SimControl/libs/libbattle-com/include/BC/BasicQueueReceiver.hpp

#pragma once
/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/.
*/

/**
* @file
* @copyright MPLv2
*/
#include <BC/receiveable.hpp>
#include <BC/BasicMessageQueue.hpp>
#include <condition_variable>
#include <iostream>
#include <chrono>

namespace BC
{
  /**
    * @brief class BasicQueueReceiver
    *
    * Derived class from receiveable (libbattle-com++) to receive messages
    * published in the battle-com network.
    *
    * This class is a basic component for applications that need to connect to a
    * battle-com network, like e.g. the prototype CMS.
    * The receiver will be moved to a thread by the service it is used from. If
    * the receive method gets called and it is still busy with the previous
    * message, the new message will get lost.
    *
    * Therefor messages that are received by this BasicQueueReceiver are pushed
    * to a message queue (short receive method). From there the other components
    * of the application can take the messages as needed. This implementation
    * ensures that the receive method is short so no information get lost.
    */
  class BasicQueueReceiver : public BC::receiveable
  {
  private:
    /// threadsafe queue to store received messages
    BC::BasicMessageQueue messages;
  public:
    /**
      * @brief default constructor for class Receiver
      */
    BasicQueueReceiver();

    /**
      * @brief tryGetMessage
      *
      * This method tries to get a message from the message queue.
      * Calles getMessage from message queue. This method rethrows the exception
      * that can be trown by called method.
      *
      * @result msg - raw pointer to new message from the network
      * @throws length_error - if queue is empty this method throws length_error exception
      */
    [[deprecated("Replaced by bool tryGetMessage(BC::Message **msg)")]]
    BC::Message * tryGetMessage();

    /**
      * @brief tryGetMessage
      *
      * This method tries to get a message from the message queue.
      * Calles getMessage from message queue. This method rethrows the exception
      * that can be trown by called method.
      *
      * @TODO: change param msg to smart pointer (when switching from raw to smart pointer in this project)
      *
      * @result true - a message was get successfully
      * @return false - there was no message in the queue, the pointer is invalid and equals nullptr
      * @param msg - raw pointer to new message from the network that should be get from the queue
      */
    [[deprecated("Replaced by function that uses unique_ptr")]]
     bool tryGetMessage(BC::Message **msg);

    /**
      * @brief waitForNewMessage
      *
      * Calles waitForNewMessage method from corresponding message queue. After
      * notification the new message will be returned.
      * This method catches the exception: empty queue.
      *
      * @result msg - raw pointer to new message from the network
      * @rethrow - rethrows an exception that is not empty queue exception
      */
    [[deprecated("Replaced by function that uses unique_ptr")]]
    BC::Message * waitForNewMessage();

    /**
      * @brief getMessage
      *
      * This method gets a message form the message queue if there is a message
      * in the queue. If the message queue is empty this method throw an 
      * exception
      *
      * @result - unique pointer to received message
      * @throws length_error - if queue is empty this method throws length_error exception
      */
    std::unique_ptr<BC::Message> getMessage();

    /**
      * @brief waits given time in seconds for new message to be recieved
      *
      * This method tries to get one BC::Message from the receiver for a
      * specific time. If no message can be taken after this time the class
      * function returns a nullpointer.
      *
      * @param time - time duration in seconds the method tries to get a message from the queue
      * @result - unique pointer to BC::Message from message queue
      * @result nullptr - returns nullptr if message queue stays empty
      */
    std::unique_ptr<BC::Message> waitSecondsForNewMessage(std::uint16_t time);

    /**
      * @brief waits given time in milliseconds for new message to be recieved
      *
      * This method tries to get one BC::Message from the receiver for a
      * specific time. If no message can be taken after this time the class
      * function returns a nullpointer.
      *
      * @param time - time duration in milliseconds the method tries to get a message from the queue
      * @result - unique pointer to BC::Message from message queue
      * @result nullptr - returns nullptr if message queue stays empty
      */
    std::unique_ptr<BC::Message> waitMillisecondsForNewMessage(std::uint16_t time);

    /**
      * @brief gets number of messages in the queue
      *
      * This method returns the queue size which means the number of messages
      * stored at the queue.
      *
      * @result size - size of message queue
      */
    unsigned int getQueueSize();

    /**
      * @brief virtual function receive
      *
      * This function is called if there are new messages published.
      * These messages are pushed to the message queue.
      *
      * @param m - raw pointer to the received message
      */
    virtual void receive(BC::Message *m) override;

  }; // class BasicQueueReceiver

}; // namespace BC