Add ds_clean flag to trigger index rebuilds, SL #2095, #2317

This gives us more complete coverage of cases where ENOSPC or
other errors are hit when creating/updating datastore entries.

Without this patch, using the Journal on ENOSPC sometimes leads
to an "empty" Journal after restart. Datastore entries exist on
disk but are not in the index (Xapian DB).

With this patch, failure to complete create/update/delete forces
an index rebuild on restart.

Signed-off-by: Martin Langhoff <martin@laptop.org>
Tested-by: Samuel Greenfeld <greenfeld@laptop.org>
Acked-by: Simon Schampijer <simon@laptop.org>

1 files changed, 30 insertions, 1 deletions

diff --git a/src/carquinyol/datastore.py b/src/carquinyol/datastore.py
index de79500..1f098b4 100644
--- a/src/carquinyol/datastore.py
+++ b/src/carquinyol/datastore.py
@@ -66,6 +66,9 @@ class DataStore(dbus.service.Object):
         self._index_store = IndexStore()
         self._index_updating = False
 
+        root_path = layoutmanager.get_instance().get_root_path()
+        self._cleanflag = os.path.join(root_path, 'ds_clean')
+
         if migrated:
             self._rebuild_index()
             return
@@ -83,6 +86,25 @@ class DataStore(dbus.service.Object):
         elif not self._index_store.index_updated:
             logging.debug('Index is not up-to-date, will update')
             self._update_index()
+        elif not os.path.exists(self._cleanflag):
+            logging.debug('DS state is not clean, will update')
+            self._update_index()
+        self._mark_clean()
+
+
+    def _mark_clean(self):
+        try:
+             f = open(self._cleanflag, 'w')
+             os.fsync(f.fileno())
+             f.close()
+        except Exception:
+             logging.exception("Could not mark the datastore clean")
+
+    def _mark_dirty(self):
+        try:
+            os.remove(self._cleanflag)
+        except:
+            pass
 
     def _open_layout(self):
         """Open layout manager, check version of data store on disk and
@@ -178,6 +200,7 @@ class DataStore(dbus.service.Object):
         self.Created(uid)
         self._optimizer.optimize(uid)
         logger.debug('created %s', uid)
+        self._mark_clean()
         async_cb(uid)
 
     @dbus.service.method(DS_DBUS_INTERFACE,
@@ -190,6 +213,8 @@ class DataStore(dbus.service.Object):
         uid = str(uuid.uuid4())
         logging.debug('datastore.create %r', uid)
 
+        self._mark_dirty()
+
         if not props.get('timestamp', ''):
             props['timestamp'] = int(time.time())
 
@@ -232,6 +257,7 @@ class DataStore(dbus.service.Object):
         self.Updated(uid)
         self._optimizer.optimize(uid)
         logger.debug('updated %s', uid)
+        self._mark_clean()
         async_cb()
 
     @dbus.service.method(DS_DBUS_INTERFACE,
@@ -243,6 +269,8 @@ class DataStore(dbus.service.Object):
                async_cb, async_err_cb):
         logging.debug('datastore.update %r', uid)
 
+        self._mark_dirty()
+
         if not props.get('timestamp', ''):
             props['timestamp'] = int(time.time())
 
@@ -393,6 +421,7 @@ class DataStore(dbus.service.Object):
              in_signature='s',
              out_signature='')
     def delete(self, uid):
+        self._mark_dirty()
         self._optimizer.remove(uid)
 
         self._index_store.delete(uid)
@@ -404,7 +433,7 @@ class DataStore(dbus.service.Object):
 
         self.Deleted(uid)
         logger.debug('deleted %s', uid)
-
+        self._mark_clean()
     @dbus.service.signal(DS_DBUS_INTERFACE, signature="s")
     def Deleted(self, uid):
         pass