summary refs log tree commit diff
path: root/synapse/handlers/sync.py
blob: 8c7681a48de2d25093007d425c3854fd6a95f9f5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
# -*- coding: utf-8 -*-
# Copyright 2015 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 ._base import BaseHandler

from synapse.streams.config import PaginationConfig
from synapse.api.constants import Membership

from twisted.internet import defer

import collections
import logging

logger = logging.getLogger(__name__)


SyncConfig = collections.namedtuple("SyncConfig", [
    "user",
    "device",
    "limit",
    "gap",
    "sort",
    "backfill",
    "filter",
])


class RoomSyncResult(collections.namedtuple("RoomSyncResult", [
    "room_id",
    "limited",
    "published",
    "events",
    "state",
    "prev_batch",
    "ephemeral",
])):
    __slots__ = []

    def __nonzero__(self):
        return bool(self.events or self.state or self.ephemeral)


class SyncResult(collections.namedtuple("SyncResult", [
    "next_batch",  # Token for the next sync
    "private_user_data",  # List of private events for the user.
    "public_user_data",  # List of public events for all users.
    "rooms",  # RoomSyncResult for each room.
])):
    __slots__ = []

    def __nonzero__(self):
        return bool(
            self.private_user_data or self.public_user_data or self.rooms
        )


class SyncHandler(BaseHandler):

    def __init__(self, hs):
        super(SyncHandler, self).__init__(hs)
        self.event_sources = hs.get_event_sources()
        self.clock = hs.get_clock()

    @defer.inlineCallbacks
    def wait_for_sync_for_user(self, sync_config, since_token=None, timeout=0):
        """Get the sync for a client if we have new data for it now. Otherwise
        wait for new data to arrive on the server. If the timeout expires, then
        return an empty sync result.
        Returns:
            A Deferred SyncResult.
        """
        if timeout == 0 or since_token is None:
            result = yield self.current_sync_for_user(sync_config, since_token)
            defer.returnValue(result)
        else:
            def current_sync_callback():
                return self.current_sync_for_user(sync_config, since_token)

            rm_handler = self.hs.get_handlers().room_member_handler
            room_ids = yield rm_handler.get_rooms_for_user(sync_config.user)
            result = yield self.notifier.wait_for_events(
                sync_config.user, room_ids,
                sync_config.filter, timeout, current_sync_callback
            )
            defer.returnValue(result)

    def current_sync_for_user(self, sync_config, since_token=None):
        """Get the sync for client needed to match what the server has now.
        Returns:
            A Deferred SyncResult.
        """
        if since_token is None:
            return self.initial_sync(sync_config)
        else:
            if sync_config.gap:
                return self.incremental_sync_with_gap(sync_config, since_token)
            else:
                #TODO(mjark): Handle gapless sync
                pass

    @defer.inlineCallbacks
    def initial_sync(self, sync_config):
        """Get a sync for a client which is starting without any state
        Returns:
            A Deferred SyncResult.
        """
        if sync_config.sort == "timeline,desc":
            # TODO(mjark): Handle going through events in reverse order?.
            # What does "most recent events" mean when applying the limits mean
            # in this case?
            raise NotImplementedError()

        now_token = yield self.event_sources.get_current_token()

        presence_stream = self.event_sources.sources["presence"]
        # TODO (mjark): This looks wrong, shouldn't we be getting the presence
        # UP to the present rather than after the present?
        pagination_config = PaginationConfig(from_token=now_token)
        presence, _ = yield presence_stream.get_pagination_rows(
            user=sync_config.user,
            pagination_config=pagination_config.get_source_config("presence"),
            key=None
        )
        room_list = yield self.store.get_rooms_for_user_where_membership_is(
            user_id=sync_config.user.to_string(),
            membership_list=[Membership.INVITE, Membership.JOIN]
        )

        # TODO (mjark): Does public mean "published"?
        published_rooms = yield self.store.get_rooms(is_public=True)
        published_room_ids = set(r["room_id"] for r in published_rooms)

        rooms = []
        for event in room_list:
            room_sync = yield self.initial_sync_for_room(
                event.room_id, sync_config, now_token, published_room_ids
            )
            rooms.append(room_sync)

        defer.returnValue(SyncResult(
            public_user_data=presence,
            private_user_data=[],
            rooms=rooms,
            next_batch=now_token,
        ))

    @defer.inlineCallbacks
    def initial_sync_for_room(self, room_id, sync_config, now_token,
                              published_room_ids):
        """Sync a room for a client which is starting without any state
        Returns:
            A Deferred RoomSyncResult.
        """
        recent_events, token = yield self.store.get_recent_events_for_room(
            room_id,
            limit=sync_config.limit,
            end_token=now_token.room_key,
        )
        prev_batch_token = now_token.copy_and_replace("room_key", token[0])
        current_state_events = yield self.state_handler.get_current_state(
            room_id
        )

        defer.returnValue(RoomSyncResult(
            room_id=room_id,
            published=room_id in published_room_ids,
            events=recent_events,
            prev_batch=prev_batch_token,
            state=current_state_events,
            limited=True,
            ephemeral=[],
        ))

