KMessageServer

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#include <KGame/KMessageServer>

Inheritance diagram for KMessageServer:

Public Types

enum  {
  REQ_BROADCAST = 1, REQ_FORWARD, REQ_CLIENT_ID, REQ_ADMIN_ID,
  REQ_ADMIN_CHANGE, REQ_REMOVE_CLIENT, REQ_MAX_NUM_CLIENTS, REQ_CLIENT_LIST,
  REQ_MAX_REQ = 0xffff
}
 
enum  {
  MSG_BROADCAST = 101, MSG_FORWARD, ANS_CLIENT_ID, ANS_ADMIN_ID,
  ANS_CLIENT_LIST, EVNT_CLIENT_CONNECTED, EVNT_CLIENT_DISCONNECTED, EVNT_MAX_EVNT = 0xffff
}
 

Signals

void clientConnected (KMessageIO *client)
 
void connectionLost (KMessageIO *client)
 
void messageReceived (const QByteArray &data, quint32 clientID, bool &unknown)
 

Public Slots

void addClient (KMessageIO *)
 
void deleteClients ()
 
void removeClient (KMessageIO *io, bool broken)
 

Public Member Functions

 KMessageServer (quint16 cookie=42, QObject *parent=nullptr)
 
quint32 adminID () const
 
virtual void broadcastMessage (const QByteArray &msg)
 
int clientCount () const
 
QList< quint32 > clientIDs () const
 
virtual void Debug ()
 
KMessageIOfindClient (quint32 no) const
 
bool initNetwork (quint16 port=0)
 
bool isOfferingConnections () const
 
int maxClients () const
 
virtual void sendMessage (const QList< quint32 > &ids, const QByteArray &msg)
 
virtual void sendMessage (quint32 id, const QByteArray &msg)
 
quint16 serverPort () const
 
void setAdmin (quint32 adminID)
 
void setMaxClients (int maxnumber)
 
void stopNetwork ()
 
- Public Member Functions inherited from QObject
 QObject (QObject *parent)
 
bool blockSignals (bool block)
 
const QObjectListchildren () const const
 
QMetaObject::Connection connect (const QObject *sender, const char *signal, const char *method, Qt::ConnectionType type) const const
 
void deleteLater ()
 
void destroyed (QObject *obj)
 
bool disconnect (const char *signal, const QObject *receiver, const char *method) const const
 
bool disconnect (const QObject *receiver, const char *method) const const
 
void dumpObjectInfo ()
 
void dumpObjectInfo () const const
 
void dumpObjectTree ()
 
void dumpObjectTree () const const
 
QList< QByteArraydynamicPropertyNames () const const
 
virtual bool event (QEvent *e)
 
virtual bool eventFilter (QObject *watched, QEvent *event)
 
findChild (const QString &name, Qt::FindChildOptions options) const const
 
QList< T > findChildren (const QRegExp &regExp, Qt::FindChildOptions options) const const
 
QList< T > findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const
 
QList< T > findChildren (const QString &name, Qt::FindChildOptions options) const const
 
bool inherits (const char *className) const const
 
void installEventFilter (QObject *filterObj)
 
bool isWidgetType () const const
 
bool isWindowType () const const
 
void killTimer (int id)
 
virtual const QMetaObjectmetaObject () const const
 
void moveToThread (QThread *targetThread)
 
QString objectName () const const
 
void objectNameChanged (const QString &objectName)
 
QObjectparent () const const
 
QVariant property (const char *name) const const
 
 Q_CLASSINFO (Name, Value)
 
 Q_DISABLE_COPY (Class)
 
 Q_DISABLE_COPY_MOVE (Class)
 
 Q_DISABLE_MOVE (Class)
 
 Q_EMIT Q_EMIT
 
 Q_ENUM (...)
 
 Q_ENUM_NS (...)
 
 Q_ENUMS (...)
 
 Q_FLAG (...)
 
 Q_FLAG_NS (...)
 
 Q_FLAGS (...)
 
 Q_GADGET Q_GADGET
 
 Q_INTERFACES (...)
 
 Q_INVOKABLE Q_INVOKABLE
 
 Q_NAMESPACE Q_NAMESPACE
 
 Q_NAMESPACE_EXPORT (EXPORT_MACRO)
 
 Q_OBJECT Q_OBJECT
 
 Q_PROPERTY (...)
 
