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Diffstat (limited to 'synapse/storage/monthly_active_users.py')
| -rw-r--r-- | synapse/storage/monthly_active_users.py | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/synapse/storage/monthly_active_users.py b/synapse/storage/monthly_active_users.py new file mode 100644 index 0000000000..8b3beaf26a --- /dev/null +++ b/synapse/storage/monthly_active_users.py @@ -0,0 +1,162 @@ +# -*- coding: utf-8 -*- +# Copyright 2018 New Vector +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from twisted.internet import defer + +from synapse.util.caches.descriptors import cached + +from ._base import SQLBaseStore + +# Number of msec of granularity to store the monthly_active_user timestamp +# This means it is not necessary to update the table on every request +LAST_SEEN_GRANULARITY = 60 * 60 * 1000 + + +class MonthlyActiveUsersStore(SQLBaseStore): + def __init__(self, dbconn, hs): + super(MonthlyActiveUsersStore, self).__init__(None, hs) + self._clock = hs.get_clock() + self.hs = hs + + def reap_monthly_active_users(self): + """ + Cleans out monthly active user table to ensure that no stale + entries exist. + + Returns: + Deferred[] + """ + def _reap_users(txn): + + thirty_days_ago = ( + int(self._clock.time_msec()) - (1000 * 60 * 60 * 24 * 30) + ) + # Purge stale users + sql = "DELETE FROM monthly_active_users WHERE timestamp < ?" + txn.execute(sql, (thirty_days_ago,)) + + # 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 + # incompatibilities in how sqlite and postgres support the feature. + # sqlite requires 'LIMIT -1 OFFSET ?', the LIMIT must be present + # While Postgres does not require 'LIMIT', but also does not support + # negative LIMIT values. So there is no way to write it that both can + # support + sql = """ + DELETE FROM monthly_active_users + WHERE user_id NOT IN ( + SELECT user_id FROM monthly_active_users + ORDER BY timestamp DESC + LIMIT ? + ) + """ + txn.execute(sql, (self.hs.config.max_mau_value,)) + + yield self.runInteraction("reap_monthly_active_users", _reap_users) + # It seems poor to invalidate the whole cache, Postgres supports + # 'Returning' which would allow me to invalidate only the + # specific users, but sqlite has no way to do this and instead + # I would need to SELECT and the DELETE which without locking + # is racy. + # Have resolved to invalidate the whole cache for now and do + # something about it if and when the perf becomes significant + self._user_last_seen_monthly_active.invalidate_all() + self.get_monthly_active_count.invalidate_all() + + @cached(num_args=0) + def get_monthly_active_count(self): + """Generates current count of monthly active users + + Returns: + Defered[int]: Number of current monthly active users + """ + + def _count_users(txn): + sql = "SELECT COALESCE(count(*), 0) FROM monthly_active_users" + + txn.execute(sql) + count, = txn.fetchone() + return count + return self.runInteraction("count_users", _count_users) + + def upsert_monthly_active_user(self, user_id): + """ + Updates or inserts monthly active user member + Arguments: + user_id (str): user to add/update + Deferred[bool]: True if a new entry was created, False if an + existing one was updated. + """ + is_insert = self._simple_upsert( + desc="upsert_monthly_active_user", + table="monthly_active_users", + keyvalues={ + "user_id": user_id, + }, + values={ + "timestamp": int(self._clock.time_msec()), + }, + lock=False, + ) + if is_insert: + self._user_last_seen_monthly_active.invalidate((user_id,)) + self.get_monthly_active_count.invalidate(()) + + @cached(num_args=1) + def _user_last_seen_monthly_active(self, user_id): + """ + Checks if a given user is part of the monthly active user group + Arguments: + user_id (str): user to add/update + Return: + int : timestamp since last seen, None if never seen + + """ + + return(self._simple_select_one_onecol( + table="monthly_active_users", + keyvalues={ + "user_id": user_id, + }, + retcol="timestamp", + allow_none=True, + desc="_user_last_seen_monthly_active", + )) + + @defer.inlineCallbacks + def populate_monthly_active_users(self, user_id): + """Checks on the state of monthly active user limits and optionally + add the user to the monthly active tables + + Args: + user_id(str): the user_id to query + """ + + if self.hs.config.limit_usage_by_mau: + last_seen_timestamp = yield self._user_last_seen_monthly_active(user_id) + now = self.hs.get_clock().time_msec() + + # We want to reduce to the total number of db writes, and are happy + # to trade accuracy of timestamp in order to lighten load. This means + # We always insert new users (where MAU threshold has not been reached), + # but only update if we have not previously seen the user for + # LAST_SEEN_GRANULARITY ms + if last_seen_timestamp is None: + count = yield self.get_monthly_active_count() + if count < self.hs.config.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) |