[[!comment format=mdwn
 username="joey"
 subject="""comment 5"""
 date="2020-07-01T18:36:17Z"
 content="""
Tried implementing avoiding the redundant location log lookups in the
second pass of --all. But, a Set holding 100000 keys uses 60 mb of memory
(mostly for the tree, not the elements). If it has to convert back to a
bloom filter, add 32 mb memory more, and this is looking too memory hungry.

The Set could be converted at a smaller size than 100000, eg 50000 keys
needs 25mb. But git-annex sync --content --all with 50000 keys takes
7 minutes w/o this optimisation, so it would probably only save a few
minutes. So, abandoning this approach for now.

([[!commit 7e2c4ed21622a4fefab58e709528a14866e0d133]] has a nice data
type I built that starts off a Set and converts to a Bloom filter.)
"""]]
