text: /**
   *    Copyright (C) 2015 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.
   */
  
  #include "mongol/platform/basic.h"
  
  #include "mongol/db/commands.h"
  #include "mongol/db/wire_version.h"
  #include "mongol/s/catalog/forwarding_catalog_manager.h"
  #include "mongol/s/grid.h"
  #include "mongol/s/write_ops/batched_command_request.h"
  
  namespace mongol {
  namespace {
  
  class CmdIsMaster : public Command {
  public:
      CmdIsMaster() : Command("isMaster", false, "ismaster") {}
  
      virtual bool isWriteCommandForConfigServer() const {
          return false;
      }
  
      virtual bool slaveOk() const {
          return true;
      }
  
      virtual void help(std::stringstream& help) const {
          help << "test if this is master half of a replica pair";
      }
  
      virtual void addRequiredPrivileges(const std::string& dbname,
                                         const BSONObj& cmdObj,
                                         std::vector<Privilege>* out) {
          // No auth required
      }
  
      virtual bool run(OperationContext* txn,
                       const std::string& dbname,
                       BSONObj& cmdObj,
                       int options,
                       std::string& errmsg,
                       BSONObjBuilder& result) {
          result.appendBool("ismaster", true);
          result.append("msg", "isdbgrid");
          result.appendNumber("maxBsonObjectSize", BSONObjMaxUserSize);
          result.appendNumber("maxMessageSizeBytes", MaxMessageSizeBytes);
          result.appendNumber("maxWriteBatchSize", BatchedCommandRequest::kMaxWriteBatchSize);
          result.appendDate("localTime", jsTime());
  
          // Mongos tries to keep exactly the same version range of the server for which
          // it is compiled.
          result.append("maxWireVersion", maxWireVersion);
          result.append("minWireVersion", minWireVersion);
  
          return true;
      }
  
  } isMaster;
  
  }  // namespace
  }  // namespace mongol
  