-/* accumulate_input_
- Read (up to #read_block_sz bytes at a time) from #fd (until EOF) into an
- accumulator buffer. For each #delimiter character found in what was just
- read, occasionally remember the preceeding characters.
+/* accumulate_input_
+ Read (up to #read_block_sz bytes at a time, or until EOF) from #fd into
+ an accumulator buffer. For each #delimiter character found in what was
+ just read, occasionally remember the group of preceeding characters.
+ This behavioral logic lives here, rather than being contained in the
+ reservoir module, simply because it was easier to reduce the number of
+ allocations by handling it here.