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 | Short Description |
---|---|---|---|
closed |
bool |
r | Is the stream closed |
input-stream |
Gio.InputStream |
r | The Gio.InputStream to read from |
output-stream |
Gio.OutputStream |
r | The Gio.OutputStream to write to |
Signals¶
Inherited: | GObject.Object (1) |
---|
Class Details¶
-
class
Gio.
IOStream
(**kwargs)¶ Bases: GObject.Object
Abstract: Yes Structure: Gio.IOStreamClass
Gio.IOStream
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
Gio.IOStream
objects areGio.SocketConnection
, which represents a two-way network connection; andGio.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
Gio.IOStream.get_input_stream
() andGio.IOStream.get_output_stream
().The
Gio.IOStream
object owns the input and the output streams, not the other way around, so keeping the substreams alive will not keep theGio.IOStream
object alive. If theGio.IOStream
object is freed it will be closed, thus closing the substreams, so even if the substreams stay alive they will always returnGio.IOErrorEnum.CLOSED
for all operations.To close a stream use
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 theGio.IOStream
may still be open. However, some streams may support “half-closed” states where one direction of the stream is actually shut down.Operations on
Gio.IOStreams
cannot be started while another operation on theGio.IOStream
or its substreams is in progress. Specifically, an application can read from theGio.InputStream
and write to theGio.OutputStream
simultaneously (either in separate threads, or as asynchronous operations in the same thread), but an application cannot start anyGio.IOStream
operation while there is aGio.IOStream
,Gio.InputStream
orGio.OutputStream
operation in progress, and an application can’t start anyGio.InputStream
orGio.OutputStream
operation while there is aGio.IOStream
operation in progress.This is a product of individual stream operations being associated with a given
GLib.MainContext
(the thread-default context at the time the operation was started), rather than entire streams being associated with a singleGLib.MainContext
.GIO may run operations on
Gio.IOStreams
from other (worker) threads, and this may be exposed to application code in the behaviour of wrapper streams, such asGio.BufferedInputStream
orGio.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
) – aGio.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.
-
close
(cancellable)[source]¶ Parameters: cancellable ( Gio.Cancellable
orNone
) – optionalGio.Cancellable
object,None
to ignoreRaises: GLib.Error
Returns: True
on success,False
on failureReturn 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 errorGio.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
orNone
) – optional cancellable object - callback (
Gio.AsyncReadyCallback
orNone
) – callback to call when the request is satisfied - user_data (
object
orNone
) – 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.
- io_priority (
-
close_finish
(result)[source]¶ Parameters: result ( Gio.AsyncResult
) – aGio.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 theGio.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 theGio.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
) – aGio.IOStream
. - flags (
Gio.IOStreamSpliceFlags
) – a set ofGio.IOStreamSpliceFlags
. - io_priority (
int
) – the io priority of the request. - cancellable (
Gio.Cancellable
orNone
) – optionalGio.Cancellable
object,None
to ignore. - callback (
Gio.AsyncReadyCallback
orNone
) – aGio.AsyncReadyCallback
. - user_data (
object
orNone
) – user data passed to callback.
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.
- stream2 (
-
do_close_async
(io_priority, cancellable, callback, *user_data) virtual¶ Parameters: - io_priority (
int
) – the io priority of the request - cancellable (
Gio.Cancellable
orNone
) – optional cancellable object - callback (
Gio.AsyncReadyCallback
orNone
) – callback to call when the request is satisfied - user_data (
object
orNone
) – 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.
- io_priority (
-
do_close_finish
(result) virtual¶ Parameters: result ( Gio.AsyncResult
) – aGio.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
orNone
) –Return type: bool
-
do_get_input_stream
() virtual¶ Returns: a Gio.InputStream
, owned by theGio.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 theGio.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.
-
classmethod
Property Details¶
-
Gio.IOStream.props.
closed
¶ Name: closed
Type: bool
Default Value: False
Flags: READABLE
Is the stream closed
-
Gio.IOStream.props.
input_stream
¶ Name: input-stream
Type: Gio.InputStream
Default Value: None
Flags: READABLE
The
Gio.InputStream
to read from
-
Gio.IOStream.props.
output_stream
¶ Name: output-stream
Type: Gio.OutputStream
Default Value: None
Flags: READABLE
The
Gio.OutputStream
to write to