 Q_REVISION Q_REVISION
 
 Q_SET_OBJECT_NAME (Object)
 
 Q_SIGNAL Q_SIGNAL
 
 Q_SIGNALS Q_SIGNALS
 
 Q_SLOT Q_SLOT
 
 Q_SLOTS Q_SLOTS
 
qFindChild (const QObject *obj, const QString &name)
 
QList< T > qFindChildren (const QObject *obj, const QRegExp &regExp)
 
QList< T > qFindChildren (const QObject *obj, const QString &name)
 
qobject_cast (const QObject *object)
 
qobject_cast (QObject *object)
 
 QT_NO_NARROWING_CONVERSIONS_IN_CONNECT QT_NO_NARROWING_CONVERSIONS_IN_CONNECT
 
void removeEventFilter (QObject *obj)
 
void setObjectName (const QString &name)
 
void setParent (QObject *parent)
 
bool setProperty (const char *name, const QVariant &value)
 
bool signalsBlocked () const const
 
int startTimer (int interval, Qt::TimerType timerType)
 
int startTimer (std::chrono::milliseconds time, Qt::TimerType timerType)
 
QThreadthread () const const
 

Protected Slots

virtual void getReceivedMessage (const QByteArray &msg)
 
virtual void processOneMessage ()
 

Protected Member Functions

quint32 uniqueClientNumber () const
 
- Protected Member Functions inherited from QObject
virtual void childEvent (QChildEvent *event)
 
virtual void connectNotify (const QMetaMethod &signal)
 
virtual void customEvent (QEvent *event)
 
virtual void disconnectNotify (const QMetaMethod &signal)
 
bool isSignalConnected (const QMetaMethod &signal) const const
 
int receivers (const char *signal) const const
 
QObjectsender () const const
 
int senderSignalIndex () const const
 
virtual void timerEvent (QTimerEvent *event)
 

Additional Inherited Members

- Properties inherited from QObject
 objectName
 
- Static Public Member Functions inherited from QObject
QMetaObject::Connection connect (const QObject *sender, const char *signal, const QObject *receiver, const char *method, Qt::ConnectionType type)
 
QMetaObject::Connection connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type)
 
QMetaObject::Connection connect (const QObject *sender, PointerToMemberFunction signal, const QObject *context, Functor functor, Qt::ConnectionType type)
 
QMetaObject::Connection connect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method, Qt::ConnectionType type)
 
QMetaObject::Connection connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)
 
bool disconnect (const QMetaObject::Connection &connection)
 
bool disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *method)
 
bool disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method)
 
bool disconnect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method)
 
QString tr (const char *sourceText, const char *disambiguation, int n)
 
QString trUtf8 (const char *sourceText, const char *disambiguation, int n)
 
- Public Attributes inherited from QObject
typedef QObjectList
 

Detailed Description

A server for message sending and broadcasting, using TCP/IP connections.

An object of this class listens for incoming connections via TCP/IP sockets and creates KMessageSocket objects for every established connection. It receives messages from the "clients", analyzes them and processes an appropriate reaction.

You can also use other KMessageIO objects with KMessageServer, not only TCP/IP socket based ones. Use addClient to connect via an object of any KMessageIO subclass. (For clients within the same process, you can e.g. use KMessageDirect.) This object already has to be connected.

The messages are always packages of an arbitrary length. The format of the messages is given below. All the data is stored and received with QDataStream, to be platform independent.

Setting up a KMessageServer can be done like this:

KMessageServer *server = new KMessageServer ();
server->initNetwork (TCP/IP-Portnumber);

Usually that is everything you will do. There are a lot of public methods to administrate the object (maximum number of clients, finding clients, removing clients, setting the admin client, ...), but this functionality can also be done by messages from the clients. So you can administrate the object completely on remote.

If you want to extend the Server for your own needs (e.g. additional message types), you can either create a subclass and overwrite the method processOneMessage. (But don't forget to call the method of the superclass!) Or you can connect to the signal messageReceived, and analyze the messages there.

Every client has a unique ID, so that messages can be sent to another dedicated client or a list of clients.

One of the clients (the admin) has a special administration right. Some of the administration messages can only be used with him. The admin can give the admin status to another client. You can send a message to the admin by using clientID 0. This is always interpreted as the admin client, of its real clientID.

