QAbstractSocket Class Reference

The QAbstractSocket class provides the base functionality common to all socket types. More...

#include <qabstractsocket.h>

Inheritance diagram for QAbstractSocket:

Public Types
enum	NetworkLayerProtocol { IPv4Protocol, IPv6Protocol, UnknownNetworkLayerProtocol = -1 }
	This enum describes the network layer protocol values used in Qt. More...
enum	SocketError {   ConnectionRefusedError, RemoteHostClosedError, HostNotFoundError, SocketAccessError,   SocketResourceError, SocketTimeoutError, DatagramTooLargeError, NetworkError,   AddressInUseError, SocketAddressNotAvailableError, UnsupportedSocketOperationError, UnfinishedSocketOperationError,   ProxyAuthenticationRequiredError, SslHandshakeFailedError, ProxyConnectionRefusedError, ProxyConnectionClosedError,   ProxyConnectionTimeoutError, ProxyNotFoundError, ProxyProtocolError, UnknownSocketError = -1 }
	This enum describes the socket errors that can occur. More...
enum	SocketOption { LowDelayOption, KeepAliveOption, MulticastTtlOption, MulticastLoopbackOption }
	This enum represents the options that can be set on a socket. More...
enum	SocketState {   UnconnectedState, HostLookupState, ConnectingState, ConnectedState,   BoundState, ListeningState, ClosingState }
	This enum describes the different states in which a socket can be. More...
enum	SocketType { TcpSocket, UdpSocket, UnknownSocketType = -1 }
	This enum describes the transport layer protocol. More...
Public Types inherited from QIODevice
enum	OpenModeFlag {   NotOpen = 0x0000, ReadOnly = 0x0001, WriteOnly = 0x0002, ReadWrite = ReadOnly | WriteOnly,   Append = 0x0004, Truncate = 0x0008, Text = 0x0010, Unbuffered = 0x0020 }
	This enum is used with open() to describe the mode in which a device is opened. More...

Signals
void	connected ()
	This signal is emitted after connectToHost() has been called and a connection has been successfully established. More...
void	disconnected ()
	This signal is emitted when the socket has been disconnected. More...
void	error (QAbstractSocket::SocketError)
	This signal is emitted after an error occurred. More...
void	hostFound ()
	This signal is emitted after connectToHost() has been called and the host lookup has succeeded. More...
void	proxyAuthenticationRequired (const QNetworkProxy &proxy, QAuthenticator *authenticator)
void	stateChanged (QAbstractSocket::SocketState)
	This signal is emitted whenever QAbstractSocket's state changes. More...
Signals inherited from QIODevice
void	aboutToClose ()
	This signal is emitted when the device is about to close. More...
void	bytesWritten (qint64 bytes)
	This signal is emitted every time a payload of data has been written to the device. More...
void	readChannelFinished ()
	This signal is emitted when the input (reading) stream is closed in this device. More...
void	readyRead ()
	This signal is emitted once every time new data is available for reading from the device. More...
Signals inherited from QObject
void	destroyed (QObject *=0)
	This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More...

Public Functions
void	abort ()
	Aborts the current connection and resets the socket. More...
bool	atEnd () const
	Returns true if no more data is currently available for reading; otherwise returns false. More...
qint64	bytesAvailable () const
	Returns the number of incoming bytes that are waiting to be read. More...
qint64	bytesToWrite () const
	Returns the number of bytes that are waiting to be written. More...
bool	canReadLine () const
	Returns true if a line of data can be read from the socket; otherwise returns false. More...
void	close ()
	Closes the I/O device for the socket, disconnects the socket's connection with the host, closes the socket, and resets the name, address, port number and underlying socket descriptor. More...
void	connectToHost (const QString &hostName, quint16 port, OpenMode mode=ReadWrite)
	Attempts to make a connection to hostName on the given port. More...
void	connectToHost (const QHostAddress &address, quint16 port, OpenMode mode=ReadWrite)
	Attempts to make a connection to address on port port. More...
void	disconnectFromHost ()
	Attempts to close the socket. More...
SocketError	error () const
	Returns the type of error that last occurred. More...
bool	flush ()
	This function writes as much as possible from the internal write buffer to the underlying network socket, without blocking. More...
bool	isSequential () const
	Reimplemented Function More...
bool	isValid () const
	Returns true if the socket is valid and ready for use; otherwise returns false. More...
QHostAddress	localAddress () const
	Returns the host address of the local socket if available; otherwise returns QHostAddress::Null. More...
quint16	localPort () const
	Returns the host port number (in native byte order) of the local socket if available; otherwise returns 0. More...
QHostAddress	peerAddress () const
	Returns the address of the connected peer if the socket is in ConnectedState; otherwise returns QHostAddress::Null. More...
QString	peerName () const
	Returns the name of the peer as specified by connectToHost(), or an empty QString if connectToHost() has not been called. More...
quint16	peerPort () const
	Returns the port of the connected peer if the socket is in ConnectedState; otherwise returns 0. More...
QNetworkProxy	proxy () const
	Returns the network proxy for this socket. More...
	QAbstractSocket (SocketType socketType, QObject *parent)
	Creates a new abstract socket of type socketType. More...
qint64	readBufferSize () const
	Returns the size of the internal read buffer. More...
void	setProxy (const QNetworkProxy &networkProxy)
	Sets the explicit network proxy for this socket to networkProxy. More...
void	setReadBufferSize (qint64 size)
	Sets the size of QAbstractSocket's internal read buffer to be size bytes. More...
bool	setSocketDescriptor (int socketDescriptor, SocketState state=ConnectedState, OpenMode openMode=ReadWrite)
	Initializes QAbstractSocket with the native socket descriptor socketDescriptor. More...
void	setSocketOption (QAbstractSocket::SocketOption option, const QVariant &value)
	Sets the given option to the value described by value. More...
int	socketDescriptor () const
	Returns the native socket descriptor of the QAbstractSocket object if this is available; otherwise returns -1. More...
QVariant	socketOption (QAbstractSocket::SocketOption option)
	Returns the value of the option option. More...
SocketType	socketType () const
	Returns the socket type (TCP, UDP, or other). More...
SocketState	state () const
	Returns the state of the socket. More...
bool	waitForBytesWritten (int msecs=30000)
	Reimplemented Function More...
bool	waitForConnected (int msecs=30000)
	Waits until the socket is connected, up to msecs milliseconds. More...
bool	waitForDisconnected (int msecs=30000)
	Waits until the socket has disconnected, up to msecs milliseconds. More...
bool	waitForReadyRead (int msecs=30000)
	This function blocks until new data is available for reading and the QIODevice::readyRead() signal has been emitted. More...
virtual	~QAbstractSocket ()
	Destroys the socket. More...
Public Functions inherited from QIODevice
QString	errorString () const
	Returns a human-readable description of the last device error that occurred. More...
bool	getChar (char *c)
	Reads one character from the device and stores it in c. More...
bool	isOpen () const
	Returns true if the device is open; otherwise returns false. More...
bool	isReadable () const
	Returns true if data can be read from the device; otherwise returns false. More...
bool	isTextModeEnabled () const
	Returns true if the Text flag is enabled; otherwise returns false. More...
bool	isWritable () const
	Returns true if data can be written to the device; otherwise returns false. More...
virtual bool	open (OpenMode mode)
	Opens the device and sets its OpenMode to mode. More...
OpenMode	openMode () const
	Returns the mode in which the device has been opened; i.e. More...
qint64	peek (char *data, qint64 maxlen)
	Reads at most maxSize bytes from the device into data, without side effects (i. More...
QByteArray	peek (qint64 maxlen)
	Peeks at most maxSize bytes from the device, returning the data peeked as a QByteArray. More...
virtual qint64	pos () const
	For random-access devices, this function returns the position that data is written to or read from. More...
bool	putChar (char c)
	Writes the character c to the device. More...
	QIODevice ()
	Constructs a QIODevice object. More...
	QIODevice (QObject *parent)
	Constructs a QIODevice object with the given parent. More...
qint64	read (char *data, qint64 maxlen)
	Reads at most maxSize bytes from the device into data, and returns the number of bytes read. More...
QByteArray	read (qint64 maxlen)
	Reads at most maxSize bytes from the device, and returns the data read as a QByteArray. More...
QByteArray	readAll ()
	Reads all available data from the device, and returns it as a QByteArray. More...
qint64	readLine (char *data, qint64 maxlen)
	This function reads a line of ASCII characters from the device, up to a maximum of maxSize - 1 bytes, stores the characters in data, and returns the number of bytes read. More...
QByteArray	readLine (qint64 maxlen=0)
	Reads a line from the device, but no more than maxSize characters, and returns the result as a QByteArray. More...
virtual bool	reset ()
	Seeks to the start of input for random-access devices. More...
virtual bool	seek (qint64 pos)
	For random-access devices, this function sets the current position to pos, returning true on success, or false if an error occurred. More...
void	setTextModeEnabled (bool enabled)
	If enabled is true, this function sets the Text flag on the device; otherwise the Text flag is removed. More...
virtual qint64	size () const
	For open random-access devices, this function returns the size of the device. More...
void	ungetChar (char c)
	Puts the character c back into the device, and decrements the current position unless the position is 0. More...
qint64	write (const char *data, qint64 len)
	Writes at most maxSize bytes of data from data to the device. More...
qint64	write (const char *data)
	Writes data from a zero-terminated string of 8-bit characters to the device. More...
qint64	write (const QByteArray &data)
	Writes the content of byteArray to the device. More...
virtual	~QIODevice ()
	The destructor is virtual, and QIODevice is an abstract base class. More...
Public Functions inherited from QObject
bool	blockSignals (bool b)
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). More...
const QObjectList &	children () const
	Returns a list of child objects. More...
bool	connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool	disconnect (const char *signal=0, const QObject *receiver=0, const char *member=0)
bool	disconnect (const QObject *receiver, const char *member=0)
void	dumpObjectInfo ()
	Dumps information about signal connections, etc. More...
void	dumpObjectTree ()
	Dumps a tree of children to the debug output. More...
QList< QByteArray >	dynamicPropertyNames () const
	Returns the names of all properties that were dynamically added to the object using setProperty(). More...
virtual bool	event (QEvent *)
	This virtual function receives events to an object and should return true if the event e was recognized and processed. More...
virtual bool	eventFilter (QObject *, QEvent *)
	Filters events if this object has been installed as an event filter for the watched object. More...
template<typename T >
T	findChild (const QString &aName=QString()) const
	Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More...
template<typename T >
QList< T >	findChildren (const QString &aName=QString()) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. More...
template<typename T >
QList< T >	findChildren (const QRegExp &re) const
bool	inherits (const char *classname) const
	Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false. More...
void	installEventFilter (QObject *)
	Installs an event filter filterObj on this object. More...
bool	isWidgetType () const
	Returns true if the object is a widget; otherwise returns false. More...
void	killTimer (int id)
	Kills the timer with timer identifier, id. More...
virtual const QMetaObject *	metaObject () const
	Returns a pointer to the meta-object of this object. More...
void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children. More...
QString	objectName () const
QObject *	parent () const
	Returns a pointer to the parent object. More...
QVariant	property (const char *name) const
	Returns the value of the object's name property. More...
Q_INVOKABLE	QObject (QObject *parent=0)
	Constructs an object with parent object parent. More...
void	removeEventFilter (QObject *)
	Removes an event filter object obj from this object. More...
void	setObjectName (const QString &name)
void	setParent (QObject *)
	Makes the object a child of parent. More...
bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value. More...
void	setUserData (uint id, QObjectUserData *data)
bool	signalsBlocked () const
	Returns true if signals are blocked; otherwise returns false. More...
int	startTimer (int interval)
	Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More...
QThread *	thread () const
	Returns the thread in which the object lives. More...
QObjectUserData *	userData (uint id) const
virtual	~QObject ()
	Destroys the object, deleting all its child objects. More...

