Describe: add support for core.abbrev config option

If core.abbrev is unset or "auto" estimate abbreviation length like C
git does:
- Estimate repository's object count by only considering packed objects,
  round up to next power of 2
- With the order of 2^len objects, we expect a collision at 2^(len/2).
  But we also care about hex chars, not bits, and there are 4 bits per
  hex. So all together we need to divide by 2; but we also want to round
  odd numbers up, hence adding one before dividing.
- For small repos use at least 7 hexdigits
- If object database fails to determine object count use 7 hexdigits as
  fallback

If it is set to "no" do not abbreviate object-ids.

Otherwise set it to the configured value capped to the range between 4
and length of an unabbreviated object-id.

Change-Id: I425f9724b69813dbb57872466bf2d2e1d6dc72c6

0 files changed, 0 insertions, 0 deletions