Here is a list of the messages the KMessageServer understands: << means, the value is inserted into the QByteArray using QDataStream. The messageIDs (REQ_BROADCAST, ...) are of type quint32.

  • QByteArray << static_cast<quint32>( REQ_BROADCAST ) << raw_data

    When the server receives this message, it sends the following message to ALL connected clients (a broadcast), where the raw_data is left unchanged: QByteArray << static_cast <quint32>( MSG_BROADCAST ) << clientID << raw_data quint32 clientID; // the ID of the client that sent the broadcast request

  • QByteArray << static_cast<quint32>( REQ_FORWARD ) << client_list << raw_data QValueList <quint32> client_list; // list of receivers

    When the server receives this message, it sends the following message to the clients in client_list: QByteArray << static_cast<quint32>( MSG_FORWARD ) << senderID << client_list << raw_data quint32 senderID; // the sender of the forward request QValueList <quint32> client_list; // a copy of the receiver list

    Note: Every client receives the message as many times as he is in the client_list. Note: Since the client_list is sent to all the clients, every client can see who else got the message. If you want to prevent this, send a single REQ_FORWARD message for every receiver.

  • QByteArray << static_cast<quint32>( REQ_CLIENT_ID )

    When the server receives this message, it sends the following message to the asking client: QByteArray << static_cast<quint32>( ANS_CLIENT_ID ) << clientID quint32 clientID; // The ID of the client who asked for it

    Note: This answer is also automatically sent to a new connected client, so that he can store his ID. The ID of a client doesn't change during his lifetime, and is unique for this KMessageServer.

  • QByteArray << static_cast<quint32>( REQ_ADMIN_ID )

    When the server receives this message, it sends the following message to the asking client: QByteArray << ANS_ADMIN_ID << adminID quint32 adminID; // The ID of the admin

    Note: This answer is also automatically sent to a new connected client, so that he can see if he is the admin or not. It will also be sent to all connected clients when a new admin is set (see REQ_ADMIN_CHANGE).

  • QByteArray << static_cast<quint32>( REQ_ADMIN_CHANGE ) << new_admin quint32 new_admin; // the ID of the new admin, or 0 for no admin

    When the server receives this message, it sets the admin to the new ID. If no client with that ID exists, nothing happens. With new_admin == 0 no client is a admin. ONLY THE ADMIN ITSELF CAN USE THIS MESSAGE!

    Note: The server sends a ANS_ADMIN_ID message to every connected client.

  • QByteArray << static_cast<quint32>( REQ_REMOVE_CLIENT ) << client_list QValueList <quint32> client_list; // The list of clients to be removed

    When the server receives this message, it removes the clients with the ids stored in client_list, disconnecting the connection to them. ONLY THE ADMIN CAN USE THIS MESSAGE!

    Note: If one of the clients is the admin himself, he will also be deleted. Another client (if any left) will become the new admin.

  • QByteArray << static_cast<quint32>( REQ_MAX_NUM_CLIENTS ) << maximum_clients qint32 maximum_clients; // The maximum of clients connected, or infinite if -1

    When the server receives this message, it limits the number of clients to the number given, or sets it unlimited for maximum_clients == -1. ONLY THE ADMIN CAN USE THIS MESSAGE!

    Note: If there are already more clients, they are not affected. It only prevents new Clients to be added. To assure this limit, remove clients afterwards (REQ_REMOVE_CLIENT)

  • QByteArray << static_cast<quint32>( REQ_CLIENT_LIST )

    When the server receives this message, it answers by sending a list of IDs of all the clients that are connected at the moment. So it sends the following message to the asking client: QByteArray << static_cast<quint32>( ANS_CLIENT_LIST ) << clientList QValueList <quint32> clientList; // The IDs of the connected clients

    Note: This message is also sent to every new connected client, so that he knows the other clients.

There are two more messages that are sent from the server to the every client automatically when a new client connects or a connection to a client is lost:

  QByteArray << static_cast&lt;quint32>( EVNT_CLIENT_CONNECTED ) << clientID;
  quint32 clientID;   // the ID of the new connected client

  QByteArray << static_cast&lt;quint32>( EVNT_CLIENT_DISCONNECTED ) << clientID;
  quint32 clientID;   // the ID of the client that lost the connection
  quint8 broken;      // 1 if the network connection was closed, 0 if it was disconnected

on purpose

Author
Andreas Beckermann b_man[email protected][email protected][email protected]x.de, Burkhard Lehner Burkh[email protected]ard.[email protected]Lehne[email protected][email protected][email protected]x.de

Definition at line 167 of file kmessageserver.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

MessageIDs for messages from a client to the message server.

