(minor) refactor redis GC and fix TX calls,

add indicator that metrics are running

frontend/http/frontend.go

@@ -17,6 +17,7 @@ import (
 	"github.com/sot-tech/mochi/frontend"
 	"github.com/sot-tech/mochi/pkg/conf"
 	"github.com/sot-tech/mochi/pkg/log"
+	"github.com/sot-tech/mochi/pkg/metrics"
 	"github.com/sot-tech/mochi/pkg/stop"
 )
 
@@ -285,17 +286,15 @@ func injectRouteParamsToContext(ctx context.Context, ps httprouter.Params) conte
 func (f *Frontend) announceRoute(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
 	var err error
 	var start time.Time
-	if f.EnableRequestTiming {
-		start = time.Now()
-	}
 	var addr netip.Addr
-	defer func() {
-		if f.EnableRequestTiming {
-			recordResponseDuration("announce", addr, err, time.Since(start))
-		} else {
-			recordResponseDuration("announce", addr, err, time.Duration(0))
-		}
-	}()
+	if f.EnableRequestTiming && metrics.Enabled() {
+		start = time.Now()
+		defer func() {
+			if f.EnableRequestTiming && metrics.Enabled() {
+				recordResponseDuration("announce", addr, err, time.Since(start))
+			}
+		}()
+	}
 
 	req, err := ParseAnnounce(r, f.ParseOptions)
 	if err != nil {
@@ -325,17 +324,15 @@ func (f *Frontend) announceRoute(w http.ResponseWriter, r *http.Request, ps http
 func (f *Frontend) scrapeRoute(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
 	var err error
 	var start time.Time
-	if f.EnableRequestTiming {
-		start = time.Now()
-	}
 	var addr netip.Addr
-	defer func() {
-		if f.EnableRequestTiming {
-			recordResponseDuration("scrape", addr, err, time.Since(start))
-		} else {
-			recordResponseDuration("scrape", addr, err, time.Duration(0))
-		}
-	}()
+	if f.EnableRequestTiming && metrics.Enabled() {
+		start = time.Now()
+		defer func() {
+			if f.EnableRequestTiming && metrics.Enabled() {
+				recordResponseDuration("scrape", addr, err, time.Since(start))
+			}
+		}()
+	}
 
 	req, err := ParseScrape(r, f.ParseOptions)
 	if err != nil {

frontend/http/parser.go

@@ -79,7 +79,7 @@ func ParseAnnounce(r *http.Request, opts ParseOptions) (*bittorrent.AnnounceRequ
 	}
 	request.Peer.ID, err = bittorrent.NewPeerID([]byte(peerID))
 	if err != nil {
-		return nil, err
+		return nil, errInvalidPeerID
 	}
 	// Determine the number of remaining bytes for the client.
 	request.Left, err = qp.Uint("left", 64)

frontend/udp/frontend.go

@@ -18,6 +18,7 @@ import (
 	"github.com/sot-tech/mochi/frontend/udp/bytepool"
 	"github.com/sot-tech/mochi/pkg/conf"
 	"github.com/sot-tech/mochi/pkg/log"
+	"github.com/sot-tech/mochi/pkg/metrics"
 	"github.com/sot-tech/mochi/pkg/stop"
 	"github.com/sot-tech/mochi/pkg/timecache"
 )
@@ -214,17 +215,15 @@ func (t *Frontend) serve() error {
 			// Handle the request.
 			addr := addrPort.Addr().Unmap()
 			var start time.Time
-			if t.EnableRequestTiming {
+			if t.EnableRequestTiming && metrics.Enabled() {
 				start = time.Now()
 			}
 			action, err := t.handleRequest(
 				Request{(*buffer)[:n], addr},
 				ResponseWriter{t.socket, addrPort},
 			)
-			if t.EnableRequestTiming {
+			if t.EnableRequestTiming && metrics.Enabled() {
 				recordResponseDuration(action, addr, err, time.Since(start))
-			} else {
-				recordResponseDuration(action, addr, err, time.Duration(0))
 			}
 		}()
 	}

frontend/udp/parser.go

@@ -45,6 +45,8 @@ var (
 	errUnknownAction     = bittorrent.ClientError("unknown action ID")
 	errBadConnectionID   = bittorrent.ClientError("bad connection ID")
 	errUnknownOptionType = bittorrent.ClientError("unknown option type")
+	errInvalidInfoHash   = bittorrent.ClientError("invalid info hash")
+	errInvalidPeerID     = bittorrent.ClientError("invalid info hash")
 )
 
 // ParseOptions is the configuration used to parse an Announce Request.
@@ -117,12 +119,12 @@ func ParseAnnounce(r Request, v6Action bool, opts ParseOptions) (*bittorrent.Ann
 
 	ih, err := bittorrent.NewInfoHash(infohash)
 	if err != nil {
-		return nil, err
+		return nil, errInvalidInfoHash
 	}
 
 	peerID, err := bittorrent.NewPeerID(peerIDBytes)
 	if err != nil {
-		return nil, err
+		return nil, errInvalidPeerID
 	}
 
 	request := &bittorrent.AnnounceRequest{