Also reduce hits on query API

cmd/roomserver-integration-tests/main.go

@@ -270,7 +270,7 @@ func testRoomserver(input []string, wantOutput []string, checkQueries func(api.R
 	cmd.Args = []string{"dendrite-room-server", "--config", filepath.Join(dir, test.ConfigFile)}
 
 	gotOutput, err := runAndReadFromTopic(cmd, cfg.RoomServerURL()+"/metrics", doInput, outputTopic, len(wantOutput), func() {
-		queryAPI, _ := api.NewRoomserverQueryAPIHTTP("http://"+string(cfg.Listen.RoomServer), &http.Client{Timeout: timeoutHTTP})
+		queryAPI, _ := api.NewRoomserverQueryAPIHTTP("http://"+string(cfg.Listen.RoomServer), &http.Client{Timeout: timeoutHTTP}, nil)
 		checkQueries(queryAPI)
 	})
 	if err != nil {

common/basecomponent/base.go

@@ -23,6 +23,7 @@ import (
 
 	"golang.org/x/crypto/ed25519"
 
+	"github.com/matrix-org/dendrite/common/caching"
 	"github.com/matrix-org/dendrite/common/keydb"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/gomatrixserverlib"
@@ -56,6 +57,7 @@ type BaseDendrite struct {
 	APIMux        *mux.Router
 	httpClient    *http.Client
 	Cfg           *config.Dendrite
+	Cache         caching.Cache
 	KafkaConsumer sarama.Consumer
 	KafkaProducer sarama.SyncProducer
 }
@@ -87,6 +89,7 @@ func NewBaseDendrite(cfg *config.Dendrite, componentName string) *BaseDendrite {
 		componentName: componentName,
 		tracerCloser:  closer,
 		Cfg:           cfg,
+		Cache:         caching.NewInMemoryLRUCache(), // TODO: make configurable
 		APIMux:        mux.NewRouter().UseEncodedPath(),
 		httpClient:    &http.Client{Timeout: HTTPClientTimeout},
 		KafkaConsumer: kafkaConsumer,
@@ -116,7 +119,6 @@ func (b *BaseDendrite) CreateHTTPRoomserverAPIs() (
 	roomserverAPI.RoomserverInputAPI,
 	roomserverAPI.RoomserverQueryAPI,
 ) {
-
 	alias, err := roomserverAPI.NewRoomserverAliasAPIHTTP(b.Cfg.RoomServerURL(), b.httpClient)
 	if err != nil {
 		logrus.WithError(err).Panic("NewRoomserverAliasAPIHTTP failed")
@@ -125,7 +127,7 @@ func (b *BaseDendrite) CreateHTTPRoomserverAPIs() (
 	if err != nil {
 		logrus.WithError(err).Panic("NewRoomserverInputAPIHTTP failed", b.httpClient)
 	}
-	query, err := roomserverAPI.NewRoomserverQueryAPIHTTP(b.Cfg.RoomServerURL(), b.httpClient)
+	query, err := roomserverAPI.NewRoomserverQueryAPIHTTP(b.Cfg.RoomServerURL(), b.httpClient, b.Cache)
 	if err != nil {
 		logrus.WithError(err).Panic("NewRoomserverQueryAPIHTTP failed", b.httpClient)
 	}

common/caching/inmemorylru.go

@@ -1,7 +1,6 @@
 package caching
 
 import (
-	"fmt"
 	"sync"
 
 	"github.com/golang/groupcache/lru"
@@ -20,7 +19,6 @@ func NewInMemoryLRUCache() *InMemoryLRUCache {
 }
 
 func (c *InMemoryLRUCache) GetRoomVersion(roomID string) (gomatrixserverlib.RoomVersion, bool) {
-	fmt.Println("Cache hit for", roomID)
 	if c == nil {
 		return "", false
 	}
@@ -36,7 +34,6 @@ func (c *InMemoryLRUCache) GetRoomVersion(roomID string) (gomatrixserverlib.Room
 }
 
 func (c *InMemoryLRUCache) StoreRoomVersion(roomID string, roomVersion gomatrixserverlib.RoomVersion) {
-	fmt.Println("Cache store for", roomID)
 	if c == nil {
 		return
 	}

roomserver/api/query.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"net/http"
 
+	"github.com/matrix-org/dendrite/common/caching"
 	commonHTTP "github.com/matrix-org/dendrite/common/http"
 	"github.com/matrix-org/gomatrixserverlib"
 	opentracing "github.com/opentracing/opentracing-go"
@@ -411,16 +412,17 @@ const RoomserverQueryRoomVersionForRoomPath = "/api/roomserver/queryRoomVersionF
 
 // NewRoomserverQueryAPIHTTP creates a RoomserverQueryAPI implemented by talking to a HTTP POST API.
 // If httpClient is nil an error is returned
-func NewRoomserverQueryAPIHTTP(roomserverURL string, httpClient *http.Client) (RoomserverQueryAPI, error) {
+func NewRoomserverQueryAPIHTTP(roomserverURL string, httpClient *http.Client, cache caching.Cache) (RoomserverQueryAPI, error) {
 	if httpClient == nil {
 		return nil, errors.New("NewRoomserverQueryAPIHTTP: httpClient is <nil>")
 	}
-	return &httpRoomserverQueryAPI{roomserverURL, httpClient}, nil
+	return &httpRoomserverQueryAPI{roomserverURL, httpClient, cache}, nil
 }
 
 type httpRoomserverQueryAPI struct {
 	roomserverURL string
 	httpClient    *http.Client
+	cache         caching.Cache
 }
 
 // QueryLatestEventsAndState implements RoomserverQueryAPI
@@ -585,9 +587,18 @@ func (h *httpRoomserverQueryAPI) QueryRoomVersionForRoom(
 	request *QueryRoomVersionForRoomRequest,
 	response *QueryRoomVersionForRoomResponse,
 ) error {
+	if roomVersion, ok := h.cache.GetRoomVersion(request.RoomID); ok {
+		response.RoomVersion = roomVersion
+		return nil
+	}
+
 	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryRoomVersionForRoom")
 	defer span.Finish()
 
 	apiURL := h.roomserverURL + RoomserverQueryRoomVersionForRoomPath
-	return commonHTTP.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+	err := commonHTTP.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+	if err == nil {
+		h.cache.StoreRoomVersion(request.RoomID, response.RoomVersion)
+	}
+	return err
 }

roomserver/query/query.go

@@ -902,6 +902,7 @@ func (r *RoomserverQueryAPI) QueryRoomVersionForRoom(
 		response.RoomVersion = roomVersion
 		return nil
 	}
+
 	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, request.RoomID)
 	if err != nil {
 		return err

roomserver/roomserver.go

@@ -21,7 +21,6 @@ import (
 
 	asQuery "github.com/matrix-org/dendrite/appservice/query"
 	"github.com/matrix-org/dendrite/common/basecomponent"
-	"github.com/matrix-org/dendrite/common/caching"
 	"github.com/matrix-org/dendrite/roomserver/alias"
 	"github.com/matrix-org/dendrite/roomserver/input"
 	"github.com/matrix-org/dendrite/roomserver/query"
@@ -51,7 +50,7 @@ func SetupRoomServerComponent(
 
 	queryAPI := query.RoomserverQueryAPI{
 		DB:    roomserverDB,
-		Cache: caching.NewInMemoryLRUCache(),
+		Cache: base.Cache,
 	}
 
 	queryAPI.SetupHTTP(http.DefaultServeMux)