Protected Slots
void	connectToHostImplementation (const QString &hostName, quint16 port, OpenMode mode=ReadWrite)
	Contains the implementation of connectToHost(). More...
void	disconnectFromHostImplementation ()
	Contains the implementation of disconnectFromHost(). More...

Protected Functions
	QAbstractSocket (SocketType socketType, QAbstractSocketPrivate &dd, QObject *parent=0)
	Constructs a new abstract socket of type socketType. More...
qint64	readData (char *data, qint64 maxlen)
	Reimplemented Function More...
qint64	readLineData (char *data, qint64 maxlen)
	Reimplemented Function More...
void	setLocalAddress (const QHostAddress &address)
	Sets the address on the local side of a connection to address. More...
void	setLocalPort (quint16 port)
	Sets the port on the local side of a connection to port. More...
void	setPeerAddress (const QHostAddress &address)
	Sets the address of the remote side of the connection to address. More...
void	setPeerName (const QString &name)
	Sets the host name of the remote peer to name. More...
void	setPeerPort (quint16 port)
	Sets the port of the remote side of the connection to port. More...
void	setSocketError (SocketError socketError)
	Sets the type of error that last occurred to socketError. More...
void	setSocketState (SocketState state)
	Sets the state of the socket to state. More...
qint64	writeData (const char *data, qint64 len)
	Reimplemented Function More...
Protected Functions inherited from QIODevice
	QIODevice (QIODevicePrivate &dd, QObject *parent=0)
void	setErrorString (const QString &errorString)
	Sets the human readable description of the last device error that occurred to str. More...
void	setOpenMode (OpenMode openMode)
	Sets the OpenMode of the device to openMode. More...
Protected Functions inherited from QObject
virtual void	childEvent (QChildEvent *)
	This event handler can be reimplemented in a subclass to receive child events. More...
virtual void	connectNotify (const char *signal)
	This virtual function is called when something has been connected to signal in this object. More...
virtual void	customEvent (QEvent *)
	This event handler can be reimplemented in a subclass to receive custom events. More...
virtual void	disconnectNotify (const char *signal)
	This virtual function is called when something has been disconnected from signal in this object. More...
	QObject (QObjectPrivate &dd, QObject *parent=0)
int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal. More...
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns 0. More...
int	senderSignalIndex () const
virtual void	timerEvent (QTimerEvent *)
	This event handler can be reimplemented in a subclass to receive timer events for the object. More...

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. More...
Static Public Functions inherited from QObject
static bool	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
	Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More...
static bool	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
static bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
	Disconnects signal in object sender from method in object receiver. More...
static bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static uint	registerUserData ()
static QString	tr (const char *sourceText, const char *comment=0, int n=-1)
static QString	trUtf8 (const char *sourceText, const char *comment=0, int n=-1)
Static Public Variables inherited from QObject
static const QMetaObject	staticMetaObject
	This variable stores the meta-object for the class. More...
Protected Variables inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Static Protected Variables inherited from QObject
static const QMetaObject	staticQtMetaObject
Related Functions inherited from QObject
T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QRegExp &regExp)()
T *	qobject_cast (QObject *object)
	QObjectList
void *	qt_find_obj_child (QObject *parent, const char *type, const QString &name)
	Returns a pointer to the object named name that inherits type and with a given parent. More...

Detailed Description

The QAbstractSocket class provides the base functionality common to all socket types.

Note

This class or function is reentrant.

Attention

Module: QtNetwork

QAbstractSocket is the base class for QTcpSocket and QUdpSocket and contains all common functionality of these two classes. If you need a socket, you have two options:

• Instantiate QTcpSocket or QUdpSocket.
• Create a native socket descriptor, instantiate QAbstractSocket, and call setSocketDescriptor() to wrap the native socket.

TCP (Transmission Control Protocol) is a reliable, stream-oriented, connection-oriented transport protocol. UDP (User Datagram Protocol) is an unreliable, datagram-oriented, connectionless protocol. In practice, this means that TCP is better suited for continuous transmission of data, whereas the more lightweight UDP can be used when reliability isn't important.

QAbstractSocket's API unifies most of the differences between the two protocols. For example, although UDP is connectionless, connectToHost() establishes a virtual connection for UDP sockets, enabling you to use QAbstractSocket in more or less the same way regardless of the underlying protocol. Internally, QAbstractSocket remembers the address and port passed to connectToHost(), and functions like read() and write() use these values.

At any time, QAbstractSocket has a state (returned by state()). The initial state is UnconnectedState. After calling connectToHost(), the socket first enters HostLookupState. If the host is found, QAbstractSocket enters ConnectingState and emits the hostFound() signal. When the connection has been established, it enters ConnectedState and emits connected(). If an error occurs at any stage, error() is emitted. Whenever the state changes, stateChanged() is emitted. For convenience, isValid() returns true if the socket is ready for reading and writing, but note that the socket's state must be ConnectedState before reading and writing can occur.

Read or write data by calling read() or write(), or use the convenience functions readLine() and readAll(). QAbstractSocket also inherits getChar(), putChar(), and ungetChar() from QIODevice, which work on single bytes. The bytesWritten() signal is emitted when data has been written to the socket (i.e., when the client has read the data). Note that Qt does not limit the write buffer size. You can monitor its size by listening to this signal.

The readyRead() signal is emitted every time a new chunk of data has arrived. bytesAvailable() then returns the number of bytes that are available for reading. Typically, you would connect the readyRead() signal to a slot and read all available data there. If you don't read all the data at once, the remaining data will still be available later, and any new incoming data will be appended to QAbstractSocket's internal read buffer. To limit the size of the read buffer, call setReadBufferSize().

To close the socket, call disconnectFromHost(). QAbstractSocket enters QAbstractSocket::ClosingState. After all pending data has been written to the socket, QAbstractSocket actually closes the socket, enters QAbstractSocket::ClosedState, and emits disconnected(). If you want to abort a connection immediately, discarding all pending data, call abort() instead. If the remote host closes the connection, QAbstractSocket will emit error(QAbstractSocket::RemoteHostClosedError), during which the socket state will still be ConnectedState, and then the disconnected() signal will be emitted.

The port and address of the connected peer is fetched by calling peerPort() and peerAddress(). peerName() returns the host name of the peer, as passed to connectToHost(). localPort() and localAddress() return the port and address of the local socket.

QAbstractSocket provides a set of functions that suspend the calling thread until certain signals are emitted. These functions can be used to implement blocking sockets:

• waitForConnected() blocks until a connection has been established.

• waitForReadyRead() blocks until new data is available for reading.

• waitForBytesWritten() blocks until one payload of data has been written to the socket.

• waitForDisconnected() blocks until the connection has closed.

We show an example:

    int numRead = 0, numReadTotal = 0;
    char buffer[50];

    forever {
    numRead  = socket.read(buffer, 50);

    // do whatever with array
    
    numReadTotal += numRead;
    if (numRead == 0 && !socket.waitForReadyRead()) 
        break;
    }

If QIODevice::waitForReadyRead() returns false, the connection has been closed or an error has occurred.

Programming with a blocking socket is radically different from programming with a non-blocking socket. A blocking socket doesn't require an event loop and typically leads to simpler code. However, in a GUI application, blocking sockets should only be used in non-GUI threads, to avoid freezing the user interface. See the network/fortuneclient and network/blockingfortuneclient examples for an overview of both approaches.

Note

We discourage the use of the blocking functions together with signals. One of the two possibilities should be used.

QAbstractSocket can be used with QTextStream and QDataStream's stream operators (operator<<() and operator>>()). There is one issue to be aware of, though: You must make sure that enough data is available before attempting to read it using operator>>().

See also

QFtp, QNetworkAccessManager, QTcpServer

Definition at line 64 of file qabstractsocket.h.

Enumerations

NetworkLayerProtocol

enum QAbstractSocket::NetworkLayerProtocol

This enum describes the network layer protocol values used in Qt.

• IPv4Protocol IPv4
• IPv6Protocol IPv6
• UnknownNetworkLayerProtocol Other than IPv4 and IPv6

See also

QHostAddress::protocol()

Enumerator
IPv4Protocol
IPv6Protocol
UnknownNetworkLayerProtocol

Definition at line 74 of file qabstractsocket.h.

                              {
        IPv4Protocol,
        IPv6Protocol,
        UnknownNetworkLayerProtocol = -1
    };

SocketError

enum QAbstractSocket::SocketError

This enum describes the socket errors that can occur.

