text: ////////////////////////////////////////////////////////////////////////////////
  /// DISCLAIMER
  ///
  /// Copyright 2014-2016 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 Jan Christoph Uhde
  ////////////////////////////////////////////////////////////////////////////////
  
  #ifndef ARANGODB_STORAGE_ENGINE_ROCKSDB_OPTION_FEATURE_H
  #define ARANGODB_STORAGE_ENGINE_ROCKSDB_OPTION_FEATURE_H 1
  
  #include <cstdint>
  #include <memory>
  #include <string>
  
  #include "ApplicationFeatures/ApplicationFeature.h"
  #include "Basics/Common.h"
  
  namespace arangodb {
  namespace application_features {
  class ApplicationServer;
  }
  namespace options {
  class ProgramOptions;
  }
  
  // This feature is used to configure RocksDB in a central place.
  //
  // The RocksDB-Storage-Engine and the MMFiles-Persistent-Index
  // that are never activated at the same time take options set
  // in this feature
  
  class RocksDBOptionFeature final : public application_features::ApplicationFeature {
   public:
    explicit RocksDBOptionFeature(application_features::ApplicationServer& server);
    ~RocksDBOptionFeature() = default;
  
    void collectOptions(std::shared_ptr<options::ProgramOptions>) override final;
    void validateOptions(std::shared_ptr<options::ProgramOptions>) override final;
    void start() override final;
  
    int64_t _transactionLockTimeout;
    std::string _walDirectory;
    uint64_t _totalWriteBufferSize;
    uint64_t _writeBufferSize;
    // Update max_write_buffer_number above if you change number of families used
    uint64_t _maxWriteBufferNumber;
    int64_t _maxWriteBufferSizeToMaintain;
    uint64_t _maxTotalWalSize;
    uint64_t _delayedWriteRate;
    uint64_t _minWriteBufferNumberToMerge;
    uint64_t _numLevels;
    uint64_t _numUncompressedLevels;
    uint64_t _maxBytesForLevelBase;
    double _maxBytesForLevelMultiplier;
    int32_t _maxBackgroundJobs;
    uint64_t _maxSubcompactions;
    uint32_t _numThreadsHigh;
    uint32_t _numThreadsLow;
    uint64_t _targetFileSizeBase;
    uint64_t _targetFileSizeMultiplier;
    uint64_t _blockCacheSize;
    int64_t _blockCacheShardBits;
    uint64_t _tableBlockSize;
    uint64_t _compactionReadaheadSize;
    int64_t _level0CompactionTrigger;
    int64_t _level0SlowdownTrigger;
    int64_t _level0StopTrigger;
    bool _recycleLogFileNum;
    bool _enforceBlockCacheSizeLimit;
    bool _cacheIndexAndFilterBlocks;
    bool _cacheIndexAndFilterBlocksWithHighPriority;
    bool _pinl0FilterAndIndexBlocksInCache;
    bool _pinTopLevelIndexAndFilter;
    bool _blockAlignDataBlocks;
    bool _enablePipelinedWrite;
    bool _optimizeFiltersForHits;
    bool _useDirectReads;
    bool _useDirectIoForFlushAndCompaction;
    bool _useFSync;
    bool _skipCorrupted;
    bool _dynamicLevelBytes;
    bool _enableStatistics;
    bool _useFileLogging;
    bool _limitOpenFilesAtStartup;
    bool _allowFAllocate;
    bool _exclusiveWrites;
  };
  
  }  // namespace arangodb
  
  #endif
  