Use HTTP API for roomserver input. (#161)

* Use HTTP API for roomserver input.

* Use synchronous HTTP API for writing events to the roomserver

* Remove unused config for kafka topic

* Tweak comments

src/github.com/matrix-org/dendrite/clientapi/producers/roomserver.go

@@ -15,35 +15,24 @@
 package producers
 
 import (
-	"encoding/json"
-	"fmt"
-
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
-	sarama "gopkg.in/Shopify/sarama.v1"
 )
 
 // RoomserverProducer produces events for the roomserver to consume.
 type RoomserverProducer struct {
-	Topic    string
-	Producer sarama.SyncProducer
+	InputAPI api.RoomserverInputAPI
 }
 
 // NewRoomserverProducer creates a new RoomserverProducer
-func NewRoomserverProducer(kafkaURIs []string, topic string) (*RoomserverProducer, error) {
-	producer, err := sarama.NewSyncProducer(kafkaURIs, nil)
-	if err != nil {
-		return nil, err
-	}
+func NewRoomserverProducer(roomserverURI string) *RoomserverProducer {
 	return &RoomserverProducer{
-		Topic:    topic,
-		Producer: producer,
-	}, nil
+		InputAPI: api.NewRoomserverInputAPIHTTP(roomserverURI, nil),
+	}
 }
 
 // SendEvents writes the given events to the roomserver input log. The events are written with KindNew.
 func (c *RoomserverProducer) SendEvents(events []gomatrixserverlib.Event, sendAsServer gomatrixserverlib.ServerName) error {
-	eventIDs := make([]string, len(events))
 	ires := make([]api.InputRoomEvent, len(events))
 	for i, event := range events {
 		ires[i] = api.InputRoomEvent{
@@ -52,9 +41,8 @@ func (c *RoomserverProducer) SendEvents(events []gomatrixserverlib.Event, sendAs
 			AuthEventIDs: event.AuthEventIDs(),
 			SendAsServer: string(sendAsServer),
 		}
-		eventIDs[i] = event.EventID()
 	}
-	return c.SendInputRoomEvents(ires, eventIDs)
+	return c.SendInputRoomEvents(ires)
 }
 
 // SendEventWithState writes an event with KindNew to the roomserver input log
@@ -65,7 +53,6 @@ func (c *RoomserverProducer) SendEventWithState(state gomatrixserverlib.RespStat
 		return err
 	}
 
-	eventIDs := make([]string, len(outliers)+1)
 	ires := make([]api.InputRoomEvent, len(outliers)+1)
 	for i, outlier := range outliers {
 		ires[i] = api.InputRoomEvent{
@@ -73,7 +60,6 @@ func (c *RoomserverProducer) SendEventWithState(state gomatrixserverlib.RespStat
 			Event:        outlier,
 			AuthEventIDs: outlier.AuthEventIDs(),
 		}
-		eventIDs[i] = outlier.EventID()
 	}
 
 	stateEventIDs := make([]string, len(state.StateEvents))
@@ -88,41 +74,14 @@ func (c *RoomserverProducer) SendEventWithState(state gomatrixserverlib.RespStat
 		HasState:      true,
 		StateEventIDs: stateEventIDs,
 	}
-	eventIDs[len(outliers)] = event.EventID()
 
-	return c.SendInputRoomEvents(ires, eventIDs)
+	return c.SendInputRoomEvents(ires)
 }
 
