1 files changed, 151 insertions, 0 deletions
diff --git a/syncapi/consumers/receipts.go b/syncapi/consumers/receipts.go
new file mode 100644
index 00000000..6bb0747f
--- /dev/null
+++ b/syncapi/consumers/receipts.go
@@ -0,0 +1,151 @@
+// 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"
+	"database/sql"
+	"fmt"
+	"strconv"
+
+	"github.com/getsentry/sentry-go"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/setup/jetstream"
+	"github.com/matrix-org/dendrite/setup/process"
+	"github.com/matrix-org/dendrite/syncapi/notifier"
+	"github.com/matrix-org/dendrite/syncapi/producers"
+	"github.com/matrix-org/dendrite/syncapi/storage"
+	"github.com/matrix-org/dendrite/syncapi/types"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/nats-io/nats.go"
+	"github.com/sirupsen/logrus"
+	log "github.com/sirupsen/logrus"
+)
+
+// OutputReceiptEventConsumer consumes events that originated in the EDU server.
+type OutputReceiptEventConsumer struct {
+	ctx        context.Context
+	jetstream  nats.JetStreamContext
+	durable    string
+	topic      string
+	db         storage.Database
+	stream     types.StreamProvider
+	notifier   *notifier.Notifier
+	serverName gomatrixserverlib.ServerName
+	producer   *producers.UserAPIReadProducer
+}
+
+// NewOutputReceiptEventConsumer creates a new OutputReceiptEventConsumer.
+// Call Start() to begin consuming from the EDU server.
+func NewOutputReceiptEventConsumer(
+	process *process.ProcessContext,
+	cfg *config.SyncAPI,
+	js nats.JetStreamContext,
+	store storage.Database,
+	notifier *notifier.Notifier,
+	stream types.StreamProvider,
+	producer *producers.UserAPIReadProducer,
+) *OutputReceiptEventConsumer {
+	return &OutputReceiptEventConsumer{
+		ctx:        process.Context(),
+		jetstream:  js,
+		topic:      cfg.Matrix.JetStream.Prefixed(jetstream.OutputReceiptEvent),
+		durable:    cfg.Matrix.JetStream.Durable("SyncAPIReceiptConsumer"),
+		db:         store,
+		notifier:   notifier,
+		stream:     stream,
+		serverName: cfg.Matrix.ServerName,
+		producer:   producer,
+	}
+}
+
+// Start consuming receipts events.
+func (s *OutputReceiptEventConsumer) Start() error {
+	return jetstream.JetStreamConsumer(
+		s.ctx, s.jetstream, s.topic, s.durable, s.onMessage,
+		nats.DeliverAll(), nats.ManualAck(),
+	)
+}
+
+func (s *OutputReceiptEventConsumer) onMessage(ctx context.Context, msg *nats.Msg) bool {
+	output := types.OutputReceiptEvent{
+		UserID:  msg.Header.Get(jetstream.UserID),
+		RoomID:  msg.Header.Get(jetstream.RoomID),
+		EventID: msg.Header.Get(jetstream.EventID),
+		Type:    msg.Header.Get("type"),
+	}
+
+	timestamp, err := strconv.Atoi(msg.Header.Get("timestamp"))
+	if err != nil {
+		// If the message was invalid, log it and move on to the next message in the stream
+		log.WithError(err).Errorf("output log: message parse failure")
+		sentry.CaptureException(err)
+		return true
+	}
+
+	output.Timestamp = gomatrixserverlib.Timestamp(timestamp)
+
+	streamPos, err := s.db.StoreReceipt(
+		s.ctx,
+		output.RoomID,
+		output.Type,
+		output.UserID,
+		output.EventID,
+		output.Timestamp,
+	)
+	if err != nil {
+		sentry.CaptureException(err)
+		return true
+	}
+
+	if err = s.sendReadUpdate(ctx, output); err != nil {
+		log.WithError(err).WithFields(logrus.Fields{
+			"user_id": output.UserID,
+			"room_id": output.RoomID,
+		}).Errorf("Failed to generate read update")
+		sentry.CaptureException(err)
+		return false
+	}
+
+	s.stream.Advance(streamPos)
+	s.notifier.OnNewReceipt(output.RoomID, types.StreamingToken{ReceiptPosition: streamPos})
+
+	return true
+}
+
+func (s *OutputReceiptEventConsumer) sendReadUpdate(ctx context.Context, output types.OutputReceiptEvent) error {
+	if output.Type != "m.read" {
+		return nil
+	}
+	_, serverName, err := gomatrixserverlib.SplitID('@', output.UserID)
+	if err != nil {
+		return fmt.Errorf("gomatrixserverlib.SplitID: %w", err)
+	}
+	if serverName != s.serverName {
+		return nil
+	}
+	var readPos types.StreamPosition
+	if output.EventID != "" {
+		if _, readPos, err = s.db.PositionInTopology(ctx, output.EventID); err != nil && err != sql.ErrNoRows {
+			return fmt.Errorf("s.db.PositionInTopology (Read): %w", err)
+		}
+	}
+	if readPos > 0 {
+		if err := s.producer.SendReadUpdate(output.UserID, output.RoomID, readPos, 0); err != nil {
+			return fmt.Errorf("s.producer.SendReadUpdate: %w", err)
+		}
+	}
+	return nil
+}