* - study and optimize block sizes (later)
* - Clean up the different ways diffs are handled in writing and reading
* - Keep a merge-count in the firstpp, and if the block has already been
* merged, reduce it to a larger size even if it could fit in a small one!
* - Keep minimum freespace in the category table, and use that in reduce!
* - study and optimize block sizes (later)
* - Clean up the different ways diffs are handled in writing and reading
* - Keep a merge-count in the firstpp, and if the block has already been
* merged, reduce it to a larger size even if it could fit in a small one!
* - Keep minimum freespace in the category table, and use that in reduce!