 // SendInputRoomEvents writes the given input room events to the roomserver input log. The length of both
 // arrays must match, and each element must correspond to the same event.
-func (c *RoomserverProducer) SendInputRoomEvents(ires []api.InputRoomEvent, eventIDs []string) error {
-	// TODO: Nicer way of doing this. Options are:
-	// A) Like this
-	// B) Add EventID field to InputRoomEvent
-	// C) Add wrapper struct with the EventID and the InputRoomEvent
-	if len(eventIDs) != len(ires) {
-		return fmt.Errorf("WriteInputRoomEvents: length mismatch %d != %d", len(eventIDs), len(ires))
-	}
-
-	msgs := make([]*sarama.ProducerMessage, len(ires))
-	for i := range ires {
-		msg, err := c.toProducerMessage(ires[i], eventIDs[i])
-		if err != nil {
-			return err
-		}
-		msgs[i] = msg
-	}
-	return c.Producer.SendMessages(msgs)
-}
-
-func (c *RoomserverProducer) toProducerMessage(ire api.InputRoomEvent, eventID string) (*sarama.ProducerMessage, error) {
-	value, err := json.Marshal(ire)
-	if err != nil {
-		return nil, err
-	}
-	var m sarama.ProducerMessage
-	m.Topic = c.Topic
-	m.Key = sarama.StringEncoder(eventID)
-	m.Value = sarama.ByteEncoder(value)
-	return &m, nil
+func (c *RoomserverProducer) SendInputRoomEvents(ires []api.InputRoomEvent) error {
+	request := api.InputRoomEventsRequest{InputRoomEvents: ires}
+	var response api.InputRoomEventsResponse
+	return c.InputAPI.InputRoomEvents(&request, &response)
 }

src/github.com/matrix-org/dendrite/cmd/dendrite-client-api-server/main.go

@@ -51,9 +51,9 @@ func main() {
 
 	log.Info("config: ", cfg)
 
-	roomserverProducer, err := producers.NewRoomserverProducer(
-		cfg.Kafka.Addresses, string(cfg.Kafka.Topics.InputRoomEvent),
-	)
+	queryAPI := api.NewRoomserverQueryAPIHTTP(cfg.RoomServerURL(), nil)
+
+	roomserverProducer := producers.NewRoomserverProducer(cfg.RoomServerURL())
 	userUpdateProducer, err := producers.NewUserUpdateProducer(
 		cfg.Kafka.Addresses, string(cfg.Kafka.Topics.UserUpdates),
 	)
@@ -65,7 +65,6 @@ func main() {
 		cfg.Matrix.ServerName, cfg.Matrix.KeyID, cfg.Matrix.PrivateKey,
 	)
 
-	queryAPI := api.NewRoomserverQueryAPIHTTP(cfg.RoomServerURL(), nil)
 	accountDB, err := accounts.NewDatabase(string(cfg.Database.Account), cfg.Matrix.ServerName)
 	if err != nil {
 		log.Panicf("Failed to setup account database(%q): %s", cfg.Database.Account, err.Error())

src/github.com/matrix-org/dendrite/cmd/dendrite-federation-api-server/main.go

@@ -67,9 +67,7 @@ func main() {
 
 	queryAPI := api.NewRoomserverQueryAPIHTTP(cfg.RoomServerURL(), nil)
 
-	roomserverProducer, err := producers.NewRoomserverProducer(
-		cfg.Kafka.Addresses, string(cfg.Kafka.Topics.InputRoomEvent),
-	)
+	roomserverProducer := producers.NewRoomserverProducer(cfg.RoomServerURL())
 
 	if err != nil {
 		log.Panicf("Failed to setup kafka producers(%s): %s", cfg.Kafka.Addresses, err)

src/github.com/matrix-org/dendrite/cmd/dendrite-room-server/main.go

@@ -16,11 +16,9 @@ package main
 
 import (
 	"flag"
-	"fmt"
 	"net/http"
 	_ "net/http/pprof"
 	"os"
-	"strconv"
 
 	log "github.com/Sirupsen/logrus"
 	"github.com/matrix-org/dendrite/common"
@@ -35,7 +33,6 @@ import (
 var (
 	logDir     = os.Getenv("LOG_DIR")
 	configPath = flag.String("config", "", "The path to the config file. For more information, see the config file in this repository.")
-	stopProcessingAfter = os.Getenv("STOP_AFTER")
 )
 
 func main() {
@@ -56,49 +53,25 @@ func main() {
 		panic(err)
 	}
 
-	kafkaConsumer, err := sarama.NewConsumer(cfg.Kafka.Addresses, nil)
-	if err != nil {
-		panic(err)
-	}
-
 	kafkaProducer, err := sarama.NewSyncProducer(cfg.Kafka.Addresses, nil)
 	if err != nil {
 		panic(err)
 	}
 
