class: GPollableOutputStream

[19:7] extends: object

GPollableOutputStream is implemented by [class@Gio.OutputStream]s 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 [method@Gio.PollableOutputStream.can_poll] returns false, then the behavior of other GPollableOutputStream methods is undefined.

Members

handleObj
lib
retainedCallbacks
signalHandlerNames
signalSetterHandlers

Methods

GPollableOutputStream (Handle = null)

Creates a new PollableOutputStream by wrapping a native handle or another wrapper.
- @p Handle is the native handle or another wrapper whose handle to adopt.
toNativeHandle (Source)

Normalizes a constructor argument into a raw pointer carrier. Accepts a raw NativeHandle, a raw NativeBuffer returned from fn.call(...), another generated wrapper exposing handle(), or null. Returns null when the argument carries no pointer.
- @p Source is the raw handle, raw buffer, wrapper, or null.
- @r A raw pointer carrier or null when no pointer is present.
getLib ()

Returns the opened native library for this generated wrapper.
- @r The opened native library.
handle ()

Returns the wrapped NativeHandle.
- @r The wrapped NativeHandle.
isNull ()

Returns true when the wrapped handle is null.
- @r A bool.
describe ()

Returns a small string for debugging generated wrappers.
- @r A string.
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. For any given stream, the value returned by this method is constant; a stream cannot switch from pollable to non-pollable or vice versa.
- @r %TRUE if @stream is pollable, %FALSE if not..
create_source (object cancellable)

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. As with g_pollable_output_stream_is_writable(), it is possible that the stream may not actually be writable even after the source triggers, so you should use g_pollable_output_stream_write_nonblocking() rather than g_output_stream_write() from the callback. The behaviour of this method is undefined if g_pollable_output_stream_can_poll() returns %FALSE for
- @stream. ``
- @p cancellable is a #GCancellable, or %NULL.
- @r a new #GSource.
is_writable ()

Checks if @stream can be written. Note that some stream types may not be able to implement this 100% reliably, and it is possible that a call to g_output_stream_write() after this returns %TRUE would still block. To guarantee non-blocking behavior, you should always use g_pollable_output_stream_write_nonblocking(), which will return a %G_IO_ERROR_WOULD_BLOCK error rather than blocking. The behaviour of this method is undefined if g_pollable_output_stream_can_poll() returns %FALSE for @stream.
- @r %TRUE if @stream is writable, %FALSE if not. If an error has occurred on @stream, this will result in g_pollable_output_stream_is_writable() returning %TRUE, and the next attempt to write will return the error..
write_nonblocking (list buffer, object cancellable)

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. Note that since this method never blocks, you cannot actually use @cancellable to cancel it. However, it will return an error if @cancellable has already been cancelled when you call, which may happen if you call this method after a source triggers due to having been cancelled. Also note that if %G_IO_ERROR_WOULD_BLOCK is returned some underlying transports like D/TLS require that you re-send the same @buffer and @count in the next write call. The behaviour of this method is undefined if g_pollable_output_stream_can_poll() returns %FALSE for @stream.
- @p buffer is a buffer to write data from.
- @p count is the number of bytes you want to write.
- @p cancellable is a #GCancellable, or %NULL.
- @r the number of bytes written, or -1 on error (including %G_IO_ERROR_WOULD_BLOCK)..
writev_nonblocking (list vectors, object cancellable)

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. Note that since this method never blocks, you cannot actually use @cancellable to cancel it. However, it will return an error if @cancellable has already been cancelled when you call, which may happen if you call this method after a source triggers due to having been cancelled. Also note that if %G_POLLABLE_RETURN_WOULD_BLOCK is returned some underlying transports like D/TLS require that you re-send the same
- @vectors and @n_vectors in the next write call. The behaviour of this method is undefined if g_pollable_output_stream_can_poll() returns %FALSE for @stream.
- @p vectors is the buffer containing the #GOutputVectors to write..
- @p n_vectors is the number of vectors to write.
- @p bytes_written is location to store the number of bytes that were written to the stream.
- @p cancellable is a #GCancellable, or %NULL.
- @r %@G_POLLABLE_RETURN_OK on success, %G_POLLABLE_RETURN_WOULD_BLOCK if the stream is not currently writable (and @error is not set), or %G_POLLABLE_RETURN_FAILED if there was an error in which case @error will be set..