anonymousland-synapse/synapse/push/emailpusher.py
David Baker a15ad60849 Email unsubscribing that may in theory, work
Were it not for that fact that you can't use the base handler in the pusher because it pulls in the world. Comitting while I fix that on a different branch.
2016-06-02 11:44:15 +01:00

278 lines
10 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket Ltd
#
# 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, reactor
import logging
from synapse.util.metrics import Measure
from synapse.util.logcontext import LoggingContext
from mailer import Mailer
logger = logging.getLogger(__name__)
# The amount of time we always wait before ever emailing about a notification
# (to give the user a chance to respond to other push or notice the window)
DELAY_BEFORE_MAIL_MS = 10 * 60 * 1000
# THROTTLE is the minimum time between mail notifications sent for a given room.
# Each room maintains its own throttle counter, but each new mail notification
# sends the pending notifications for all rooms.
THROTTLE_START_MS = 10 * 60 * 1000
THROTTLE_MAX_MS = 24 * 60 * 60 * 1000 # 24h
# THROTTLE_MULTIPLIER = 6 # 10 mins, 1 hour, 6 hours, 24 hours
THROTTLE_MULTIPLIER = 144 # 10 mins, 24 hours - i.e. jump straight to 1 day
# If no event triggers a notification for this long after the previous,
# the throttle is released.
# 12 hours - a gap of 12 hours in conversation is surely enough to merit a new
# notification when things get going again...
THROTTLE_RESET_AFTER_MS = (12 * 60 * 60 * 1000)
# does each email include all unread notifs, or just the ones which have happened
# since the last mail?
INCLUDE_ALL_UNREAD_NOTIFS = True
class EmailPusher(object):
"""
A pusher that sends email notifications about events (approximately)
when they happen.
This shares quite a bit of code with httpusher: it would be good to
factor out the common parts
"""
def __init__(self, hs, pusherdict):
self.hs = hs
self.store = self.hs.get_datastore()
self.clock = self.hs.get_clock()
self.pusher_id = pusherdict['id']
self.user_id = pusherdict['user_name']
self.app_id = pusherdict['app_id']
self.email = pusherdict['pushkey']
self.last_stream_ordering = pusherdict['last_stream_ordering']
self.timed_call = None
self.throttle_params = None
# See httppusher
self.max_stream_ordering = None
self.processing = False
if self.hs.config.email_enable_notifs:
self.mailer = Mailer(self.hs)
else:
self.mailer = None
@defer.inlineCallbacks
def on_started(self):
if self.mailer is not None:
self.throttle_params = yield self.store.get_throttle_params_by_room(
self.pusher_id
)
yield self._process()
def on_stop(self):
if self.timed_call:
self.timed_call.cancel()
@defer.inlineCallbacks
def on_new_notifications(self, min_stream_ordering, max_stream_ordering):
self.max_stream_ordering = max(max_stream_ordering, self.max_stream_ordering)
yield self._process()
def on_new_receipts(self, min_stream_id, max_stream_id):
# We could wake up and cancel the timer but there tend to be quite a
# lot of read receipts so it's probably less work to just let the
# timer fire
return defer.succeed(None)
@defer.inlineCallbacks
def on_timer(self):
self.timed_call = None
yield self._process()
@defer.inlineCallbacks
def _process(self):
if self.processing:
return
with LoggingContext("emailpush._process"):
with Measure(self.clock, "emailpush._process"):
try:
self.processing = True
# if the max ordering changes while we're running _unsafe_process,
# call it again, and so on until we've caught up.
while True:
starting_max_ordering = self.max_stream_ordering
try:
yield self._unsafe_process()
except:
logger.exception("Exception processing notifs")
if self.max_stream_ordering == starting_max_ordering:
break
finally:
self.processing = False
@defer.inlineCallbacks
def _unsafe_process(self):
"""
Main logic of the push loop without the wrapper function that sets
up logging, measures and guards against multiple instances of it
being run.