-	consumer := input.Consumer{
-		ContinualConsumer: common.ContinualConsumer{
-			Topic:          string(cfg.Kafka.Topics.InputRoomEvent),
-			Consumer:       kafkaConsumer,
-			PartitionStore: db,
-		},
-		DB:                   db,
-		Producer:             kafkaProducer,
-		OutputRoomEventTopic: string(cfg.Kafka.Topics.OutputRoomEvent),
-	}
-
-	if stopProcessingAfter != "" {
-		count, err := strconv.ParseInt(stopProcessingAfter, 10, 64)
-		if err != nil {
-			panic(err)
-		}
-		consumer.StopProcessingAfter = &count
-		consumer.ShutdownCallback = func(message string) {
-			fmt.Println("Stopping roomserver", message)
-			os.Exit(0)
-		}
-	}
-
-	if err = consumer.Start(); err != nil {
-		panic(err)
-	}
-
 	queryAPI := query.RoomserverQueryAPI{
 		DB: db,
 	}
 
 	queryAPI.SetupHTTP(http.DefaultServeMux)
 
+	inputAPI := input.RoomserverInputAPI{
+		DB:                   db,
+		Producer:             kafkaProducer,
+		OutputRoomEventTopic: string(cfg.Kafka.Topics.OutputRoomEvent),
+	}
+
+	inputAPI.SetupHTTP(http.DefaultServeMux)
+
 	http.DefaultServeMux.Handle("/metrics", prometheus.Handler())
 
 	log.Info("Started room server on ", cfg.Listen.RoomServer)

src/github.com/matrix-org/dendrite/cmd/roomserver-integration-tests/main.go

@@ -23,6 +23,10 @@ import (
 	"strings"
 	"time"
 
+	"encoding/json"
+
+	"net/http"
+
 	"github.com/matrix-org/dendrite/common/test"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
@@ -90,7 +94,7 @@ func createDatabase(database string) error {
 // messages is reached or after a timeout. It kills the command before it returns.
 // It returns a list of the messages read from the command on success or an error
 // on failure.
-func runAndReadFromTopic(runCmd *exec.Cmd, topic string, count int, checkQueryAPI func()) ([]string, error) {
+func runAndReadFromTopic(runCmd *exec.Cmd, readyURL string, doInput func(), topic string, count int, checkQueryAPI func()) ([]string, error) {
 	type result struct {
 		// data holds all of stdout on success.
 		data []byte
@@ -107,6 +111,11 @@ func runAndReadFromTopic(runCmd *exec.Cmd, topic string, count int, checkQueryAP
 	)
 	// Send stderr to our stderr so the user can see any error messages.
 	readCmd.Stderr = os.Stderr
+
+	// Kill both processes before we exit.
+	defer func() { runCmd.Process.Kill() }()
+	defer func() { readCmd.Process.Kill() }()
+
 	// Run the command, read the messages and wait for a timeout in parallel.
 	go func() {
 		// Read all of stdout.
@@ -131,14 +140,40 @@ func runAndReadFromTopic(runCmd *exec.Cmd, topic string, count int, checkQueryAP
 		time.Sleep(timeout)
 		done <- result{nil, fmt.Errorf("Timeout reading %d messages from topic %q", count, topic)}
 	}()
+
+	// Poll the HTTP listener of the process waiting for it to be ready to receive requests.
+	ready := make(chan struct{})
+	go func() {
+		delay := 10 * time.Millisecond
+		for {
+			time.Sleep(delay)
+			if delay < 100*time.Millisecond {
+				delay *= 2
+			}
+			resp, err := http.Get(readyURL)
+			if err != nil {
+				continue
+			}
+			if resp.StatusCode == 200 {
+				break
+			}
+		}
+		ready <- struct{}{}
+	}()
+
+	// Wait for the roomserver to be ready to receive input or for it to crash.
+	select {
+	case <-ready:
+	case r := <-done:
+		return nil, r.err
+	}
+
+	// Write the input now that the server is running.
+	doInput()
+
 	// Wait for one of the tasks to finsh.
 	r := <-done
 
-	// Kill both processes. We don't check if the processes are running and
-	// we ignore failures since we are just trying to clean up before returning.
-	runCmd.Process.Kill()
-	readCmd.Process.Kill()
-
 	if r.err != nil {
 		return nil, r.err
 	}
@@ -153,6 +188,20 @@ func runAndReadFromTopic(runCmd *exec.Cmd, topic string, count int, checkQueryAP
 	return lines, nil
 }
 
