QLocalSocket¶
The
QLocalSocket
class provides a local socket. More…
Synopsis¶
Functions¶
def
abort
()def
connectToServer
([openMode=QIODevice.ReadWrite])def
connectToServer
(name[, openMode=QIODevice.ReadWrite])def
disconnectFromServer
()def
error
()def
flush
()def
fullServerName
()def
isValid
()def
readBufferSize
()def
serverName
()def
setReadBufferSize
(size)def
setServerName
(name)def
setSocketDescriptor
(socketDescriptor[, socketState=ConnectedState[, openMode=QIODevice.ReadWrite]])def
socketDescriptor
()def
state
()def
waitForConnected
([msecs=30000])def
waitForDisconnected
([msecs=30000])
Signals¶
def
connected
()def
disconnected
()def
error
(socketError)def
errorOccurred
(socketError)def
stateChanged
(socketState)
Detailed Description¶
On Windows this is a named pipe and on Unix this is a local domain socket.
If an error occurs,
error()
returns the type of error, anderrorString()
can be called to get a human readable description of what happened.Although
QLocalSocket
is designed for use with an event loop, it’s possible to use it without one. In that case, you must usewaitForConnected()
,waitForReadyRead()
,waitForBytesWritten()
, andwaitForDisconnected()
which blocks until the operation is complete or the timeout expires.See also
- class PySide2.QtNetwork.QLocalSocket([parent=None])¶
- param parent:
Creates a new local socket. The
parent
argument is passed toQObject
‘s constructor.
- PySide2.QtNetwork.QLocalSocket.LocalSocketError¶
The LocalServerError enumeration represents the errors that can occur. The most recent error can be retrieved through a call to
error()
.Constant
Description
QLocalSocket.ConnectionRefusedError
The connection was refused by the peer (or timed out).
QLocalSocket.PeerClosedError
The remote socket closed the connection. Note that the client socket (i.e., this socket) will be closed after the remote close notification has been sent.
QLocalSocket.ServerNotFoundError
The local socket name was not found.
QLocalSocket.SocketAccessError
The socket operation failed because the application lacked the required privileges.
QLocalSocket.SocketResourceError
The local system ran out of resources (e.g., too many sockets).
QLocalSocket.SocketTimeoutError
The socket operation timed out.
QLocalSocket.DatagramTooLargeError
The datagram was larger than the operating system’s limit (which can be as low as 8192 bytes).
QLocalSocket.ConnectionError
An error occurred with the connection.
QLocalSocket.UnsupportedSocketOperationError
The requested socket operation is not supported by the local operating system.
QLocalSocket.OperationError
An operation was attempted while the socket was in a state that did not permit it.
QLocalSocket.UnknownSocketError
An unidentified error occurred.
- PySide2.QtNetwork.QLocalSocket.LocalSocketState¶
This enum describes the different states in which a socket can be.
Constant
Description
QLocalSocket.UnconnectedState
The socket is not connected.
QLocalSocket.ConnectingState
The socket has started establishing a connection.
QLocalSocket.ConnectedState
A connection is established.
QLocalSocket.ClosingState
The socket is about to close (data may still be waiting to be written).
See also
- PySide2.QtNetwork.QLocalSocket.abort()¶
Aborts the current connection and resets the socket. Unlike
disconnectFromServer()
, this function immediately closes the socket, clearing any pending data in the write buffer.See also
disconnectFromServer()
close()
- PySide2.QtNetwork.QLocalSocket.connectToServer([openMode=QIODevice.ReadWrite])¶
- Parameters:
openMode –
OpenMode
Attempts to make a connection to
serverName()
.setServerName()
must be called before you open the connection. Alternatively you can use (constQString
&name,OpenMode
openMode
);The socket is opened in the given
openMode
and first entersConnectingState
. If a connection is established,QLocalSocket
entersConnectedState
and emitsconnected()
.After calling this function, the socket can emit
errorOccurred()
to signal that an error occurred.See also
- PySide2.QtNetwork.QLocalSocket.connectToServer(name[, openMode=QIODevice.ReadWrite])
- Parameters:
name – str
openMode –
OpenMode
This is an overloaded function.
Set the server
name
and attempts to make a connection to it.The socket is opened in the given
openMode
and first entersConnectingState
. If a connection is established,QLocalSocket
entersConnectedState
and emitsconnected()
.After calling this function, the socket can emit
errorOccurred()
to signal that an error occurred.See also
- PySide2.QtNetwork.QLocalSocket.connected()¶
- PySide2.QtNetwork.QLocalSocket.disconnectFromServer()¶
Attempts to close the socket. If there is pending data waiting to be written,
QLocalSocket
will enterClosingState
and wait until all data has been written. Eventually, it will enterUnconnectedState
and emit the disconnectedFromServer() signal.See also
- PySide2.QtNetwork.QLocalSocket.disconnected()¶
- PySide2.QtNetwork.QLocalSocket.error(socketError)¶
- Parameters:
socketError –
LocalSocketError
Note
This function is deprecated.
