Implement read receipts (#1528)

* fix conversion from int to string yields a string of one rune, not a string of digits

* Add receipts table to syncapi

* Use StreamingToken as the since value

* Add required method to testEDUProducer

* Make receipt json creation "easier" to read

* Add receipts api to the eduserver

* Add receipts endpoint

* Add eduserver kafka consumer

* Add missing kafka config

* Add passing tests to whitelist

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Fix copy & paste error

* Fix column count error

* Make outbound federation receipts pass

* Make "Inbound federation rejects receipts from wrong remote" pass

* Don't use errors package

* - Add TODO for batching requests
- Rename variable

* Return a better error message

* - Use OutputReceiptEvent instead of InputReceiptEvent as result
- Don't use the errors package for errors
- Defer CloseAndLogIfError to close rows
- Fix Copyright

* Better creation/usage of JoinResponse

* Query all joined rooms instead of just one

* Update gomatrixserverlib

* Add sqlite3 migration

* Add postgres migration

* Ensure required sequence exists before running migrations

* Clarification on comment

* - Fix a bug when creating client receipts
- Use concrete types instead of interface{}

* Remove dead code
Use key for timestamp

* Fix postgres query...

* Remove single purpose struct

* Use key/value directly

* Only apply receipts on initial sync or if edu positions differ,
otherwise we'll be sending the same receipts over and over again.

* Actually update the id, so it is correctly send in syncs

* Set receipt on request to /read_markers

* Fix issue with receipts getting overwritten

* Use fmt.Errorf instead of pkg/errors

* Revert "Add postgres migration"

This reverts commit 722fe5a04628882b787d096942459961db159b06.

* Revert "Add sqlite3 migration"

This reverts commit d113b03f6495a4b8f8bcf158a3d00b510b4240cc.

* Fix selectRoomReceipts query

* Make golangci-lint happy

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

syncapi/consumers/eduserver_receipts.go

@@ -0,0 +1,94 @@
+// 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 consumers
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/matrix-org/dendrite/syncapi/types"
+
+	"github.com/Shopify/sarama"
+	"github.com/matrix-org/dendrite/eduserver/api"
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/config"
+	"github.com/matrix-org/dendrite/syncapi/storage"
+	"github.com/matrix-org/dendrite/syncapi/sync"
+	log "github.com/sirupsen/logrus"
+)
+
+// OutputReceiptEventConsumer consumes events that originated in the EDU server.
+type OutputReceiptEventConsumer struct {
+	receiptConsumer *internal.ContinualConsumer
+	db              storage.Database
+	notifier        *sync.Notifier
+}
+
+// NewOutputReceiptEventConsumer creates a new OutputReceiptEventConsumer.
+// Call Start() to begin consuming from the EDU server.
+func NewOutputReceiptEventConsumer(
+	cfg *config.SyncAPI,
+	kafkaConsumer sarama.Consumer,
+	n *sync.Notifier,
+	store storage.Database,
+) *OutputReceiptEventConsumer {
+
+	consumer := internal.ContinualConsumer{
+		ComponentName:  "syncapi/eduserver/receipt",
+		Topic:          cfg.Matrix.Kafka.TopicFor(config.TopicOutputReceiptEvent),
+		Consumer:       kafkaConsumer,
+		PartitionStore: store,
+	}
+
+	s := &OutputReceiptEventConsumer{
+		receiptConsumer: &consumer,
+		db:              store,
+		notifier:        n,
+	}
+
+	consumer.ProcessMessage = s.onMessage
+
+	return s
+}
+
+// Start consuming from EDU api
+func (s *OutputReceiptEventConsumer) Start() error {
+	return s.receiptConsumer.Start()
+}
+
+func (s *OutputReceiptEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
+	var output api.OutputReceiptEvent
+	if err := json.Unmarshal(msg.Value, &output); err != nil {
+		// If the message was invalid, log it and move on to the next message in the stream
+		log.WithError(err).Errorf("EDU server output log: message parse failure")
+		return nil
+	}
+
+	streamPos, err := s.db.StoreReceipt(
+		context.TODO(),
+		output.RoomID,
+		output.Type,
+		output.UserID,
+		output.EventID,
+		output.Timestamp,
+	)
+	if err != nil {
+		return err
+	}
+	// update stream position
+	s.notifier.OnNewReceipt(types.NewStreamToken(0, streamPos, nil))
+
+	return nil
+}