SocketControlMessage

Added in version 2.22.

class SocketControlMessage(**properties: Any)

Superclasses: Object

Subclasses: UnixCredentialsMessage, UnixFDMessage

A GSocketControlMessage is a special-purpose utility message that can be sent to or received from a Socket. These types of messages are often called ‘ancillary data’.

The message can represent some sort of special instruction to or information from the socket or can represent a special kind of transfer to the peer (for example, sending a file descriptor over a UNIX socket).

These messages are sent with send_message and received with receive_message.

To extend the set of control message that can be sent, subclass this class and override the get_size, get_level, get_type and serialize methods.

To extend the set of control messages that can be received, subclass this class and implement the deserialize method. Also, make sure your class is registered with the Type type system before calling receive_message to read such a message.

Methods

class SocketControlMessage

deserialize(level: int, type: int, data: Sequence[int]) → SocketControlMessage | None

Tries to deserialize a socket control message of a given level and type. This will ask all known (to GType) subclasses of SocketControlMessage if they can understand this kind of message and if so deserialize it into a SocketControlMessage.

If there is no implementation for this kind of control message, None will be returned.

Added in version 2.22.

Parameters:

• level – a socket level

• type – a socket control message type for the given level

• data – pointer to the message data

get_level() → int

Returns the “level” (i.e. the originating protocol) of the control message. This is often SOL_SOCKET.

Added in version 2.22.

get_msg_type() → int

Returns the protocol specific type of the control message. For instance, for UNIX fd passing this would be SCM_RIGHTS.

Added in version 2.22.

get_size() → int

Returns the space required for the control message, not including headers or alignment.

Added in version 2.22.

serialize(data: None) → None

Converts the data in the message to bytes placed in the message.

data is guaranteed to have enough space to fit the size returned by get_size() on this object.

Added in version 2.22.

Parameters:

data – A buffer to write data to

Virtual Methods

class SocketControlMessage

do_get_level() → int

Returns the “level” (i.e. the originating protocol) of the control message. This is often SOL_SOCKET.

Added in version 2.22.

do_get_size() → int

Returns the space required for the control message, not including headers or alignment.

Added in version 2.22.

do_get_type() → int

do_serialize(data: None) → None

Converts the data in the message to bytes placed in the message.

data is guaranteed to have enough space to fit the size returned by get_size() on this object.

Added in version 2.22.

Parameters:

data – A buffer to write data to

Fields

class SocketControlMessage

parent_instance

priv