Send-to-device support (#1072)

* Groundwork for send-to-device messaging

* Update sample config

* Add unstable routing for now

* Send to device consumer in sync API

* Start the send-to-device consumer

* fix indentation in dendrite-config.yaml

* Create send-to-device database tables, other tweaks

* Add some logic for send-to-device messages, add them into sync stream

* Handle incoming send-to-device messages, count them with EDU stream pos

* Undo changes to test

* pq.Array

* Fix sync

* Logging

* Fix a couple of transaction things, fix client API

* Add send-to-device test, hopefully fix bugs

* Comments

* Refactor a bit

* Fix schema

* Fix queries

* Debug logging

* Fix storing and retrieving of send-to-device messages

* Try to avoid database locks

* Update sync position

* Use latest sync position

* Jiggle about sync a bit

* Fix tests

* Break out the retrieval from the update/delete behaviour

* Comments

* nolint on getResponseWithPDUsForCompleteSync

* Try to line up sync tokens again

* Implement wildcard

* Add all send-to-device tests to whitelist, what could possibly go wrong?

* Only care about wildcard when targeted locally

* Deduplicate transactions

* Handle tokens properly, return immediately if waiting send-to-device messages

* Fix sync

* Update sytest-whitelist

* Fix copyright notice (need to do more of this)

* Comments, copyrights

* Return errors from Do, fix dendritejs

* Review comments

* Comments

* Constructor for TransactionWriter

* defletions

* Update gomatrixserverlib, sytest-blacklist

1 files changed, 39 insertions, 0 deletions

diff --git a/syncapi/storage/tables/interface.go b/syncapi/storage/tables/interface.go
index bc3b6941..0b7d1595 100644
--- a/syncapi/storage/tables/interface.go
+++ b/syncapi/storage/tables/interface.go
@@ -1,3 +1,17 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// 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.
+
 package tables
 
 import (
@@ -94,3 +108,28 @@ type BackwardsExtremities interface {
 	// DeleteBackwardExtremity removes a backwards extremity for a room, if one existed.
 	DeleteBackwardExtremity(ctx context.Context, txn *sql.Tx, roomID, knownEventID string) (err error)
 }
+
+// SendToDevice tracks send-to-device messages which are sent to individual
+// clients. Each message gets inserted into this table at the point that we
+// receive it from the EDU server.
+//
+// We're supposed to try and do our best to deliver send-to-device messages
+// once, but the only way that we can really guarantee that they have been
+// delivered is if the client successfully requests the next sync as given
+// in the next_batch. Each time the device syncs, we will request all of the
+// updates that either haven't been sent yet, along with all updates that we
+// *have* sent but we haven't confirmed to have been received yet. If it's the
+// first time we're sending a given update then we update the table to say
+// what the "since" parameter was when we tried to send it.
+//
+// When the client syncs again, if their "since" parameter is *later* than
+// the recorded one, we drop the entry from the DB as it's "sent". If the
+// sync parameter isn't later then we will keep including the updates in the
+// sync response, as the client is seemingly trying to repeat the same /sync.
+type SendToDevice interface {
+	InsertSendToDeviceMessage(ctx context.Context, txn *sql.Tx, userID, deviceID, content string) (err error)
+	SelectSendToDeviceMessages(ctx context.Context, txn *sql.Tx, userID, deviceID string) (events []types.SendToDeviceEvent, err error)
+	UpdateSentSendToDeviceMessages(ctx context.Context, txn *sql.Tx, token string, nids []types.SendToDeviceNID) (err error)
+	DeleteSendToDeviceMessages(ctx context.Context, txn *sql.Tx, nids []types.SendToDeviceNID) (err error)
+	CountSendToDeviceMessages(ctx context.Context, txn *sql.Tx, userID, deviceID string) (count int, err error)
+}