Re: [PATCH v2 2/2] index-pack: kill union delta_base to save memory

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 1, 2015, 02:37 UTC
Message-ID: <xmqqegp9igsr.fsf@gitster.dls.corp.google.com>
In-Reply-To: <CACsJy8A3MxpQRwboVjyv7akvzgf3y23ZsnAaxuHXkm2U=tUk0A@mail.gmail.com>

Duy Nguyen <pclouds@gmail.com> writes:

Show 10 quoted lines

>> Probably "Not so ancient versions of Git tries to use ofs-delta
>> encoding whenever possible, so it is expected that objects encoded
>> using ref-delta are minority" may be closer to the truth.  And that
>> observation does justify why using two separate pools (one with
>> 8-byte entries for ofs-delta, the other with 20-byte entries for
>> ref-delta) is a better idean than using one pool with 20-byte
>> entries for both kinds.
>
> Yes. Looks good. Should I send a patch, or you fix the commit
> message locally?

Thinking about the above again, I do not think there is any point saying "not so ancient versions of Git", as the receiving index-pack would not even know what implementaiton of Git sits on the other end of the connection; it may even be a jGit based server, for example. So something like:

    Because ofs-delta encoding is more efficient space-wise and more
    performant at runtime than ref-delta encoding, Git packers try
    to use ofs-delta whenever possible, and it is expected that
    objects encoded as ref-delta are minority.

perhaps?