vrpn_Forwarder.h

Go to the documentation of this file.

#ifndef VRPN_FORWARDER_H
#define VRPN_FORWARDER_H
 
#include "vrpn_Configure.h"  // for VRPN_API, VRPN_CALLBACK
#include "vrpn_Connection.h" // for vrpn_Connection (ptr only), etc
#include "vrpn_Types.h"      // for vrpn_int32, vrpn_uint32
 
// vrpn_Forwarder
// Tom Hudson, August 1998
//
// Class to take messages from one VRPN connection and send them out
// on another.
 
// Design decisions:
//   Scale of forwarding:
//     Could write a forwarder per stream (serviceName per instantiation)
//     or per connection (serviceName per forward() call).  Latter is
//     more flexible, but takes up more memory if few distinct streams need
//     to be forwarded, has a clunkier syntax, ...
//   Flexibility of naming:
//     We allow users to take in a message of one name and send it out
//     with another name;  this is useful and dangerous.
 
// Faults:
//   There is currently no way to specify vrpn_SENDER_ANY as a source.
// If we do, it isn't clear what sender to specify to the destination.
 
class VRPN_API vrpn_ConnectionForwarder {
 
public:
    // Set up to forward messages from <source> to <destination>
    vrpn_ConnectionForwarder(vrpn_Connection *source,
                             vrpn_Connection *destination);
 
    ~vrpn_ConnectionForwarder(void);
 
    // Begins forwarding of a message type.
    // Forwards messages of type <sourceName> and sender <sourceServiceName>,
    // sending them out as type <destinationName> from sender
    // <destinationServiceName>.
    // Return nonzero on failure.
    int forward(const char *sourceName, const char *sourceServiceName,
                const char *destinationName, const char *destinationServiceName,
                vrpn_uint32 classOfService = vrpn_CONNECTION_RELIABLE);
 
    // Stops forwarding of a message type.
    // Return nonzero on failure.
    int unforward(const char *sourceName, const char *sourceServiceName,
                  const char *destinationName,
                  const char *destinationServiceName,
                  vrpn_uint32 classOfService = vrpn_CONNECTION_RELIABLE);
 
private:
    static int VRPN_CALLBACK handle_message(void *, vrpn_HANDLERPARAM);
 
    // Translates (id, serviceId) from source to destination
    // and looks up intended class of service.
    // Returns nonzero if lookup fails.
    vrpn_int32 map(vrpn_int32 *id, vrpn_int32 *serviceId,
                   vrpn_uint32 *serviceClass);
 
    vrpn_Connection *d_source;
    vrpn_Connection *d_destination;
 
    struct vrpn_CONNECTIONFORWARDERRECORD {
 
        vrpn_CONNECTIONFORWARDERRECORD(vrpn_Connection *, vrpn_Connection *,
                                       const char *, const char *, const char *,
                                       const char *, vrpn_uint32);
 
        vrpn_int32 sourceId;             // source's type id
        vrpn_int32 sourceServiceId;      // source's sender id
        vrpn_int32 destinationId;        // destination's type id
        vrpn_int32 destinationServiceId; // destination's sender id
        vrpn_uint32 classOfService;      // class of service to send
 
        vrpn_CONNECTIONFORWARDERRECORD *next;
    };
 
    vrpn_CONNECTIONFORWARDERRECORD *d_list;
};
 
class VRPN_API vrpn_StreamForwarder {
 
public:
    // Set up to forward messages from sender <sourceServiceName> on <source>
    // to <destination>, as if from sender <destinationServiceName>
    vrpn_StreamForwarder(vrpn_Connection *source, const char *sourceServiceName,
                         vrpn_Connection *destination,
                         const char *destinationServiceName);
 
    ~vrpn_StreamForwarder(void);
 
    // Begins forwarding of a message type.
    // Return nonzero on failure.
    int forward(const char *sourceName, const char *destinationName,
                vrpn_uint32 classOfService = vrpn_CONNECTION_RELIABLE);
 
    // Stops forwarding of a message type.
    // Return nonzero on failure.
    int unforward(const char *sourceName, const char *destinationName,
                  vrpn_uint32 classOfService = vrpn_CONNECTION_RELIABLE);
 
private:
    static int VRPN_CALLBACK handle_message(void *, vrpn_HANDLERPARAM);
 
    // Translates (id, serviceId) from source to destination
    // and looks up intended class of service.
    // Returns nonzero if lookup fails.
    vrpn_int32 map(vrpn_int32 *id, vrpn_uint32 *serviceClass);
 
    vrpn_Connection *d_source;
    vrpn_int32 d_sourceService;
    vrpn_Connection *d_destination;
    vrpn_int32 d_destinationService;
 
    struct vrpn_STREAMFORWARDERRECORD {
 
        vrpn_STREAMFORWARDERRECORD(vrpn_Connection *, vrpn_Connection *,
                                   const char *, const char *, vrpn_uint32);
 
        vrpn_int32 sourceId;        // source's type id
        vrpn_int32 destinationId;   // destination's type id
        vrpn_uint32 classOfService; // class of service to send
 
        vrpn_STREAMFORWARDERRECORD *next;
    };
 
    vrpn_STREAMFORWARDERRECORD *d_list;
};
 
#endif // VRPN_FORWARDER_H