text: ////////////////////////////////////////////////////////////////////////////////
  /// DISCLAIMER
  ///
  /// Copyright 2014-2021 ArangoDB GmbH, Cologne, Germany
  /// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
  ///
  /// Licensed under the Apache License, Version 2.0 (the "License");
  /// you may not use this file except in compliance with the License.
  /// You may obtain a copy of the License at
  ///
  ///     http://www.apache.org/licenses/LICENSE-2.0
  ///
  /// Unless required by applicable law or agreed to in writing, software
  /// distributed under the License is distributed on an "AS IS" BASIS,
  /// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  /// See the License for the specific language governing permissions and
  /// limitations under the License.
  ///
  /// Copyright holder is ArangoDB GmbH, Cologne, Germany
  ///
  /// @author Andreas Streichardt
  ////////////////////////////////////////////////////////////////////////////////
  
  #pragma once
  
  #include "Agency/AgencyCommon.h"
  
  namespace arangodb {
  namespace consensus {
  class AgentInterface {
   public:
    /// @brief Possible outcome of write process
    enum raft_commit_t { OK, UNKNOWN, TIMEOUT };
  
    struct WriteMode {
      bool _discardStartup;
      bool _privileged;
      WriteMode(bool d = false, bool p = false)
          : _discardStartup(d), _privileged(p) {}
      bool privileged() const { return _privileged; }
      bool discardStartup() const { return _discardStartup; }
      bool operator==(WriteMode const& other) const {
        return other._discardStartup == _discardStartup && other._privileged == _privileged;
      }
      bool operator!=(WriteMode const& other) const {
        return other._discardStartup != _discardStartup || other._privileged != _privileged;
      }
    };
  
    /// @brief Attempt write
    virtual write_ret_t write(query_t const&, WriteMode const& mode = WriteMode()) = 0;
  
    /// @brief Attempt write
    virtual trans_ret_t transient(query_t const&) = 0;
  
    /// @brief Attempt write
    virtual trans_ret_t transact(query_t const&) = 0;
  
    /// @brief Wait for followers to confirm appended entries
    virtual raft_commit_t waitFor(index_t last_entry, double timeout = 2.0) = 0;
  
    /// @brief Wait for followers to confirm appended entries
    virtual bool isCommitted(index_t last_entry) const = 0;
  
    // Suffice warnings
    virtual ~AgentInterface() = default;
  };
  }  // namespace consensus
  }  // namespace arangodb
  