OutputStream.writeAsync

Request an asynchronous write of count bytes from buffer into the stream. When the operation is finished callback will be called. You can then call [gio.output_stream.OutputStream.writeFinish] to get the result of the operation.

During an async request no other sync and async calls are allowed, and will result in [gio.types.IOErrorEnum.Pending] errors.

A value of count larger than G_MAXSSIZE will cause a [gio.types.IOErrorEnum.InvalidArgument] error.

On success, the number of bytes written will be passed to the callback. It is not an error if this is not the same as the requested size, as it can happen e.g. on a partial I/O error, but generally we try to write as many bytes as requested.

You are guaranteed that this method will never fail with [gio.types.IOErrorEnum.WouldBlock] - if stream can't accept more data, the method will just wait until this changes.

Any outstanding I/O request with higher priority (lower numerical value) will be executed before an outstanding request with lower priority. Default priority is [glib.types.PRIORITY_DEFAULT].

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.

For the synchronous, blocking version of this function, see [gio.output_stream.OutputStream.write].

Note that no copy of buffer will be made, so it must stay valid until callback is called. See [gio.output_stream.OutputStream.writeBytesAsync] for a #GBytes version that will automatically hold a reference to the contents (without copying) for the duration of the call.