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.
#!/usr/bin/env python
"""Test the running system for features availability. Exit with zero
if all features are there, non-zero otherwise. If a feature name is
prefixed with "no-", the absence of feature is tested.
"""
import hghave
import optparse
import os
import sys
checks = hghave.checks
def list_features():
for name, feature in sorted(checks.items()):
desc = feature[1]
print(name + ':', desc)
def test_features():
failed = 0
for name, feature in checks.items():
check, _ = feature
try:
check()
except Exception as e:
print("feature %s failed: %s" % (name, e))
failed += 1
return failed
parser = optparse.OptionParser("%prog [options] [features]")
parser.add_option(
"--test-features", action="store_true", help="test available features"
)
parser.add_option(
"--list-features", action="store_true", help="list available features"
)
def _loadaddon():
if 'TESTDIR' in os.environ:
# loading from '.' isn't needed, because `hghave` should be
# running at TESTTMP in this case
path = os.environ['TESTDIR']
else:
path = '.'
if not os.path.exists(os.path.join(path, 'hghaveaddon.py')):
return
sys.path.insert(0, path)
try:
import hghaveaddon
assert hghaveaddon # silence pyflakes
except BaseException as inst:
sys.stderr.write(
'failed to import hghaveaddon.py from %r: %s\n' % (path, inst)
)
sys.exit(2)
sys.path.pop(0)
if __name__ == '__main__':
options, args = parser.parse_args()
_loadaddon()
if options.list_features:
list_features()
sys.exit(0)
if options.test_features:
sys.exit(test_features())
hghave.require(args)