Data available for reading in a GIOChannel

["Jonathan Winterflood" <jonathan winterflood gmail com>]

Hi,

I need to read a large amount of data from a GIOChannel (200K, over the internet).

So far, I use the gnet library to create the socket, and then I use the GIOChannel to integrate the read/writing into the program's loop (a GTK application)
 
I use g_io_add_watch(_channel, G_IO_IN, &(_imageDataReadyForReading), this); to register the callback for data reading.
 
How can I determine the number of bytes available for reading, so as not to block on reading the data?

Thanks, 
Jonathan