Move _find_unreferenced_groups

This commit is contained in:
Erik Johnston 2018-10-29 14:23:34 +00:00
parent 664b192a3b
commit ad88460e0d
2 changed files with 83 additions and 81 deletions

View File

@ -2052,9 +2052,11 @@ class EventsStore(StateGroupWorkerStore, EventFederationStore, EventsWorkerStore
logger.info("[purge] finding state groups that can be deleted")
state_groups_to_delete, remaining_state_groups = self._find_unreferenced_groups(
state_groups_to_delete, remaining_state_groups = (
self._find_unreferenced_groups_during_purge(
txn, referenced_state_groups,
)
)
logger.info(
"[purge] found %i state groups to delete",
@ -2209,6 +2211,85 @@ class EventsStore(StateGroupWorkerStore, EventFederationStore, EventsWorkerStore
logger.info("[purge] done")
def _find_unreferenced_groups_during_purge(self, txn, state_groups):
"""Used when purging history to figure out which state groups can be
deleted and which need to be de-delta'ed (due to one of its prev groups
being scheduled for deletion).
Args:
txn
state_groups (set[int]): Set of state groups referenced by events
that are going to be deleted.
Returns:
tuple[set[int], set[int]]: The set of state groups that can be
deleted and the set of state groups that need to be de-delta'ed
"""
# Graph of state group -> previous group
graph = {}
# Set of events that we have found to be referenced by events
referenced_groups = set()
# Set of state groups we've already seen
state_groups_seen = set(state_groups)
# Set of state groups to handle next.
next_to_search = set(state_groups)
while next_to_search:
# We bound size of groups we're looking up at once, to stop the
# SQL query getting too big
if len(next_to_search) < 100:
current_search = next_to_search
next_to_search = set()
else:
current_search = set(itertools.islice(next_to_search, 100))
next_to_search -= current_search
# Check if state groups are referenced
sql = """
SELECT DISTINCT state_group FROM event_to_state_groups
LEFT JOIN events_to_purge AS ep USING (event_id)
WHERE state_group IN (%s) AND ep.event_id IS NULL
""" % (",".join("?" for _ in current_search),)
txn.execute(sql, list(current_search))
referenced = set(sg for sg, in txn)
referenced_groups |= referenced
# We don't continue iterating up the state group graphs for state
# groups that are referenced.
current_search -= referenced
rows = self._simple_select_many_txn(
txn,
table="state_group_edges",
column="prev_state_group",
iterable=current_search,
keyvalues={},
retcols=("prev_state_group", "state_group",),
)
prevs = set(row["state_group"] for row in rows)
# We don't bother re-handling groups we've already seen
prevs -= state_groups_seen
next_to_search |= prevs
state_groups_seen |= prevs
for row in rows:
# Note: Each state group can have at most one prev group
graph[row["state_group"]] = row["prev_state_group"]
to_delete = state_groups_seen - referenced_groups
to_dedelta = set()
for sg in referenced_groups:
prev_sg = graph.get(sg)
if prev_sg and prev_sg in to_delete:
to_dedelta.add(sg)
return to_delete, to_dedelta
@defer.inlineCallbacks
def is_event_after(self, event_id1, event_id2):
"""Returns True if event_id1 is after event_id2 in the stream

View File

@ -1234,85 +1234,6 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
return count
def _find_unreferenced_groups(self, txn, state_groups):
"""Used when purging history to figure out which state groups can be
deleted and which need to be de-delta'ed (due to one of its prev groups
being scheduled for deletion).
Args:
txn
state_groups (set[int]): Set of state groups referenced by events
that are going to be deleted.
Returns:
tuple[set[int], set[int]]: The set of state groups that can be
deleted and the set of state groups that need to be de-delta'ed
"""
# Graph of state group -> previous group
graph = {}
# Set of events that we have found to be referenced by events
referenced_groups = set()
# Set of state groups we've already seen
state_groups_seen = set(state_groups)
# Set of state groups to handle next.
next_to_search = set(state_groups)
while next_to_search:
# We bound size of groups we're looking up at once, to stop the
# SQL query getting too big
if len(next_to_search) < 100:
current_search = next_to_search
next_to_search = set()
else:
current_search = set(islice(next_to_search, 100))
next_to_search -= current_search
# Check if state groups are referenced
sql = """
SELECT DISTINCT state_group FROM event_to_state_groups
LEFT JOIN events_to_purge AS ep USING (event_id)
WHERE state_group IN (%s) AND ep.event_id IS NULL
""" % (",".join("?" for _ in current_search),)
txn.execute(sql, list(current_search))
referenced = set(sg for sg, in txn)
referenced_groups |= referenced
# We don't continue iterating up the state group graphs for state
# groups that are referenced.
current_search -= referenced
rows = self._simple_select_many_txn(
txn,
table="state_group_edges",
column="prev_state_group",
iterable=current_search,
keyvalues={},
retcols=("prev_state_group", "state_group",),
)
prevs = set(row["state_group"] for row in rows)
# We don't bother re-handling groups we've already seen
prevs -= state_groups_seen
next_to_search |= prevs
state_groups_seen |= prevs
for row in rows:
# Note: Each state group can have at most one prev group
graph[row["state_group"]] = row["prev_state_group"]
to_delete = state_groups_seen - referenced_groups
to_dedelta = set()
for sg in referenced_groups:
prev_sg = graph.get(sg)
if prev_sg and prev_sg in to_delete:
to_dedelta.add(sg)
return to_delete, to_dedelta
class StateStore(StateGroupWorkerStore, BackgroundUpdateStore):
""" Keeps track of the state at a given event.