Clean empty, day old, lobbies on a 30min timer. (#63)

Currently all lobbies stay in the database even if they are empty. This
change introduces a simple timer that deletes day old empty lobbies
every 30 minutes.

This is needed for better lobby listing (filters, private etc) in the
future.

Also snuck in the disabling of websocket compression, see
coder/websocket#218 (comment)

Author: koenbollen

Diff for: internal/signaling/handler.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"net/http"
-	"strings"
 	"sync"
 	"time"
 
@@ -19,12 +18,32 @@ import (
 
 const MaxConnectionTime = 1 * time.Hour
 
+const LobbyCleanInterval = 30 * time.Minute
+const LobbyCleanThreshold = 24 * time.Hour
+
 func Handler(ctx context.Context, store stores.Store, cloudflare *cloudflare.CredentialsClient) (*sync.WaitGroup, http.HandlerFunc) {
 	manager := &TimeoutManager{
 		Store: store,
 	}
 	go manager.Run(ctx)
 
+	go func() {
+		logger := logging.GetLogger(ctx)
+		ticker := time.NewTicker(LobbyCleanInterval)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-ticker.C:
+				logger.Info("cleaning empty lobbies")
+				if err := store.CleanEmptyLobbies(ctx, time.Now().Add(-LobbyCleanThreshold)); err != nil {
+					logger.Error("failed to clean empty lobbies", zap.Error(err))
+				}
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
+
 	wg := &sync.WaitGroup{}
 	return wg, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		ctx := r.Context()
@@ -34,17 +53,10 @@ func Handler(ctx context.Context, store stores.Store, cloudflare *cloudflare.Cre
 		ctx, cancel := context.WithTimeout(ctx, MaxConnectionTime)
 		defer cancel()
 
-		userAgentLower := strings.ToLower(r.Header.Get("User-Agent"))
-		isSafari := strings.Contains(userAgentLower, "safari") && !strings.Contains(userAgentLower, "chrome") && !strings.Contains(userAgentLower, "android")
 		acceptOptions := &websocket.AcceptOptions{
-			// Allow any origin/game to connect.
-			InsecureSkipVerify: true,
-		}
-
-		if isSafari {
-			acceptOptions.CompressionMode = websocket.CompressionDisabled
+			InsecureSkipVerify: true, // Allow any origin/game to connect.
+			CompressionMode:    websocket.CompressionDisabled,
 		}
-
 		conn, err := websocket.Accept(w, r, acceptOptions)
 		if err != nil {
 			util.ErrorAndAbort(w, r, http.StatusBadRequest, "", err)

Diff for: internal/signaling/stores/postgres.go

@@ -151,11 +151,12 @@ func (s *PostgresStore) CreateLobby(ctx context.Context, game, lobbyCode, peerID
 		logger.Warn("peer id too long", zap.String("peerID", peerID))
 		return ErrInvalidPeerID
 	}
+	now := util.Now(ctx)
 	res, err := s.DB.Exec(ctx, `
-		INSERT INTO lobbies (code, game, public)
-		VALUES ($1, $2, true)
+		INSERT INTO lobbies (code, game, public, created_at, updated_at)
+		VALUES ($1, $2, true, $3, $3)
 		ON CONFLICT DO NOTHING
-	`, lobbyCode, game)
+	`, lobbyCode, game, now)
 	if err != nil {
 		return err
 	}
@@ -171,6 +172,9 @@ func (s *PostgresStore) JoinLobby(ctx context.Context, game, lobbyCode, peerID s
 		logger.Warn("peer id too long", zap.String("peerID", peerID))
 		return nil, ErrInvalidPeerID
 	}
+
+	now := util.Now(ctx)
+
 	tx, err := s.DB.Begin(ctx)
 	if err != nil {
 		return nil, err
@@ -200,10 +204,12 @@ func (s *PostgresStore) JoinLobby(ctx context.Context, game, lobbyCode, peerID s
 
 	_, err = tx.Exec(ctx, `
 		UPDATE lobbies
-		SET peers = array_append(peers, $1)
-		WHERE code = $2
-		AND game = $3
-	`, peerID, lobbyCode, game)
+		SET
+			peers = array_append(peers, $1),
+			updated_at = $2
+		WHERE code = $3
+		AND game = $4
+	`, peerID, now, lobbyCode, game)
 	if err != nil {
 		return nil, err
 	}
@@ -232,14 +238,18 @@ func (s *PostgresStore) IsPeerInLobby(ctx context.Context, game, lobbyCode, peer
 }
 
 func (s *PostgresStore) LeaveLobby(ctx context.Context, game, lobbyCode, peerID string) ([]string, error) {
+	now := util.Now(ctx)
+
 	var peerlist []string
 	err := s.DB.QueryRow(ctx, `
 		UPDATE lobbies
-		SET peers = array_remove(peers, $1)
-		WHERE code = $2
-		AND game = $3
+		SET
+			peers = array_remove(peers, $1),
+			updated_at = $2
+		WHERE code = $3
+		AND game = $4
 		RETURNING peers
-	`, peerID, lobbyCode, game).Scan(&peerlist)
+	`, peerID, now, lobbyCode, game).Scan(&peerlist)
 	if err != nil && !errors.Is(err, pgx.ErrNoRows) {
 		return nil, err
 	}
@@ -392,3 +402,12 @@ func (s *PostgresStore) ClaimNextTimedOutPeer(ctx context.Context, threshold tim
 
 	return true, tx.Commit(ctx)
 }
+
+func (s *PostgresStore) CleanEmptyLobbies(ctx context.Context, olderThan time.Time) error {
+	_, err := s.DB.Exec(ctx, `
+		DELETE FROM lobbies
+		WHERE updated_at < $1
+		AND peers = '{}'
+	`, olderThan)
+	return err
+}

Diff for: internal/signaling/stores/shared.go

@@ -29,6 +29,8 @@ type Store interface {
 	TimeoutPeer(ctx context.Context, peerID, secret, gameID string, lobbies []string) error
 	ReconnectPeer(ctx context.Context, peerID, secret, gameID string) (bool, []string, error)
 	ClaimNextTimedOutPeer(ctx context.Context, threshold time.Duration, callback func(peerID, gameID string, lobbies []string) error) (bool, error)
+
+	CleanEmptyLobbies(ctx context.Context, olderThan time.Time) error
 }
 
 type Lobby struct {