[MERGE] Review feedback on hash trie inventories, and describe radix tree inventories, plus some details on hash trie implementation.

[Vincent Ladeuil]

>>>>> "robert" == Robert Collins <robertc at robertcollins.net> writes:

    robert> Meta-note, I have had no bb:COMMAND message for this patch, so its
    robert> outstanding.

I voted tweak (mostly to ask that your explanations get included)
but it seems BB didn't see it...

    robert> On Thu, 2008-08-28 at 11:29 -0500, John Arbash Meinel wrote:

<snip/>

    >> The downside is that 8kB * 19k revisions (for bzr.dev) =
    >> 149 MB. Right now my whole bzr pack file is 77MB, and I
    >> just did checks to see that inventory is 38.8MB of it. And
    >> I felt that inventory being 50% of the storage was
    >> wasteful.  I really feel like inventory management should
    >> be under 25% of total storage.

    robert> Its not an apples and oranges test. Whats the
    robert> uncompressed size of all the inventories? :).

Agreed. On the other hand we should really look at how your
proposal *is* compressed (surely less, but yet).

  Vincent

P.S.: I've read the "Ideal hash trees" article you pointed me
at. I've still to re-read it in parallel with your proposal to
see how you adapted it, I'll comment again ASAP.