+func writeToRoomServer(input []string, roomserverURL string) error {
+	var request api.InputRoomEventsRequest
+	var response api.InputRoomEventsResponse
+	var err error
+	request.InputRoomEvents = make([]api.InputRoomEvent, len(input))
+	for i := range input {
+		if err = json.Unmarshal([]byte(input[i]), &request.InputRoomEvents[i]); err != nil {
+			return err
+		}
+	}
+	x := api.NewRoomserverInputAPIHTTP(roomserverURL, nil)
+	return x.InputRoomEvents(&request, &response)
+}
+
 // testRoomserver is used to run integration tests against a single roomserver.
 // It creates new kafka topics for the input and output of the roomserver.
 // It writes the input messages to the input kafka topic, formatting each message
@@ -176,25 +225,23 @@ func testRoomserver(input []string, wantOutput []string, checkQueries func(api.R
 		panic(err)
 	}
 
-	inputTopic := string(cfg.Kafka.Topics.InputRoomEvent)
 	outputTopic := string(cfg.Kafka.Topics.OutputRoomEvent)
 
-	exe.DeleteTopic(inputTopic)
-	if err := exe.CreateTopic(inputTopic); err != nil {
-		panic(err)
-	}
 	exe.DeleteTopic(outputTopic)
 	if err := exe.CreateTopic(outputTopic); err != nil {
 		panic(err)
 	}
 
-	if err := exe.WriteToTopic(inputTopic, canonicalJSONInput(input)); err != nil {
+	if err = createDatabase(testDatabaseName); err != nil {
 		panic(err)
 	}
 
-	if err = createDatabase(testDatabaseName); err != nil {
+	doInput := func() {
+		fmt.Printf("Roomserver is ready to receive input, sending %d events\n", len(input))
+		if err = writeToRoomServer(input, cfg.RoomServerURL()); err != nil {
 			panic(err)
 		}
+	}
 
 	cmd := exec.Command(filepath.Join(filepath.Dir(os.Args[0]), "dendrite-room-server"))
 
@@ -205,7 +252,7 @@ func testRoomserver(input []string, wantOutput []string, checkQueries func(api.R
 	cmd.Stderr = os.Stderr
 	cmd.Args = []string{"dendrite-room-server", "--config", filepath.Join(dir, test.ConfigFile)}
 
-	gotOutput, err := runAndReadFromTopic(cmd, outputTopic, len(wantOutput), func() {
+	gotOutput, err := runAndReadFromTopic(cmd, cfg.RoomServerURL()+"/metrics", doInput, outputTopic, len(wantOutput), func() {
 		queryAPI := api.NewRoomserverQueryAPIHTTP("http://"+string(cfg.Listen.RoomServer), nil)
 		checkQueries(queryAPI)
 	})

src/github.com/matrix-org/dendrite/common/config/config.go

@@ -19,13 +19,14 @@ import (
 	"crypto/sha256"
 	"encoding/pem"
 	"fmt"
-	"github.com/matrix-org/gomatrixserverlib"
-	"golang.org/x/crypto/ed25519"
-	"gopkg.in/yaml.v2"
 	"io/ioutil"
 	"path/filepath"
 	"strings"
 	"time"
+
+	"github.com/matrix-org/gomatrixserverlib"
+	"golang.org/x/crypto/ed25519"
+	"gopkg.in/yaml.v2"
 )
 
 // Version is the current version of the config format.
@@ -95,8 +96,6 @@ type Dendrite struct {
 		Addresses []string `yaml:"addresses"`
 		// The names of the topics to use when reading and writing from kafka.
 		Topics struct {
-			// Topic for roomserver/api.InputRoomEvent events.
-			InputRoomEvent Topic `yaml:"input_room_event"`
 			// Topic for roomserver/api.OutputRoomEvent events.
 			OutputRoomEvent Topic `yaml:"output_room_event"`
 			// Topic for user updates (profile, presence)
@@ -298,7 +297,6 @@ func (config *Dendrite) check() error {
 	}
 
