how to create variable size buffer in simulink (Embedded Matlab Function)?

Following is the pseudo code i need to create..

function [output]=CircularBuffer(input,receive_status,send_status)

persistent buffer idx

if receive_status==1

buffer(idx,1)=input %%%input is variable sized array for e.g 1x368 or 1x460 

idx=idx+1;

end

output=0

if send_status==1

   output=buffer(1,:)
   buffer=buffer(2:end,:)
   idx=idx-1
end
%%I do not have signal processing toolbox so cannot use in-built library for queue