• ConnectionRefusedError The connection was refused by the peer (or timed out).
• RemoteHostClosedError The remote host closed the connection. Note that the client socket (i.e., this socket) will be closed after the remote close notification has been sent.
• HostNotFoundError The host address was not found.
• SocketAccessError The socket operation failed because the application lacked the required privileges.
• SocketResourceError The local system ran out of resources (e.g., too many sockets).
• SocketTimeoutError The socket operation timed out.
• DatagramTooLargeError The datagram was larger than the operating system's limit (which can be as low as 8192 bytes).
• NetworkError An error occurred with the network (e.g., the network cable was accidentally plugged out).
• AddressInUseError The address specified to QUdpSocket::bind() is already in use and was set to be exclusive.
• SocketAddressNotAvailableError The address specified to QUdpSocket::bind() does not belong to the host.
• UnsupportedSocketOperationError The requested socket operation is not supported by the local operating system (e.g., lack of IPv6 support).
• ProxyAuthenticationRequiredError The socket is using a proxy, and the proxy requires authentication.
• SslHandshakeFailedError The SSL/TLS handshake failed, so the connection was closed (only used in QSslSocket) (This value was introduced in 4.4.)
• UnfinishedSocketOperationError Used by QAbstractSocketEngine only, The last operation attempted has not finished yet (still in progress in the background). (This value was introduced in 4.4.)
• ProxyConnectionRefusedError Could not contact the proxy server because the connection to that server was denied (This value was introduced in 4.5.)
• ProxyConnectionClosedError The connection to the proxy server was closed unexpectedly (before the connection to the final peer was established) (This value was introduced in 4.5.)
• ProxyConnectionTimeoutError The connection to the proxy server timed out or the proxy server stopped responding in the authentication phase. (This value was introduced in 4.5.)
• ProxyNotFoundError The proxy address set with setProxy() (or the application proxy) was not found. (This value was introduced in 4.5.)
• ProxyProtocolError The connection negotiation with the proxy server because the response from the proxy server could not be understood. (This value was introduced in 4.5.)

• UnknownSocketError An unidentified error occurred.

  See also

  QAbstractSocket::error()

Enumerator
ConnectionRefusedError
RemoteHostClosedError
HostNotFoundError
SocketAccessError
SocketResourceError
SocketTimeoutError
DatagramTooLargeError
NetworkError
AddressInUseError
SocketAddressNotAvailableError
UnsupportedSocketOperationError
UnfinishedSocketOperationError
ProxyAuthenticationRequiredError
SslHandshakeFailedError
ProxyConnectionRefusedError
ProxyConnectionClosedError
ProxyConnectionTimeoutError
ProxyNotFoundError
ProxyProtocolError
UnknownSocketError

Definition at line 79 of file qabstractsocket.h.

                     {
        ConnectionRefusedError,
        RemoteHostClosedError,
        HostNotFoundError,
        SocketAccessError,
        SocketResourceError,
        SocketTimeoutError,                     /* 5 */
        DatagramTooLargeError,
        NetworkError,
        AddressInUseError,
        SocketAddressNotAvailableError,
        UnsupportedSocketOperationError,        /* 10 */
        UnfinishedSocketOperationError,
        ProxyAuthenticationRequiredError,
        SslHandshakeFailedError,
        ProxyConnectionRefusedError,
        ProxyConnectionClosedError,             /* 15 */
        ProxyConnectionTimeoutError,
        ProxyNotFoundError,
        ProxyProtocolError,

        UnknownSocketError = -1
    };

SocketOption

enum QAbstractSocket::SocketOption

This enum represents the options that can be set on a socket.

Since

4.6

If desired, they can be set after having received the connected() signal from the socket or after having received a new socket from a QTcpServer.

• LowDelayOption Try to optimize the socket for low latency. For a QTcpSocket this would set the TCP_NODELAY option and disable Nagle's algorithm. Set this to 1 to enable.
• KeepAliveOption Set this to 1 to enable the SO_KEEPALIVE socket option

• MulticastTtlOption Set this to an integer value to set IP_MULTICAST_TTL (TTL for multicast datagrams) socket option.

• MulticastLoopbackOption Set this to 1 to enable the IP_MULTICAST_LOOP (multicast loopback) socket option.

See also

QAbstractSocket::setSocketOption(), QAbstractSocket::socketOption()

Enumerator
LowDelayOption
KeepAliveOption
MulticastTtlOption
MulticastLoopbackOption

Definition at line 120 of file qabstractsocket.h.

                      {
        LowDelayOption, // TCP_NODELAY
        KeepAliveOption, // SO_KEEPALIVE
        MulticastTtlOption, // IP_MULTICAST_TTL
        MulticastLoopbackOption // IP_MULTICAST_LOOPBACK
    };

SocketState

enum QAbstractSocket::SocketState

This enum describes the different states in which a socket can be.

• UnconnectedState The socket is not connected.
• HostLookupState The socket is performing a host name lookup.
• ConnectingState The socket has started establishing a connection.
• ConnectedState A connection is established.
• BoundState The socket is bound to an address and port (for servers).
• ClosingState The socket is about to close (data may still be waiting to be written).
• ListeningState For internal use only.
• Idle
• HostLookup
• Connecting
• Connected
• Closing
• Connection

See also

QAbstractSocket::state()

Enumerator
UnconnectedState
HostLookupState
ConnectingState
ConnectedState
BoundState
ListeningState
ClosingState

Definition at line 102 of file qabstractsocket.h.

                     {
        UnconnectedState,
        HostLookupState,
        ConnectingState,
        ConnectedState,
        BoundState,
        ListeningState,
        ClosingState
#ifdef QT3_SUPPORT
        ,
        Idle = UnconnectedState,
        HostLookup = HostLookupState,
        Connecting = ConnectingState,
        Connected = ConnectedState,
        Closing = ClosingState,
        Connection = ConnectedState
#endif
    };

SocketType

enum QAbstractSocket::SocketType

This enum describes the transport layer protocol.

• TcpSocket TCP
• UdpSocket UDP
• UnknownSocketType Other than TCP and UDP

See also

QAbstractSocket::socketType()

Enumerator
TcpSocket
UdpSocket
UnknownSocketType

Definition at line 69 of file qabstractsocket.h.

                    {
        TcpSocket,
        UdpSocket,
        UnknownSocketType = -1
    };

Constructors and Destructors

QAbstractSocket() [1/2]

QAbstractSocket::QAbstractSocket	(	SocketType	socketType,
		QObject *	parent
	)

Creates a new abstract socket of type socketType.

The parent argument is passed to QObject's constructor.

See also

socketType(), QTcpSocket, QUdpSocket

Definition at line 1351 of file qabstractsocket.cpp.

    : QIODevice(*new QAbstractSocketPrivate, parent)
{
    Q_D(QAbstractSocket);
#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::QAbstractSocket(%p)", parent);
#endif
    d->socketType = socketType;
}

~QAbstractSocket()

QAbstractSocket::~QAbstractSocket ( )

virtual

Destroys the socket.

Definition at line 1364 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::~QAbstractSocket()");
#endif
    if (d->state != UnconnectedState)
        abort();
}

QAbstractSocket() [2/2]

QAbstractSocket::QAbstractSocket ( SocketType  socketType, QAbstractSocketPrivate &  dd, QObject *  parent = 0  )

protected

Constructs a new abstract socket of type socketType.

Warning

This function is not part of the public interface.

The parent argument is passed to QObject's constructor.

Definition at line 1332 of file qabstractsocket.cpp.

    : QIODevice(dd, parent)
{
    Q_D(QAbstractSocket);
#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::QAbstractSocket(%sSocket, QAbstractSocketPrivate == %p, parent == %p)",
           socketType == TcpSocket ? "Tcp" : socketType == UdpSocket
           ? "Udp" : "Unknown", &dd, parent);
#endif
    d->socketType = socketType;
}

Functions

abort()

void QAbstractSocket::abort

(

)

Aborts the current connection and resets the socket.

Unlike disconnectFromHost(), this function immediately closes the socket, discarding any pending data in the write buffer.

See also

disconnectFromHost(), close()

Definition at line 2151 of file qabstractsocket.cpp.

Referenced by QHttpPrivate::_q_slotError(), QHttpPrivate::_q_slotSendRequest(), QFtpDTP::abortConnection(), QSocks5SocketEnginePrivate::reauthenticate(), and ~QAbstractSocket().

{
    Q_D(QAbstractSocket);
#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::abort()");
#endif
    if (d->state == UnconnectedState)
        return;
#ifndef QT_NO_OPENSSL
    if (QSslSocket *socket = qobject_cast<QSslSocket *>(this)) {
        socket->abort();
        return;
    }
#endif
    if (d->connectTimer) {
        d->connectTimer->stop();
        delete d->connectTimer;
        d->connectTimer = 0;
    }

    d->writeBuffer.clear();
    d->abortCalled = true;
    close();
}

atEnd()

bool QAbstractSocket::atEnd ( ) const

virtual

Returns true if no more data is currently available for reading; otherwise returns false.

Reimplemented Function

This function is most commonly used when reading data from the socket in a loop. For example:

 // This slot is connected to QAbstractSocket::readyRead()
 void SocketClass::readyReadSlot()
 {
     while (!socket.atEnd()) {
         QByteArray data = socket.read(100);
         ....
     }
 }

See also

bytesAvailable(), readyRead()

Reimplemented from QIODevice.

Reimplemented in QSslSocket.

Definition at line 2198 of file qabstractsocket.cpp.

{
    return QIODevice::atEnd() && (!isOpen() || d_func()->readBuffer.isEmpty());
}

bytesAvailable()

qint64 QAbstractSocket::bytesAvailable ( ) const

virtual

Returns the number of incoming bytes that are waiting to be read.

See also

bytesToWrite(), read()

Reimplemented from QIODevice.

Reimplemented in QSslSocket.

Definition at line 1558 of file qabstractsocket.cpp.

Referenced by QHttpNetworkConnectionChannel::_q_error(), QHttpNetworkConnectionChannel::_q_readyRead(), QSslSocketPrivate::_q_readyReadSlot(), QHttpNetworkConnectionChannel::_q_receiveReply(), QHttpPrivate::_q_slotReadyRead(), QFtpDTP::abortConnection(), QHttpNetworkConnectionChannel::allDone(), QFtpDTP::bytesAvailable(), QVNCServer::clientCutText(), QSocks5PasswordAuthenticator::continueAuthenticate(), QSslSocketBackendPrivate::disconnected(), QHttpNetworkReplyPrivate::getChunkSize(), QSocks5SocketEnginePrivate::parseAuthenticationMethodReply(), QRfbSetEncodings::read(), QRfbFrameBufferUpdateRequest::read(), QRfbKeyEvent::read(), QRfbPointerEvent::read(), QRfbClientCutText::read(), QHttpNetworkReplyPrivate::readBody(), QHttpNetworkReplyPrivate::readBodyFast(), QVNCServer::readClient(), QHttpNetworkReplyPrivate::readReplyBodyChunked(), QHttpNetworkReplyPrivate::readReplyBodyRaw(), QHttpNetworkConnectionChannel::sendRequest(), QVNCServer::setEncodings(), QVNCServer::setPixelFormat(), QFtpDTP::socketReadyRead(), and QSslSocketBackendPrivate::transmit().

