This program is used as the primary L3 farm process.
It is a standard JANA program, but has the ability
to reconstitute single events based only on the
low-level objects in memory. The code for this is
contained mainly in JEventProcessor_L3proc. This
is done in a way that allows the reconstitution to
be done multi-threaded. This involves using a buffer
pool for the EVIO events. The buffer pool itself is
maintained by the L3farm_out class. This class keeps
track of buffers of events so it can stack them up
into single EVIO blocks for writing. This should mainly
benefit the online environment where writing many events
into a single ET event improves efficiency.