Circular Buffer Mode for CommandableFragmentGenerator
The trigger BoardReader at protoDUNE reads out data continuously, and they want to have a 10-second window of data from the trigger system for each trigger issued. The current implementation of CFG stops reading out data when the buffer is full, which is undesirable for this usage.
I have implemented a FHiCL parameter, circular_buffer_mode, which instructs CFG to treat the data buffer as a circular buffer, dropping old data and continuing to collect new when the buffer is full. I have also implemented a test in CommandableFragmentGenerator_t.