{
    Q_D(const QAbstractSocket);
    qint64 available = QIODevice::bytesAvailable();

    available += (qint64) d->readBuffer.size();

    if (!d->isBuffered && d->socketEngine && d->socketEngine->isValid())
        available += d->socketEngine->bytesAvailable();

#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::bytesAvailable() == %llu", available);
#endif
    return available;
}

bytesToWrite()

qint64 QAbstractSocket::bytesToWrite ( ) const

virtual

Returns the number of bytes that are waiting to be written.

The bytes are written when control goes back to the event loop or when flush() is called.

See also

bytesAvailable(), flush()

Reimplemented from QIODevice.

Reimplemented in QSslSocket.

Definition at line 1544 of file qabstractsocket.cpp.

Referenced by QHttpPrivate::postMoreData(), QHttpNetworkConnectionChannel::sendRequest(), and QFtpDTP::writeData().

{
    Q_D(const QAbstractSocket);
#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::bytesToWrite() == %i", d->writeBuffer.size());
#endif
    return (qint64)d->writeBuffer.size();
}

canReadLine()

bool QAbstractSocket::canReadLine ( ) const

virtual

Returns true if a line of data can be read from the socket; otherwise returns false.

See also

readLine()

Reimplemented from QIODevice.

Reimplemented in QSslSocket.

Definition at line 1644 of file qabstractsocket.cpp.

Referenced by QHttpPrivate::_q_slotReadyRead(), QFtpPI::readyRead(), and QFtpDTP::socketReadyRead().

{
    bool hasLine = d_func()->readBuffer.canReadLine();
#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::canReadLine() == %s, buffer size = %d, size = %d", hasLine ? "true" : "false",
           d_func()->readBuffer.size(), d_func()->buffer.size());
#endif
    return hasLine || QIODevice::canReadLine();
}

close()

void QAbstractSocket::close ( )

virtual

Closes the I/O device for the socket, disconnects the socket's connection with the host, closes the socket, and resets the name, address, port number and underlying socket descriptor.

See QIODevice::close() for a description of the actions that occur when an I/O device is closed.

See also

abort()

Reimplemented from QIODevice.

Reimplemented in QSslSocket.

Definition at line 2550 of file qabstractsocket.cpp.

Referenced by QHttpPrivate::_q_slotReadyRead(), abort(), QSslSocket::close(), QHttpNetworkConnectionChannel::close(), QHttpPrivate::closeConn(), QFtpPI::connectionClosed(), QSocks5PasswordAuthenticator::continueAuthenticate(), QSocks5SocketEnginePrivate::parseAuthenticationMethodReply(), QSocks5SocketEnginePrivate::parseRequestMethodReply(), QSocks5SocketEnginePrivate::reauthenticate(), QFtpDTP::socketReadyRead(), waitForBytesWritten(), waitForDisconnected(), waitForReadyRead(), QFtpDTP::writeData(), and QHttpNetworkConnectionPrivate::~QHttpNetworkConnectionPrivate().

{
    Q_D(QAbstractSocket);
#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::close()");
#endif
    QIODevice::close();
    if (d->state != UnconnectedState) {
        d->closeCalled = true;
        disconnectFromHost();
    }

    d->localPort = 0;
    d->peerPort = 0;
    d->localAddress.clear();
    d->peerAddress.clear();
    d->peerName.clear();
    d->cachedSocketDescriptor = -1;
}

connected

void QAbstractSocket::connected ( )

signal

This signal is emitted after connectToHost() has been called and a connection has been successfully established.

Note

On some operating systems the connected() signal may be directly emitted from the connectToHost() call for connections to the localhost.

See also

connectToHost(), disconnected()

connectToHost() [1/2]

void QAbstractSocket::connectToHost	(	const QString &	hostName,
		quint16	port,
		OpenMode	openMode = ReadWrite
	)

Attempts to make a connection to hostName on the given port.

The socket is opened in the given openMode and first enters HostLookupState, then performs a host name lookup of hostName. If the lookup succeeds, hostFound() is emitted and QAbstractSocket enters ConnectingState. It then attempts to connect to the address or addresses returned by the lookup. Finally, if a connection is established, QAbstractSocket enters ConnectedState and emits connected().

At any point, the socket can emit error() to signal that an error occurred.

hostName may be an IP address in string form (e.g., "43.195.83.32"), or it may be a host name (e.g., "example.com"). QAbstractSocket will do a lookup only if required. port is in native byte order.

See also

state(), peerName(), peerAddress(), peerPort(), waitForConnected()

Definition at line 1409 of file qabstractsocket.cpp.

Referenced by QHttpPrivate::_q_slotSendRequest(), QFtpDTP::connectToHost(), connectToHost(), QFtpPI::connectToHost(), QHttpNetworkConnectionChannel::ensureConnection(), and QSocks5SocketEnginePrivate::reauthenticate().

{
    QMetaObject::invokeMethod(this, "connectToHostImplementation",
                              Qt::DirectConnection,
                              Q_ARG(QString, hostName),
                              Q_ARG(quint16, port),
                              Q_ARG(OpenMode, openMode));
}

connectToHost() [2/2]

void QAbstractSocket::connectToHost	(	const QHostAddress &	address,
		quint16	port,
		OpenMode	openMode = ReadWrite
	)

Attempts to make a connection to address on port port.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 1527 of file qabstractsocket.cpp.

{
#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::connectToHost([%s], %i, %i)...",
           address.toString().toLatin1().constData(), port, (int) openMode);
#endif
    connectToHost(address.toString(), port, openMode);
}

connectToHostImplementation

void QAbstractSocket::connectToHostImplementation ( const QString &  hostName, quint16  port, OpenMode  openMode = ReadWrite  )

protectedslot

Contains the implementation of connectToHost().

Since

4.1

Attempts to make a connection to hostName on the given port. The socket is opened in the given openMode.

Definition at line 1430 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::connectToHost(\"%s\", %i, %i)...", qPrintable(hostName), port,
           (int) openMode);
#endif

    if (d->state == ConnectedState || d->state == ConnectingState
        || d->state == ClosingState || d->state == HostLookupState) {
        qWarning("QAbstractSocket::connectToHost() called when already looking up or connecting/connected to \"%s\"", qPrintable(hostName));
        return;
    }

    d->hostName = hostName;
    d->port = port;
    d->state = UnconnectedState;
    d->readBuffer.clear();
    d->writeBuffer.clear();
    d->abortCalled = false;
    d->closeCalled = false;
    d->pendingClose = false;
    d->localPort = 0;
    d->peerPort = 0;
    d->localAddress.clear();
    d->peerAddress.clear();
    d->peerName = hostName;
    if (d->hostLookupId != -1) {
        QHostInfo::abortHostLookup(d->hostLookupId);
        d->hostLookupId = -1;
    }

#ifndef QT_NO_NETWORKPROXY
    // Get the proxy information
    d->resolveProxy(hostName, port);
    if (d->proxyInUse.type() == QNetworkProxy::DefaultProxy) {
        // failed to setup the proxy
        d->socketError = QAbstractSocket::UnsupportedSocketOperationError;
        setErrorString(QAbstractSocket::tr("Operation on socket is not supported"));
        emit error(d->socketError);
        return;
    }
#endif

    if (openMode & QIODevice::Unbuffered)
        d->isBuffered = false; // Unbuffered QTcpSocket
    else if (!d_func()->isBuffered)
        openMode |= QAbstractSocket::Unbuffered; // QUdpSocket

    QIODevice::open(openMode);
    d->state = HostLookupState;
    emit stateChanged(d->state);

    QHostAddress temp;
    if (temp.setAddress(hostName)) {
        QHostInfo info;
        info.setAddresses(QList<QHostAddress>() << temp);
        d->_q_startConnecting(info);
#ifndef QT_NO_NETWORKPROXY
    } else if (d->proxyInUse.capabilities() & QNetworkProxy::HostNameLookupCapability) {
        // the proxy supports connection by name, so use it
        d->startConnectingByName(hostName);
        return;
#endif
    } else {
        if (d->threadData->eventDispatcher) {
            // this internal API for QHostInfo either immediately gives us the desired
            // QHostInfo from cache or later calls the _q_startConnecting slot.
            bool immediateResultValid = false;
            QHostInfo hostInfo = qt_qhostinfo_lookup(hostName,
                                                     this,
                                                     SLOT(_q_startConnecting(QHostInfo)),
                                                     &immediateResultValid,
                                                     &d->hostLookupId);
            if (immediateResultValid) {
                d->hostLookupId = -1;
                d->_q_startConnecting(hostInfo);
            }
        }
    }

#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::connectToHost(\"%s\", %i) == %s%s", hostName.toLatin1().constData(), port,
           (d->state == ConnectedState) ? "true" : "false",
           (d->state == ConnectingState || d->state == HostLookupState)
           ? " (connection in progress)" : "");
#endif
}

disconnected

void QAbstractSocket::disconnected ( )

signal

This signal is emitted when the socket has been disconnected.

Warning

If you need to delete the sender() of this signal in a slot connected to it, use the deleteLater() function.

See also

connectToHost(), disconnectFromHost(), abort()

Referenced by disconnectFromHostImplementation().

disconnectFromHost()

void QAbstractSocket::disconnectFromHost

(

)

Attempts to close the socket.

If there is pending data waiting to be written, QAbstractSocket will enter ClosingState and wait until all data has been written. Eventually, it will enter UnconnectedState and emit the disconnected() signal.

See also

connectToHost()

Definition at line 2578 of file qabstractsocket.cpp.

Referenced by close(), QSslSocketBackendPrivate::disconnectFromHost(), QSslSocketBackendPrivate::startHandshake(), and waitForConnected().

{
    QMetaObject::invokeMethod(this, "disconnectFromHostImplementation",
                              Qt::DirectConnection);
}

disconnectFromHostImplementation

void QAbstractSocket::disconnectFromHostImplementation ( )

protectedslot

Contains the implementation of disconnectFromHost().

