plugin_state.h

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/*
  Copyright (c) 2022, 2025, Oracle and/or its affiliates.
 
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License, version 2.0,
  as published by the Free Software Foundation.
 
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  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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*/
 
#ifndef ROUTER_SRC_HARNESS_INCLUDE_MYSQL_HARNESS_PLUGIN_STATE_H_
#define ROUTER_SRC_HARNESS_INCLUDE_MYSQL_HARNESS_PLUGIN_STATE_H_
 
#include <atomic>
#include <map>
#include <memory>
#include <mutex>
#include <vector>
 
#include "mysql/harness/plugin_state_observer.h"
 
#include "harness_export.h"
 
namespace mysql_harness {
 
class HARNESS_EXPORT PluginState {
 public:
  using PluginName = std::string;
  using Plugins = std::vector<PluginName>;
  using ObserverId = uint32_t;
  using ObserverPtr = std::weak_ptr<PluginStateObserver>;
  using MapOfListeners = std::map<ObserverId, ObserverPtr>;
 
  constexpr static ObserverId k_invalid_id_ = 0;
 
 public:
  virtual ~PluginState() = default;
 
  static PluginState *get_instance();
 
  virtual ObserverId push_back_observer(ObserverPtr psl);
  virtual std::vector<ObserverId> push_back_observers(
      const std::vector<ObserverPtr> &array);
  virtual void remove_observer(ObserverId k);
  virtual void remove_observers(const std::vector<ObserverId> &k);
 
  virtual void dispatch_register_waitable(const PluginName &name);
  virtual void dispatch_startup(const PluginName &name);
  virtual void dispatch_shutdown(const PluginName &name);
 
  virtual Plugins get_running_plugins() const;
  virtual Plugins get_loaded_plugins() const;
 
 protected:
  class PluginStateOp;
  PluginState();
 
  std::atomic<ObserverId> last_used_id_{k_invalid_id_};
  mutable std::mutex mutex_guard_listeners_;
  MapOfListeners listeners_;
  Plugins running_plugins_;
  Plugins stopped_plugins_;
  Plugins loaded_plugins_;
  std::shared_ptr<PluginStateObserver> default_observer_;
};
 
}  // namespace mysql_harness
 
#endif  // ROUTER_SRC_HARNESS_INCLUDE_MYSQL_HARNESS_PLUGIN_STATE_H_