#pragma once

#include "envoy/upstream/cluster_manager.h"

namespace Envoy {

namespace Upstream {

/**

 * Keeps track of cluster updates in order to spot addition and removal.

 *

 * Use this class as a performance optimization to avoid going through ClusterManager::get()

 * on the hot path.

 */

class ClusterUpdateTracker : public ClusterUpdateCallbacks {

public:

  ClusterUpdateTracker(ClusterManager& cm, const std::string& cluster_name);

  // ClusterUpdateCallbacks

  void onClusterAddOrUpdate(absl::string_view cluster_name,

                            ThreadLocalClusterCommand& get_cluster) override;

  void onClusterRemoval(const std::string& cluster) override;

private:

  const std::string cluster_name_;

  const ClusterUpdateCallbacksHandlePtr cluster_update_callbacks_handle_;

  ThreadLocalClusterOptRef thread_local_cluster_;

};

} // namespace Upstream

} // namespace Envoy