Mercurial > hg
view hgext/fetch.py @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | 5cb8158a61f7 |
children | 2372284d9457 |
line wrap: on
line source
# 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]'), helpcategory=command.CATEGORY_REMOTE_REPO_MANAGEMENT) 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 = repo.dirstate.p1() 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)