Definition at line 175 of file kmessageserver.h.

◆ anonymous enum

anonymous enum

MessageIDs for messages from the message server to a client.

Definition at line 189 of file kmessageserver.h.

Constructor & Destructor Documentation

◆ KMessageServer()

KMessageServer::KMessageServer ( quint16  cookie = 42,
QObject parent = nullptr 
)
explicit

Create a KGameNetwork object.

Definition at line 86 of file kmessageserver.cpp.

Member Function Documentation

◆ addClient

void KMessageServer::addClient ( KMessageIO client)
slot

Adds a new KMessageIO object to the communication server.

This "client" gets a unique ID.

This slot method is automatically called for any incoming TCP/IP connection. You can use it to add other types of connections, e.g. local connections (KMessageDirect) to the server manually.

NOTE: The KMessageIO object gets owned by the KMessageServer, so don't delete or manipulate it afterwards. It is automatically deleted when the connection is broken or the communication server is deleted. So, add a KMessageIO object to just ONE KMessageServer.

Definition at line 165 of file kmessageserver.cpp.

◆ adminID()

quint32 KMessageServer::adminID ( ) const

Returns the clientID of the admin, if there is a admin, 0 otherwise.

NOTE: Most often you don't need to know that id, since you can use clientID 0 to specify the admin.

Definition at line 301 of file kmessageserver.cpp.

◆ broadcastMessage()

void KMessageServer::broadcastMessage ( const QByteArray msg)
virtual

Sends a message to all connected clients.

The message is NOT translated in any way. This method calls KMessageIO::send for every client added.

Definition at line 337 of file kmessageserver.cpp.

◆ clientConnected

void KMessageServer::clientConnected ( KMessageIO client)
signal

A new client connected to the game.

Parameters
clientthe client object that connected

◆ clientCount()

int KMessageServer::clientCount ( ) const

returns the current number of connected clients.

Returns
the number of clients

Definition at line 273 of file kmessageserver.cpp.

◆ clientIDs()

QList< quint32 > KMessageServer::clientIDs ( ) const

returns a list of the unique IDs of all clients.

Definition at line 278 of file kmessageserver.cpp.

◆ connectionLost

void KMessageServer::connectionLost ( KMessageIO client)
signal

A network connection got broken.

Note that the client will automatically get deleted after this signal is emitted. The signal is not emitted when the client was removed regularly.

Parameters
clientthe client which left the game

◆ Debug()

void KMessageServer::Debug ( )
virtual

Gives debug output of the game status.

Definition at line 501 of file kmessageserver.cpp.

◆ deleteClients

void KMessageServer::deleteClients ( )
slot

Deletes all connections to the clients.

Definition at line 242 of file kmessageserver.cpp.

◆ findClient()

KMessageIO * KMessageServer::findClient ( quint32  no) const

Find the KMessageIO object to the given client number.

Parameters
nothe client number to look for, or 0 to look for the admin
Returns
address of the client, or 0 if no client with that number exists

Definition at line 286 of file kmessageserver.cpp.

◆ getReceivedMessage

void KMessageServer::getReceivedMessage ( const QByteArray msg)
protectedvirtualslot

This slot receives all the messages from the KMessageIO::received signals.

It stores the messages in a queue. The messages are later taken out of the queue by getReceivedMessage.

NOTE: It is important that this slot may only be called from the signal KMessageIO::received, since the sender() object is used to find out the client that sent the message!

Definition at line 356 of file kmessageserver.cpp.

◆ initNetwork()

bool KMessageServer::initNetwork ( quint16  port = 0)

Starts the Communication server to listen for incoming TCP/IP connections.

Parameters
portThe port on which the service is offered, or 0 to let the system pick a free port
Returns
true if it worked

Definition at line 113 of file kmessageserver.cpp.

◆ isOfferingConnections()

bool KMessageServer::isOfferingConnections ( ) const

Are we still offer offering server connections?

Returns
true, if we are still listening to connections requests

Definition at line 158 of file kmessageserver.cpp.

