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.
#require test-repo pylint
Run pylint for known rules we care about.
-----------------------------------------
There should be no recorded failures; fix the codebase before introducing a
new check.
Current checks:
- W0102: no mutable default argument
- C0321: only one statement on a single line
$ touch $TESTTMP/fakerc
$ pylint --rcfile=$TESTTMP/fakerc --disable=all \
> --enable=W0102,C0321 \
> --reports=no \
> --ignore=thirdparty \
> mercurial hgdemandimport hgext hgext3rd | sed 's/\r$//'
Using config file *fakerc (glob) (?)
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------------------------------------* (glob) (?)
Your code has been rated at 10.00/10* (glob) (?)
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