bisect: avoid adding irrelevant revisions to bisect state...
bisect: avoid adding irrelevant revisions to bisect state
When adding new revisions to the bisect state, it only makes sense to add
information about revisions that are under consideration (i.e., those that are
topologically between the known good and bad revisions). However, if the user
passes in a revset (e.g., '!merge()' to exclude merge commits), hg will resolve
the revset first and add all matching revisions to the bisect state (which in
this case would likely be the majority of revisions in the repo). To avoid this,
revisions should only be added to the bisect state if they are between the good
and bad revisions (and therefore relevant to the bisection).
--
Here are the results of some performance tests using the `mozilla-central` repo
(since it is one of the largest freely-available hg repositories in the wild).
These tests compare the performance of a locally-built `hg` before and after
application of this series. Note that `--noupdate` is passed to avoid including
update time (which should not vary across cases).
Setup (run between each test):
$ hg bisect --reset
$ hg bisect --noupdate --bad
56c3ad4bde5c70714b784ccf15d099e0df0f5bde
$ hg bisect --noupdate --good
57426696adaf08298af3027fa77486fee0633b13
Test using a revset that returns a very large number of revisions:
$ time hg bisect --noupdate --skip '!merge()' > /dev/null
Before:
real 0m9.398s
user 0m9.233s
sys 0m0.120s
After:
real 0m1.513s
user 0m1.425s
sys 0m0.052s
Test using a revset that is expensive to compute:
$ time hg bisect --noupdate --skip 'desc("Bug")' > /dev/null
Before:
real 0m49.853s
user 0m49.580s
sys 0m0.243s
After:
real 0m4.120s
user 0m4.036s
sys 0m0.048s
