Class
GioIOStream
since: 2.22
Description
abstract class Gio.IOStream : GObject.Object
{
/* No available fields */
}
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 GSocketConnection
, which represents
a two-way network connection; and GFileIOStream
, which represents a
file handle opened in read-write mode.
To do the actual reading and writing you need to get the substreams
with g_io_stream_get_input_stream()
and g_io_stream_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 g_io_stream_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 GIOStreams
cannot be started while another operation on the
GIOStream
or its substreams is in progress. Specifically, an application can
read from the GInputStream
and write to the GOutputStream
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 GMainContext
(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 GIOStreams
from other (worker) threads, and this
may be exposed to application code in the behaviour of wrapper streams, such
as GBufferedInputStream
or GTlsConnection
. 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).
Available since: 2.22
Instance methods
g_io_stream_close
Closes the stream, releasing resources related to it. This will also close the individual input and output streams, if they are not already closed.
since: 2.22
g_io_stream_close_async
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 g_io_stream_close_finish()
to get
the result of the operation.
since: 2.22
g_io_stream_get_input_stream
Gets the input stream for this object. This is used for reading.
since: 2.22
g_io_stream_get_output_stream
Gets the output stream for this object. This is used for writing.
since: 2.22
g_io_stream_set_pending
Sets stream
to have actions pending. If the pending flag is
already set or stream
is closed, it will return FALSE
and set
error
.
since: 2.22
g_io_stream_splice_async
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
.
since: 2.28
Signals
Signals inherited from GObject (1)
GObject::notify
The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.
Class structure
struct GioIOStreamClass {
GObjectClass parent_class;
GInputStream* (* get_input_stream) (
GIOStream* stream
);
GOutputStream* (* get_output_stream) (
GIOStream* stream
);
gboolean (* close_fn) (
GIOStream* stream,
GCancellable* cancellable,
GError** error
);
void (* close_async) (
GIOStream* stream,
int io_priority,
GCancellable* cancellable,
GAsyncReadyCallback callback,
gpointer user_data
);
gboolean (* close_finish) (
GIOStream* stream,
GAsyncResult* result,
GError** error
);
void (* _g_reserved1) (
void
);
void (* _g_reserved2) (
void
);
void (* _g_reserved3) (
void
);
void (* _g_reserved4) (
void
);
void (* _g_reserved5) (
void
);
void (* _g_reserved6) (
void
);
void (* _g_reserved7) (
void
);
void (* _g_reserved8) (
void
);
void (* _g_reserved9) (
void
);
void (* _g_reserved10) (
void
);
}
Class members
parent_class: GObjectClass
- No description available.
get_input_stream: GInputStream* (* get_input_stream) ( GIOStream* stream )
- No description available.
get_output_stream: GOutputStream* (* get_output_stream) ( GIOStream* stream )
- No description available.
close_fn: gboolean (* close_fn) ( GIOStream* stream, GCancellable* cancellable, GError** error )
- No description available.
close_async: void (* close_async) ( GIOStream* stream, int io_priority, GCancellable* cancellable, GAsyncReadyCallback callback, gpointer user_data )
- No description available.
close_finish: gboolean (* close_finish) ( GIOStream* stream, GAsyncResult* result, GError** error )
- No description available.
_g_reserved1: void (* _g_reserved1) ( void )
- No description available.
_g_reserved2: void (* _g_reserved2) ( void )
- No description available.
_g_reserved3: void (* _g_reserved3) ( void )
- No description available.
_g_reserved4: void (* _g_reserved4) ( void )
- No description available.
_g_reserved5: void (* _g_reserved5) ( void )
- No description available.
_g_reserved6: void (* _g_reserved6) ( void )
- No description available.
_g_reserved7: void (* _g_reserved7) ( void )
- No description available.
_g_reserved8: void (* _g_reserved8) ( void )
- No description available.
_g_reserved9: void (* _g_reserved9) ( void )
- No description available.
_g_reserved10: void (* _g_reserved10) ( void )
- No description available.
Virtual methods
Gio.IOStreamClass.close_async
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 g_io_stream_close_finish()
to get
the result of the operation.
since: 2.22
Gio.IOStreamClass.get_input_stream
Gets the input stream for this object. This is used for reading.
since: 2.22
Gio.IOStreamClass.get_output_stream
Gets the output stream for this object. This is used for writing.
since: 2.22