The read callback is triggered when new data arrives in the input
buffer and the amount of readable data exceed the low watermark
which is 0 by default.
The write callback is triggered if the write buffer has been
exhausted or fell below its low watermark.
@param bev the bufferevent that triggered the callback
@param ctx the user-specified context for this bufferevent
A read or write callback for a bufferevent.
The read callback is triggered when new data arrives in the input buffer and the amount of readable data exceed the low watermark which is 0 by default.
The write callback is triggered if the write buffer has been exhausted or fell below its low watermark.
@param bev the bufferevent that triggered the callback @param ctx the user-specified context for this bufferevent