text: /**
   *    Copyright (C) 2017 MongoDB, Inc.
   *
   *    This program is free software: you can redistribute it and/or  modify
   *    it under the terms of the GNU Affero General Public License, version 3,
   *    as published by the Free Software Foundation.
   *
   *    This program is distributed in the hope that it will be useful,
   *    but WITHOUT ANY WARRANTY; without even the implied warranty of
   *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *    GNU Affero General Public License for more details.
   *
   *    You should have received a copy of the GNU Affero General Public License
   *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
   *
   *    As a special exception, the copyright holders give permission to link the
   *    code of portions of this program with the OpenSSL library under certain
   *    conditions as described in each individual source file and distribute
   *    linked combinations including the program with the OpenSSL library. You
   *    must comply with the GNU Affero General Public License in all respects for
   *    all of the code used other than as permitted herein. If you modify file(s)
   *    with this exception, you may extend this exception to your version of the
   *    file(s), but you are not obligated to do so. If you do not wish to do so,
   *    delete this exception statement from your version. If you delete this
   *    exception statement from all source files in the program, then also delete
   *    it in the license file.
   */
  
  #pragma once
  
  #include <vector>
  
  #include "mongo/base/status_with.h"
  #include "mongo/base/string_data.h"
  #include "mongo/db/keys_collection_document.h"
  
  namespace mongo {
  
  class BSONObj;
  class LogicalTime;
  class OperationContext;
  
  class KeysCollectionClient {
  public:
      virtual ~KeysCollectionClient() = default;
  
      /**
       * Returns keys for the given purpose and with an expiresAt value greater than newerThanThis.
       */
      virtual StatusWith<std::vector<KeysCollectionDocument>> getNewKeys(
          OperationContext* opCtx, StringData purpose, const LogicalTime& newerThanThis) = 0;
  
      /**
      * Directly inserts a key document to the storage
      */
      virtual Status insertNewKey(OperationContext* opCtx, const BSONObj& doc) = 0;
  
      /**
       * Returns true if it performs majority reads
       */
      virtual bool supportsMajorityReads() const = 0;
  };
  
  }  // namespace mongo
  