/**
* g_pollable_input_stream_can_poll:
* @stream: a #GPollableInputStream.
*
* Checks if @stream is actually pollable. Some classes may implement
* #GPollableInputStream but have only certain instances of that class
* be pollable. If this method returns %FALSE, then the behavior of
* other #GPollableInputStream 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: %TRUE if @stream is pollable, %FALSE if not.
*
* Since: 2.28
*/
gboolean
g_pollable_input_stream_can_poll (GPollableInputStream *stream)
{
g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (stream), FALSE);
return G_POLLABLE_INPUT_STREAM_GET_INTERFACE (stream)->can_poll (stream);
}
/**
* g_pollable_input_stream_create_source:
* @stream: a #GPollableInputStream.
* @cancellable: (allow-none): a #GCancellable, or %NULL
*
* Creates a #GSource that triggers when @stream can be read, or
* @cancellable is triggered or an error occurs. The callback on the
* source is of the #GPollableSourceFunc 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.
*
* Returns: (transfer full): a new #GSource
*
* Since: 2.28
*/
GSource *
g_pollable_input_stream_create_source (GPollableInputStream *stream,
GCancellable *cancellable)
{
g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (stream), NULL);
return G_POLLABLE_INPUT_STREAM_GET_INTERFACE (stream)->
create_source (stream, cancellable);
}
/**
* g_pollable_input_stream_read_nonblocking:
* @stream: a #GPollableInputStream
* @buffer: a buffer to read data into (which should be at least @size
* bytes long).
* @size: the number of bytes you want to read
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @error: #GError for error reporting, or %NULL to ignore.
*
* Attempts to read up to @size bytes from @stream into @buffer, as
* with g_input_stream_read(). If @stream is not currently readable,
* this will immediately return %G_IO_ERROR_WOULD_BLOCK, and you can
* use g_pollable_input_stream_create_source() to create a #GSource
* 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.
*
* Virtual: read_nonblocking
* Return value: the number of bytes read, or -1 on error (including
* %G_IO_ERROR_WOULD_BLOCK).
*/
gssize
g_pollable_input_stream_read_nonblocking (GPollableInputStream *stream,
void *buffer,
gsize size,
GCancellable *cancellable,
GError **error)
{
g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (stream), -1);
if (g_cancellable_set_error_if_cancelled (cancellable, error))
return -1;
return G_POLLABLE_INPUT_STREAM_GET_INTERFACE (stream)->
read_nonblocking (stream, buffer, size, error);
}
/**
* g_pollable_input_stream_read_nonblocking:
* @stream: a #GPollableInputStream
* @buffer: a buffer to read data into (which should be at least @count
* bytes long).
* @count: the number of bytes you want to read
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @error: #GError for error reporting, or %NULL to ignore.
*
* 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 %G_IO_ERROR_WOULD_BLOCK, and you can
* use g_pollable_input_stream_create_source() to create a #GSource
* 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.
*
* Virtual: read_nonblocking
* Returns: the number of bytes read, or -1 on error (including
* %G_IO_ERROR_WOULD_BLOCK).
*/
gssize
g_pollable_input_stream_read_nonblocking (GPollableInputStream *stream,
void *buffer,
gsize count,
GCancellable *cancellable,
GError **error)
{
gssize res;
g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (stream), -1);
g_return_val_if_fail (buffer != NULL, 0);
if (g_cancellable_set_error_if_cancelled (cancellable, error))
return -1;
if (count == 0)
return 0;
if (((gssize) count) < 0)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
_("Too large count value passed to %s"), G_STRFUNC);
return -1;
}
if (cancellable)
g_cancellable_push_current (cancellable);
res = G_POLLABLE_INPUT_STREAM_GET_INTERFACE (stream)->
read_nonblocking (stream, buffer, count, error);
if (cancellable)
g_cancellable_pop_current (cancellable);
return res;
}
