fncache: avoid loading the filename cache when not actually modifying it
With time, fncache can become very large. The mozilla-central repo for example,
has a 31M and growing fncache file. Loading this file takes time (280ms for the
mozilla-central repository).
In many scenarios, we don't need to load fncache at all. For example, when
committing changes to existing files, or pushing such commits to another clone.
This patch detects when a name is added via store.vfs(), and only loads the
cache if a) the data metadata file doesn't already exist, or b) when opening
for appending, the data or metadata file exists but has size (a transaction
rollback leaves behind such files).
Benchmarks (run on Macos 10.13 on a 2017-model Macbook Pro with Core i7 2.9GHz
and flash drive), each test without and with patch run 5 times:
* committing to an existing file, against the mozilla-central repository.
Baseline real time average 2.3736, with patch 1.9884.
* unbundling a large changeset consisting *only* of existing-file modifications
(159 revisions, 1050 modifications, mozilla-central
4a250a0e4f29:
beea9ac7d823), into a clone limited to the ancestor revision of
that revset). Baseline real time average 1.5048, with patch 1.3108.
# fetch.py - pull and merge remote changes
#
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''pull, update and merge in one command (DEPRECATED)'''
from __future__ import absolute_import
from mercurial.i18n import _
from mercurial.node import (
short,
)
from mercurial import (
cmdutil,
error,
exchange,
hg,
lock,
pycompat,
registrar,
util,
)
from mercurial.utils import dateutil
release = lock.release
cmdtable = {}
command = registrar.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'
@command('fetch',
[('r', 'rev', [],
_('a specific revision you would like to pull'), _('REV')),
('', 'edit', None, _('invoke editor on commit messages')),
('', 'force-editor', None, _('edit commit message (DEPRECATED)')),
('', 'switch-parent', None, _('switch parents when merging')),
] + cmdutil.commitopts + cmdutil.commitopts2 + cmdutil.remoteopts,
_('hg fetch [SOURCE]'))
def fetch(ui, repo, source='default', **opts):
'''pull changes from a remote repository, merge new changes if needed.
This finds all changes from the repository at the specified path
or URL and adds them to the local repository.
If the pulled changes add a new branch head, the head is
automatically merged, and the result of the merge is committed.
Otherwise, the working directory is updated to include the new
changes.
When a merge is needed, the working directory is first updated to
the newly pulled changes. Local changes are then merged into the
pulled changes. To switch the merge order, use --switch-parent.
See :hg:`help dates` for a list of formats valid for -d/--date.
Returns 0 on success.
'''
opts = pycompat.byteskwargs(opts)
date = opts.get('date')
if date:
opts['date'] = dateutil.parsedate(date)
parent, _p2 = repo.dirstate.parents()
branch = repo.dirstate.branch()
try:
branchnode = repo.branchtip(branch)
except error.RepoLookupError:
branchnode = None
if parent != branchnode:
raise error.Abort(_('working directory not at branch tip'),
hint=_("use 'hg update' to check out branch tip"))
wlock = lock = None
try:
wlock = repo.wlock()
lock = repo.lock()
cmdutil.bailifchanged(repo)
bheads = repo.branchheads(branch)
bheads = [head for head in bheads if len(repo[head].children()) == 0]
if len(bheads) > 1:
raise error.Abort(_('multiple heads in this branch '
'(use "hg heads ." and "hg merge" to merge)'))
other = hg.peer(repo, opts, ui.expandpath(source))
ui.status(_('pulling from %s\n') %
util.hidepassword(ui.expandpath(source)))
revs = None
if opts['rev']:
try:
revs = [other.lookup(rev) for rev in opts['rev']]
except error.CapabilityError:
err = _("other repository doesn't support revision lookup, "
"so a rev cannot be specified.")
raise error.Abort(err)
# Are there any changes at all?
modheads = exchange.pull(repo, other, heads=revs).cgresult
if modheads == 0:
return 0
# Is this a simple fast-forward along the current branch?
newheads = repo.branchheads(branch)
newchildren = repo.changelog.nodesbetween([parent], newheads)[2]
if len(newheads) == 1 and len(newchildren):
if newchildren[0] != parent:
return hg.update(repo, newchildren[0])
else:
return 0
# Are there more than one additional branch heads?
newchildren = [n for n in newchildren if n != parent]
newparent = parent
if newchildren:
newparent = newchildren[0]
hg.clean(repo, newparent)
newheads = [n for n in newheads if n != newparent]
if len(newheads) > 1:
ui.status(_('not merging with %d other new branch heads '
'(use "hg heads ." and "hg merge" to merge them)\n') %
(len(newheads) - 1))
return 1
if not newheads:
return 0
# Otherwise, let's merge.
err = False
if newheads:
# By default, we consider the repository we're pulling
# *from* as authoritative, so we merge our changes into
# theirs.
if opts['switch_parent']:
firstparent, secondparent = newparent, newheads[0]
else:
firstparent, secondparent = newheads[0], newparent
ui.status(_('updating to %d:%s\n') %
(repo.changelog.rev(firstparent),
short(firstparent)))
hg.clean(repo, firstparent)
ui.status(_('merging with %d:%s\n') %
(repo.changelog.rev(secondparent), short(secondparent)))
err = hg.merge(repo, secondparent, remind=False)
if not err:
# we don't translate commit messages
message = (cmdutil.logmessage(ui, opts) or
('Automated merge with %s' %
util.removeauth(other.url())))
editopt = opts.get('edit') or opts.get('force_editor')
editor = cmdutil.getcommiteditor(edit=editopt, editform='fetch')
n = repo.commit(message, opts['user'], opts['date'], editor=editor)
ui.status(_('new changeset %d:%s merges remote changes '
'with local\n') % (repo.changelog.rev(n),
short(n)))
return err
finally:
release(lock, wlock)