diff options
| -rw-r--r-- | changelog.d/16383.misc | 1 | ||||
| -rw-r--r-- | synapse/storage/databases/state/bg_updates.py | 18 |
2 files changed, 17 insertions, 2 deletions
diff --git a/changelog.d/16383.misc b/changelog.d/16383.misc new file mode 100644 index 0000000000..d8d84cc184 --- /dev/null +++ b/changelog.d/16383.misc @@ -0,0 +1 @@ +Improve comments in `StateGroupBackgroundUpdateStore`. diff --git a/synapse/storage/databases/state/bg_updates.py b/synapse/storage/databases/state/bg_updates.py index 5b8ba436d4..6ff533a129 100644 --- a/synapse/storage/databases/state/bg_updates.py +++ b/synapse/storage/databases/state/bg_updates.py @@ -94,6 +94,18 @@ class StateGroupBackgroundUpdateStore(SQLBaseStore): groups: List[int], state_filter: Optional[StateFilter] = None, ) -> Mapping[int, StateMap[str]]: + """ + Given a number of state groups, fetch the latest state for each group. + + Args: + txn: The transaction object. + groups: The given state groups that you want to fetch the latest state for. + state_filter: The state filter to apply the state we fetch state from the database. + + Returns: + Map from state_group to a StateMap at that point. + """ + state_filter = state_filter or StateFilter.all() results: Dict[int, MutableStateMap[str]] = {group: {} for group in groups} @@ -206,8 +218,10 @@ class StateGroupBackgroundUpdateStore(SQLBaseStore): if where_clause: where_clause = " AND (%s)" % (where_clause,) - # We don't use WITH RECURSIVE on sqlite3 as there are distributions - # that ship with an sqlite3 version that doesn't support it (e.g. wheezy) + # XXX: We could `WITH RECURSIVE` here since it's supported on SQLite 3.8.3 + # or higher and our minimum supported version is greater than that. + # + # We just haven't put in the time to refactor this. for group in groups: next_group: Optional[int] = group |