Interface

Gio-2.0 ▶ Gio ▶ PollableInputStream ▶ Interface

Interface for implementing PollableInputStream. Contains only the virtual methods that need to be implemented.

interface Interface {
    vfunc_can_poll(): boolean;
    vfunc_create_source(cancellable?: Gio.Cancellable): GLib.Source;
    vfunc_is_readable(): boolean;
    vfunc_read_nonblocking(): [number, Uint8Array<ArrayBufferLike>];
}

Hierarchy (View Summary)

Index

Methods

vfunc_can_poll vfunc_create_source vfunc_is_readable vfunc_read_nonblocking

Methods

  • Checks if stream is actually pollable. Some classes may implement Gio.PollableInputStream but have only certain instances of that class be pollable. If this method returns false, then the behavior of other Gio.PollableInputStream 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.

    Returns boolean

  • Creates a GLib.Source that triggers when stream can be read, or cancellable is triggered or an error occurs. The callback on the source is of the Gio.PollableSourceFunc type.

    As with g_pollable_input_stream_is_readable(), it is possible that the stream may not actually be readable even after the source triggers, so you should use g_pollable_input_stream_read_nonblocking() rather than g_input_stream_read() from the callback.

    The behaviour of this method is undefined if g_pollable_input_stream_can_poll() returns false for stream.

    Parameters

    Returns GLib.Source

  • Checks if stream can be read.

    Note that some stream types may not be able to implement this 100% reliably, and it is possible that a call to g_input_stream_read() after this returns true would still block. To guarantee non-blocking behavior, you should always use g_pollable_input_stream_read_nonblocking(), which will return a Gio.IOErrorEnum.WOULD_BLOCK error rather than blocking.

    The behaviour of this method is undefined if g_pollable_input_stream_can_poll() returns false for stream.

    Returns boolean

  • Attempts to read up to count bytes from stream into buffer, as with g_input_stream_read(). If stream is not currently readable, this will immediately return Gio.IOErrorEnum.WOULD_BLOCK, and you can use g_pollable_input_stream_create_source() to create a GLib.Source that will be triggered when stream is readable.

    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.

    The behaviour of this method is undefined if g_pollable_input_stream_can_poll() returns false for stream.

    Returns [number, Uint8Array<ArrayBufferLike>]