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

namespace mozc {
namespace emacs {

class ClientPool {
 public:
  typedef mozc::client::Client Client;

  ClientPool();
  virtual ~ClientPool() {}

  // 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.
  linked_ptr<Client> GetClient(int id);

 private:
  mozc::storage::LRUCache<int, linked_ptr<Client> > lru_cache_;
  int next_id_;

  DISALLOW_COPY_AND_ASSIGN(ClientPool);
};

}  // namespace emacs
}  // namespace mozc

#endif  // MOZC_UNIX_EMACS_CLIENT_POOL_H_