Method handleWatch

agent/agentgit/api.go:41–164

(rw http.ResponseWriter, r *http.Request)

}

func (a *API) handleWatch(rw http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	var watchChatID uuid.UUID
	var hasWatchChatID bool
	if chatIDStr := r.URL.Query().Get("chat_id"); chatIDStr != "" {
		if parsedChatID, parseErr := uuid.Parse(chatIDStr); parseErr == nil {
			watchChatID = parsedChatID
			hasWatchChatID = true

			// Reuse header-derived ancestors only when the query chat
			// matches the header chat. Otherwise the ancestors belong
			// to a different chat and would be misleading in logs.
			var ancestors []uuid.UUID
			if chatContext, ok := agentchat.FromContext(ctx); ok && chatContext.ID == watchChatID {
				ancestors = chatContext.AncestorIDs
			}
			ctx = agentchat.WithContext(ctx, watchChatID, ancestors)
		}
	}
	logger := a.logger.With(agentchat.Fields(ctx)...)

	conn, err := websocket.Accept(rw, r, &websocket.AcceptOptions{
		CompressionMode: websocket.CompressionNoContextTakeover,
	})
	if err != nil {
		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
			Message: "Failed to accept WebSocket.",
			Detail:  err.Error(),
		})
		return
	}

	// 4 MiB read limit — subscribe messages with many paths can exceed the
	// default 32 KB limit. Matches the SDK/proxy side.
	conn.SetReadLimit(1 << 22)

	stream := wsjson.NewStream[
		codersdk.WorkspaceAgentGitClientMessage,
		codersdk.WorkspaceAgentGitServerMessage,
	](conn, websocket.MessageText, websocket.MessageText, logger)

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	go httpapi.HeartbeatClose(ctx, logger, cancel, conn)

	handler := NewHandler(logger, a.opts...)

	// Scan returns nil only when no roots are subscribed; once any
	// root lands it returns either a delta or a heartbeat message.
	scanAndSend := func() {
		msg := handler.Scan(ctx)
		if msg == nil {
			return
		}
		if err := stream.Send(*msg); err != nil {
			logger.Debug(ctx, "failed to send changes", slog.Error(err))