text: //
  // ReplicaSet.cpp
  //
  // $Id$
  //
  // Library: MongoDB
  // Package: MongoDB
  // Module:  ReplicaSet
  //
  // Implementation of the ReplicaSet class.
  //
  // Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
  // and Contributors.
  //
  // Permission is hereby granted, free of charge, to any person or organization
  // obtaining a copy of the software and accompanying documentation covered by
  // this license (the "Software") to use, reproduce, display, distribute,
  // execute, and transmit the Software, and to prepare derivative works of the
  // Software, and to permit third-parties to whom the Software is furnished to
  // do so, all subject to the following:
  //
  // The copyright notices in the Software and this entire statement, including
  // the above license grant, this restriction and the following disclaimer,
  // must be included in all copies of the Software, in whole or in part, and
  // all derivative works of the Software, unless such copies or derivative
  // works are solely in the form of machine-executable object code generated by
  // a source language processor.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  // DEALINGS IN THE SOFTWARE.
  //
  #include "Poco/MongoDB/ReplicaSet.h"
  #include "Poco/MongoDB/QueryRequest.h"
  #include "Poco/MongoDB/ResponseMessage.h"
  
  namespace Poco
  {
  namespace MongoDB
  {
  
  ReplicaSet::ReplicaSet(const std::vector<Net::SocketAddress> &addresses) : _addresses(addresses)
  {
  }
  
  ReplicaSet::~ReplicaSet()
  {
  }
  
  
  Connection::Ptr ReplicaSet::findMaster()
  {
  	Connection::Ptr master;
  
  	for(std::vector<Net::SocketAddress>::iterator it = _addresses.begin(); it != _addresses.end(); ++it)
  	{
  		master = isMaster(*it);
  		if ( ! master.isNull() )
  		{
  			break;
  		}
  	}
  
  	return master;
  }
  
  Connection::Ptr ReplicaSet::isMaster(const Net::SocketAddress& address)
  {
  	Connection::Ptr conn = new Connection();
  
  	try
  	{
  		conn->connect(address);
  
  		QueryRequest request("admin.$cmd");
  		request.setNumberToReturn(1);
  		request.query().add("isMaster", 1);
  
  		ResponseMessage response;
  		conn->sendRequest(request, response);
  
  		if ( response.documents().size() > 0 )
  		{
  			Document::Ptr doc = response.documents()[0];
  			if ( doc->get<bool>("ismaster") )
  			{
  				return conn;
  			}
  			else if ( doc->exists("primary") )
  			{
  				return isMaster(Net::SocketAddress(doc->get<std::string>("primary")));
  			}
  		}
  	}
  	catch(...)
  	{
  		conn = NULL;
  	}
  	
  	return NULL; 
  }
  
  
  }} // Poco::MongoDB
  