Live: array for Processor, Outputter and Subscriber in channel rule top level (#39677)

pkg/services/live/pipeline/data_output_local_subscribers.go

@@ -0,0 +1,38 @@
+package pipeline
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/grafana/grafana/pkg/services/live/orgchannel"
+
+	"github.com/centrifugal/centrifuge"
+)
+
+type LocalSubscribersDataOutput struct {
+	// TODO: refactor to depend on interface (avoid Centrifuge dependency here).
+	node *centrifuge.Node
+}
+
+func NewLocalSubscribersDataOutput(node *centrifuge.Node) *LocalSubscribersDataOutput {
+	return &LocalSubscribersDataOutput{node: node}
+}
+
+const DataOutputTypeLocalSubscribers = "localSubscribers"
+
+func (out *LocalSubscribersDataOutput) Type() string {
+	return DataOutputTypeLocalSubscribers
+}
+
+func (out *LocalSubscribersDataOutput) OutputData(_ context.Context, vars Vars, data []byte) ([]*ChannelData, error) {
+	channelID := vars.Channel
+	channel := orgchannel.PrependOrgID(vars.OrgID, channelID)
+	pub := &centrifuge.Publication{
+		Data: data,
+	}
+	err := out.node.Hub().BroadcastPublication(channel, pub, centrifuge.StreamPosition{})
+	if err != nil {
+		return nil, fmt.Errorf("error publishing %s: %w", string(data), err)
+	}
+	return nil, nil
+}