 	checkNotZero("kafka.addresses", int64(len(config.Kafka.Addresses)))
-	checkNotEmpty("kafka.topics.input_room_event", string(config.Kafka.Topics.InputRoomEvent))
 	checkNotEmpty("kafka.topics.output_room_event", string(config.Kafka.Topics.OutputRoomEvent))
 	checkNotEmpty("database.account", string(config.Database.Account))
 	checkNotEmpty("database.device", string(config.Database.Device))

src/github.com/matrix-org/dendrite/common/test/config.go

@@ -21,14 +21,15 @@ import (
 	"encoding/base64"
 	"encoding/pem"
 	"fmt"
-	"github.com/matrix-org/dendrite/common/config"
-	"github.com/matrix-org/gomatrixserverlib"
-	"gopkg.in/yaml.v2"
 	"io/ioutil"
 	"math/big"
 	"os"
 	"path/filepath"
 	"time"
+
+	"github.com/matrix-org/dendrite/common/config"
+	"github.com/matrix-org/gomatrixserverlib"
+	"gopkg.in/yaml.v2"
 )
 
 const (
@@ -80,7 +81,6 @@ func MakeConfig(configDir, kafkaURI, database, host string, startPort int) (*con
 	cfg.Kafka.Addresses = []string{kafkaURI}
 	// TODO: Different servers should be using different topics.
 	// Make this configurable somehow?
-	cfg.Kafka.Topics.InputRoomEvent = "test.room.input"
 	cfg.Kafka.Topics.OutputRoomEvent = "test.room.output"
 
 	// TODO: Use different databases for the different schemas.

src/github.com/matrix-org/dendrite/roomserver/input/consumer.go

@@ -1,133 +0,0 @@
-// 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 input contains the code that writes
-package input
-
-import (
-	"encoding/json"
-	"fmt"
-	"sync/atomic"
-
-	"github.com/matrix-org/dendrite/common"
-	"github.com/matrix-org/dendrite/roomserver/api"
-	sarama "gopkg.in/Shopify/sarama.v1"
-)
-
-// A ConsumerDatabase has the storage APIs needed by the consumer.
-type ConsumerDatabase interface {
-	RoomEventDatabase
-	common.PartitionStorer
-}
-
-// An ErrorLogger handles the errors encountered by the consumer.
-type ErrorLogger interface {
-	OnError(message *sarama.ConsumerMessage, err error)
-}
-
-// A Consumer consumes a kafkaesque stream of room events.
-// The room events are supplied as api.InputRoomEvent structs serialised as JSON.
-// The events should be valid matrix events.
-// The events needed to authenticate the event should already be stored on the roomserver.
-// The events needed to construct the state at the event should already be stored on the roomserver.
-// If the event is not valid then it will be discarded and an error will be logged.
-type Consumer struct {
-	ContinualConsumer common.ContinualConsumer
-	// The database used to store the room events.
-	DB       ConsumerDatabase
-	Producer sarama.SyncProducer
-	// The kafkaesque topic to output new room events to.
-	// This is the name used in kafka to identify the stream to write events to.
-	OutputRoomEventTopic string
-	// The ErrorLogger for this consumer.
-	// If left as nil then the consumer will panic when it encounters an error
-	ErrorLogger ErrorLogger
-	// If non-nil then the consumer will stop processing messages after this
-	// many messages and will shutdown. Malformed messages are included in the count.
-	StopProcessingAfter *int64
-	// If not-nil then the consumer will call this to shutdown the server.
-	ShutdownCallback func(reason string)
-	// How many messages the consumer has processed.
-	processed int64
-}
-
-// WriteOutputRoomEvent implements OutputRoomEventWriter
-func (c *Consumer) WriteOutputRoomEvent(output api.OutputNewRoomEvent) error {
-	var m sarama.ProducerMessage
-	oe := api.OutputEvent{
-		Type:         api.OutputTypeNewRoomEvent,
-		NewRoomEvent: &output,
-	}
-	value, err := json.Marshal(oe)
-	if err != nil {
-		return err
-	}
-	m.Topic = c.OutputRoomEventTopic
-	m.Key = sarama.StringEncoder("")
-	m.Value = sarama.ByteEncoder(value)
-	_, _, err = c.Producer.SendMessage(&m)
-	return err
-}
-
-// Start starts the consumer consuming.
-// Starts up a goroutine for each partition in the kafka stream.
-// Returns nil once all the goroutines are started.
-// Returns an error if it can't start consuming for any of the partitions.
-func (c *Consumer) Start() error {
-	c.ContinualConsumer.ProcessMessage = c.processMessage
-	c.ContinualConsumer.ShutdownCallback = c.shutdown
-	return c.ContinualConsumer.Start()
-}
-
-func (c *Consumer) processMessage(message *sarama.ConsumerMessage) error {
-	var input api.InputRoomEvent
-	if err := json.Unmarshal(message.Value, &input); err != nil {
-		// If the message is invalid then log it and move onto the next message in the stream.
-		c.logError(message, err)
-	} else {
-		if err := processRoomEvent(c.DB, c, input); err != nil {
-			// If there was an error processing the message then log it and
-			// move onto the next message in the stream.
-			// TODO: If the error was due to a problem talking to the database
-			// then we shouldn't move onto the next message and we should either
-			// retry processing the message, or panic and kill ourselves.
-			c.logError(message, err)
-		}
-	}
-	// Update the number of processed messages using atomic addition because it is accessed from multiple goroutines.
-	processed := atomic.AddInt64(&c.processed, 1)
-	// Check if we should stop processing.
-	// Note that since we have multiple goroutines it's quite likely that we'll overshoot by a few messages.
-	// If we try to stop processing after M message and we have N goroutines then we will process somewhere
-	// between M and (N + M) messages because the N goroutines could all try to process what they think will be the
-	// last message. We could be more careful here but this is good enough for getting rough benchmarks.
-	if c.StopProcessingAfter != nil && processed >= int64(*c.StopProcessingAfter) {
-		return common.ErrShutdown
-	}
-	return nil
-}
-
-func (c *Consumer) shutdown() {
-	if c.ShutdownCallback != nil {
-		c.ShutdownCallback(fmt.Sprintf("Stopping processing after %d messages", c.processed))
-	}
-}
-
-// logError is a convenience method for logging errors.
-func (c *Consumer) logError(message *sarama.ConsumerMessage, err error) {
-	if c.ErrorLogger == nil {
-		panic(err)
-	}
-	c.ErrorLogger.OnError(message, err)
-}

