text: ////////////////////////////////////////////////////////////////////////////////
  /// DISCLAIMER
  ///
  /// Copyright 2014-2018 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 Kaveh Vahedipour
  ////////////////////////////////////////////////////////////////////////////////
  
  #include "Compactor.h"
  
  #include "Agency/Agent.h"
  #include "Basics/ConditionLocker.h"
  
  using namespace arangodb::consensus;
  
  // @brief Construct with agent
  Compactor::Compactor(Agent* agent)
      : Thread("Compactor"), _agent(agent), _wakeupCompactor(false), _waitInterval(1000000) {}
  
  /// Dtor shuts down thread
  Compactor::~Compactor() {
    if (!isStopping()) {
      shutdown();
    }
  }
  
  // @brief Run
  void Compactor::run() {
    LOG_TOPIC(DEBUG, Logger::AGENCY) << "Starting compactor personality";
  
    while (true) {
      {
        CONDITION_LOCKER(guard, _cv);
        if (!_wakeupCompactor) {
          _cv.wait(5000000);  // just in case we miss a wakeup call!
        }
        _wakeupCompactor = false;
      }
  
      if (this->isStopping()) {
        break;
      }
  
      try {
        _agent->compact();  // Note that this checks nextCompactionAfter again!
      } catch (std::exception const& e) {
        LOG_TOPIC(ERR, Logger::AGENCY)
            << "Exception during compaction, details: " << e.what();
      }
    }
  }
  
  // @brief Wake up compaction
  void Compactor::wakeUp() {
    CONDITION_LOCKER(guard, _cv);
    _wakeupCompactor = true;
    _cv.signal();
  }
  
  // @brief Begin shutdown
  void Compactor::beginShutdown() {
    LOG_TOPIC(DEBUG, Logger::AGENCY) << "Shutting down compactor personality";
  
    Thread::beginShutdown();
  
    wakeUp();
  }
  