Since

4.1

Definition at line 2592 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
#if defined(QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::disconnectFromHost()");
#endif

    if (d->state == UnconnectedState) {
#if defined(QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::disconnectFromHost() was called on an unconnected socket");
#endif
        return;
    }

    if (!d->abortCalled && (d->state == ConnectingState || d->state == HostLookupState)) {
#if defined(QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::disconnectFromHost() but we're still connecting");
#endif
        d->pendingClose = true;
        return;
    }

#ifdef QT3_SUPPORT
    emit connectionClosed(); // compat signal
#endif

    // Disable and delete read notification
    if (d->socketEngine)
        d->socketEngine->setReadNotificationEnabled(false);

    if (d->abortCalled) {
#if defined(QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::disconnectFromHost() aborting immediately");
#endif
        if (d->state == HostLookupState) {
            QHostInfo::abortHostLookup(d->hostLookupId);
            d->hostLookupId = -1;
        }
    } else {
        // Perhaps emit closing()
        if (d->state != ClosingState) {
            d->state = ClosingState;
#if defined(QABSTRACTSOCKET_DEBUG)
            qDebug("QAbstractSocket::disconnectFromHost() emits stateChanged()(ClosingState)");
#endif
            emit stateChanged(d->state);
        } else {
#if defined(QABSTRACTSOCKET_DEBUG)
            qDebug("QAbstractSocket::disconnectFromHost() return from delayed close");
#endif
        }

        // Wait for pending data to be written.
        if (d->socketEngine && d->socketEngine->isValid() && (d->writeBuffer.size() > 0
            || d->socketEngine->bytesToWrite() > 0)) {
            // hack: when we are waiting for the socket engine to write bytes (only
            // possible when using Socks5 or HTTP socket engine), then close
            // anyway after 2 seconds. This is to prevent a timeout on Mac, where we
            // sometimes just did not get the write notifier from the underlying
            // CFSocket and no progress was made.
            if (d->writeBuffer.size() == 0 && d->socketEngine->bytesToWrite() > 0) {
                if (!d->disconnectTimer) {
                    d->disconnectTimer = new QTimer(this);
                    connect(d->disconnectTimer, SIGNAL(timeout()), this,
                            SLOT(_q_forceDisconnect()), Qt::DirectConnection);
                }
                if (!d->disconnectTimer->isActive())
                    d->disconnectTimer->start(2000);
            }
            d->socketEngine->setWriteNotificationEnabled(true);

#if defined(QABSTRACTSOCKET_DEBUG)
            qDebug("QAbstractSocket::disconnectFromHost() delaying disconnect");
#endif
            return;
        } else {
#if defined(QABSTRACTSOCKET_DEBUG)
            qDebug("QAbstractSocket::disconnectFromHost() disconnecting immediately");
#endif
        }
    }

    SocketState previousState = d->state;
    d->resetSocketLayer();
    d->state = UnconnectedState;
    emit stateChanged(d->state);
    emit readChannelFinished();       // we got an EOF

#ifdef QT3_SUPPORT
    emit delayedCloseFinished(); // compat signal
#endif
    // only emit disconnected if we were connected before
    if (previousState == ConnectedState || previousState == ClosingState)
        emit disconnected();

    d->localPort = 0;
    d->peerPort = 0;
    d->localAddress.clear();
    d->peerAddress.clear();

#if defined(QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::disconnectFromHost() disconnected!");
#endif

    if (d->closeCalled) {
#if defined(QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::disconnectFromHost() closed!");
#endif
        d->readBuffer.clear();
        d->writeBuffer.clear();
        QIODevice::close();
    }
}

error() [1/2]

QAbstractSocket::SocketError QAbstractSocket::error

(

)

const

Returns the type of error that last occurred.

See also

state(), errorString()

Definition at line 2803 of file qabstractsocket.cpp.

Referenced by QSocks5SocketEnginePrivate::_q_emitPendingReadNotification(), QSslSocketPrivate::_q_errorSlot(), QHttpNetworkConnectionChannel::_q_readyRead(), QUdpSocket::bind(), QSocks5SocketEngine::bind(), connectToHostImplementation(), QUdpSocket::readDatagram(), QSocks5SocketEnginePrivate::setErrorState(), QSslSocketBackendPrivate::transmit(), waitForBytesWritten(), waitForDisconnected(), waitForReadyRead(), and QUdpSocket::writeDatagram().

{
    return d_func()->socketError;
}

error [2/2]

void QAbstractSocket::error ( QAbstractSocket::SocketError  socketError )

signal

This signal is emitted after an error occurred.

The socketError parameter describes the type of error that occurred.

QAbstractSocket::SocketError is not a registered metatype, so for queued connections, you will have to register it with Q_DECLARE_METATYPE() and qRegisterMetaType().

See also

error(), errorString(), {Creating Custom Qt Types}

flush()

bool QAbstractSocket::flush

(

)

This function writes as much as possible from the internal write buffer to the underlying network socket, without blocking.

If any data was written, this function returns true; otherwise false is returned.

Call this function if you need QAbstractSocket to start sending buffered data immediately. The number of bytes successfully written depends on the operating system. In most cases, you do not need to call this function, because QAbstractSocket will start sending data automatically once control goes back to the event loop. In the absence of an event loop, call waitForBytesWritten() instead.

See also

write(), waitForBytesWritten()

Definition at line 2218 of file qabstractsocket.cpp.

Referenced by QDeclarativeDebugConnectionPrivate::advertisePlugins(), QDeclarativeDebugConnectionPrivate::connected(), QVNCDirtyMap::QVNCDirtyMap(), QSocks5SocketEnginePrivate::sendRequestMethod(), QRfbRawEncoder::write(), and QRfbHextileEncoder< SRC >::write().

{
    Q_D(QAbstractSocket);
#ifndef QT_NO_OPENSSL
    // Manual polymorphism; flush() isn't virtual, but QSslSocket overloads
    // it.
    if (QSslSocket *socket = qobject_cast<QSslSocket *>(this))
        return socket->flush();
#endif
    Q_CHECK_SOCKETENGINE(false);
    return d->flush();
}

hostFound

void QAbstractSocket::hostFound ( )

signal

This signal is emitted after connectToHost() has been called and the host lookup has succeeded.

Note

Since Qt 4.6.3 QAbstractSocket may emit hostFound() directly from the connectToHost() call since a DNS result could have been cached.

See also

connected()

isSequential()

bool QAbstractSocket::isSequential ( ) const

virtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 2178 of file qabstractsocket.cpp.

{
    return true;
}

isValid()

bool QAbstractSocket::isValid

(

)

const

Returns true if the socket is valid and ready for use; otherwise returns false.

Note: The socket's state must be ConnectedState before reading and writing can occur.

See also

state()

Definition at line 1383 of file qabstractsocket.cpp.

Referenced by QUdpSocket::setMulticastInterface(), and QSslSocketBackendPrivate::transmit().

{
    return d_func()->socketEngine ? d_func()->socketEngine->isValid() : isOpen();
}

localAddress()

QHostAddress QAbstractSocket::localAddress

(

)

const

Returns the host address of the local socket if available; otherwise returns QHostAddress::Null.

This is normally the main IP address of the host, but can be QHostAddress::LocalHost (127.0.0.1) for connections to the local host.

See also

localPort(), peerAddress(), setLocalAddress()

Definition at line 1596 of file qabstractsocket.cpp.

Referenced by QSslSocketPrivate::_q_connectedSlot(), and QFtpPI::startNextCmd().

{
    Q_D(const QAbstractSocket);
    return d->localAddress;
}

localPort()

quint16 QAbstractSocket::localPort

(

)

const

Returns the host port number (in native byte order) of the local socket if available; otherwise returns 0.

See also

localAddress(), peerPort(), setLocalPort()

Definition at line 1580 of file qabstractsocket.cpp.

Referenced by QSslSocketPrivate::_q_connectedSlot(), and QSocks5SocketEngine::bind().

{
    Q_D(const QAbstractSocket);
    return d->localPort;
}

peerAddress()

QHostAddress QAbstractSocket::peerAddress

(

)

const

Returns the address of the connected peer if the socket is in ConnectedState; otherwise returns QHostAddress::Null.

See also

peerName(), peerPort(), localAddress(), setPeerAddress()

Definition at line 1620 of file qabstractsocket.cpp.

Referenced by QSslSocketPrivate::_q_connectedSlot(), and QFtpPI::processReply().

{
    Q_D(const QAbstractSocket);
    return d->peerAddress;
}

peerName()

QString QAbstractSocket::peerName

(

)

const

Returns the name of the peer as specified by connectToHost(), or an empty QString if connectToHost() has not been called.

See also

peerAddress(), peerPort(), setPeerName()

Definition at line 1632 of file qabstractsocket.cpp.

Referenced by QSslSocketPrivate::_q_connectedSlot(), QHttpPrivate::_q_slotError(), QHttpPrivate::_q_slotSendRequest(), QFtpPI::error(), QHttpNetworkConnectionPrivate::errorDetail(), and QFtpPI::processReply().

{
    Q_D(const QAbstractSocket);
    return d->peerName.isEmpty() ? d->hostName : d->peerName;
}

peerPort()

quint16 QAbstractSocket::peerPort

(

)

const

Returns the port of the connected peer if the socket is in ConnectedState; otherwise returns 0.

See also

peerAddress(), localPort(), setPeerPort()

Definition at line 1608 of file qabstractsocket.cpp.

Referenced by QSslSocketPrivate::_q_connectedSlot(), and QHttpPrivate::_q_slotSendRequest().

{
    Q_D(const QAbstractSocket);
    return d->peerPort;
}

proxy()

QNetworkProxy QAbstractSocket::proxy

(

)

const

Returns the network proxy for this socket.

Since

4.1

By default QNetworkProxy::DefaultProxy is used, which means this socket will query the default proxy settings for the application.

See also

setProxy(), QNetworkProxy, QNetworkProxyFactory

Definition at line 2859 of file qabstractsocket.cpp.

Referenced by QHttpNetworkConnectionChannel::ensureConnection().

{
    Q_D(const QAbstractSocket);
    return d->proxy;
}

proxyAuthenticationRequired

void QAbstractSocket::proxyAuthenticationRequired ( const QNetworkProxy &  proxy, QAuthenticator *  authenticator  )

signal

Since

4.3

This signal can be emitted when a proxy that requires authentication is used. The authenticator object can then be filled in with the required details to allow authentication and continue the connection.

Note

It is not possible to use a QueuedConnection to connect to this signal, as the connection will fail if the authenticator has not been filled in with new information when the signal returns.

See also

QAuthenticator, QNetworkProxy

readBufferSize()

qint64 QAbstractSocket::readBufferSize

(

)

const

Returns the size of the internal read buffer.

This limits the amount of data that the client can receive before you call read() or readAll().

A read buffer size of 0 (the default) means that the buffer has no size limit, ensuring that no data is lost.

See also

setReadBufferSize(), read()

Definition at line 2716 of file qabstractsocket.cpp.

{
    return d_func()->readBufferMaxSize;
}

readData()

qint64 QAbstractSocket::readData ( char *  data, qint64  maxlen  )

protectedvirtual

Reimplemented Function

Implements QIODevice.

