How to get information on number of input data samples in C++ OOT

Hello GNURadio Community, 

I am writing a Gnuradio C++ OOT block and need to get the number of complex input data samples fed into my block by the scheduler on each iteration of data delivery. I need to know this information because the relationship between my input and output stream is not as simple as say a one to one I/O as the "sync" block.

In Python, it is easy, I can find the value by doing: numInputs = len(input_items[0]). In the C++ general_work method which I paste below, I have not been able to extract the number of input samples from any of the parameters.

I will appreciate any help provided.

Thank you!

George