src/github.com/matrix-org/dendrite/roomserver/storage/sql.go

@@ -16,12 +16,9 @@ package storage
 
 import (
 	"database/sql"
-
-	"github.com/matrix-org/dendrite/common"
 )
 
 type statements struct {
-	common.PartitionOffsetStatements
 	eventTypeStatements
 	eventStateKeyStatements
 	roomStatements
@@ -35,10 +32,6 @@ type statements struct {
 func (s *statements) prepare(db *sql.DB) error {
 	var err error
 
-	if err = s.PartitionOffsetStatements.Prepare(db); err != nil {
-		return err
-	}
-
 	if err = s.eventTypeStatements.prepare(db); err != nil {
 		return err
 	}

src/github.com/matrix-org/dendrite/roomserver/storage/storage.go

@@ -18,7 +18,6 @@ import (
 	"database/sql"
 	// Import the postgres database driver.
 	_ "github.com/lib/pq"
-	"github.com/matrix-org/dendrite/common"
 	"github.com/matrix-org/dendrite/roomserver/types"
 	"github.com/matrix-org/gomatrixserverlib"
 )
@@ -42,16 +41,6 @@ func Open(dataSourceName string) (*Database, error) {
 	return &d, nil
 }
 
-// PartitionOffsets implements input.ConsumerDatabase
-func (d *Database) PartitionOffsets(topic string) ([]common.PartitionOffset, error) {
-	return d.statements.SelectPartitionOffsets(topic)
-}
-
-// SetPartitionOffset implements input.ConsumerDatabase
-func (d *Database) SetPartitionOffset(topic string, partition int32, offset int64) error {
-	return d.statements.UpsertPartitionOffset(topic, partition, offset)
-}
-
 // StoreEvent implements input.EventDatabase
 func (d *Database) StoreEvent(event gomatrixserverlib.Event, authEventNIDs []types.EventNID) (types.RoomNID, types.StateAtEvent, error) {
 	var (