From 59bec69bf961d5f49f047ee43c6110b1a5d8e923 Mon Sep 17 00:00:00 2001
From: Till Faelligen <tfaelligen@gmail.com>
Date: Thu, 15 Oct 2020 15:36:55 +0200
Subject: [PATCH] Add eduserver kafka consumer

---
 syncapi/consumers/eduserver_receipts.go | 94 +++++++++++++++++++++++++
 syncapi/sync/notifier.go                | 10 +++
 syncapi/syncapi.go                      |  7 ++
 3 files changed, 111 insertions(+)
 create mode 100644 syncapi/consumers/eduserver_receipts.go

diff --git a/syncapi/consumers/eduserver_receipts.go b/syncapi/consumers/eduserver_receipts.go
new file mode 100644
index 000000000..1b405c222
--- /dev/null
+++ b/syncapi/consumers/eduserver_receipts.go
@@ -0,0 +1,94 @@
+// Copyright 2019 Alex Chen
+//
+// 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
+}
diff --git a/syncapi/sync/notifier.go b/syncapi/sync/notifier.go
index fcac3f16c..daa3a1d8c 100644
--- a/syncapi/sync/notifier.go
+++ b/syncapi/sync/notifier.go
@@ -149,6 +149,16 @@ func (n *Notifier) OnNewSendToDevice(
 	n.wakeupUserDevice(userID, deviceIDs, latestPos)
 }
 
+// OnNewReceipt updates the current position
+func (n *Notifier) OnNewReceipt(
+	posUpdate types.StreamingToken,
+) {
+	n.streamLock.Lock()
+	defer n.streamLock.Unlock()
+	latestPos := n.currPos.WithUpdates(posUpdate)
+	n.currPos = latestPos
+}
+
 func (n *Notifier) OnNewKeyChange(
 	posUpdate types.StreamingToken, wakeUserID, keyChangeUserID string,
 ) {
diff --git a/syncapi/syncapi.go b/syncapi/syncapi.go
index 43e2455b6..6c9d0ebd4 100644
--- a/syncapi/syncapi.go
+++ b/syncapi/syncapi.go
@@ -98,5 +98,12 @@ func AddPublicRoutes(
 		logrus.WithError(err).Panicf("failed to start send-to-device consumer")
 	}
 
+	receiptConsumer := consumers.NewOutputReceiptEventConsumer(
+		cfg, consumer, notifier, syncDB,
+	)
+	if err = receiptConsumer.Start(); err != nil {
+		logrus.WithError(err).Panicf("failed to start receipts consumer")
+	}
+
 	routing.Setup(router, requestPool, syncDB, userAPI, federation, rsAPI, cfg)
 }