tree b0d8711a6a47bb66fc1d2cc33bd35f6f725e8912
parent 5c9b8d6c99449afb67f0ae95a6938ef470817c7a
author Dave Borowitz <dborowitz@google.com> 1400718265 -0700
committer Dave Borowitz <dborowitz@google.com> 1400784386 -0700

Load from blame cache on last commit that modified a path

Walk the history of a blob until we find the last commit that modified
that path. This should increase cache hits by not caching blame
results for lots of commits that don't modify the path.

This does come at some cost, but usually one step of logging a path
should be a negligible proportion of the total blame cost. And for
those files that take a very long time to blame, the increased cache
hit rate (and to a lesser extent smaller cache size) should more than
make up for the cost here.

Change-Id: I760cfdf9529d7042241aa170262a601cb3073e95