////////////////////////////////////////////////////////////////////////////////
/// @brief ZeroMQ queue thread
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2012 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 triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Copyright 2012, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "ZeroMQQueueThread.h"

#include <czmq.h>

#include "Logger/Logger.h"

using namespace triagens::basics;
using namespace triagens::rest;
using namespace std;

// -----------------------------------------------------------------------------
// --SECTION--                                      constructors and destructors
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ZeroMQ
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// @brief constructor
////////////////////////////////////////////////////////////////////////////////

ZeroMQQueueThread::ZeroMQQueueThread (zctx_t* context,
                                      string const& connection,
                                      string const& inproc)
  : Thread("zeromq-queue"),
    ZeroMQThread(context),
    _connection(connection),
    _inproc(inproc) {
}

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

// -----------------------------------------------------------------------------
// --SECTION--                                                    Thread methods
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup ZeroMQ
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// {@inheritDoc}
////////////////////////////////////////////////////////////////////////////////

void ZeroMQQueueThread::run () {

  // create a socket for the workers
  void* workers = zsocket_new(_context, ZMQ_DEALER);

  if (workers == 0) {
    LOGGER_FATAL << "cannot initialize ZeroMQ workers socket: " << strerror(errno);
    zctx_destroy(&_context);
    exit(EXIT_FAILURE);
  }

  // and bind it to the connection
  zsocket_bind(workers, _inproc.c_str());

  // create a socket for the server
  void* clients = zsocket_new(_context, ZMQ_ROUTER);

  if (clients == 0) {
    LOGGER_FATAL << "cannot initialize ZeroMQ clients socket: " << strerror(errno);
    zsocket_destroy(_context, &workers);
    zctx_destroy(&_context);
    exit(EXIT_FAILURE);
  }

  // and bind it to the connection
  int res = zsocket_bind(clients, _connection.c_str());

  if (res == 0) {
    LOGGER_FATAL << "cannot bind ZeroMQ clients socket '" << _connection << "': " << strerror(errno);
    zsocket_destroy(_context, &clients);
    zsocket_destroy(_context, &workers);
    zctx_destroy(&_context);
    exit(EXIT_FAILURE);
  }

  // loop until we are stopping
  while (_stopping == 0) {
    zmq_pollitem_t items[] = {
      { clients, 0, ZMQ_POLLIN, 0 },
      { workers, 0, ZMQ_POLLIN, 0 }
    };

    zmq_poll(items, 2, -1);

    if (items[0].revents & ZMQ_POLLIN) {
      zmsg_t *msg = zmsg_recv(clients);

      // puts("Request from client:");
      // zmsg_dump (msg);

      zmsg_send(&msg, workers);
    }

    if (items[1].revents & ZMQ_POLLIN) {
      zmsg_t *msg = zmsg_recv(workers);

      // puts("Reply from worker:");
      // zmsg_dump (msg);

      zmsg_send(&msg, clients);
    }
  }

  zsocket_destroy(_context, &clients);
  zsocket_destroy(_context, &workers);
}

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

// -----------------------------------------------------------------------------
// --SECTION--                                                       END-OF-FILE
// -----------------------------------------------------------------------------

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