Re: Commit cache to speed up rev-list and merge

> In Linus' Linux kernel tree there are currently about 323,178 commits.
> If we store just the pre-parsed commit time as an int32 field this is
> an additional 1.2 MiB of data in the pack-*.idx file, assuming we can
> use additional data like pack offset position to correlate commit to
> the parsed int. If we stored parent pointers in a similar way you
> probably need at least 3.6 MiB of additional disk space on the index.
> For example, use 12 bytes for each commit to store enough of the
> parsed commit time to sort commits, and up to 2 parent pointers per
> commit.... with a reserved magic value for octopus merges to mean the
> commit itself has to be parsed to get the graph structure correct.