view hgext/graphlog.py @ 48671:f1ed5c304f45

encoding: fix trim() to be O(n) instead of O(n^2)

`encoding.trim()` iterated over the possible lengths smaller than the
input and created a slice for each. It then calculated the column
width of the result, which is of course O(n), so the overall algorithm
was O(n). This patch rewrites it to iterate over the unicode
characters, keeping track of the length so far. Also, the old
algorithm started from the end of the string, which made it much worse
when the input is large and the limit is small (such as the typical 72
we pass to it).

You can time it by running something like this:

```
time python3 -c 'from mercurial.utils import stringutil; print(stringutil.ellipsis(b"0123456789" * 1000, 5))'
```

That drops from 4.05 s to 83 ms with this patch (and most of that is
of course startup time).

Differential Revision: https://phab.mercurial-scm.org/D12089

# 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. Please use :hg:`log -G ...` instead.

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 __future__ import absolute_import

from mercurial.i18n import _
from mercurial import (
    cmdutil,
    commands,
    registrar,
)

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 = b'ships-with-hg-core'


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

    This is an alias to :hg:`log -G`.
    """
    opts['graph'] = True
    return commands.log(ui, repo, *pats, **opts)