Turn CHATHISTORY and backlog limits into constants

downstream.go

@@ -1161,7 +1161,7 @@ func (dc *downstreamConn) welcome() error {
 	}
 
 	isupport := []string{
-		fmt.Sprintf("CHATHISTORY=%v", dc.srv.HistoryLimit),
+		fmt.Sprintf("CHATHISTORY=%v", chatHistoryLimit),
 		"CASEMAPPING=ascii",
 	}
 
@@ -1331,9 +1331,8 @@ func (dc *downstreamConn) sendTargetBacklog(net *network, target, msgID string)
 	ctx, cancel := context.WithTimeout(context.TODO(), messageStoreTimeout)
 	defer cancel()
 
-	limit := 4000
 	targetCM := net.casemap(target)
-	history, err := dc.user.msgStore.LoadLatestID(ctx, &net.Network, targetCM, msgID, limit)
+	history, err := dc.user.msgStore.LoadLatestID(ctx, &net.Network, targetCM, msgID, backlogLimit)
 	if err != nil {
 		dc.logger.Printf("failed to send backlog for %q: %v", target, err)
 		return
@@ -2328,7 +2327,7 @@ func (dc *downstreamConn) handleMessageRegistered(msg *irc.Message) error {
 		}
 
 		limit, err := strconv.Atoi(limitStr)
-		if err != nil || limit < 0 || limit > dc.srv.HistoryLimit {
+		if err != nil || limit < 0 || limit > chatHistoryLimit {
 			return ircError{&irc.Message{
 				Command: "FAIL",
 				Params:  []string{"CHATHISTORY", "INVALID_PARAMS", subcommand, limitStr, "Invalid limit"},

server.go

@@ -26,6 +26,8 @@ var writeTimeout = 10 * time.Second
 var upstreamMessageDelay = 2 * time.Second
 var upstreamMessageBurst = 10
 var messageStoreTimeout = 10 * time.Second
+var chatHistoryLimit = 1000
+var backlogLimit = 4000
 
 type Logger interface {
 	Print(v ...interface{})
@@ -53,7 +55,6 @@ type Server struct {
 	Hostname        string
 	Title           string
 	Logger          Logger
-	HistoryLimit    int
 	LogPath         string
 	Debug           bool
 	HTTPOrigins     []string
@@ -75,7 +76,6 @@ type Server struct {
 func NewServer(db Database) *Server {
 	srv := &Server{
 		Logger:          log.New(log.Writer(), "", log.LstdFlags),
-		HistoryLimit:    1000,
 		MaxUserNetworks: -1,
 		db:              db,
 		listeners:       make(map[net.Listener]struct{}),