Reimplemented in QSslSocket.

Definition at line 2233 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);

    // This is for a buffered QTcpSocket
    if (d->isBuffered && d->readBuffer.isEmpty())
        // if we're still connected, return 0 indicating there may be more data in the future
        // if we're not connected, return -1 indicating EOF
        return d->state == QAbstractSocket::ConnectedState ? qint64(0) : qint64(-1);

    // short cut for a char read if we have something in the buffer
    if (maxSize == 1 && !d->readBuffer.isEmpty()) {
        *data = d->readBuffer.getChar();
#if defined (QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::readData(%p '%c (0x%.2x)', 1) == 1 [char buffer]",
               data, isprint(int(uchar(*data))) ? *data : '?', *data);
#endif
        if (d->readBuffer.isEmpty() && d->socketEngine && d->socketEngine->isValid())
            d->socketEngine->setReadNotificationEnabled(true);
        return 1;
    }

    // Special case for an Unbuffered QTcpSocket
    // Re-filling the buffer.
    if (d->socketType == TcpSocket
            && !d->isBuffered
            && d->readBuffer.size() < maxSize
            && d->readBufferMaxSize > 0
            && maxSize < d->readBufferMaxSize
            && d->socketEngine
            && d->socketEngine->isValid()) {
        // Our buffer is empty and a read() was requested for a byte amount that is smaller
        // than the readBufferMaxSize. This means that we should fill our buffer since we want
        // such small reads come from the buffer and not always go to the costly socket engine read()
        qint64 bytesToRead = d->socketEngine->bytesAvailable();
        if (bytesToRead > 0) {
            char *ptr = d->readBuffer.reserve(bytesToRead);
            qint64 readBytes = d->socketEngine->read(ptr, bytesToRead);
            if (readBytes == -2) {
                // No bytes currently available for reading.
                d->readBuffer.chop(bytesToRead);
            } else {
                d->readBuffer.chop(int(bytesToRead - (readBytes < 0 ? qint64(0) : readBytes)));
            }
        }
   }

    // First try to satisfy the read from the buffer
    qint64 bytesToRead = qMin(qint64(d->readBuffer.size()), maxSize);
    qint64 readSoFar = 0;
    while (readSoFar < bytesToRead) {
        const char *ptr = d->readBuffer.readPointer();
        int bytesToReadFromThisBlock = qMin(int(bytesToRead - readSoFar),
                                            d->readBuffer.nextDataBlockSize());
        memcpy(data + readSoFar, ptr, bytesToReadFromThisBlock);
        readSoFar += bytesToReadFromThisBlock;
        d->readBuffer.free(bytesToReadFromThisBlock);
    }

    if (d->socketEngine && !d->socketEngine->isReadNotificationEnabled() && d->socketEngine->isValid())
        d->socketEngine->setReadNotificationEnabled(true);

    if (readSoFar > 0) {
        // we read some data from buffer.
        // Just return, readyRead will be emitted again
#if defined (QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::readData(%p '%c (0x%.2x)', %lli) == %lli [buffer]",
               data, isprint(int(uchar(*data))) ? *data : '?', *data, maxSize, readSoFar);
#endif

        if (d->readBuffer.isEmpty() && d->socketEngine)
            d->socketEngine->setReadNotificationEnabled(true);
        return readSoFar;
    }

    // This code path is for Unbuffered QTcpSocket or for connected UDP

    if (!d->isBuffered) {
        if (!d->socketEngine)
            return -1;          // no socket engine is probably EOF
        if (!d->socketEngine->isValid())
            return -1; // This is for unbuffered TCP when we already had been disconnected
        if (d->state != QAbstractSocket::ConnectedState)
            return -1; // This is for unbuffered TCP if we're not connected yet
        qint64 readBytes = d->socketEngine->read(data, maxSize);
        if (readBytes == -2) {
            // -2 from the engine means no bytes available (EAGAIN) so read more later
            return 0;
        } else if (readBytes < 0) {
            d->socketError = d->socketEngine->error();
            setErrorString(d->socketEngine->errorString());
            d->resetSocketLayer();
            d->state = QAbstractSocket::UnconnectedState;
        } else if (!d->socketEngine->isReadNotificationEnabled()) {
            // Only do this when there was no error
            d->socketEngine->setReadNotificationEnabled(true);
        }

#if defined (QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::readData(%p \"%s\", %lli) == %lld [engine]",
               data, qt_prettyDebug(data, 32, readBytes).data(), maxSize,
               readBytes);
#endif
        return readBytes;
    }


#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::readData(%p \"%s\", %lli) == %lld [unreachable]",
           data, qt_prettyDebug(data, qMin<qint64>(32, readSoFar), readSoFar).data(),
           maxSize, readSoFar);
#endif
    return readSoFar;
}

readLineData()

qint64 QAbstractSocket::readLineData ( char *  data, qint64  maxlen  )

protectedvirtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 2350 of file qabstractsocket.cpp.

{
    return QIODevice::readLineData(data, maxlen);
}

setLocalAddress()

void QAbstractSocket::setLocalAddress ( const QHostAddress &  address )

protected

Sets the address on the local side of a connection to address.

Since

4.1

You can call this function in a subclass of QAbstractSocket to change the return value of the localAddress() function after a connection has been established. This feature is commonly used by proxy connections for virtual connection settings.

Note that this function does not bind the local address of the socket prior to a connection (e.g., QUdpSocket::bind()).

See also

localAddress(), setLocalPort(), setPeerAddress()

Definition at line 2469 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
    d->localAddress = address;
}

setLocalPort()

void QAbstractSocket::setLocalPort ( quint16  port )

protected

Sets the port on the local side of a connection to port.

Since

4.1

You can call this function in a subclass of QAbstractSocket to change the return value of the localPort() function after a connection has been established. This feature is commonly used by proxy connections for virtual connection settings.

Note that this function does not bind the local port of the socket prior to a connection (e.g., QUdpSocket::bind()).

See also

localAddress(), setLocalAddress(), setPeerPort()

Definition at line 2444 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
    d->localPort = port;
}

setPeerAddress()

void QAbstractSocket::setPeerAddress ( const QHostAddress &  address )

protected

Sets the address of the remote side of the connection to address.

Since

4.1

You can call this function in a subclass of QAbstractSocket to change the return value of the peerAddress() function after a connection has been established. This feature is commonly used by proxy connections for virtual connection settings.

See also

peerAddress(), setPeerPort(), setLocalAddress()

Definition at line 2513 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
    d->peerAddress = address;
}

setPeerName()

void QAbstractSocket::setPeerName ( const QString &  name )

protected

Sets the host name of the remote peer to name.

Since

4.1

You can call this function in a subclass of QAbstractSocket to change the return value of the peerName() function after a connection has been established. This feature is commonly used by proxy connections for virtual connection settings.

See also

peerName()

Definition at line 2534 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
    d->peerName = name;
}

setPeerPort()

void QAbstractSocket::setPeerPort ( quint16  port )

protected

Sets the port of the remote side of the connection to port.

Since

4.1

You can call this function in a subclass of QAbstractSocket to change the return value of the peerPort() function after a connection has been established. This feature is commonly used by proxy connections for virtual connection settings.

See also

peerPort(), setPeerAddress(), setLocalPort()

Definition at line 2491 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
    d->peerPort = port;
}

setProxy()

void QAbstractSocket::setProxy

(

const QNetworkProxy &

networkProxy

)

Sets the explicit network proxy for this socket to networkProxy.

Since

4.1

To disable the use of a proxy for this socket, use the QNetworkProxy::NoProxy proxy type:

socket->setProxy(QNetworkProxy::NoProxy);

The default value for the proxy is QNetworkProxy::DefaultProxy, which means the socket will use the application settings: if a proxy is set with QNetworkProxy::setApplicationProxy, it will use that; otherwise, if a factory is set with QNetworkProxyFactory::setApplicationProxyFactory, it will query that factory with type QNetworkProxyQuery::TcpSocket.

See also

proxy(), QNetworkProxy, QNetworkProxyFactory::queryProxy()

Definition at line 2841 of file qabstractsocket.cpp.

Referenced by QHttpPrivate::_q_slotSendRequest(), QSocks5SocketEngine::bind(), QHttpNetworkConnectionChannel::init(), and QSocks5SocketEnginePrivate::initialize().

{
    Q_D(QAbstractSocket);
    d->proxy = networkProxy;
}

setReadBufferSize()

void QAbstractSocket::setReadBufferSize

(

qint64

size

)

Sets the size of QAbstractSocket's internal read buffer to be size bytes.

If the buffer size is limited to a certain size, QAbstractSocket won't buffer more than this size of data. Exceptionally, a buffer size of 0 means that the read buffer is unlimited and all incoming data is buffered. This is the default.

This option is useful if you only read the data at certain points in time (e.g., in a real-time streaming application) or if you want to protect your socket against receiving too much data, which may eventually cause your application to run out of memory.

Only QTcpSocket uses QAbstractSocket's internal buffer; QUdpSocket does not use any buffering at all, but rather relies on the implicit buffering provided by the operating system. Because of this, calling this function on QUdpSocket has no effect.

See also

readBufferSize(), read()

Definition at line 2743 of file qabstractsocket.cpp.

Referenced by QHttpNetworkConnectionChannel::ensureConnection(), and QSslSocketBackendPrivate::startHandshake().

{
    Q_D(QAbstractSocket);

#ifndef QT_NO_OPENSSL
    // Manual polymorphism; setReadBufferSize() isn't virtual, but QSslSocket overloads
    // it.
    if (QSslSocket *socket = qobject_cast<QSslSocket *>(this)) {
        socket->setReadBufferSize(size);
        return;
    }
#endif

    if (d->readBufferMaxSize == size)
        return;
    d->readBufferMaxSize = size;
    if (!d->readSocketNotifierCalled && d->socketEngine) {
        // ensure that the read notification is enabled if we've now got
        // room in the read buffer
        // but only if we're not inside canReadNotification -- that will take care on its own
        if ((size == 0 || d->readBuffer.size() < size) && d->state == QAbstractSocket::ConnectedState) // Do not change the notifier unless we are connected.
            d->socketEngine->setReadNotificationEnabled(true);
    }
}

setSocketDescriptor()

bool QAbstractSocket::setSocketDescriptor	(	int	socketDescriptor,
		SocketState	socketState = ConnectedState,
		OpenMode	openMode = ReadWrite
	)

Initializes QAbstractSocket with the native socket descriptor socketDescriptor.

