:right-sidebar: True IOStream =================================================================== .. currentmodule:: gi.repository.Gio .. versionadded:: 2.22 .. class:: IOStream(**properties: ~typing.Any) :no-contents-entry: Superclasses: :class:`~gi.repository.GObject.Object` Subclasses: :class:`~gi.repository.Gio.FileIOStream`, :class:`~gi.repository.Gio.SimpleIOStream`, :class:`~gi.repository.Gio.SocketConnection`, :class:`~gi.repository.Gio.TlsConnection` ``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 :obj:`~gi.repository.Gio.SocketConnection`\, which represents a two-way network connection; and :obj:`~gi.repository.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 :obj:`~gi.repository.Gio.IOStream.get_input_stream` and :obj:`~gi.repository.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 :obj:`~gi.repository.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 :obj:`~gi.repository.Gio.InputStream` and write to the :obj:`~gi.repository.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 :obj:`~gi.repository.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 :obj:`~gi.repository.Gio.BufferedInputStream` or :obj:`~gi.repository.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). Methods ------- .. rst-class:: interim-class .. class:: IOStream :no-index: .. method:: clear_pending() -> None Clears the pending flag on ``stream``\. .. versionadded:: 2.22 .. method:: close(cancellable: ~gi.repository.Gio.Cancellable | None = None) -> 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 :const:`~gi.repository.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 :const:`~gi.repository.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 NULL, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error :const:`~gi.repository.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. .. versionadded:: 2.22 :param cancellable: optional :obj:`~gi.repository.Gio.Cancellable` object, :const:`None` to ignore .. method:: close_async(io_priority: int, cancellable: ~gi.repository.Gio.Cancellable | None = None, callback: ~typing.Callable[[~gi.repository.GObject.Object | None, ~gi.repository.Gio.AsyncResult, ~typing.Any], None] | None = None, user_data: ~typing.Any = None) -> None 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 :func:`~gi.repository.Gio.IOStream.close_finish` to get the result of the operation. For behaviour details see :func:`~gi.repository.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. .. versionadded:: 2.22 :param io_priority: the io priority of the request :param cancellable: optional cancellable object :param callback: a :obj:`~gi.repository.Gio.AsyncReadyCallback` to call when the request is satisfied :param user_data: the data to pass to callback function .. method:: close_finish(result: ~gi.repository.Gio.AsyncResult) -> bool Closes a stream. .. versionadded:: 2.22 :param result: a :obj:`~gi.repository.Gio.AsyncResult` .. method:: do_close_async(self, io_priority: int, cancellable: ~gi.repository.Gio.Cancellable | None = None, callback: ~typing.Callable[[~gi.repository.GObject.Object | None, ~gi.repository.Gio.AsyncResult, ~typing.Any], None] | None = None, user_data: ~typing.Any = None) -> None :param io_priority: :param cancellable: :param callback: :param user_data: .. method:: do_close_finish(self, result: ~gi.repository.Gio.AsyncResult) -> bool :param result: .. method:: do_close_fn(self, cancellable: ~gi.repository.Gio.Cancellable | None = None) -> bool :param cancellable: .. method:: do_get_input_stream(self) -> ~gi.repository.Gio.InputStream .. method:: do_get_output_stream(self) -> ~gi.repository.Gio.OutputStream .. method:: get_input_stream() -> ~gi.repository.Gio.InputStream Gets the input stream for this object. This is used for reading. .. versionadded:: 2.22 .. method:: get_output_stream() -> ~gi.repository.Gio.OutputStream Gets the output stream for this object. This is used for writing. .. versionadded:: 2.22 .. method:: has_pending() -> bool Checks if a stream has pending actions. .. versionadded:: 2.22 .. method:: is_closed() -> bool Checks if a stream is closed. .. versionadded:: 2.22 .. method:: set_pending() -> bool Sets ``stream`` to have actions pending. If the pending flag is already set or ``stream`` is closed, it will return :const:`False` and set ``error``\. .. versionadded:: 2.22 .. method:: splice_async(stream2: ~gi.repository.Gio.IOStream, flags: ~gi.repository.Gio.IOStreamSpliceFlags, io_priority: int, cancellable: ~gi.repository.Gio.Cancellable | None = None, callback: ~typing.Callable[[~gi.repository.GObject.Object | None, ~gi.repository.Gio.AsyncResult, ~typing.Any], None] | None = None, user_data: ~typing.Any = None) -> None Asynchronously splice the output stream of ``stream1`` to the input stream of ``stream2``\, and splice the output stream of ``stream2`` to the input stream of ``stream1``\. When the operation is finished ``callback`` will be called. You can then call :func:`~gi.repository.Gio.IOStream.splice_finish` to get the result of the operation. .. versionadded:: 2.28 :param stream2: a :obj:`~gi.repository.Gio.IOStream`\. :param flags: a set of :obj:`~gi.repository.Gio.IOStreamSpliceFlags`\. :param io_priority: the io priority of the request. :param cancellable: optional :obj:`~gi.repository.Gio.Cancellable` object, :const:`None` to ignore. :param callback: a :obj:`~gi.repository.Gio.AsyncReadyCallback` to call when the request is satisfied :param user_data: the data to pass to callback function .. classmethod:: splice_finish() -> bool Finishes an asynchronous io stream splice operation. .. versionadded:: 2.28 Properties ---------- .. rst-class:: interim-class .. class:: IOStream :no-index: .. attribute:: props.closed :type: bool The type of the None singleton. .. versionadded:: 2.22 .. attribute:: props.input_stream :type: ~gi.repository.Gio.InputStream The type of the None singleton. .. versionadded:: 2.22 .. attribute:: props.output_stream :type: ~gi.repository.Gio.OutputStream The type of the None singleton. .. versionadded:: 2.22 Virtual Methods --------------- .. rst-class:: interim-class .. class:: IOStream :no-index: .. method:: do_close_async(io_priority: int, cancellable: ~gi.repository.Gio.Cancellable | None = None, callback: ~typing.Callable[[~gi.repository.GObject.Object | None, ~gi.repository.Gio.AsyncResult, ~typing.Any], None] | None = None, user_data: ~typing.Any = None) -> None 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 :func:`~gi.repository.Gio.IOStream.close_finish` to get the result of the operation. For behaviour details see :func:`~gi.repository.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. .. versionadded:: 2.22 :param io_priority: the io priority of the request :param cancellable: optional cancellable object :param callback: a :obj:`~gi.repository.Gio.AsyncReadyCallback` to call when the request is satisfied :param user_data: the data to pass to callback function .. method:: do_close_finish(result: ~gi.repository.Gio.AsyncResult) -> bool Closes a stream. .. versionadded:: 2.22 :param result: a :obj:`~gi.repository.Gio.AsyncResult` .. method:: do_close_fn(cancellable: ~gi.repository.Gio.Cancellable | None = None) -> bool The type of the None singleton. :param cancellable: .. method:: do_get_input_stream() -> ~gi.repository.Gio.InputStream Gets the input stream for this object. This is used for reading. .. versionadded:: 2.22 .. method:: do_get_output_stream() -> ~gi.repository.Gio.OutputStream Gets the output stream for this object. This is used for writing. .. versionadded:: 2.22 Fields ------ .. rst-class:: interim-class .. class:: IOStream :no-index: .. attribute:: parent_instance .. attribute:: priv