Merge keyserver & userapi (#2972)

As discussed yesterday, a first draft of merging the keyserver and the
userapi.

userapi/producers/keychange.go

@@ -0,0 +1,107 @@
+// 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 producers
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/matrix-org/dendrite/setup/jetstream"
+	"github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/dendrite/userapi/storage"
+	"github.com/nats-io/nats.go"
+	"github.com/sirupsen/logrus"
+)
+
+// KeyChange produces key change events for the sync API and federation sender to consume
+type KeyChange struct {
+	Topic     string
+	JetStream JetStreamPublisher
+	DB        storage.KeyChangeDatabase
+}
+
+// ProduceKeyChanges creates new change events for each key
+func (p *KeyChange) ProduceKeyChanges(keys []api.DeviceMessage) error {
+	userToDeviceCount := make(map[string]int)
+	for _, key := range keys {
+		id, err := p.DB.StoreKeyChange(context.Background(), key.UserID)
+		if err != nil {
+			return err
+		}
+		key.DeviceChangeID = id
+		value, err := json.Marshal(key)
+		if err != nil {
+			return err
+		}
+
+		m := &nats.Msg{
+			Subject: p.Topic,
+			Header:  nats.Header{},
+		}
+		m.Header.Set(jetstream.UserID, key.UserID)
+		m.Data = value
+
+		_, err = p.JetStream.PublishMsg(m)
+		if err != nil {
+			return err
+		}
+
+		userToDeviceCount[key.UserID]++
+	}
+	for userID, count := range userToDeviceCount {
+		logrus.WithFields(logrus.Fields{
+			"user_id":         userID,
+			"num_key_changes": count,
+		}).Tracef("Produced to key change topic '%s'", p.Topic)
+	}
+	return nil
+}
+
+func (p *KeyChange) ProduceSigningKeyUpdate(key api.CrossSigningKeyUpdate) error {
+	output := &api.DeviceMessage{
+		Type: api.TypeCrossSigningUpdate,
+		OutputCrossSigningKeyUpdate: &api.OutputCrossSigningKeyUpdate{
+			CrossSigningKeyUpdate: key,
+		},
+	}
+
+	id, err := p.DB.StoreKeyChange(context.Background(), key.UserID)
+	if err != nil {
+		return err
+	}
+	output.DeviceChangeID = id
+
+	value, err := json.Marshal(output)
+	if err != nil {
+		return err
+	}
+
+	m := &nats.Msg{
+		Subject: p.Topic,
+		Header:  nats.Header{},
+	}
+	m.Header.Set(jetstream.UserID, key.UserID)
+	m.Data = value
+
+	_, err = p.JetStream.PublishMsg(m)
+	if err != nil {
+		return err
+	}
+
+	logrus.WithFields(logrus.Fields{
+		"user_id": key.UserID,
+	}).Tracef("Produced to cross-signing update topic '%s'", p.Topic)
+	return nil
+}

userapi/producers/syncapi.go

@@ -19,13 +19,13 @@ type JetStreamPublisher interface {
 
 // SyncAPI produces messages for the Sync API server to consume.
 type SyncAPI struct {
-	db                    storage.Database
+	db                    storage.Notification
 	producer              JetStreamPublisher
 	clientDataTopic       string
 	notificationDataTopic string
 }
 
-func NewSyncAPI(db storage.Database, js JetStreamPublisher, clientDataTopic string, notificationDataTopic string) *SyncAPI {
+func NewSyncAPI(db storage.UserDatabase, js JetStreamPublisher, clientDataTopic string, notificationDataTopic string) *SyncAPI {
 	return &SyncAPI{
 		db:                    db,
 		producer:              js,