Add and use signal distribution infrastructure

Once we have multiple D-Bus interfaces, we need to send signals on all of
them.

Signed-off-by: Sascha Silbe <sascha-pgp@silbe.org>

1 files changed, 36 insertions, 3 deletions

diff --git a/gdatastore/datastore.py b/gdatastore/datastore.py
index b8cf032..9db437e 100644
--- a/gdatastore/datastore.py
+++ b/gdatastore/datastore.py
@@ -75,6 +75,10 @@ class DBusApiSugarV2(dbus.service.Object):
                                         allow_replacement=False,
                                         do_not_queue=True)
         dbus.service.Object.__init__(self, bus_name, DBUS_PATH_SUGAR_V2)
+        self._internal_api.add_callback('change_metadata',
+                                        self.__change_metadata_cb)
+        self._internal_api.add_callback('delete', self.__delete_cb)
+        self._internal_api.add_callback('save', self.__save_cb)
 
     @dbus.service.method(DBUS_INTERFACE_SUGAR_V2,
                          in_signature='a{sv}sb', out_signature='s',
@@ -83,7 +87,6 @@ class DBusApiSugarV2(dbus.service.Object):
     def create(self, props, file_path, transfer_ownership,
                async_cb, async_err_cb):
         def success_cb(tree_id, child_id):
-            self.Created(tree_id)
             async_cb(tree_id)
 
         self._internal_api.save(tree_id='', parent_id='', metadata=props,
@@ -104,7 +107,6 @@ class DBusApiSugarV2(dbus.service.Object):
     def update(self, uid, props, file_path, transfer_ownership,
                async_cb, async_err_cb):
         def success_cb(tree_id, child_id):
-            self.Updated(tree_id)
             async_cb()
 
         latest_versions = self._get_latest(uid)
@@ -187,7 +189,6 @@ class DBusApiSugarV2(dbus.service.Object):
             raise ValueError('Entry %s does not exist' % (uid, ))
 
         self._internal_api.delete((uid, latest_versions[0]['version_id']))
-        self.Deleted(uid)
 
     @dbus.service.signal(DBUS_INTERFACE_SUGAR_V2, signature='s')
     def Deleted(self, uid):
@@ -227,10 +228,29 @@ class DBusApiSugarV2(dbus.service.Object):
         child_checksum = calculate_checksum(child_data_path)
         return parent_checksum == child_checksum
 
+    def __change_metadata_cb(self, (tree_id, version_id), metadata):
+        self.Updated(tree_id)
+
+    def __delete_cb(self, (tree_id, version_id)):
+        if self._get_latest(tree_id):
+            self.Updated(tree_id)
+        else:
+            self.Deleted(tree_id)
+
+    def __save_cb(self, tree_id, child_id, parent_id, metadata):
+        if parent_id:
+            self.Updated(tree_id)
+        else:
+            self.Created(tree_id)
+
 
 class InternalApi(object):
+
+    SIGNALS = ['change_metadata', 'delete', 'save']
+
     def __init__(self, base_dir):
         self._base_dir = base_dir
+        self._callbacks = {}
         self._checkouts_dir = os.path.join(base_dir, 'checkouts')
         if not os.path.exists(self._checkouts_dir):
             os.makedirs(self._checkouts_dir)
@@ -243,6 +263,12 @@ class InternalApi(object):
         self._index = Index(os.path.join(self._base_dir, 'index'))
         self._migrate()
 
+    def add_callback(self, signal, callback):
+        if signal not in InternalApi.SIGNALS:
+            raise ValueError('Invalid signal %r' % (signal, ))
+
+        self._callbacks.setdefault(signal, []).append(callback)
+
     def change_metadata(self, object_id, metadata):
         logging.debug('change_metadata(%r, %r)', object_id, metadata)
         metadata['tree_id'], metadata['version_id'] = object_id
@@ -251,11 +277,13 @@ class InternalApi(object):
             metadata['creation_time'] = old_metadata['creation_time']
 
         self._index.store(object_id, metadata)
+        self._invoke_callbacks('change_metadata', object_id, metadata)
 
     def delete(self, object_id):
         logging.debug('delete(%r)', object_id)
         self._index.delete(object_id)
         self._git_call('update-ref', ['-d', _format_ref(*object_id)])
+        self._invoke_callbacks('delete', object_id)
 
     def get_data_path(self, (tree_id, version_id), sender=None):
         logging.debug('get_data_path((%r, %r), %r)', tree_id, version_id,
@@ -348,6 +376,7 @@ class InternalApi(object):
         # TODO: check metadata for validity first (index?)
         self._store_entry(tree_id, child_id, parent_id, path, metadata)
         self._index.store((tree_id, child_id), metadata)
+        self._invoke_callbacks('save', tree_id, child_id, parent_id, metadata)
         async_cb(tree_id, child_id)
 
     def stop(self):
@@ -424,6 +453,10 @@ class InternalApi(object):
             raise GitError(pipe.returncode, stderr)
         return stdout
 
+    def _invoke_callbacks(self, signal, *args):
+        for callback in self._callbacks.get(signal, []):
+            callback(*args)
+
     def _migrate(self):
         if not os.path.exists(self._git_dir):
             return self._create_repo()