Returns true if socketDescriptor is accepted as a valid socket descriptor; otherwise returns false. The socket is opened in the mode specified by openMode, and enters the socket state specified by socketState.

Note: It is not possible to initialize two abstract sockets with the same native socket descriptor.

See also

socketDescriptor()

Definition at line 1684 of file qabstractsocket.cpp.

Referenced by QTcpServer::incomingConnection().

{
    Q_D(QAbstractSocket);
#ifndef QT_NO_OPENSSL
    if (QSslSocket *socket = qobject_cast<QSslSocket *>(this))
        return socket->setSocketDescriptor(socketDescriptor, socketState, openMode);
#endif

    d->resetSocketLayer();
    d->socketEngine = QAbstractSocketEngine::createSocketEngine(socketDescriptor, this);
    if (!d->socketEngine) {
        d->socketError = UnsupportedSocketOperationError;
        setErrorString(tr("Operation on socket is not supported"));
        return false;
    }
#ifndef QT_NO_BEARERMANAGEMENT
    //copy network session down to the socket engine (if it has been set)
    d->socketEngine->setProperty("_q_networksession", property("_q_networksession"));
#endif
    bool result = d->socketEngine->initialize(socketDescriptor, socketState);
    if (!result) {
        d->socketError = d->socketEngine->error();
        setErrorString(d->socketEngine->errorString());
        return false;
    }

    if (d->threadData->eventDispatcher)
        d->socketEngine->setReceiver(d);

    QIODevice::open(openMode);

    if (d->state != socketState) {
        d->state = socketState;
        emit stateChanged(d->state);
    }

    d->pendingClose = false;
    d->socketEngine->setReadNotificationEnabled(true);
    d->localPort = d->socketEngine->localPort();
    d->peerPort = d->socketEngine->peerPort();
    d->localAddress = d->socketEngine->localAddress();
    d->peerAddress = d->socketEngine->peerAddress();
    d->cachedSocketDescriptor = socketDescriptor;

    return true;
}

setSocketError()

void QAbstractSocket::setSocketError ( SocketError  socketError )

protected

Sets the type of error that last occurred to socketError.

See also

setSocketState(), setErrorString()

Definition at line 2813 of file qabstractsocket.cpp.

{
    d_func()->socketError = socketError;
}

setSocketOption()

void QAbstractSocket::setSocketOption	(	QAbstractSocket::SocketOption	option,
		const QVariant &	value
	)

Sets the given option to the value described by value.

Since

4.6

See also

socketOption()

Definition at line 1741 of file qabstractsocket.cpp.

Referenced by QHttpNetworkConnectionChannel::_q_connected(), and QFtpPI::connected().

{
#ifndef QT_NO_OPENSSL
    if (QSslSocket *sslSocket = qobject_cast<QSslSocket*>(this)) {
        sslSocket->setSocketOption(option, value);
        return;
    }
#endif

    if (!d_func()->socketEngine)
        return;

    switch (option) {
        case LowDelayOption:
            d_func()->socketEngine->setOption(QAbstractSocketEngine::LowDelayOption, value.toInt());
            break;

        case KeepAliveOption:
            d_func()->socketEngine->setOption(QAbstractSocketEngine::KeepAliveOption, value.toInt());
            break;

        case MulticastTtlOption:
                d_func()->socketEngine->setOption(QAbstractSocketEngine::MulticastTtlOption, value.toInt());
                break;

        case MulticastLoopbackOption:
                d_func()->socketEngine->setOption(QAbstractSocketEngine::MulticastLoopbackOption, value.toInt());
                break;
    }
}

setSocketState()

void QAbstractSocket::setSocketState ( SocketState  state )

protected

Sets the state of the socket to state.

See also

state()

Definition at line 2783 of file qabstractsocket.cpp.

{
    d_func()->state = state;
}

socketDescriptor()

int QAbstractSocket::socketDescriptor

(

)

const

Returns the native socket descriptor of the QAbstractSocket object if this is available; otherwise returns -1.

If the socket is using QNetworkProxy, the returned descriptor may not be usable with native socket functions.

The socket descriptor is not available when QAbstractSocket is in UnconnectedState.

See also

setSocketDescriptor()

Definition at line 1666 of file qabstractsocket.cpp.

Referenced by QSslSocketPrivate::_q_connectedSlot(), QLocalServerPrivate::_q_onNewConnection(), QLocalSocket::setSocketDescriptor(), and setSocketDescriptor().

{
    Q_D(const QAbstractSocket);
    return d->cachedSocketDescriptor;
}

socketOption()

QVariant QAbstractSocket::socketOption

(

QAbstractSocket::SocketOption

option

)

Returns the value of the option option.

Since

4.6

See also

setSocketOption()

Definition at line 1781 of file qabstractsocket.cpp.

{
#ifndef QT_NO_OPENSSL
    if (QSslSocket *sslSocket = qobject_cast<QSslSocket*>(this)) {
        return sslSocket->socketOption(option);
    }
#endif

    if (!d_func()->socketEngine)
        return QVariant();

    int ret = -1;
    switch (option) {
        case LowDelayOption:
            ret = d_func()->socketEngine->option(QAbstractSocketEngine::LowDelayOption);
            break;

        case KeepAliveOption:
            ret = d_func()->socketEngine->option(QAbstractSocketEngine::KeepAliveOption);
            break;

        case MulticastTtlOption:
                ret = d_func()->socketEngine->option(QAbstractSocketEngine::MulticastTtlOption);
                break;
        case MulticastLoopbackOption:
                ret = d_func()->socketEngine->option(QAbstractSocketEngine::MulticastLoopbackOption);
                break;
    }
    if (ret == -1)
        return QVariant();
    else
        return QVariant(ret);
}

socketType()

QAbstractSocket::SocketType QAbstractSocket::socketType

(

)

const

Returns the socket type (TCP, UDP, or other).

See also

QTcpSocket, QUdpSocket

Definition at line 2793 of file qabstractsocket.cpp.

Referenced by QAbstractSocket().

{
    return d_func()->socketType;
}

state()

QAbstractSocket::SocketState QAbstractSocket::state

(

)

const

Returns the state of the socket.

See also

error()

Definition at line 2773 of file qabstractsocket.cpp.

Referenced by QSocks5SocketEnginePrivate::_q_emitPendingReadNotification(), QHttpNetworkConnectionChannel::_q_readyRead(), QHttpNetworkConnectionChannel::_q_receiveReply(), QHttpPrivate::_q_slotSendRequest(), QHttpNetworkConnectionPrivate::_q_startNextRequest(), QHttpNetworkConnectionChannel::allDone(), QUdpSocket::bind(), QFtpDTP::bytesAvailable(), QHttpNetworkConnectionChannel::close(), QHttpNetworkConnectionChannel::detectPipeliningSupport(), QHttpNetworkConnectionChannel::ensureConnection(), QHttpNetworkConnectionPrivate::fillPipeline(), QDeclarativeDebugConnection::isConnected(), QVNCDirtyMap::QVNCDirtyMap(), QFtpDTP::read(), QFtpDTP::readAll(), QFtpPI::sendCommands(), setSocketState(), QFtpDTP::state(), QSslSocketBackendPrivate::transmit(), waitForBytesWritten(), waitForConnected(), waitForDisconnected(), waitForReadyRead(), QRfbRawEncoder::write(), and QRfbHextileEncoder< SRC >::write().

{
    return d_func()->state;
}

stateChanged

void QAbstractSocket::stateChanged ( QAbstractSocket::SocketState  socketState )

signal

This signal is emitted whenever QAbstractSocket's state changes.

The socketState parameter is the new state.

QAbstractSocket::SocketState is not a registered metatype, so for queued connections, you will have to register it with Q_REGISTER_METATYPE() and qRegisterMetaType().

See also

state(), {Creating Custom Qt Types}

Referenced by QUdpSocket::bind(), connectToHostImplementation(), disconnectFromHostImplementation(), setSocketDescriptor(), and waitForConnected().

waitForBytesWritten()

bool QAbstractSocket::waitForBytesWritten ( int  msecs = 30000 )

virtual

Reimplemented Function

Reimplemented from QIODevice.

Reimplemented in QSslSocket.

Definition at line 2006 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::waitForBytesWritten(%i)", msecs);
#endif

    // require calling connectToHost() before waitForBytesWritten()
    if (state() == UnconnectedState) {
        qWarning("QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState");
        return false;
    }

    if (d->writeBuffer.isEmpty())
        return false;

    QElapsedTimer stopWatch;
    stopWatch.start();

    // handle a socket in connecting state
    if (state() == HostLookupState || state() == ConnectingState) {
        if (!waitForConnected(msecs))
            return false;
    }

    forever {
        bool readyToRead = false;
        bool readyToWrite = false;
        if (!d->socketEngine->waitForReadOrWrite(&readyToRead, &readyToWrite, true, !d->writeBuffer.isEmpty(),
                                               qt_timeout_value(msecs, stopWatch.elapsed()))) {
            d->socketError = d->socketEngine->error();
            setErrorString(d->socketEngine->errorString());
#if defined (QABSTRACTSOCKET_DEBUG)
            qDebug("QAbstractSocket::waitForBytesWritten(%i) failed (%i, %s)",
                   msecs, d->socketError, errorString().toLatin1().constData());
#endif
            emit error(d->socketError);
            if (d->socketError != SocketTimeoutError)
                close();
            return false;
        }

        if (readyToRead) {
#if defined (QABSTRACTSOCKET_DEBUG)
            qDebug("QAbstractSocket::waitForBytesWritten calls canReadNotification");
#endif
            if(!d->canReadNotification())
                return false;
        }


        if (readyToWrite) {
            if (d->canWriteNotification()) {
#if defined (QABSTRACTSOCKET_DEBUG)
                qDebug("QAbstractSocket::waitForBytesWritten returns true");
#endif
                return true;
            }
        }

        if (state() != ConnectedState)
            return false;
    }
    return false;
}

waitForConnected()

bool QAbstractSocket::waitForConnected

(

int

msecs = 30000

)

Waits until the socket is connected, up to msecs milliseconds.

If the connection has been established, this function returns true; otherwise it returns false. In the case where it returns false, you can call error() to determine the cause of the error.

The following example waits up to one second for a connection to be established:

socket->connectToHost("imap", 143);
if (socket->waitForConnected(1000))
    qDebug("Connected!");

If msecs is -1, this function will not time out.

Note

This function may wait slightly longer than msecs, depending on the time it takes to complete the host lookup.

Multiple calls to this functions do not accumulate the time. If the function times out, the connecting process will be aborted.

