tree ad4f316055152375d333e0acba65e491936f7c1a
parent bff1d06e40f70566a779880b2edeb53ad1930609
author Jeremy Stribling <strib@alum.mit.edu> 1503703564 -0700
committer Jeremy Stribling <strib@alum.mit.edu> 1503940216 -0700

plumbing: use sliding window in delta calculations, like git CL

This sets a default sliding window of 10 for the delta calculation,
just like git CL:
https://git-scm.com/docs/git-pack-objects#git-pack-objects---windowltngt

For a big-ish repo with 35K objects (17K commits), this reduced the
time for calling `deltaSelection.walk` during a push from more than 14
minutes to about a minute.