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.
import os
import sys
import time
from mercurial import (
commands,
hg,
pycompat,
ui as uimod,
util,
)
TESTDIR = os.environ["TESTDIR"]
BUNDLEPATH = os.path.join(TESTDIR, 'bundles', 'test-no-symlinks.hg')
# only makes sense to test on os which supports symlinks
if not getattr(os, "symlink", False):
sys.exit(80) # SKIPPED_STATUS defined in run-tests.py
u = uimod.ui.load()
# hide outer repo
hg.peer(u, {}, b'.', create=True)
# unbundle with symlink support
hg.peer(u, {}, b'test0', create=True)
repo = hg.repository(u, b'test0')
commands.unbundle(u, repo, pycompat.fsencode(BUNDLEPATH), update=True)
# wait a bit, or the status call wont update the dirstate
time.sleep(1)
commands.status(u, repo)
# now disable symlink support -- this is what os.symlink would do on a
# non-symlink file system
def symlink_failure(src, dst):
raise OSError(1, "Operation not permitted")
os.symlink = symlink_failure
def islink_failure(path):
return False
os.path.islink = islink_failure
# dereference links as if a Samba server has exported this to a
# Windows client
for f in b'test0/a.lnk', b'test0/d/b.lnk':
os.unlink(f)
fp = open(f, 'wb')
fp.write(util.readfile(f[:-4]))
fp.close()
# reload repository
u = uimod.ui.load()
repo = hg.repository(u, b'test0')
commands.status(u, repo)
# try unbundling a repo which contains symlinks
u = uimod.ui.load()
repo = hg.repository(u, b'test1', create=True)
commands.unbundle(u, repo, pycompat.fsencode(BUNDLEPATH), update=True)