    @defer.inlineCallbacks
    def incremental_sync_with_gap(self, sync_config, since_token):
        """ Get the incremental delta needed to bring the client up to
        date with the server.
        Returns:
            A Deferred SyncResult.
        """
        if sync_config.sort == "timeline,desc":
            # TODO(mjark): Handle going through events in reverse order?.
            # What does "most recent events" mean when applying the limits mean
            # in this case?
            raise NotImplementedError()

        now_token = yield self.event_sources.get_current_token()

        presence_source = self.event_sources.sources["presence"]
        presence, presence_key = yield presence_source.get_new_events_for_user(
            user=sync_config.user,
            from_key=since_token.presence_key,
            limit=sync_config.limit,
        )
        now_token = now_token.copy_and_replace("presence_key", presence_key)

        typing_source = self.event_sources.sources["typing"]
        typing, typing_key = yield typing_source.get_new_events_for_user(
            user=sync_config.user,
            from_key=since_token.typing_key,
            limit=sync_config.limit,
        )
        now_token = now_token.copy_and_replace("typing_key", typing_key)

        typing_by_room = {event["room_id"]: [event] for event in typing}
        for event in typing:
            event.pop("room_id")
        logger.debug("Typing %r", typing_by_room)

        rm_handler = self.hs.get_handlers().room_member_handler
        room_ids = yield rm_handler.get_rooms_for_user(sync_config.user)

        # TODO (mjark): Does public mean "published"?
        published_rooms = yield self.store.get_rooms(is_public=True)
        published_room_ids = set(r["room_id"] for r in published_rooms)

        room_events, _ = yield self.store.get_room_events_stream(
            sync_config.user.to_string(),
            from_key=since_token.room_key,
            to_key=now_token.room_key,
            room_id=None,
            limit=sync_config.limit + 1,
        )

        rooms = []
        if len(room_events) <= sync_config.limit:
            # There is no gap in any of the rooms. Therefore we can just
            # partition the new events by room and return them.
            events_by_room_id = {}
            for event in room_events:
                events_by_room_id.setdefault(event.room_id, []).append(event)

            for room_id in room_ids:
                recents = events_by_room_id.get(room_id, [])
                state = [event for event in recents if event.is_state()]
                if recents:
                    prev_batch = now_token.copy_and_replace(
                        "room_key", recents[0].internal_metadata.before
                    )
                else:
                    prev_batch = now_token
                room_sync = RoomSyncResult(
                    room_id=room_id,
                    published=room_id in published_room_ids,
                    events=recents,
                    prev_batch=prev_batch,
                    state=state,
                    limited=False,
                    ephemeral=typing_by_room.get(room_id, [])
                )
                if room_sync:
                    rooms.append(room_sync)
        else:
            for room_id in room_ids:
                room_sync = yield self.incremental_sync_with_gap_for_room(
                    room_id, sync_config, since_token, now_token,
                    published_room_ids, typing_by_room
                )
                if room_sync:
                    rooms.append(room_sync)

        defer.returnValue(SyncResult(
            public_user_data=presence,
            private_user_data=[],
            rooms=rooms,
            next_batch=now_token,
        ))

    @defer.inlineCallbacks
    def incremental_sync_with_gap_for_room(self, room_id, sync_config,
                                           since_token, now_token,
                                           published_room_ids, typing_by_room):
        """ Get the incremental delta needed to bring the client up to date for
        the room. Gives the client the most recent events and the changes to
        state.
        Returns:
            A Deferred RoomSyncResult
        """
        # TODO(mjark): Check if they have joined the room between
        # the previous sync and this one.
        # TODO(mjark): Apply the event filter in sync_config
        # TODO(mjark): Check for redactions we might have missed.
        recents, token = yield self.store.get_recent_events_for_room(
            room_id,
            limit=sync_config.limit + 1,
            from_token=since_token.room_key,
            end_token=now_token.room_key,
        )

        logging.debug("Recents %r", recents)

        if len(recents) > sync_config.limit:
            limited = True
            recents = recents[1:]
        else:
            limited = False

        prev_batch_token = now_token.copy_and_replace("room_key", token[0])

        # TODO(mjark): This seems racy since this isn't being passed a
        # token to indicate what point in the stream this is
        current_state_events = yield self.state_handler.get_current_state(
            room_id
        )

        state_at_previous_sync = yield self.get_state_at_previous_sync(
            room_id, since_token=since_token
        )

        state_events_delta = yield self.compute_state_delta(
            since_token=since_token,
            previous_state=state_at_previous_sync,
            current_state=current_state_events,
        )

        room_sync = RoomSyncResult(
            room_id=room_id,
            published=room_id in published_room_ids,
            events=recents,
            prev_batch=prev_batch_token,
            state=state_events_delta,
            limited=limited,
            typing=typing_by_room.get(room_id, None)
        )

        logging.debug("Room sync: %r", room_sync)

        defer.returnValue(room_sync)

    @defer.inlineCallbacks
    def get_state_at_previous_sync(self, room_id, since_token):
        """ Get the room state at the previous sync the client made.
        Returns:
            A Deferred list of Events.
        """
        last_events, token = yield self.store.get_recent_events_for_room(
            room_id, end_token=since_token.room_key, limit=1,
        )

        if last_events:
            last_event = last_events[0]
            last_context = yield self.state_handler.compute_event_context(
                last_event
            )
            if last_event.is_state():
                state = [last_event] + last_context.current_state.values()
            else:
                state = last_context.current_state.values()
        else:
            state = ()
        defer.returnValue(state)

    def compute_state_delta(self, since_token, previous_state, current_state):
        """ Works out the differnce in state between the current state and the
        state the client got when it last performed a sync.
        Returns:
            A list of events.
        """
        # TODO(mjark) Check if the state events were received by the server
        # after the previous sync, since we need to include those state
        # updates even if they occured logically before the previous event.
        # TODO(mjark) Check for new redactions in the state events.
        previous_dict = {event.event_id: event for event in previous_state}
        state_delta = []
        for event in current_state:
            if event.event_id not in previous_dict:
                state_delta.append(event)
        return state_delta