fsfw/tcdistribution/TcDistributor.h

#ifndef TCDISTRIBUTOR_H_
#define TCDISTRIBUTOR_H_
#include "../objectmanager/ObjectManagerIF.h"
#include "../objectmanager/SystemObject.h"
#include "../returnvalues/HasReturnvaluesIF.h"
#include "../storagemanager/StorageManagerIF.h"
#include "../tasks/ExecutableObjectIF.h"
#include "../tmtcservices/TmTcMessage.h"
#include "../ipc/MessageQueueIF.h"
#include <map>


/**
 * \defgroup tc_distribution Telecommand Distribution
 * All classes associated with Routing and Distribution of Telecommands belong to this group.
 */

/**
 * This typedef simplifies writing down the \c map iterator.
 */
typedef std::map<uint32_t, MessageQueueId_t>::iterator iterator_t;

/**
 * This is the base class to implement distributors for Space Packets.
 * Typically, the distribution is required to forward Telecommand packets
 * over the satellite applications and services. The class receives
 * Space Packets over a message queue and holds a map that links other
 * message queue ids to some identifier. The process of unpacking the
 * destination information from the packet is handled by the child class
 * implementations.
 * \ingroup tc_distribution
 */
class TcDistributor : public SystemObject, public ExecutableObjectIF, public HasReturnvaluesIF {
private:
	/**
	 * This constant sets the maximum number of packets distributed per call.
	 */
	static const uint8_t DISTRIBUTER_MAX_PACKETS = 128;
protected:
	/**
	 * This is the receiving queue for incoming Telecommands.
	 * The child classes must make its queue id public.
	 */
	MessageQueueIF* tcQueue;
	/**
	 * The last received incoming packet information is stored in this
	 * member.
	 * As different child classes unpack the incoming packet differently
	 * (i.e. as a CCSDS Space Packet or as a PUS Telecommand Packet), it
	 * is not tried to unpack the packet information within this class.
	 */
	TmTcMessage currentMessage;
	/**
	 * The map that links certain packet information to a destination.
	 * The packet information may be the APID of the packet or the service
	 * identifier. Filling of the map is under control of the different child
	 * classes.
	 */
	std::map<uint32_t, MessageQueueId_t> queueMap;
	/**
	 * This method shall unpack the routing information from the incoming
	 * packet and select the map entry which represents the packet's target.
	 * @return	An iterator to the map element to forward to or queuMap.end().
	 */
	virtual iterator_t selectDestination() = 0;
	/**
	 * The handlePacket method calls the child class's selectDestination method
	 * and forwards the packet to its destination, if found.
	 * @return The message queue return value or \c RETURN_FAILED, in case no
	 * 		destination was found.
	 */
	ReturnValue_t handlePacket();
	/**
	 * This method gives the child class a chance to perform some kind of operation
	 * after the parent tried to forward the message.
	 * A typically application would be sending success/failure messages.
	 * The default implementation just returns \c RETURN_OK.
	 * @param queueStatus	The status of the message queue after an attempt to send the TC.
	 * @return	- \c RETURN_OK on success
	 * 			- \c RETURN_FAILED on failure
	 */
	virtual ReturnValue_t callbackAfterSending( ReturnValue_t queueStatus );
public:
	static const uint8_t INTERFACE_ID = CLASS_ID::PACKET_DISTRIBUTION;
	static const ReturnValue_t PACKET_LOST = MAKE_RETURN_CODE( 1 );
	static const ReturnValue_t DESTINATION_NOT_FOUND = MAKE_RETURN_CODE( 2 );
	/**
	 * Within the default constructor, the SystemObject id is set and the
	 * message queue is initialized.
	 * Filling the map is under control of the child classes.
	 * @param set_object_id	This id is assigned to the distributor
	 * 		implementation.
	 */
	TcDistributor( object_id_t set_object_id );
	/**
	 * The destructor is empty, the message queues are not in the vicinity of
	 * this class.
	 */
	virtual ~TcDistributor();
	/**
	 * The method is called cyclically and fetches new incoming packets from
	 * the message queue.
	 * In case a new packet is found, it calls the handlePacket method to deal
	 * with distribution.
	 * @return The error code of the message queue call.
	 */
	ReturnValue_t performOperation(uint8_t opCode);
	/**
	 * A simple debug print, that prints all distribution information stored in
	 * queueMap.
	 */
	void print();
};


#endif /* TCDISTRIBUTOR_H_ */