epics_metric.cc

// epics_metric.cc: Epics Metric Plugin
// Author: Eric Flumerfelt
// Last Modified: 09/25/2015
//
// An implementation of the MetricPlugin interface for Epics/ChannelAccess

#ifndef __EPICS_METRIC__
#define __EPICS_METRIC__ 1

#include <unordered_map>
#include "artdaq-utilities/Plugins/MetricMacros.hh"
#include "messagefacility/MessageLogger/MessageLogger.h"
#undef STATIC_ASSERT

#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-parameter"
#endif
#include <cadef.h>
#ifdef __clang__
#pragma clang diagnostic pop
#endif

namespace artdaq {
class EpicsMetric : public MetricPlugin {
 private:
  std::string prefix_;
  std::unordered_map<std::string, chid> channels_;

  bool checkChannel_(std::string name) {
    if (!channels_.count(name)) {
      chid channel;
      ca_search(name.c_str(), &channel);
      auto sts = ca_pend_io(5.0);
      if (sts != ECA_NORMAL) {
        SEVCHK(ca_clear_channel(channel), NULL);
        mf::LogWarning("EPICS Plugin") << "Channel " << name << " not found!";
        channels_[name] = nullptr;
        return false;
      }
      channels_[name] = channel;
      return true;
    }
    return channels_[name] != nullptr;
  }

 public:
  explicit EpicsMetric(fhicl::ParameterSet const& pset, std::string const& app_name)
      : MetricPlugin(pset, app_name), prefix_(pset.get<std::string>("channel_name_prefix", "artdaq")), channels_() {}

  virtual ~EpicsMetric() { MetricPlugin::stopMetrics(); }

  std::string getLibName() const override { return "epics"; }

  void stopMetrics_() override {
    for (auto channel : channels_) {
      SEVCHK(ca_clear_channel(channel.second), NULL);
    }
    channels_.clear();
  }

  void startMetrics_() override {}

  void sendMetric_(const std::string& name, const std::string& value, const std::string& unit) override {
    std::string caName = prefix_ + ":" + name;
    std::string tmpValue = value + " " + unit;

    if (checkChannel_(caName)) {
      // DBR_STRING, 40 characters
      if (tmpValue.size() > 40) {
        tmpValue = tmpValue.erase(40);
      }
      SEVCHK(ca_put(DBR_STRING, channels_[caName], tmpValue.c_str()), NULL);
      SEVCHK(ca_flush_io(), NULL);
    }
  }

  void sendMetric_(const std::string& name, const int& value, const std::string& unit) override {
    // DBR_LONG
    std::string caName = prefix_ + ":" + name;
    if (unit.size() > 0) {
      mf::LogDebug("EPICS Plugin") << "Not sure if I can send ChannelAccess Units...configure in db instead.";
    }

    if (checkChannel_(caName)) {
      dbr_long_t val = static_cast<dbr_long_t>(value);
      SEVCHK(ca_put(DBR_LONG, channels_[caName], &val), NULL);
      SEVCHK(ca_flush_io(), NULL);
    }
  }

  void sendMetric_(const std::string& name, const double& value, const std::string& unit) override {
    // DBR_DOUBLE
    std::string caName = prefix_ + ":" + name;
    if (unit.size() > 0) {
      mf::LogDebug("EPICS Plugin") << "Not sure if I can send ChannelAccess Units...configure in db instead.";
    }

    if (checkChannel_(caName)) {
      dbr_double_t val = static_cast<dbr_double_t>(value);
      SEVCHK(ca_put(DBR_DOUBLE, channels_[caName], &val), NULL);
      SEVCHK(ca_flush_io(), NULL);
    }
  }

  void sendMetric_(const std::string& name, const float& value, const std::string& unit) override {
    // DBR_FLOAT
    std::string caName = prefix_ + ":" + name;
    if (unit.size() > 0) {
      mf::LogDebug("EPICS Plugin") << "Not sure if I can send ChannelAccess Units...configure in db instead.";
    }

    if (checkChannel_(caName)) {
      dbr_float_t val = static_cast<dbr_float_t>(value);
      SEVCHK(ca_put(DBR_FLOAT, channels_[caName], &val), NULL);
      SEVCHK(ca_flush_io(), NULL);
    }
  }

  void sendMetric_(const std::string& name, const unsigned long int& value, const std::string& unit) override {
    // DBR_LONG, only unsigned type is only 16 bits, use widest integral field
    std::string caName = prefix_ + ":" + name;
    if (unit.size() > 0) {
      mf::LogDebug("EPICS Plugin") << "Not sure if I can send ChannelAccess Units...configure in db instead.";
    }

    if (checkChannel_(caName)) {
      dbr_ulong_t val = static_cast<dbr_ulong_t>(value);
      SEVCHK(ca_put(DBR_LONG, channels_[caName], &val), NULL);
      SEVCHK(ca_flush_io(), NULL);
    }
  }
};
}  // End namespace artdaq

DEFINE_ARTDAQ_METRIC(artdaq::EpicsMetric)

#endif  // End ifndef __EPICS_METRIC__