revset: optimize baseset.__sub__ (issue4313)
dd716807fd23 regressed performance of baseset.__sub__ by introducing
a lazyset. This patch restores that lost performance by eagerly
evaluating baseset.__sub__ if the other set is a baseset.
revsetbenchmark.py results impacted by this change:
revset #6: roots(0::tip)
0) wall 2.923473 comb 2.920000 user 2.920000 sys 0.000000 (best of 4)
1) wall 0.077614 comb 0.080000 user 0.080000 sys 0.000000 (best of 100)
revset #23: roots((0:tip)::)
0) wall 2.875178 comb 2.880000 user 2.880000 sys 0.000000 (best of 4)
1) wall 0.154519 comb 0.150000 user 0.150000 sys 0.000000 (best of 61)
On the author's machine, this slowdown manifested during evaluation of
'roots(%ln::)' in phases.retractboundary after unbundling the Firefox
repository. Using `time hg unbundle firefox.hg` as a benchmark:
Before: 8:00
After: 4:28
Delta: -3:32
For reference, the subset and cs baseset instances impacted by this
change were of lengths 193634 and 193627, respectively.
Explicit test coverage of roots(%ln::), while similar to the existing
roots(0::tip) benchmark, has been added.
# repair.py - functions for repository repair for mercurial
#
# Copyright 2005, 2006 Chris Mason <mason@suse.com>
# Copyright 2007 Matt Mackall
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from mercurial import changegroup, exchange
from mercurial.node import short
from mercurial.i18n import _
import errno
def _bundle(repo, bases, heads, node, suffix, compress=True):
"""create a bundle with the specified revisions as a backup"""
cg = changegroup.changegroupsubset(repo, bases, heads, 'strip')
backupdir = "strip-backup"
vfs = repo.vfs
if not vfs.isdir(backupdir):
vfs.mkdir(backupdir)
name = "%s/%s-%s.hg" % (backupdir, short(node), suffix)
if compress:
bundletype = "HG10BZ"
else:
bundletype = "HG10UN"
return changegroup.writebundle(cg, name, bundletype, vfs)
def _collectfiles(repo, striprev):
"""find out the filelogs affected by the strip"""
files = set()
for x in xrange(striprev, len(repo)):
files.update(repo[x].files())
return sorted(files)
def _collectbrokencsets(repo, files, striprev):
"""return the changesets which will be broken by the truncation"""
s = set()
def collectone(revlog):
_, brokenset = revlog.getstrippoint(striprev)
s.update([revlog.linkrev(r) for r in brokenset])
collectone(repo.manifest)
for fname in files:
collectone(repo.file(fname))
return s
def strip(ui, repo, nodelist, backup="all", topic='backup'):
repo = repo.unfiltered()
repo.destroying()
cl = repo.changelog
# TODO handle undo of merge sets
if isinstance(nodelist, str):
nodelist = [nodelist]
striplist = [cl.rev(node) for node in nodelist]
striprev = min(striplist)
keeppartialbundle = backup == 'strip'
# Some revisions with rev > striprev may not be descendants of striprev.
# We have to find these revisions and put them in a bundle, so that
# we can restore them after the truncations.
# To create the bundle we use repo.changegroupsubset which requires
# the list of heads and bases of the set of interesting revisions.
# (head = revision in the set that has no descendant in the set;
# base = revision in the set that has no ancestor in the set)
tostrip = set(striplist)
for rev in striplist:
for desc in cl.descendants([rev]):
tostrip.add(desc)
files = _collectfiles(repo, striprev)
saverevs = _collectbrokencsets(repo, files, striprev)
# compute heads
saveheads = set(saverevs)
for r in xrange(striprev + 1, len(cl)):
if r not in tostrip:
saverevs.add(r)
saveheads.difference_update(cl.parentrevs(r))
saveheads.add(r)
saveheads = [cl.node(r) for r in saveheads]
# compute base nodes
if saverevs:
descendants = set(cl.descendants(saverevs))
saverevs.difference_update(descendants)
savebases = [cl.node(r) for r in saverevs]
stripbases = [cl.node(r) for r in tostrip]
# For a set s, max(parents(s) - s) is the same as max(heads(::s - s)), but
# is much faster
newbmtarget = repo.revs('max(parents(%ld) - (%ld))', tostrip, tostrip)
if newbmtarget:
newbmtarget = repo[newbmtarget[0]].node()
else:
newbmtarget = '.'
bm = repo._bookmarks
updatebm = []
for m in bm:
rev = repo[bm[m]].rev()
if rev in tostrip:
updatebm.append(m)
# create a changegroup for all the branches we need to keep
backupfile = None
vfs = repo.vfs
if backup == "all":
backupfile = _bundle(repo, stripbases, cl.heads(), node, topic)
repo.ui.status(_("saved backup bundle to %s\n") %
vfs.join(backupfile))
repo.ui.log("backupbundle", "saved backup bundle to %s\n",
vfs.join(backupfile))
if saveheads or savebases:
# do not compress partial bundle if we remove it from disk later
chgrpfile = _bundle(repo, savebases, saveheads, node, 'temp',
compress=keeppartialbundle)
mfst = repo.manifest
tr = repo.transaction("strip")
offset = len(tr.entries)
try:
tr.startgroup()
cl.strip(striprev, tr)
mfst.strip(striprev, tr)
for fn in files:
repo.file(fn).strip(striprev, tr)
tr.endgroup()
try:
for i in xrange(offset, len(tr.entries)):
file, troffset, ignore = tr.entries[i]
repo.sopener(file, 'a').truncate(troffset)
if troffset == 0:
repo.store.markremoved(file)
tr.close()
except: # re-raises
tr.abort()
raise
if saveheads or savebases:
ui.note(_("adding branch\n"))
f = vfs.open(chgrpfile, "rb")
gen = exchange.readbundle(ui, f, chgrpfile, vfs)
if not repo.ui.verbose:
# silence internal shuffling chatter
repo.ui.pushbuffer()
changegroup.addchangegroup(repo, gen, 'strip',
'bundle:' + vfs.join(chgrpfile), True)
if not repo.ui.verbose:
repo.ui.popbuffer()
f.close()
if not keeppartialbundle:
vfs.unlink(chgrpfile)
# remove undo files
for undovfs, undofile in repo.undofiles():
try:
undovfs.unlink(undofile)
except OSError, e:
if e.errno != errno.ENOENT:
ui.warn(_('error removing %s: %s\n') %
(undovfs.join(undofile), str(e)))
for m in updatebm:
bm[m] = repo[newbmtarget].node()
bm.write()
except: # re-raises
if backupfile:
ui.warn(_("strip failed, full bundle stored in '%s'\n")
% vfs.join(backupfile))
elif saveheads:
ui.warn(_("strip failed, partial bundle stored in '%s'\n")
% vfs.join(chgrpfile))
raise
repo.destroyed()