◆ maxClients()

int KMessageServer::maxClients ( ) const

returns the maximum number of clients

Returns
the number of clients

Definition at line 268 of file kmessageserver.cpp.

◆ messageReceived

void KMessageServer::messageReceived ( const QByteArray data,
quint32  clientID,
bool &  unknown 
)
signal

This signal is always emitted when a message from a client is received.

You can use this signal to extend the communication server without subclassing. Just connect to this signal and analyze the message, if unknown is true. If you recognize a message and process it, set unknown to false, otherwise a warning message is printed.

Parameters
datathe message data
clientIDthe ID of the KMessageIO object that received the message
unknowntrue, if the message type is not known by the KMessageServer

◆ processOneMessage

void KMessageServer::processOneMessage ( )
protectedvirtualslot

This slot is called whenever there are elements in the message queue.

This queue is filled by getReceivedMessage. This slot takes one message out of the queue and analyzes processes it, if it recognizes it. (See message types in the description of the class.) After that, the signal messageReceived is emitted. Connect to that signal if you want to process other types of messages.

Definition at line 377 of file kmessageserver.cpp.

◆ removeClient

void KMessageServer::removeClient ( KMessageIO io,
bool  broken 
)
slot

Removes the KMessageIO object from the client list and deletes it.

This destroys the connection, if it already was up. Does NOT emit connectionLost. Sends an info message to the other clients, that contains the ID of the removed client and the value of the parameter broken.

Parameters
iothe object to delete and to remove from the client list
brokentrue if the client has lost connection Mostly used internally. You will probably not need this.

Definition at line 218 of file kmessageserver.cpp.

◆ sendMessage() [1/2]

void KMessageServer::sendMessage ( const QList< quint32 > &  ids,
const QByteArray msg 
)
virtual

Sends a message to a list of clients.

Their ID is given in ids. If a client id is given more than once in the list, the message is also sent several times to that client. This is just a convenience method. You could also iterate over the list of IDs.

Definition at line 350 of file kmessageserver.cpp.

◆ sendMessage() [2/2]

void KMessageServer::sendMessage ( quint32  id,
const QByteArray msg 
)
virtual

Sends a message to a single client with the given ID.

The message is NOT translated in any way. If no client with the given id exists, nothing is done. This is just a convenience method. You could also call findClient (id)->send(msg) manually, but this method checks for errors.

Definition at line 343 of file kmessageserver.cpp.

◆ serverPort()

quint16 KMessageServer::serverPort ( ) const

Returns the TCP/IP port number we are listening to for incoming connections.

(This has to be known by other clients so that they can connect to us. It's especially necessary if you used 0 as port number in initNetwork().

Returns
the port number

Definition at line 141 of file kmessageserver.cpp.

◆ setAdmin()

void KMessageServer::setAdmin ( quint32  adminID)

Sets the admin to a new client with the given ID.

The old admin (if existed) and the new admin will get the ANS_ADMIN message. If you use 0 as new adminID, no client will be admin.

Definition at line 306 of file kmessageserver.cpp.

◆ setMaxClients()

void KMessageServer::setMaxClients ( int  maxnumber)

sets the maximum number of clients which can connect.

If this number is reached, no more clients can be added. Setting this number to -1 means unlimited number of clients.

NOTE: Existing connections are not affected. So, clientCount > maxClients is possible, if there were already more clients than allowed before reducing this value.

Parameters
maxnumberthe number of clients

Definition at line 263 of file kmessageserver.cpp.

◆ stopNetwork()

void KMessageServer::stopNetwork ( )

Stops listening for connections.

The already running connections are not affected. To listen for connections again call initNetwork again.

Definition at line 149 of file kmessageserver.cpp.

◆ uniqueClientNumber()

quint32 KMessageServer::uniqueClientNumber ( ) const
protected
Returns
A unique number which can be used as the id of a KMessageIO. It is incremented after every call so if you need the id twice you have to save it anywhere. It's currently used to initialize newly connected clients only.

Definition at line 330 of file kmessageserver.cpp.


The documentation for this class was generated from the following files:
KMessageServer(quint16 cookie=42, QObject *parent=nullptr)
Create a KGameNetwork object.
bool initNetwork(quint16 port=0)
Starts the Communication server to listen for incoming TCP/IP connections.
A server for message sending and broadcasting, using TCP/IP connections.
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