Optimise some references to hs.config (#7546)

These are surprisingly expensive, and we only really need to do them at startup.

1 files changed, 20 insertions, 8 deletions

diff --git a/synapse/storage/data_stores/main/monthly_active_users.py b/synapse/storage/data_stores/main/monthly_active_users.py
index 925bc5691b..a42c52f323 100644
--- a/synapse/storage/data_stores/main/monthly_active_users.py
+++ b/synapse/storage/data_stores/main/monthly_active_users.py
@@ -122,6 +122,10 @@ class MonthlyActiveUsersStore(MonthlyActiveUsersWorkerStore):
     def __init__(self, database: Database, db_conn, hs):
         super(MonthlyActiveUsersStore, self).__init__(database, db_conn, hs)
 
+        self._limit_usage_by_mau = hs.config.limit_usage_by_mau
+        self._mau_stats_only = hs.config.mau_stats_only
+        self._max_mau_value = hs.config.max_mau_value
+
         # Do not add more reserved users than the total allowable number
         # cur = LoggingTransaction(
         self.db.new_transaction(
@@ -130,7 +134,7 @@ class MonthlyActiveUsersStore(MonthlyActiveUsersWorkerStore):
             [],
             [],
             self._initialise_reserved_users,
-            hs.config.mau_limits_reserved_threepids[: self.hs.config.max_mau_value],
+            hs.config.mau_limits_reserved_threepids[: self._max_mau_value],
         )
 
     def _initialise_reserved_users(self, txn, threepids):
@@ -142,6 +146,15 @@ class MonthlyActiveUsersStore(MonthlyActiveUsersWorkerStore):
             threepids (list[dict]): List of threepid dicts to reserve
         """
 
+        # XXX what is this function trying to achieve?  It upserts into
+        # monthly_active_users for each *registered* reserved mau user, but why?
+        #
+        #  - shouldn't there already be an entry for each reserved user (at least
+        #    if they have been active recently)?
+        #
+        #  - if it's important that the timestamp is kept up to date, why do we only
+        #    run this at startup?
+
         for tp in threepids:
             user_id = self.get_user_id_by_threepid_txn(txn, tp["medium"], tp["address"])
 
@@ -191,8 +204,7 @@ class MonthlyActiveUsersStore(MonthlyActiveUsersWorkerStore):
 
             txn.execute(sql, query_args)
 
-            max_mau_value = self.hs.config.max_mau_value
-            if self.hs.config.limit_usage_by_mau:
+            if self._limit_usage_by_mau:
                 # If MAU user count still exceeds the MAU threshold, then delete on
                 # a least recently active basis.
                 # Note it is not possible to write this query using OFFSET due to
@@ -210,13 +222,13 @@ class MonthlyActiveUsersStore(MonthlyActiveUsersWorkerStore):
                             LIMIT ?
                         )
                         """
-                    txn.execute(sql, (max_mau_value,))
+                    txn.execute(sql, ((self._max_mau_value),))
                 # Need if/else since 'AND user_id NOT IN ({})' fails on Postgres
                 # when len(reserved_users) == 0. Works fine on sqlite.
                 else:
                     # Must be >= 0 for postgres
                     num_of_non_reserved_users_to_remove = max(
-                        max_mau_value - len(reserved_users), 0
+                        self._max_mau_value - len(reserved_users), 0
                     )
 
                     # It is important to filter reserved users twice to guard
@@ -335,7 +347,7 @@ class MonthlyActiveUsersStore(MonthlyActiveUsersWorkerStore):
         Args:
             user_id(str): the user_id to query
         """
-        if self.hs.config.limit_usage_by_mau or self.hs.config.mau_stats_only:
+        if self._limit_usage_by_mau or self._mau_stats_only:
             # Trial users and guests should not be included as part of MAU group
             is_guest = yield self.is_guest(user_id)
             if is_guest:
@@ -356,11 +368,11 @@ class MonthlyActiveUsersStore(MonthlyActiveUsersWorkerStore):
                 # In the case where mau_stats_only is True and limit_usage_by_mau is
                 # False, there is no point in checking get_monthly_active_count - it
                 # adds no value and will break the logic if max_mau_value is exceeded.
-                if not self.hs.config.limit_usage_by_mau:
+                if not self._limit_usage_by_mau:
                     yield self.upsert_monthly_active_user(user_id)
                 else:
                     count = yield self.get_monthly_active_count()
-                    if count < self.hs.config.max_mau_value:
+                    if count < self._max_mau_value:
                         yield self.upsert_monthly_active_user(user_id)
             elif now - last_seen_timestamp > LAST_SEEN_GRANULARITY:
                 yield self.upsert_monthly_active_user(user_id)