diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py
index 66a995157d..75951d0173 100644
--- a/synapse/storage/background_updates.py
+++ b/synapse/storage/background_updates.py
@@ -14,6 +14,7 @@
# limitations under the License.
from ._base import SQLBaseStore
+from . import engines
from twisted.internet import defer
@@ -106,13 +107,13 @@ class BackgroundUpdateStore(SQLBaseStore):
)
except:
logger.exception("Error doing update")
-
- if result is None:
- logger.info(
- "No more background updates to do."
- " Unscheduling background update task."
- )
- return
+ else:
+ if result is None:
+ logger.info(
+ "No more background updates to do."
+ " Unscheduling background update task."
+ )
+ return
@defer.inlineCallbacks
def do_background_update(self, desired_duration_ms):
@@ -202,6 +203,64 @@ class BackgroundUpdateStore(SQLBaseStore):
"""
self._background_update_handlers[update_name] = update_handler
+ def register_background_index_update(self, update_name, index_name,
+ table, columns):
+ """Helper for store classes to do a background index addition
+
+ To use:
+
+ 1. use a schema delta file to add a background update. Example:
+ INSERT INTO background_updates (update_name, progress_json) VALUES
+ ('my_new_index', '{}');
+
+ 2. In the Store constructor, call this method
+
+ Args:
+ update_name (str): update_name to register for
+ index_name (str): name of index to add
+ table (str): table to add index to
+ columns (list[str]): columns/expressions to include in index
+ """
+
+ # if this is postgres, we add the indexes concurrently. Otherwise
+ # we fall back to doing it inline
+ if isinstance(self.database_engine, engines.PostgresEngine):
+ conc = True
+ else:
+ conc = False
+
+ sql = "CREATE INDEX %(conc)s %(name)s ON %(table)s (%(columns)s)" \
+ % {
+ "conc": "CONCURRENTLY" if conc else "",
+ "name": index_name,
+ "table": table,
+ "columns": ", ".join(columns),
+ }
+
+ def create_index_concurrently(conn):
+ conn.rollback()
+ # postgres insists on autocommit for the index
+ conn.set_session(autocommit=True)
+ c = conn.cursor()
+ c.execute(sql)
+ conn.set_session(autocommit=False)
+
+ def create_index(conn):
+ c = conn.cursor()
+ c.execute(sql)
+
+ @defer.inlineCallbacks
+ def updater(progress, batch_size):
+ logger.info("Adding index %s to %s", index_name, table)
+ if conc:
+ yield self.runWithConnection(create_index_concurrently)
+ else:
+ yield self.runWithConnection(create_index)
+ yield self._end_background_update(update_name)
+ defer.returnValue(1)
+
+ self.register_background_update_handler(update_name, updater)
+
def start_background_update(self, update_name, progress):
"""Starts a background update running.
|
