patch: support diff data loss detection and upgrade
In worst case, generating diff in upgrade mode can be two times more expensive
than generating it in git mode directly: we may have to regenerate the whole
diff again whenever a git feature is detected. Also, the first diff attempt is
completely buffered instead of being streamed. That said, even without having
profiled it yet, I am convinced we can fast-path the upgrade mode if necessary
were it to be used in regular diff commands, and not only in mq where avoiding
data loss is worth the price.
# Extension dedicated to test patch.diff() upgrade modes
#
#
from mercurial import cmdutil, patch, util
def autodiff(ui, repo, *pats, **opts):
diffopts = patch.diffopts(ui, opts)
git = opts.get('git', 'no')
brokenfiles = set()
losedatafn = None
if git in ('yes', 'no'):
diffopts.git = git == 'yes'
diffopts.upgrade = False
elif git == 'auto':
diffopts.git = False
diffopts.upgrade = True
elif git == 'warn':
diffopts.git = False
diffopts.upgrade = True
def losedatafn(fn=None, **kwargs):
brokenfiles.add(fn)
return True
elif git == 'abort':
diffopts.git = False
diffopts.upgrade = True
def losedatafn(fn=None, **kwargs):
raise util.Abort('losing data for %s' % fn)
else:
raise util.Abort('--git must be yes, no or auto')
node1, node2 = cmdutil.revpair(repo, [])
m = cmdutil.match(repo, pats, opts)
it = patch.diff(repo, node1, node2, match=m, opts=diffopts,
losedatafn=losedatafn)
for chunk in it:
ui.write(chunk)
for fn in sorted(brokenfiles):
ui.write('data lost for: %s\n' % fn)
cmdtable = {
"autodiff":
(autodiff,
[('', 'git', '', 'git upgrade mode (yes/no/auto/warn/abort)'),
],
'[OPTION]... [FILE]...'),
}