stat):
 
@@ -120,6 +123,9 @@ class Directory(fuse.Stat):
     def remove(self, name_):
         raise IOError(errno.EACCES, os.strerror(errno.EACCES))
 
+    def setxattr(self, name_, attribute_, value_, flags_):
+        raise IOError(errno.ENOTSUP, os.strerror(errno.ENOTSUP))
+
 
 class ByTitleDirectory(Directory):
     def __init__(self, filesystem, root):
@@ -164,6 +170,19 @@ class ByTitleDirectory(Directory):
         object_id = self._filesystem.resolve_title_name(name)
         self._filesystem.remove_entry(object_id)
 
+    def setxattr(self, name, attribute, value, flags):
+        object_id = self._filesystem.resolve_title_name(name)
+        metadata = self._filesystem.get_metadata(object_id)
+        if flags & XATTR_CREATE and attribute in metadata:
+            raise IOError(errno.EEXIST, os.strerror(errno.EEXIST))
+
+        if flags & XATTR_REPLACE and attribute not in metadata:
+            # on Linux ENOATTR=ENODATA (Python errno doesn't contain ENOATTR)
+            raise IOError(errno.ENODATA, os.strerror(errno.ENODATA))
+
+        metadata[attribute] = value
+        self._filesystem.write_metadata(object_id, metadata)
+
 
 class ByIdDirectory(Directory):
     def __init__(self, filesystem):
@@ -460,6 +479,13 @@ class DataStoreFS(fuse.Fuse):
 
         return attribute_names
 
+    def setxattr(self, path, name, value, flags):
+        if not name.startswith('user.'):
+            raise IOError(errno.EACCES, os.strerror(errno.EACCES))
+
+        name = name[5:]
+        return self._delegate(path, 'setxattr', name, value, flags)
+
     def should_truncate(self, object_id):
         return object_id in self._truncate_object_ids
 
@@ -527,6 +553,12 @@ class DataStoreFS(fuse.Fuse):
         return self._data_store.update(object_id, metadata, file_name, False,
             timeout=-1, byte_arrays=True)
 
+    def write_metadata(self, object_id, metadata):
+        # Current data store doesn't support metadata-only updates
+        file_name = self.get_data(object_id)
+        return self._data_store.update(object_id, metadata, file_name,
+            True, timeout=-1, byte_arrays=True)
+
     def resolve_title_name(self, name):
         if name not in self._title_name_to_object_id:
             # FIXME: Hack to fill self._title_name_to_object_id. To be