- PySide2.QtNetwork.QLocalSocket.error()
- Return type:
Returns the type of error that last occurred.
See also
state()
errorString()
- PySide2.QtNetwork.QLocalSocket.errorOccurred(socketError)¶
- Parameters:
socketError –
LocalSocketError
- PySide2.QtNetwork.QLocalSocket.flush()¶
- Return type:
bool
This function writes as much as possible from the internal write buffer to the socket, without blocking. If any data was written, this function returns
true
; otherwise false is returned.Call this function if you need
QLocalSocket
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, becauseQLocalSocket
will start sending data automatically once control goes back to the event loop. In the absence of an event loop, callwaitForBytesWritten()
instead.See also
write()
waitForBytesWritten()
- PySide2.QtNetwork.QLocalSocket.fullServerName()¶
- Return type:
str
Returns the server path that the socket is connected to.
Note
The return value of this function is platform specific.
See also
- PySide2.QtNetwork.QLocalSocket.isValid()¶
- Return type:
bool
Returns
true
if the socket is valid and ready for use; otherwise returnsfalse
.Note
The socket’s state must be
ConnectedState
before reading and writing can occur.See also
- PySide2.QtNetwork.QLocalSocket.readBufferSize()¶
- Return type:
int
Returns the size of the internal read buffer. This limits the amount of data that the client can receive before you call
read()
orreadAll()
. 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()
- PySide2.QtNetwork.QLocalSocket.serverName()¶
- Return type:
str
Returns the name of the peer as specified by
setServerName()
, or an emptyQString
ifsetServerName()
has not been called orconnectToServer()
failed.
- PySide2.QtNetwork.QLocalSocket.setReadBufferSize(size)¶
- Parameters:
size – int
Sets the size of
QLocalSocket
‘s internal read buffer to besize
bytes.If the buffer size is limited to a certain size,
QLocalSocket
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.
See also
readBufferSize()
read()
- PySide2.QtNetwork.QLocalSocket.setServerName(name)¶
- Parameters:
name – str
Set the
name
of the peer to connect to. On Windows name is the name of a named pipe; on Unix name is the name of a local domain socket.This function must be called when the socket is not connected.
See also
- PySide2.QtNetwork.QLocalSocket.setSocketDescriptor(socketDescriptor[, socketState=ConnectedState[, openMode=QIODevice.ReadWrite]])¶
- Parameters:
socketDescriptor –
qintptr
socketState –
LocalSocketState
openMode –
OpenMode
- Return type:
bool
Initializes
QLocalSocket
with the native socket descriptorsocketDescriptor
. Returnstrue
ifsocketDescriptor
is accepted as a valid socket descriptor; otherwise returnsfalse
. The socket is opened in the mode specified byopenMode
, and enters the socket state specified bysocketState
.Note
It is not possible to initialize two local sockets with the same native socket descriptor.
See also
socketDescriptor()
state()
openMode()
- PySide2.QtNetwork.QLocalSocket.socketDescriptor()¶
- Return type:
qintptr
Returns the native socket descriptor of the
QLocalSocket
object if this is available; otherwise returns -1.The socket descriptor is not available when
QLocalSocket
is inUnconnectedState
. The type of the descriptor depends on the platform:On Windows, the returned value is a Winsock 2 Socket Handle .
With WinRT and on INTEGRITY, the returned value is the
QTcpSocket
socket descriptor and the type is defined bysocketDescriptor
.On all other UNIX-like operating systems, the type is a file descriptor representing a socket.
See also
- PySide2.QtNetwork.QLocalSocket.state()¶
- Return type:
Returns the state of the socket.
See also
- PySide2.QtNetwork.QLocalSocket.stateChanged(socketState)¶
- Parameters:
socketState –
LocalSocketState
- PySide2.QtNetwork.QLocalSocket.waitForConnected([msecs=30000])¶
- Parameters:
msecs – int
- Return type:
bool
Waits until the socket is connected, up to
msecs
milliseconds. If the connection has been established, this function returnstrue
; otherwise it returnsfalse
. In the case where it returnsfalse
, you can callerror()
to determine the cause of the error.The following example waits up to one second for a connection to be established:
socket.connectToServer("market") if (socket.waitForConnected(1000)) print("Connected!")
If
msecs
is -1, this function will not time out.See also
- PySide2.QtNetwork.QLocalSocket.waitForDisconnected([msecs=30000])¶
- Parameters:
msecs – int
- Return type:
bool
Waits until the socket has disconnected, up to
msecs
milliseconds. If the connection was successfully disconnected, this function returnstrue
; otherwise it returnsfalse
(if the operation timed out, if an error occurred, or if thisQLocalSocket
is already disconnected). In the case where it returnsfalse
, you can callerror()
to determine the cause of the error.The following example waits up to one second for a connection to be closed:
socket.disconnectFromServer() if (socket.waitForDisconnected(1000)) print("Disconnected!")
If
msecs
is -1, this function will not time out.See also
disconnectFromServer()
close()
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