Gio.IOStream¶

Subclasses:: Gio.FileIOStream, Gio.SimpleIOStream, Gio.SocketConnection, Gio.TlsConnection

Methods¶

Inherited:: GObject.Object (37)
Structs:: GObject.ObjectClass (5)

class	`splice_finish` (result)
	`clear_pending` ()
	`close` (cancellable)
	`close_async` (io_priority, cancellable, callback, *user_data)
	`close_finish` (result)
	`get_input_stream` ()
	`get_output_stream` ()
	`has_pending` ()
	`is_closed` ()
	`set_pending` ()
	`splice_async` (stream2, flags, io_priority, cancellable, callback, *user_data)

Virtual Methods¶

Inherited:: GObject.Object (7)

	`do_close_async` (io_priority, cancellable, callback, *user_data)
	`do_close_finish` (result)
	`do_close_fn` (cancellable)
	`do_get_input_stream` ()
	`do_get_output_stream` ()

Properties¶

Name	Type	Flags
`closed`	`bool`	r
`input-stream`	`Gio.InputStream`	r
`output-stream`	`Gio.OutputStream`	r

Signals¶

Inherited:: GObject.Object (1)

Fields¶

Inherited:: GObject.Object (1)

Name	Type	Access	Description
parent_instance	`GObject.Object`	r

Class Details¶

class Gio.IOStream(**kwargs)¶

Bases:: GObject.Object
Abstract:: Yes
Structure:: Gio.IOStreamClass

GIOStream represents an object that has both read and write streams. Generally the two streams act as separate input and output streams, but they share some common resources and state. For instance, for seekable streams, both streams may use the same position.

Examples of GIOStream objects are [class`Gio`.SocketConnection], which represents a two-way network connection; and [class`Gio`.FileIOStream], which represents a file handle opened in read-write mode.

To do the actual reading and writing you need to get the substreams with [method`Gio`.IOStream.get_input_stream] and [method`Gio`.IOStream.get_output_stream].

The GIOStream object owns the input and the output streams, not the other way around, so keeping the substreams alive will not keep the GIOStream object alive. If the GIOStream object is freed it will be closed, thus closing the substreams, so even if the substreams stay alive they will always return G_IO_ERROR_CLOSED for all operations.

To close a stream use [method`Gio`.IOStream.close] which will close the common stream object and also the individual substreams. You can also close the substreams themselves. In most cases this only marks the substream as closed, so further I/O on it fails but common state in the GIOStream may still be open. However, some streams may support ‘half-closed’ states where one direction of the stream is actually shut down.

Operations on GIOStream``s cannot be started while another operation on the ``GIOStream or its substreams is in progress. Specifically, an application can read from the [class`Gio`.InputStream] and write to the [class`Gio`.OutputStream] simultaneously (either in separate threads, or as asynchronous operations in the same thread), but an application cannot start any GIOStream operation while there is a GIOStream, GInputStream or GOutputStream operation in progress, and an application can’t start any GInputStream or GOutputStream operation while there is a GIOStream operation in progress.

This is a product of individual stream operations being associated with a given [type`GLib`.MainContext] (the thread-default context at the time the operation was started), rather than entire streams being associated with a single GMainContext.

GIO may run operations on ``GIOStream``s from other (worker) threads, and this may be exposed to application code in the behaviour of wrapper streams, such as [class`Gio`.BufferedInputStream] or [class`Gio`.TlsConnection]. With such wrapper APIs, application code may only run operations on the base (wrapped) stream when the wrapper stream is idle. Note that the semantics of such operations may not be well-defined due to the state the wrapper stream leaves the base stream in (though they are guaranteed not to crash).

New in version 2.22.

classmethod splice_finish(result)[source]¶

Parameters:: result (Gio.AsyncResult) – a Gio.AsyncResult.
Raises:: GLib.Error
Returns:: True on success, False otherwise.
Return type:: bool

Finishes an asynchronous io stream splice operation.

New in version 2.28.

clear_pending()[source]¶: Clears the pending flag on self.

New in version 2.22.

close(cancellable)[source]¶

Parameters:: cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, None to ignore
Raises:: GLib.Error
Returns:: True on success, False on failure
Return type:: bool

Closes the stream, releasing resources related to it. This will also close the individual input and output streams, if they are not already closed.

Once the stream is closed, all other operations will return Gio.IOErrorEnum.CLOSED. Closing a stream multiple times will not return an error.

Closing a stream will automatically flush any outstanding buffers in the stream.

Streams will be automatically closed when the last reference is dropped, but you might want to call this function to make sure resources are released as early as possible.

Some streams might keep the backing store of the stream (e.g. a file descriptor) open after the stream is closed. See the documentation for the individual stream for details.

On failure the first error that happened will be reported, but the close operation will finish as much as possible. A stream that failed to close will still return Gio.IOErrorEnum.CLOSED for all operations. Still, it is important to check and report the error to the user, otherwise there might be a loss of data as all data might not be written.

