##// END OF EJS Templates
bdiff: replace hash algorithm...
bdiff: replace hash algorithm This patch replaces lyhash with the hash algorithm used by diffutils. The algorithm has its origins in Git commit 2e9d1410, which is all the way back from 1992. The license header in the code at that revision in GPL v2. I have not performed an extensive analysis of the distribution (and therefore buckets) of hash output. However, `hg perfbdiff` gives some clear wins. I'd like to think that if it is good enough for diffutils it is good enough for us? From the mozilla-unified repository: $ perfbdiff -m 3041e4d59df2 ! wall 0.053271 comb 0.060000 user 0.060000 sys 0.000000 (best of 100) ! wall 0.035827 comb 0.040000 user 0.040000 sys 0.000000 (best of 100) $ perfbdiff 0e9928989e9c --alldata --count 100 ! wall 6.204277 comb 6.200000 user 6.200000 sys 0.000000 (best of 3) ! wall 4.309710 comb 4.300000 user 4.300000 sys 0.000000 (best of 3) From the hg repo: $ perfbdiff 35000 --alldata --count 1000 ! wall 0.660358 comb 0.660000 user 0.660000 sys 0.000000 (best of 15) ! wall 0.534092 comb 0.530000 user 0.530000 sys 0.000000 (best of 19) Looking at the generated assembly and statistical profiler output from the kernel level, I believe there is room to make this function even faster. Namely, we're still consuming data character by character instead of at the word level. This translates to more loop iterations and more instructions. At this juncture though, the real performance killer is that we're hashing every line. We should get a significant speedup if we change the algorithm to find the longest prefix, longest suffix, treat those as single "lines" and then only do the line splitting and hashing on the parts that are different. That will require a lot of C code, however. I'm optimistic this approach could result in a ~2x speedup.

File last commit:

r29841:d5883fd0 default
r30318:e1d6aa0e default
Show More
strip.py
242 lines | 9.0 KiB | text/x-python | PythonLexer
"""strip changesets and their descendants from history
This extension allows you to strip changesets and all their descendants from the
repository. See the command help for details.
"""
from __future__ import absolute_import
from mercurial.i18n import _
from mercurial import (
bookmarks as bookmarksmod,
cmdutil,
error,
hg,
lock as lockmod,
merge,
node as nodemod,
repair,
scmutil,
util,
)
nullid = nodemod.nullid
release = lockmod.release
cmdtable = {}
command = cmdutil.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'
def checksubstate(repo, baserev=None):
'''return list of subrepos at a different revision than substate.
Abort if any subrepos have uncommitted changes.'''
inclsubs = []
wctx = repo[None]
if baserev:
bctx = repo[baserev]
else:
bctx = wctx.parents()[0]
for s in sorted(wctx.substate):
wctx.sub(s).bailifchanged(True)
if s not in bctx.substate or bctx.sub(s).dirty():
inclsubs.append(s)
return inclsubs
def checklocalchanges(repo, force=False, excsuffix=''):
cmdutil.checkunfinished(repo)
s = repo.status()
if not force:
if s.modified or s.added or s.removed or s.deleted:
_("local changes found") # i18n tool detection
raise error.Abort(_("local changes found" + excsuffix))
if checksubstate(repo):
_("local changed subrepos found") # i18n tool detection
raise error.Abort(_("local changed subrepos found" + excsuffix))
return s
def strip(ui, repo, revs, update=True, backup=True, force=None, bookmarks=None):
wlock = lock = None
try:
wlock = repo.wlock()
lock = repo.lock()
if update:
checklocalchanges(repo, force=force)
urev, p2 = repo.changelog.parents(revs[0])
if (util.safehasattr(repo, 'mq') and
p2 != nullid
and p2 in [x.node for x in repo.mq.applied]):
urev = p2
hg.clean(repo, urev)
repo.dirstate.write(repo.currenttransaction())
repair.strip(ui, repo, revs, backup)
repomarks = repo._bookmarks
if bookmarks:
with repo.transaction('strip') as tr:
if repo._activebookmark in bookmarks:
bookmarksmod.deactivate(repo)
for bookmark in bookmarks:
del repomarks[bookmark]
repomarks.recordchange(tr)
for bookmark in sorted(bookmarks):
ui.write(_("bookmark '%s' deleted\n") % bookmark)
finally:
release(lock, wlock)
@command("strip",
[
('r', 'rev', [], _('strip specified revision (optional, '
'can specify revisions without this '
'option)'), _('REV')),
('f', 'force', None, _('force removal of changesets, discard '
'uncommitted changes (no backup)')),
('', 'no-backup', None, _('no backups')),
('', 'nobackup', None, _('no backups (DEPRECATED)')),
('n', '', None, _('ignored (DEPRECATED)')),
('k', 'keep', None, _("do not modify working directory during "
"strip")),
('B', 'bookmark', [], _("remove revs only reachable from given"
" bookmark"))],
_('hg strip [-k] [-f] [-B bookmark] [-r] REV...'))
def stripcmd(ui, repo, *revs, **opts):
"""strip changesets and all their descendants from the repository
The strip command removes the specified changesets and all their
descendants. If the working directory has uncommitted changes, the
operation is aborted unless the --force flag is supplied, in which
case changes will be discarded.
