use go module for dependencies (#594)

syncapi/consumers/clientapi.go

@@ -0,0 +1,95 @@
+// Copyright 2017 Vector Creations 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.
+
+package consumers
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/matrix-org/dendrite/common"
+	"github.com/matrix-org/dendrite/common/config"
+	"github.com/matrix-org/dendrite/syncapi/storage"
+	"github.com/matrix-org/dendrite/syncapi/sync"
+	log "github.com/sirupsen/logrus"
+	sarama "gopkg.in/Shopify/sarama.v1"
+)
+
+// OutputClientDataConsumer consumes events that originated in the client API server.
+type OutputClientDataConsumer struct {
+	clientAPIConsumer *common.ContinualConsumer
+	db                *storage.SyncServerDatabase
+	notifier          *sync.Notifier
+}
+
+// NewOutputClientDataConsumer creates a new OutputClientData consumer. Call Start() to begin consuming from room servers.
+func NewOutputClientDataConsumer(
+	cfg *config.Dendrite,
+	kafkaConsumer sarama.Consumer,
+	n *sync.Notifier,
+	store *storage.SyncServerDatabase,
+) *OutputClientDataConsumer {
+
+	consumer := common.ContinualConsumer{
+		Topic:          string(cfg.Kafka.Topics.OutputClientData),
+		Consumer:       kafkaConsumer,
+		PartitionStore: store,
+	}
+	s := &OutputClientDataConsumer{
+		clientAPIConsumer: &consumer,
+		db:                store,
+		notifier:          n,
+	}
+	consumer.ProcessMessage = s.onMessage
+
+	return s
+}
+
+// Start consuming from room servers
+func (s *OutputClientDataConsumer) Start() error {
+	return s.clientAPIConsumer.Start()
+}
+
+// onMessage is called when the sync server receives a new event from the client API server output log.
+// It is not safe for this function to be called from multiple goroutines, or else the
+// sync stream position may race and be incorrectly calculated.
+func (s *OutputClientDataConsumer) onMessage(msg *sarama.ConsumerMessage) error {
+	// Parse out the event JSON
+	var output common.AccountData
+	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("client API server output log: message parse failure")
+		return nil
+	}
+
+	log.WithFields(log.Fields{
+		"type":    output.Type,
+		"room_id": output.RoomID,
+	}).Info("received data from client API server")
+
+	syncStreamPos, err := s.db.UpsertAccountData(
+		context.TODO(), string(msg.Key), output.RoomID, output.Type,
+	)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"type":       output.Type,
+			"room_id":    output.RoomID,
+			log.ErrorKey: err,
+		}).Panicf("could not save account data")
+	}
+
+	s.notifier.OnNewEvent(nil, string(msg.Key), syncStreamPos)
+
+	return nil
+}