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// Pool of Client instances, implemented with LruCache.

#ifndef MOZC_UNIX_EMACS_CLIENT_POOL_H_
#define MOZC_UNIX_EMACS_CLIENT_POOL_H_

#include <memory>

#include "client/client.h"
#include "storage/lru_cache.h"

namespace mozc {
namespace emacs {

class ClientPool final {
 public:
  using Client = ::mozc::client::Client;

  ClientPool();
  ClientPool(const ClientPool&) = delete;
  ClientPool& operator=(const ClientPool&) = delete;

  // Returns a new session ID, which is not used in this pool.
  int CreateClient();

  // Deletes a client.  If the specified session ID is not in this pool,
  // does nothing.
  void DeleteClient(int id);

  // Returns a Client instance.  If the specified session ID is not in this
  // pool, creates a new Client and returns it.
  std::shared_ptr<Client> GetClient(int id);

 private:
  storage::LruCache<int, std::shared_ptr<Client>> lru_cache_;
  int next_id_;
};

}  // namespace emacs
}  // namespace mozc

#endif  // MOZC_UNIX_EMACS_CLIENT_POOL_H_
