In an attempt to prepare the Shuffler for use on the database connection in the pgsql module, I delved back into the Shuffler code again. This time I achieved 99.9% comprehension of the code.

The result is a considerable rewrite of the inner loop. The rewrite was necessary because: a. The shuffle-source-management still had memory leaks. b. The size of the buffer writes was arbitrarily large (depending on the input block size). c. The way wrap_callback results were stored resulted in (only) mostly-correct data. d. The data of sources were used ever so briefly *after* getting freed.