If a parent of the working directory is stripped, then the working
directory will automatically be updated to the most recent
available ancestor of the stripped parent after the operation
completes.
Any stripped changesets are stored in ``.hg/strip-backup`` as a
bundle (see :hg:`help bundle` and :hg:`help unbundle`). They can
be restored by running :hg:`unbundle .hg/strip-backup/BUNDLE`,
where BUNDLE is the bundle file created by the strip. Note that
the local revision numbers will in general be different after the
restore.
Use the --no-backup option to discard the backup bundle once the
operation completes.
Strip is not a history-rewriting operation and can be used on
changesets in the public phase. But if the stripped changesets have
been pushed to a remote repository you will likely pull them again.
Return 0 on success.
"""
backup = True
if opts.get('no_backup') or opts.get('nobackup'):
backup = False
cl = repo.changelog
revs = list(revs) + opts.get('rev')
revs = set(scmutil.revrange(repo, revs))
with repo.wlock():
bookmarks = set(opts.get('bookmark'))
if bookmarks:
repomarks = repo._bookmarks
if not bookmarks.issubset(repomarks):
raise error.Abort(_("bookmark '%s' not found") %
','.join(sorted(bookmarks - set(repomarks.keys()))))
# If the requested bookmark is not the only one pointing to a
# a revision we have to only delete the bookmark and not strip
# anything. revsets cannot detect that case.
nodetobookmarks = {}
for mark, node in repomarks.iteritems():
nodetobookmarks.setdefault(node, []).append(mark)
for marks in nodetobookmarks.values():
if bookmarks.issuperset(marks):
rsrevs = repair.stripbmrevset(repo, marks[0])
revs.update(set(rsrevs))
if not revs:
lock = tr = None
try:
lock = repo.lock()
tr = repo.transaction('bookmark')
for bookmark in bookmarks:
del repomarks[bookmark]
repomarks.recordchange(tr)
tr.close()
for bookmark in sorted(bookmarks):
ui.write(_("bookmark '%s' deleted\n") % bookmark)
finally:
release(lock, tr)
if not revs:
raise error.Abort(_('empty revision set'))
descendants = set(cl.descendants(revs))
strippedrevs = revs.union(descendants)
roots = revs.difference(descendants)
update = False
# if one of the wdir parent is stripped we'll need
# to update away to an earlier revision
for p in repo.dirstate.parents():
if p != nullid and cl.rev(p) in strippedrevs:
update = True
break
rootnodes = set(cl.node(r) for r in roots)
q = getattr(repo, 'mq', None)
if q is not None and q.applied:
# refresh queue state if we're about to strip
# applied patches
if cl.rev(repo.lookup('qtip')) in strippedrevs:
q.applieddirty = True
start = 0
end = len(q.applied)
for i, statusentry in enumerate(q.applied):
if statusentry.node in rootnodes:
# if one of the stripped roots is an applied
# patch, only part of the queue is stripped
start = i
break
del q.applied[start:end]
q.savedirty()
revs = sorted(rootnodes)
if update and opts.get('keep'):
urev, p2 = repo.changelog.parents(revs[0])
if (util.safehasattr(repo, 'mq') and p2 != nullid
and p2 in [x.node for x in repo.mq.applied]):
urev = p2
uctx = repo[urev]
# only reset the dirstate for files that would actually change
# between the working context and uctx
descendantrevs = repo.revs("%s::." % uctx.rev())
changedfiles = []
for rev in descendantrevs:
# blindly reset the files, regardless of what actually changed
changedfiles.extend(repo[rev].files())
# reset files that only changed in the dirstate too
dirstate = repo.dirstate
dirchanges = [f for f in dirstate if dirstate[f] != 'n']
changedfiles.extend(dirchanges)
repo.dirstate.rebuild(urev, uctx.manifest(), changedfiles)
repo.dirstate.write(repo.currenttransaction())
# clear resolve state
merge.mergestate.clean(repo, repo['.'].node())
update = False
strip(ui, repo, revs, backup=backup, update=update,
force=opts.get('force'), bookmarks=bookmarks)
return 0