branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
This test doesn't yet work due to the way fsmonitor is integrated with test runner
$ exit 80
test sparse interaction with other extensions
$ hg init myrepo
$ cd myrepo
$ cat > .hg/hgrc <<EOF
> [extensions]
> sparse=
> strip=
> EOF
Test fsmonitor integration (if available)
TODO: make fully isolated integration test a'la https://github.com/facebook/watchman/blob/master/tests/integration/WatchmanInstance.py
(this one is using the systemwide watchman instance)
$ touch .watchmanconfig
$ echo "ignoredir1/" >> .hgignore
$ hg commit -Am ignoredir1
adding .hgignore
$ echo "ignoredir2/" >> .hgignore
$ hg commit -m ignoredir2
$ hg sparse --reset
$ hg sparse -I ignoredir1 -I ignoredir2 -I dir1
$ mkdir ignoredir1 ignoredir2 dir1
$ touch ignoredir1/file ignoredir2/file dir1/file
Run status twice to compensate for a condition in fsmonitor where it will check
ignored files the second time it runs, regardless of previous state (ask @sid0)
$ hg status --config extensions.fsmonitor=
? dir1/file
$ hg status --config extensions.fsmonitor=
? dir1/file
Test that fsmonitor ignore hash check updates when .hgignore changes
$ hg up -q ".^"
$ hg status --config extensions.fsmonitor=
? dir1/file
? ignoredir2/file