branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
#!/usr/bin/env python
import sys
from mercurial import (
commands,
localrepo,
ui as uimod,
)
print_ = print
def print(*args, **kwargs):
"""print() wrapper that flushes stdout buffers to avoid py3 buffer issues
We could also just write directly to sys.stdout.buffer the way the
ui object will, but this was easier for porting the test.
"""
print_(*args, **kwargs)
sys.stdout.flush()
u = uimod.ui.load()
print('% creating repo')
repo = localrepo.instance(u, b'.', create=True)
f = open('test.py', 'w')
try:
f.write('foo\n')
finally:
f.close
print('% add and commit')
commands.add(u, repo, b'test.py')
commands.commit(u, repo, message=b'*')
commands.status(u, repo, clean=True)
print('% change')
f = open('test.py', 'w')
try:
f.write('bar\n')
finally:
f.close()
# this would return clean instead of changed before the fix
commands.status(u, repo, clean=True, modified=True)