modbus_msg_wrapper.h

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/*
 * Copyright (c) 2019 Pilz GmbH & Co. KG
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.

 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef MODBUS_MSG_WRAPPER_H
#define MODBUS_MSG_WRAPPER_H

#include <ros/time.h>

#include <prbt_hardware_support/ModbusMsgInStamped.h>
#include <prbt_hardware_support/modbus_api_spec.h>
#include <prbt_hardware_support/modbus_msg_wrapper_exception.h>

namespace prbt_hardware_support
{
class ModbusMsgWrapper
{
public:
  ModbusMsgWrapper(const ModbusMsgInStampedConstPtr& modbus_msg_raw, const ModbusApiSpec& api_spec);

  virtual ~ModbusMsgWrapper() = default;

  virtual void checkStructuralIntegrity() const;

  unsigned int getVersion() const;

  bool isDisconnect() const;

  const ros::Time& getTimeStamp() const;

protected:
  bool hasRegister(uint32_t reg) const;

  uint16_t getRegister(uint32_t reg) const;

  bool hasVersion() const;

  const ModbusApiSpec& getApiSpec() const;

private:
  const ModbusApiSpec api_spec_;
  const ModbusMsgInStampedConstPtr msg_;
};

inline ModbusMsgWrapper::ModbusMsgWrapper(const ModbusMsgInStampedConstPtr& modbus_msg_raw,
                                          const ModbusApiSpec& api_spec)
  : api_spec_(api_spec), msg_(modbus_msg_raw)
{
}

inline bool ModbusMsgWrapper::hasRegister(uint32_t reg) const
{
  uint32_t relative_idx = reg - msg_->holding_registers.layout.data_offset;

  return msg_->holding_registers.data.size() > relative_idx;
}

inline uint16_t ModbusMsgWrapper::getRegister(uint32_t reg) const
{
  return msg_->holding_registers.data.at(reg - msg_->holding_registers.layout.data_offset);
}

inline bool ModbusMsgWrapper::hasVersion() const
{
  return hasRegister(api_spec_.getRegisterDefinition(modbus_api_spec::VERSION));
}

inline unsigned int ModbusMsgWrapper::getVersion() const
{
  return getRegister(api_spec_.getRegisterDefinition(modbus_api_spec::VERSION));
}

inline bool ModbusMsgWrapper::isDisconnect() const
{
  return msg_->disconnect.data;
}

inline void ModbusMsgWrapper::checkStructuralIntegrity() const
{
  if (!hasVersion())
  {
    throw ModbusMsgWrapperException("Received message does not contain a version.");
  }
}

inline const ModbusApiSpec& ModbusMsgWrapper::getApiSpec() const
{
  return api_spec_;
}

inline const ros::Time& ModbusMsgWrapper::getTimeStamp() const
{
  return msg_->header.stamp;
}

}  // namespace prbt_hardware_support

#endif  // MODBUS_MSG_WRAPPER_H