Implement read receipts (#1528)

* fix conversion from int to string yields a string of one rune, not a string of digits

* Add receipts table to syncapi

* Use StreamingToken as the since value

* Add required method to testEDUProducer

* Make receipt json creation "easier" to read

* Add receipts api to the eduserver

* Add receipts endpoint

* Add eduserver kafka consumer

* Add missing kafka config

* Add passing tests to whitelist

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Fix copy & paste error

* Fix column count error

* Make outbound federation receipts pass

* Make "Inbound federation rejects receipts from wrong remote" pass

* Don't use errors package

* - Add TODO for batching requests
- Rename variable

* Return a better error message

* - Use OutputReceiptEvent instead of InputReceiptEvent as result
- Don't use the errors package for errors
- Defer CloseAndLogIfError to close rows
- Fix Copyright

* Better creation/usage of JoinResponse

* Query all joined rooms instead of just one

* Update gomatrixserverlib

* Add sqlite3 migration

* Add postgres migration

* Ensure required sequence exists before running migrations

* Clarification on comment

* - Fix a bug when creating client receipts
- Use concrete types instead of interface{}

* Remove dead code
Use key for timestamp

* Fix postgres query...

* Remove single purpose struct

* Use key/value directly

* Only apply receipts on initial sync or if edu positions differ,
otherwise we'll be sending the same receipts over and over again.

* Actually update the id, so it is correctly send in syncs

* Set receipt on request to /read_markers

* Fix issue with receipts getting overwritten

* Use fmt.Errorf instead of pkg/errors

* Revert "Add postgres migration"

This reverts commit 722fe5a04628882b787d096942459961db159b06.

* Revert "Add sqlite3 migration"

This reverts commit d113b03f6495a4b8f8bcf158a3d00b510b4240cc.

* Fix selectRoomReceipts query

* Make golangci-lint happy

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

internal/caching/cache_roomservernids.go

@@ -1,6 +1,8 @@
 package caching
 
 import (
+	"strconv"
+
 	"github.com/matrix-org/dendrite/roomserver/types"
 )
 
@@ -83,11 +85,11 @@ func (c Caches) GetRoomServerRoomNID(roomID string) (types.RoomNID, bool) {
 
 func (c Caches) StoreRoomServerRoomNID(roomID string, roomNID types.RoomNID) {
 	c.RoomServerRoomNIDs.Set(roomID, roomNID)
-	c.RoomServerRoomIDs.Set(string(roomNID), roomID)
+	c.RoomServerRoomIDs.Set(strconv.Itoa(int(roomNID)), roomID)
 }
 
 func (c Caches) GetRoomServerRoomID(roomNID types.RoomNID) (string, bool) {
-	val, found := c.RoomServerRoomIDs.Get(string(roomNID))
+	val, found := c.RoomServerRoomIDs.Get(strconv.Itoa(int(roomNID)))
 	if found && val != nil {
 		if roomID, ok := val.(string); ok {
 			return roomID, true

internal/config/config_kafka.go

@@ -9,6 +9,7 @@ const (
 	TopicOutputKeyChangeEvent    = "OutputKeyChangeEvent"
 	TopicOutputRoomEvent         = "OutputRoomEvent"
 	TopicOutputClientData        = "OutputClientData"
+	TopicOutputReceiptEvent      = "OutputReceiptEvent"
 )
 
 type Kafka struct {

internal/transactions/transactions_test.go

@@ -14,6 +14,7 @@ package transactions
 
 import (
 	"net/http"
+	"strconv"
 	"testing"
 
 	"github.com/matrix-org/util"
@@ -44,8 +45,8 @@ func TestCache(t *testing.T) {
 	for i := 1; i <= 100; i++ {
 		fakeTxnCache.AddTransaction(
 			fakeAccessToken,
-			fakeTxnID+string(i),
-			&util.JSONResponse{Code: http.StatusOK, JSON: fakeType{ID: string(i)}},
+			fakeTxnID+strconv.Itoa(i),
+			&util.JSONResponse{Code: http.StatusOK, JSON: fakeType{ID: strconv.Itoa(i)}},
 		)
 	}