core/monitor/monitor_client.h

/* monitor_client.h                                        -*- C++ -*-
   Wolfgang Sourdeau, January 2013
   Copyright (c) 2013 Datacratic.  All rights reserved.
*/

#pragma once

#include <mutex>
#include <vector>
#include "soa/types/date.h"
#include "soa/service/rest_proxy.h"

namespace RTBKIT {
    using namespace Datacratic;

/* This class connects to the Monitor service and queries it periodically to
 * deduce whether the current service (probably the Router) can continue
 * processing its client requests. */
struct MonitorClient : public RestProxy
{
    MonitorClient(const std::shared_ptr<zmq::context_t> & context,
                  int checkTimeout = 2)
        : RestProxy(context),
          pendingRequest(false),
          checkTimeout_(checkTimeout), lastStatus(false),
          testMode(false), testResponse(false)
    {
        onDone = std::bind(&MonitorClient::onResponseReceived, this,
                           std::placeholders::_1, std::placeholders::_2,
                           std::placeholders::_3);
    };

    ~MonitorClient();
 
    void init(std::shared_ptr<ConfigurationService> & config,
              const std::string & serviceName = "monitor");

    void shutdown();

    bool getStatus() const;

    /* private members */

    void checkStatus();

    void onResponseReceived(std::exception_ptr ext,
                            int responseCode, const std::string & body);
    RestProxy::OnDone onDone;

    bool pendingRequest;

    typedef std::unique_lock<std::mutex> Guard;
    mutable std::mutex requestLock;

    int checkTimeout_;

    bool lastStatus;

    Date lastCheck;

    bool testMode;
    bool testResponse;
};

} // RTB