"""
start = 0 if INCLUDE_ALL_UNREAD_NOTIFS else self.last_stream_ordering
unprocessed = yield self.store.get_unread_push_actions_for_user_in_range(
self.user_id, start, self.max_stream_ordering
)
soonest_due_at = None
for push_action in unprocessed:
received_at = push_action['received_ts']
if received_at is None:
received_at = 0
notif_ready_at = received_at + DELAY_BEFORE_MAIL_MS
room_ready_at = self.room_ready_to_notify_at(
push_action['room_id']
)
should_notify_at = max(notif_ready_at, room_ready_at)
if should_notify_at < self.clock.time_msec():
# one of our notifications is ready for sending, so we send
# *one* email updating the user on their notifications,
# we then consider all previously outstanding notifications
# to be delivered.
reason = {
'room_id': push_action['room_id'],
'now': self.clock.time_msec(),
'received_at': received_at,
'delay_before_mail_ms': DELAY_BEFORE_MAIL_MS,
'last_sent_ts': self.get_room_last_sent_ts(push_action['room_id']),
'throttle_ms': self.get_room_throttle_ms(push_action['room_id']),
}
yield self.send_notification(unprocessed, reason)
yield self.save_last_stream_ordering_and_success(max([
ea['stream_ordering'] for ea in unprocessed
]))
# we update the throttle on all the possible unprocessed push actions
for ea in unprocessed:
yield self.sent_notif_update_throttle(
ea['room_id'], ea
)
break
else:
if soonest_due_at is None or should_notify_at < soonest_due_at:
soonest_due_at = should_notify_at
if self.timed_call is not None:
self.timed_call.cancel()
self.timed_call = None
if soonest_due_at is not None:
self.timed_call = reactor.callLater(
self.seconds_until(soonest_due_at), self.on_timer
)
@defer.inlineCallbacks
def save_last_stream_ordering_and_success(self, last_stream_ordering):
self.last_stream_ordering = last_stream_ordering
yield self.store.update_pusher_last_stream_ordering_and_success(
self.app_id, self.email, self.user_id,
last_stream_ordering, self.clock.time_msec()
)
def seconds_until(self, ts_msec):
return (ts_msec - self.clock.time_msec()) / 1000
def get_room_throttle_ms(self, room_id):
if room_id in self.throttle_params:
return self.throttle_params[room_id]["throttle_ms"]
else:
return 0
def get_room_last_sent_ts(self, room_id):
if room_id in self.throttle_params:
return self.throttle_params[room_id]["last_sent_ts"]
else:
return 0
def room_ready_to_notify_at(self, room_id):
"""
Determines whether throttling should prevent us from sending an email
for the given room
Returns: The timestamp when we are next allowed to send an email notif
for this room
"""
last_sent_ts = self.get_room_last_sent_ts(room_id)
throttle_ms = self.get_room_throttle_ms(room_id)
may_send_at = last_sent_ts + throttle_ms
return may_send_at
@defer.inlineCallbacks
def sent_notif_update_throttle(self, room_id, notified_push_action):
# We have sent a notification, so update the throttle accordingly.
# If the event that triggered the notif happened more than
# THROTTLE_RESET_AFTER_MS after the previous one that triggered a
# notif, we release the throttle. Otherwise, the throttle is increased.
time_of_previous_notifs = yield self.store.get_time_of_last_push_action_before(
notified_push_action['stream_ordering']
)
time_of_this_notifs = notified_push_action['received_ts']
if time_of_previous_notifs is not None and time_of_this_notifs is not None:
gap = time_of_this_notifs - time_of_previous_notifs
else:
# if we don't know the arrival time of one of the notifs (it was not
# stored prior to email notification code) then assume a gap of
# zero which will just not reset the throttle
gap = 0
current_throttle_ms = self.get_room_throttle_ms(room_id)
if gap > THROTTLE_RESET_AFTER_MS:
new_throttle_ms = THROTTLE_START_MS
else:
if current_throttle_ms == 0:
new_throttle_ms = THROTTLE_START_MS
else:
new_throttle_ms = min(
current_throttle_ms * THROTTLE_MULTIPLIER,
THROTTLE_MAX_MS
)
self.throttle_params[room_id] = {
"last_sent_ts": self.clock.time_msec(),
"throttle_ms": new_throttle_ms
}
yield self.store.set_throttle_params(
self.pusher_id, room_id, self.throttle_params[room_id]
)
@defer.inlineCallbacks
def send_notification(self, push_actions, reason):
logger.info("Sending notif email for user %r", self.user_id)
yield self.mailer.send_notification_mail(
self.app_id, self.user_id, self.email, push_actions, reason
)