hgext/share.py
author Patrick Mezard <patrick@mezard.eu>
Tue, 08 May 2012 22:43:44 +0200
changeset 16777 058e14da7044
parent 16743 38caf405d010
child 18825 f0564402d059
permissions -rw-r--r--
graphlog: turn getlogrevs() into a generator This improves the poor "time to first changeset" compared to the original log command. When running: $ hg log -u user log will enumerate the changelog and display matching revisions when they are found. But: $ hg log -G -u user will first find all revisions matching the user then start to display them. Initially, I considered turning revset.match() into a generator. This is doable but requires a fair amount of work. Instead, cmdutil.increasingwindows() is reused to call the revset matcher repeatedly. This has the nice properties of: - Let us reorder the windows after filtering, which is necessary as the matcher can reorder inputs but is an internal detail not a feature. - Let us feed the matcher with windows in changelog order, which is good for performances. - Have a generator designed for log-like commands, returning small windows at first then batching larger ones. I feel that calling the matcher multiple times is correct, at least with the revsets involved in getlogrevs() because they are: - stateless (no limit()) - respecting f(a|b) = f(a) | f(b), though I have no valid argument about that. Known issues compared to log code: - Calling the revset matcher multiple times can be slow when revset functions have to create expensive data structure for filtering. This will be addressed in a followup. - Predicate combinations like "--user foo --user bar" or "--user foo and --branch bar" are inherently slower because all input revision are checked against the first condition, then against the second, and so forth. log would enumerate the input revisions once and check each of them once against all conditions, which is faster. There are solutions but nothing cheap to implement. Some numbers against mozilla repository: first line total * hg log -u rnewman /Users/pmezard/bin/hg-2.2 0.148s 7.293s /Users/pmezard/bin/hgdev 0.132s 5.747s * hg log -u rnewman -u girard /Users/pmezard/bin/hg-2.2 0.146s 7.323s /Users/pmezard/bin/hgdev 0.136s 11.096s * hg log -l 10 /Users/pmezard/bin/hg-2.2 0.137s 0.153s /Users/pmezard/bin/hgdev 0.128s 0.144s * hg log -l 10 -u rnewman /Users/pmezard/bin/hg-2.2 0.146s 0.265s /Users/pmezard/bin/hgdev 0.133s 0.236s * hg log -b GECKO193a2_20100228_RELBRANCH /Users/pmezard/bin/hg-2.2 2.332s 6.618s /Users/pmezard/bin/hgdev 1.972s 5.543s * hg log xulrunner /Users/pmezard/bin/hg-2.2 5.829s 5.958s /Users/pmezard/bin/hgdev 0.194s 6.017s * hg log --follow xulrunner/build.mk /Users/pmezard/bin/hg-2.2 0.353s 0.438s /Users/pmezard/bin/hgdev 0.394s 0.580s * hg log -u girard tools /Users/pmezard/bin/hg-2.2 5.853s 6.012s /Users/pmezard/bin/hgdev 0.195s 6.030s * hg log -b COMM2000_20110314_RELBRANCH --copies /Users/pmezard/bin/hg-2.2 2.231s 6.653s /Users/pmezard/bin/hgdev 1.897s 5.585s * hg log --follow /Users/pmezard/bin/hg-2.2 0.137s 14.140s /Users/pmezard/bin/hgdev 0.381s 44.246s * hg log --follow -r 80000:90000 /Users/pmezard/bin/hg-2.2 0.127s 1.611s /Users/pmezard/bin/hgdev 0.147s 1.847s * hg log --follow -r 90000:80000 /Users/pmezard/bin/hg-2.2 0.130s 1.702s /Users/pmezard/bin/hgdev 0.368s 6.106s * hg log --follow -r 80000:90000 js/src/jsproxy.cpp /Users/pmezard/bin/hg-2.2 0.343s 0.388s /Users/pmezard/bin/hgdev 0.437s 0.631s * hg log --follow -r 90000:80000 js/src/jsproxy.cpp /Users/pmezard/bin/hg-2.2 0.342s 0.389s /Users/pmezard/bin/hgdev 0.442s 0.628s

# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''share a common history between several working directories'''

from mercurial.i18n import _
from mercurial import hg, commands, util

testedwith = 'internal'

def share(ui, source, dest=None, noupdate=False):
    """create a new shared repository

    Initialize a new repository and working directory that shares its
    history with another repository.

    .. note::
       using rollback or extensions that destroy/modify history (mq,
       rebase, etc.) can cause considerable confusion with shared
       clones. In particular, if two shared clones are both updated to
       the same changeset, and one of them destroys that changeset
       with rollback, the other clone will suddenly stop working: all
       operations will fail with "abort: working directory has unknown
       parent". The only known workaround is to use debugsetparents on
       the broken clone to reset it to a changeset that still exists
       (e.g. tip).
    """

    return hg.share(ui, source, dest, not noupdate)

def unshare(ui, repo):
    """convert a shared repository to a normal one

    Copy the store data to the repo and remove the sharedpath data.
    """

    if repo.sharedpath == repo.path:
        raise util.Abort(_("this is not a shared repo"))

    destlock = lock = None
    lock = repo.lock()
    try:
        # we use locks here because if we race with commit, we
        # can end up with extra data in the cloned revlogs that's
        # not pointed to by changesets, thus causing verify to
        # fail

        destlock = hg.copystore(ui, repo, repo.path)

        sharefile = repo.join('sharedpath')
        util.rename(sharefile, sharefile + '.old')

        repo.requirements.discard('sharedpath')
        repo._writerequirements()
    finally:
        destlock and destlock.release()
        lock and lock.release()

    # update store, spath, sopener and sjoin of repo
    repo.__init__(ui, repo.root)

cmdtable = {
    "share":
    (share,
     [('U', 'noupdate', None, _('do not create a working copy'))],
     _('[-U] SOURCE [DEST]')),
    "unshare":
    (unshare,
    [],
    ''),
}

commands.norepo += " share"