service_client.h

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/*
 * Copyright (C) 2009, Willow Garage, Inc.
 *
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 *     contributors may be used to endorse or promote products derived from
 *     this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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#ifndef ROSCPP_SERVICE_CLIENT_H
#define ROSCPP_SERVICE_CLIENT_H

#include "ros/forwards.h"
#include "ros/common.h"
#include "ros/service_traits.h"
#include "ros/serialization.h"

namespace ros
{

class ROSCPP_DECL ServiceClient
{
public:
  ServiceClient() {}
  ServiceClient(const std::string& service_name, bool persistent, const M_string& header_values, const std::string& service_md5sum);
  ServiceClient(const ServiceClient& rhs);
  ~ServiceClient();
  ServiceClient& operator=(const ServiceClient& other) = default;

  template<class MReq, class MRes>
  bool call(MReq& req, MRes& res)
  {
    namespace st = service_traits;

    if (!isValid())
    {
      return false;
    }

    if (strcmp(st::md5sum(req), st::md5sum(res)))
    {
      ROS_ERROR("The request and response parameters to the service "
                 "call must be autogenerated from the same "
                 "server definition file (.srv). your service call "
                 "for %s appeared to use request/response types "
                 "from different .srv files. (%s vs. %s)", impl_->name_.c_str(), st::md5sum(req), st::md5sum(res));
      return false;
    }

    return call(req, res, st::md5sum(req));
  }

  template<class Service>
  bool call(Service& service)
  {
    namespace st = service_traits;

    if (!isValid())
    {
      return false;
    }

    return call(service.request, service.response, st::md5sum(service));
  }

  template<typename MReq, typename MRes>
  bool call(const MReq& req, MRes& resp, const std::string& service_md5sum)
  {
    namespace ser = serialization;
    SerializedMessage ser_req = ser::serializeMessage(req);
    SerializedMessage ser_resp;
    bool ok = call(ser_req, ser_resp, service_md5sum);
    if (!ok)
    {
      return false;
    }

    try
    {
      ser::deserializeMessage(ser_resp, resp);
    }
    catch (std::exception& e)
    {
      deserializeFailed(e);
      return false;
    }

    return true;
  }

  bool call(const SerializedMessage& req, SerializedMessage& resp, const std::string& service_md5sum);

  bool isValid() const;

  bool isPersistent() const;

  void shutdown();

  bool waitForExistence(ros::Duration timeout = ros::Duration(-1));

  bool exists();

  std::string getService();

  operator void*() const { return isValid() ? (void*)1 : (void*)0; }
  bool operator<(const ServiceClient& rhs) const
  {
    return impl_ < rhs.impl_;
  }

  bool operator==(const ServiceClient& rhs) const
  {
    return impl_ == rhs.impl_;
  }

  bool operator!=(const ServiceClient& rhs) const
  {
    return impl_ != rhs.impl_;
  }

private:
  // This works around a problem with the OSX linker that causes the static variable declared by
  // ROS_ERROR to error with missing symbols when it's used directly in the templated call() method above
  // This for some reason only showed up in the rxtools package
  void deserializeFailed(const std::exception& e)
  {
    ROS_ERROR("Exception thrown while while deserializing service call: %s", e.what());
  }

  struct Impl
  {
    Impl();
    ~Impl();

    void shutdown();
    bool isValid() const;

    ServiceServerLinkPtr server_link_;
    std::string name_;
    bool persistent_;
    M_string header_values_;
    std::string service_md5sum_;
    bool is_shutdown_;
  };
  typedef boost::shared_ptr<Impl> ImplPtr;
  typedef boost::weak_ptr<Impl> ImplWPtr;

  ImplPtr impl_;

  friend class NodeHandle;
  friend class NodeHandleBackingCollection;
};
typedef boost::shared_ptr<ServiceClient> ServiceClientPtr;

}

#endif