If cancellable is not None, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error Gio.IOErrorEnum.CANCELLED will be returned. Cancelling a close will still leave the stream closed, but some streams can use a faster close that doesn’t block to e.g. check errors.

The default implementation of this method just calls close on the individual input/output streams.

New in version 2.22.

close_async(io_priority, cancellable, callback, *user_data)[source]¶

Parameters:

io_priority (int) – the io priority of the request
cancellable (Gio.Cancellable or None) – optional cancellable object
callback (Gio.AsyncReadyCallback or None) – a Gio.AsyncReadyCallback to call when the request is satisfied
user_data (object or None) – the data to pass to callback function

Requests an asynchronous close of the stream, releasing resources related to it. When the operation is finished callback will be called. You can then call Gio.IOStream.close_finish() to get the result of the operation.

For behaviour details see Gio.IOStream.close().

The asynchronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

New in version 2.22.

close_finish(result)[source]¶

Parameters:: result (Gio.AsyncResult) – a Gio.AsyncResult
Raises:: GLib.Error
Returns:: True if stream was successfully closed, False otherwise.
Return type:: bool

Closes a stream.

New in version 2.22.

get_input_stream()[source]¶

Returns:: a Gio.InputStream, owned by the Gio.IOStream. Do not free.
Return type:: Gio.InputStream

Gets the input stream for this object. This is used for reading.

New in version 2.22.

get_output_stream()[source]¶

Returns:: a Gio.OutputStream, owned by the Gio.IOStream. Do not free.
Return type:: Gio.OutputStream

Gets the output stream for this object. This is used for writing.

New in version 2.22.

has_pending()[source]¶

Returns:: True if self has pending actions.
Return type:: bool

Checks if a stream has pending actions.

New in version 2.22.

is_closed()[source]¶

Returns:: True if the stream is closed.
Return type:: bool

Checks if a stream is closed.

New in version 2.22.

set_pending()[source]¶

Raises:: GLib.Error
Returns:: True if pending was previously unset and is now set.
Return type:: bool

Sets self to have actions pending. If the pending flag is already set or self is closed, it will return False and set error.

New in version 2.22.

splice_async(stream2, flags, io_priority, cancellable, callback, *user_data)[source]¶

Parameters:

stream2 (Gio.IOStream) – a Gio.IOStream.
flags (Gio.IOStreamSpliceFlags) – a set of Gio.IOStreamSpliceFlags.
io_priority (int) – the io priority of the request.
cancellable (Gio.Cancellable or None) – optional Gio.Cancellable object, None to ignore.
callback (Gio.AsyncReadyCallback or None) – a Gio.AsyncReadyCallback to call when the request is satisfied
user_data (object or None) – the data to pass to callback function

Asynchronously splice the output stream of self to the input stream of stream2, and splice the output stream of stream2 to the input stream of self.

When the operation is finished callback will be called. You can then call Gio.IOStream.splice_finish() to get the result of the operation.

New in version 2.28.

do_close_async(io_priority, cancellable, callback, *user_data) virtual¶

Parameters:

io_priority (int) – the io priority of the request
cancellable (Gio.Cancellable or None) – optional cancellable object
callback (Gio.AsyncReadyCallback or None) – a Gio.AsyncReadyCallback to call when the request is satisfied
user_data (object or None) – the data to pass to callback function

Requests an asynchronous close of the stream, releasing resources related to it. When the operation is finished callback will be called. You can then call Gio.IOStream.close_finish() to get the result of the operation.

For behaviour details see Gio.IOStream.close().

The asynchronous methods have a default fallback that uses threads to implement asynchronicity, so they are optional for inheriting classes. However, if you override one you must override all.

New in version 2.22.

do_close_finish(result) virtual¶

Parameters:: result (Gio.AsyncResult) – a Gio.AsyncResult
Returns:: True if stream was successfully closed, False otherwise.
Return type:: bool

Closes a stream.

New in version 2.22.

do_close_fn(cancellable) virtual¶

Parameters:: cancellable (Gio.Cancellable or None) –
Return type:: bool

do_get_input_stream() virtual¶

Returns:: a Gio.InputStream, owned by the Gio.IOStream. Do not free.
Return type:: Gio.InputStream

Gets the input stream for this object. This is used for reading.

New in version 2.22.

do_get_output_stream() virtual¶

Returns:: a Gio.OutputStream, owned by the Gio.IOStream. Do not free.
Return type:: Gio.OutputStream

Gets the output stream for this object. This is used for writing.

New in version 2.22.

Property Details¶

Gio.IOStream.props.closed¶

Name:: closed
Type:: bool
Default Value:: False
Flags:: READABLE

Whether the stream is closed.

New in version 2.22.

Gio.IOStream.props.input_stream¶

Name:: input-stream
Type:: Gio.InputStream
Default Value:: None
Flags:: READABLE

The [class`Gio`.InputStream] to read from.

New in version 2.22.

Gio.IOStream.props.output_stream¶

Name:: output-stream
Type:: Gio.OutputStream
Default Value:: None
Flags:: READABLE

The [class`Gio`.OutputStream] to write to.

New in version 2.22.