Summary:
Now that we are writing the git hash inside the commit itself, if we are translating
from hg to git hash, we should just use that rather than loading the entire map and
build a dict and look it up.
The performance of this translation will also improve quite a lot.
Some small sample benchmarking:
```
suiting@devvm5006:configerator (659199b|remote/master)$ time ~/fbcode/scm/hg/hg log -r master -T '{node} || {gitnode}\n' --config exte
nsions.fbconduit=! --config extensions.hggit=
659199bf7c7850ea9ffa9e0ad50eb84597977dea || 69f05aeec13f09c44dd00d2a85fe9d461ba6841e
real 0m0.563s
user 0m0.004s
sys 0m0.007s
suiting@devvm5006:configerator (659199b|remote/master)$ time ~/fbcode/scm/hg/hg log -r master -T '{node} || {gitnode}\n'
659199bf7c7850ea9ffa9e0ad50eb84597977dea || 69f05aeec13f09c44dd00d2a85fe9d461ba6841e
real 0m14.706s
user 0m0.006s
sys 0m0.006s
```
Reviewed By: quark-zju
Differential Revision: D16833526
fbshipit-source-id: 7d3096649cf24967d13596e70463bc125081ba4f
Summary:
In order to move our hg-git mirroring off of the main hg servers, we
need to make it possible for the hg servers to compute the hg-git mapping
without having the entire git repository available. To do so, let's store the
git hash as an extra in the hg commit.
This breaks bidirectionality, but we've long since not needed that.
Reviewed By: phillco
Differential Revision: D13362980
fbshipit-source-id: 51df709bc5e77d78bb963abf90d0c35bb743d966
