Interface
GioPollableOutputStream
since: 2.28
Description
interface Gio.PollableOutputStream : Gio.OutputStream
GPollableOutputStream is implemented by GOutputStreams that
can be polled for readiness to write. This can be used when
interfacing with a non-GIO API that expects
UNIX-file-descriptor-style asynchronous I/O rather than GIO-style.
Some classes may implement GPollableOutputStream but have only certain
instances of that class be pollable. If g_pollable_output_stream_can_poll()
returns false, then the behavior of other GPollableOutputStream methods is undefined.
Available since: 2.28
Prerequisite
In order to implement PollableOutputStream, your type must inherit fromGOutputStream.
Instance methods
g_pollable_output_stream_can_poll
Checks if stream is actually pollable. Some classes may implement
GPollableOutputStream but have only certain instances of that
class be pollable. If this method returns FALSE, then the behavior
of other GPollableOutputStream methods is undefined.
since: 2.28
g_pollable_output_stream_create_source
Creates a GSource that triggers when stream can be written, or
cancellable is triggered or an error occurs. The callback on the
source is of the GPollableSourceFunc type.
since: 2.28
g_pollable_output_stream_write_nonblocking
Attempts to write up to count bytes from buffer to stream, as
with g_output_stream_write(). If stream is not currently writable,
this will immediately return G_IO_ERROR_WOULD_BLOCK, and you can
use g_pollable_output_stream_create_source() to create a GSource
that will be triggered when stream is writable.
since: 2.0
g_pollable_output_stream_writev_nonblocking
Attempts to write the bytes contained in the n_vectors vectors to stream,
as with g_output_stream_writev(). If stream is not currently writable,
this will immediately return %G_POLLABLE_RETURN_WOULD_BLOCK, and you can
use g_pollable_output_stream_create_source() to create a GSource
that will be triggered when stream is writable. error will not be
set in that case.
since: 2.60
Interface structure
struct GioPollableOutputStreamInterface {
GTypeInterface g_iface;
gboolean (* can_poll) (
GPollableOutputStream* stream
);
gboolean (* is_writable) (
GPollableOutputStream* stream
);
GSource* (* create_source) (
GPollableOutputStream* stream,
GCancellable* cancellable
);
gssize (* write_nonblocking) (
GPollableOutputStream* stream,
void* buffer,
gsize count,
GError** error
);
GPollableReturn (* writev_nonblocking) (
GPollableOutputStream* stream,
const GOutputVector* vectors,
gsize n_vectors,
gsize* bytes_written,
GError** error
);
}
The interface for pollable output streams.
The default implementation of can_poll always returns TRUE.
The default implementation of write_nonblocking calls
g_pollable_output_stream_is_writable(), and then calls
g_output_stream_write() if it returns TRUE. This means you only
need to override it if it is possible that your is_writable
implementation may return TRUE when the stream is not actually writable.
The default implementation of writev_nonblocking calls
g_pollable_output_stream_write_nonblocking() for each vector, and converts
its return value and error (if set) to a GPollableReturn. You should
override this where possible to avoid having to allocate a GError to return
G_IO_ERROR_WOULD_BLOCK.
Interface members
g_iface |
|
The parent interface. |
|
can_poll |
|
| No description available. | |
is_writable |
|
| No description available. | |
create_source |
|
| No description available. | |
write_nonblocking |
|
| No description available. | |
writev_nonblocking |
|
| No description available. |
Virtual methods
Gio.PollableOutputStream.can_poll
Checks if stream is actually pollable. Some classes may implement
GPollableOutputStream but have only certain instances of that
class be pollable. If this method returns FALSE, then the behavior
of other GPollableOutputStream methods is undefined.
since: 2.28
Gio.PollableOutputStream.create_source
Creates a GSource that triggers when stream can be written, or
cancellable is triggered or an error occurs. The callback on the
source is of the GPollableSourceFunc type.
since: 2.28
Gio.PollableOutputStream.write_nonblocking
Attempts to write up to count bytes from buffer to stream, as
with g_output_stream_write(). If stream is not currently writable,
this will immediately return G_IO_ERROR_WOULD_BLOCK, and you can
use g_pollable_output_stream_create_source() to create a GSource
that will be triggered when stream is writable.
since: 2.0
Gio.PollableOutputStream.writev_nonblocking
Attempts to write the bytes contained in the n_vectors vectors to stream,
as with g_output_stream_writev(). If stream is not currently writable,
this will immediately return %G_POLLABLE_RETURN_WOULD_BLOCK, and you can
use g_pollable_output_stream_create_source() to create a GSource
that will be triggered when stream is writable. error will not be
set in that case.
since: 2.60