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.
# Extension dedicated to test patch.diff() upgrade modes
from mercurial import (
error,
logcmdutil,
patch,
pycompat,
registrar,
scmutil,
)
cmdtable = {}
command = registrar.command(cmdtable)
@command(
b'autodiff',
[(b'', b'git', b'', b'git upgrade mode (yes/no/auto/warn/abort)')],
b'[OPTION]... [FILE]...',
)
def autodiff(ui, repo, *pats, **opts):
opts = pycompat.byteskwargs(opts)
diffopts = patch.difffeatureopts(ui, opts)
git = opts.get(b'git', b'no')
brokenfiles = set()
losedatafn = None
if git in (b'yes', b'no'):
diffopts.git = git == b'yes'
diffopts.upgrade = False
elif git == b'auto':
diffopts.git = False
diffopts.upgrade = True
elif git == b'warn':
diffopts.git = False
diffopts.upgrade = True
def losedatafn(fn=None, **kwargs):
brokenfiles.add(fn)
return True
elif git == b'abort':
diffopts.git = False
diffopts.upgrade = True
def losedatafn(fn=None, **kwargs):
raise error.Abort(b'losing data for %s' % fn)
else:
raise error.Abort(b'--git must be yes, no or auto')
ctx1, ctx2 = logcmdutil.revpair(repo, [])
m = scmutil.match(ctx2, pats, opts)
it = patch.diff(
repo,
ctx1.node(),
ctx2.node(),
match=m,
opts=diffopts,
losedatafn=losedatafn,
)
for chunk in it:
ui.write(chunk)
for fn in sorted(brokenfiles):
ui.write((b'data lost for: %s\n' % fn))