hgext/graphlog.py

largefiles: don't rehash largefiles in updatelfiles if standin hash changed

Standins are read before and after an update/merge, and all the standins that
changes are handed to updatelfiles for getting their corresponding largefiles
updated. updatelfiles would then hash the largefile and see if it already
matched the new expected hash. If so, it would skip the update. If different,
the largefile would be updated.

It would happen very rarely that the largefile happened to match the new hash
(and thus not the old one) and the hashing would thus be pointless ... and
hashing is not cheap.

Instead, when it is known that the standin hash changed (from an update), just
update the standin unconditionally. If the largefile was "unsure" before the
update, it was hashed at that point, so we know there is nothing to preserve.
(Also, the hashing in updatelfiles was not used to preserve changes, but only
to be lazy about updating the largefile, so nothing is lost by not doing this
extra hashing.)

There might be rare situations where we now will update largefiles that didn't
have to be updated, but in all relevant cases (?) this will improve
performance.

Updates on a repo with some big largefiles has been seen to go from 9.19 s to
6.8 s - that is 26% less painful.

# ASCII graph log extension for Mercurial
#
# Copyright 2007 Joel Rosdahl <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''command to view revision graphs from a shell (DEPRECATED)

The functionality of this extension has been include in core Mercurial
since version 2.3.

This extension adds a --graph option to the incoming, outgoing and log
commands. When this options is given, an ASCII representation of the
revision graph is also shown.
'''

from mercurial.i18n import _
from mercurial import cmdutil, commands

cmdtable = {}
command = cmdutil.command(cmdtable)
testedwith = 'internal'

@command('glog',
    [('f', 'follow', None,
     _('follow changeset history, or file history across copies and renames')),
    ('', 'follow-first', None,
     _('only follow the first parent of merge changesets (DEPRECATED)')),
    ('d', 'date', '', _('show revisions matching date spec'), _('DATE')),
    ('C', 'copies', None, _('show copied files')),
    ('k', 'keyword', [],
     _('do case-insensitive search for a given text'), _('TEXT')),
    ('r', 'rev', [], _('show the specified revision or revset'), _('REV')),
    ('', 'removed', None, _('include revisions where files were removed')),
    ('m', 'only-merges', None, _('show only merges (DEPRECATED)')),
    ('u', 'user', [], _('revisions committed by user'), _('USER')),
    ('', 'only-branch', [],
     _('show only changesets within the given named branch (DEPRECATED)'),
     _('BRANCH')),
    ('b', 'branch', [],
     _('show changesets within the given named branch'), _('BRANCH')),
    ('P', 'prune', [],
     _('do not display revision or any of its ancestors'), _('REV')),
    ] + commands.logopts + commands.walkopts,
    _('[OPTION]... [FILE]'),
    inferrepo=True)
def graphlog(ui, repo, *pats, **opts):
    """show revision history alongside an ASCII revision graph

    Print a revision history alongside a revision graph drawn with
    ASCII characters.

    Nodes printed as an @ character are parents of the working
    directory.
    """
    return cmdutil.graphlog(ui, repo, *pats, **opts)