See also

connectToHost(), connected()

Definition at line 1851 of file qabstractsocket.cpp.

Referenced by waitForBytesWritten(), waitForDisconnected(), and waitForReadyRead().

{
    Q_D(QAbstractSocket);
#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::waitForConnected(%i)", msecs);
#endif

    if (state() == ConnectedState) {
#if defined (QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::waitForConnected(%i) already connected", msecs);
#endif
        return true;
    }

#ifndef QT_NO_OPENSSL
    // Manual polymorphism; this function is not virtual, but has an overload
    // in QSslSocket.
    if (QSslSocket *socket = qobject_cast<QSslSocket *>(this))
        return socket->waitForConnected(msecs);
#endif

    bool wasPendingClose = d->pendingClose;
    d->pendingClose = false;
    QElapsedTimer stopWatch;
    stopWatch.start();

    if (d->state == HostLookupState) {
#if defined (QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::waitForConnected(%i) doing host name lookup", msecs);
#endif
        QHostInfo::abortHostLookup(d->hostLookupId);
        d->hostLookupId = -1;
#ifndef QT_NO_BEARERMANAGEMENT
        QSharedPointer<QNetworkSession> networkSession;
        QVariant v(property("_q_networksession"));
        if (v.isValid()) {
            networkSession = qvariant_cast< QSharedPointer<QNetworkSession> >(v);
            d->_q_startConnecting(QHostInfoPrivate::fromName(d->hostName, networkSession));
        } else
#endif
        d->_q_startConnecting(QHostInfo::fromName(d->hostName));
    }
    if (state() == UnconnectedState)
        return false; // connect not im progress anymore!

    bool timedOut = true;
#if defined (QABSTRACTSOCKET_DEBUG)
    int attempt = 1;
#endif
    while (state() == ConnectingState && (msecs == -1 || stopWatch.elapsed() < msecs)) {
        int timeout = qt_timeout_value(msecs, stopWatch.elapsed());
        if (msecs != -1 && timeout > QT_CONNECT_TIMEOUT)
            timeout = QT_CONNECT_TIMEOUT;
#if defined (QABSTRACTSOCKET_DEBUG)
        qDebug("QAbstractSocket::waitForConnected(%i) waiting %.2f secs for connection attempt #%i",
               msecs, timeout / 1000.0, attempt++);
#endif
        timedOut = false;

        if (d->socketEngine && d->socketEngine->waitForWrite(timeout, &timedOut) && !timedOut) {
            d->_q_testConnection();
        } else {
            d->_q_connectToNextAddress();
        }
    }

    if ((timedOut && state() != ConnectedState) || state() == ConnectingState) {
        d->socketError = SocketTimeoutError;
        d->state = UnconnectedState;
        emit stateChanged(d->state);
        d->resetSocketLayer();
        setErrorString(tr("Socket operation timed out"));
    }

#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::waitForConnected(%i) == %s", msecs,
           state() == ConnectedState ? "true" : "false");
#endif
    if (state() != ConnectedState)
        return false;
    if (wasPendingClose)
        disconnectFromHost();
    return true;
}

waitForDisconnected()

bool QAbstractSocket::waitForDisconnected

(

int

msecs = 30000

)

Waits until the socket has disconnected, up to msecs milliseconds.

If the connection has been disconnected, this function returns true; otherwise it returns false. In the case where it returns false, you can call error() to determine the cause of the error.

The following example waits up to one second for a connection to be closed:

socket->disconnectFromHost();
    if (socket->state() == QAbstractSocket::UnconnectedState || 
        socket->waitForDisconnected(1000))
        qDebug("Disconnected!");

If msecs is -1, this function will not time out.

See also

disconnectFromHost(), close()

Definition at line 2088 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
#ifndef QT_NO_OPENSSL
    // Manual polymorphism; this function is not virtual, but has an overload
    // in QSslSocket.
    if (QSslSocket *socket = qobject_cast<QSslSocket *>(this))
        return socket->waitForDisconnected(msecs);
#endif

    // require calling connectToHost() before waitForDisconnected()
    if (state() == UnconnectedState) {
        qWarning("QAbstractSocket::waitForDisconnected() is not allowed in UnconnectedState");
        return false;
    }

    QElapsedTimer stopWatch;
    stopWatch.start();

    // handle a socket in connecting state
    if (state() == HostLookupState || state() == ConnectingState) {
        if (!waitForConnected(msecs))
            return false;
        if (state() == UnconnectedState)
            return true;
    }

    forever {
        bool readyToRead = false;
        bool readyToWrite = false;
        if (!d->socketEngine->waitForReadOrWrite(&readyToRead, &readyToWrite, state() == ConnectedState,
                                               !d->writeBuffer.isEmpty(),
                                               qt_timeout_value(msecs, stopWatch.elapsed()))) {
            d->socketError = d->socketEngine->error();
            setErrorString(d->socketEngine->errorString());
#if defined (QABSTRACTSOCKET_DEBUG)
            qDebug("QAbstractSocket::waitForReadyRead(%i) failed (%i, %s)",
                   msecs, d->socketError, errorString().toLatin1().constData());
#endif
            emit error(d->socketError);
            if (d->socketError != SocketTimeoutError)
                close();
            return false;
        }

        if (readyToRead)
            d->canReadNotification();
        if (readyToWrite)
            d->canWriteNotification();

        if (state() == UnconnectedState)
            return true;
    }
    return false;
}

waitForReadyRead()

bool QAbstractSocket::waitForReadyRead ( int  msecs = 30000 )

virtual

This function blocks until new data is available for reading and the QIODevice::readyRead() signal has been emitted.

The function will timeout after msecs milliseconds; the default timeout is 30000 milliseconds.

The function returns true if the readyRead() signal is emitted and there is new data available for reading; otherwise it returns false (if an error occurred or the operation timed out).

See also

waitForBytesWritten()

Reimplemented from QIODevice.

Reimplemented in QSslSocket.

Definition at line 1948 of file qabstractsocket.cpp.

Referenced by QSocks5SocketEngine::bind().

{
    Q_D(QAbstractSocket);
#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::waitForReadyRead(%i)", msecs);
#endif

    // require calling connectToHost() before waitForReadyRead()
    if (state() == UnconnectedState) {
        /* If all you have is a QIODevice pointer to an abstractsocket, you cannot check
           this, so you cannot avoid this warning. */
//        qWarning("QAbstractSocket::waitForReadyRead() is not allowed in UnconnectedState");
        return false;
    }

    QElapsedTimer stopWatch;
    stopWatch.start();

    // handle a socket in connecting state
    if (state() == HostLookupState || state() == ConnectingState) {
        if (!waitForConnected(msecs))
            return false;
    }

    Q_ASSERT(d->socketEngine);
    do {
        bool readyToRead = false;
        bool readyToWrite = false;
        if (!d->socketEngine->waitForReadOrWrite(&readyToRead, &readyToWrite, true, !d->writeBuffer.isEmpty(),
                                               qt_timeout_value(msecs, stopWatch.elapsed()))) {
            d->socketError = d->socketEngine->error();
            setErrorString(d->socketEngine->errorString());
#if defined (QABSTRACTSOCKET_DEBUG)
            qDebug("QAbstractSocket::waitForReadyRead(%i) failed (%i, %s)",
                   msecs, d->socketError, errorString().toLatin1().constData());
#endif
            emit error(d->socketError);
            if (d->socketError != SocketTimeoutError)
                close();
            return false;
        }

        if (readyToRead) {
            if (d->canReadNotification())
                return true;
        }

        if (readyToWrite)
            d->canWriteNotification();

        if (state() != ConnectedState)
            return false;
    } while (msecs == -1 || qt_timeout_value(msecs, stopWatch.elapsed()) > 0);
    return false;
}

writeData()

qint64 QAbstractSocket::writeData ( const char *  data, qint64  len  )

protectedvirtual

Reimplemented Function

Implements QIODevice.

Reimplemented in QSslSocket.

Definition at line 2357 of file qabstractsocket.cpp.

{
    Q_D(QAbstractSocket);
    if (d->state == QAbstractSocket::UnconnectedState) {
        d->socketError = QAbstractSocket::UnknownSocketError;
        setErrorString(tr("Socket is not connected"));
        return -1;
    }

    if (!d->isBuffered && d->socketType == TcpSocket && d->writeBuffer.isEmpty()) {
        // This code is for the new Unbuffered QTcpSocket use case
        qint64 written = d->socketEngine->write(data, size);
        if (written < 0) {
            d->socketError = d->socketEngine->error();
            setErrorString(d->socketEngine->errorString());
            return written;
        } else if (written < size) {
            // Buffer what was not written yet
            char *ptr = d->writeBuffer.reserve(size - written);
            memcpy(ptr, data + written, size - written);
            if (d->socketEngine)
                d->socketEngine->setWriteNotificationEnabled(true);
        }
        return size; // size=actually written + what has been buffered
    } else if (!d->isBuffered && d->socketType != TcpSocket) {
        // This is for a QUdpSocket that was connect()ed
        qint64 written = d->socketEngine->write(data, size);
        if (written < 0) {
            d->socketError = d->socketEngine->error();
            setErrorString(d->socketEngine->errorString());
        } else if (!d->writeBuffer.isEmpty()) {
            d->socketEngine->setWriteNotificationEnabled(true);
        }

#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::writeData(%p \"%s\", %lli) == %lli", data,
           qt_prettyDebug(data, qMin((int)size, 32), size).data(),
           size, written);
#endif
        if (written >= 0)
            emit bytesWritten(written);
        return written;
    }

    // This is the code path for normal buffered QTcpSocket or
    // unbuffered QTcpSocket when there was already something in the
    // write buffer and therefore we could not do a direct engine write.
    // We just write to our write buffer and enable the write notifier
    // The write notifier then flush()es the buffer.

    char *ptr = d->writeBuffer.reserve(size);
    if (size == 1)
        *ptr = *data;
    else
        memcpy(ptr, data, size);

    qint64 written = size;

    if (d->socketEngine && !d->writeBuffer.isEmpty())
        d->socketEngine->setWriteNotificationEnabled(true);

#if defined (QABSTRACTSOCKET_DEBUG)
    qDebug("QAbstractSocket::writeData(%p \"%s\", %lli) == %lli", data,
           qt_prettyDebug(data, qMin((int)size, 32), size).data(),
           size, written);
#endif
    return written;
}

---

The documentation for this class was generated from the following files:

• /src/network/socket/qabstractsocket.h
• /src/network/socket/qabstractsocket.cpp