hgext/churn.py

contrib: add a partial-merge tool for sorted lists (such as Python imports)

This is a pretty naive tool that uses a regular expression for
matching lines. It is based on a Google-internal tool that worked in a
similar way.

For now, the regular expression is hard-coded to attempt to match
single-line Python imports. The only commit I've found in the hg core
repo where the tool helped was commit 9cd6292abfdf. I think that's
because we often use multiple imports per import statement. I think
this tool is still a decent first step (especially once the regex is
made configurable in the next patch). The merging should ideally use a
proper Python parser and do the merge at the AST (or CST?) level, but
that's significantly harder, especially if you want to preserve
comments and whitespace. It's also less generic.

Differential Revision: https://phab.mercurial-scm.org/D12380

# churn.py - create a graph of revisions count grouped by template
#
# Copyright 2006 Josef "Jeff" Sipek <[e-mail]>
# Copyright 2008 Alexander Solovyov <[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 display statistics about repository history'''


import datetime
import os
import time

from mercurial.i18n import _
from mercurial.pycompat import open
from mercurial import (
    cmdutil,
    encoding,
    logcmdutil,
    patch,
    pycompat,
    registrar,
    scmutil,
)

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'


def changedlines(ui, repo, ctx1, ctx2, fmatch):
    added, removed = 0, 0
    diff = b''.join(patch.diff(repo, ctx1.node(), ctx2.node(), fmatch))
    inhunk = False
    for l in diff.split(b'\n'):
        if inhunk and l.startswith(b"+"):
            added += 1
        elif inhunk and l.startswith(b"-"):
            removed += 1
        elif l.startswith(b"@"):
            inhunk = True
        elif l.startswith(b"d"):
            inhunk = False
    return (added, removed)


def countrate(ui, repo, amap, *pats, **opts):
    """Calculate stats"""
    opts = pycompat.byteskwargs(opts)
    if opts.get(b'dateformat'):

        def getkey(ctx):
            t, tz = ctx.date()
            date = datetime.datetime(*time.gmtime(float(t) - tz)[:6])
            return encoding.strtolocal(
                date.strftime(encoding.strfromlocal(opts[b'dateformat']))
            )

    else:
        tmpl = opts.get(b'oldtemplate') or opts.get(b'template')
        tmpl = logcmdutil.maketemplater(ui, repo, tmpl)

        def getkey(ctx):
            ui.pushbuffer()
            tmpl.show(ctx)
            return ui.popbuffer()

    progress = ui.makeprogress(
        _(b'analyzing'), unit=_(b'revisions'), total=len(repo)
    )
    rate = {}

    def prep(ctx, fmatch):
        rev = ctx.rev()
        key = getkey(ctx).strip()
        key = amap.get(key, key)  # alias remap
        if opts.get(b'changesets'):
            rate[key] = (rate.get(key, (0,))[0] + 1, 0)
        else:
            parents = ctx.parents()
            if len(parents) > 1:
                ui.note(_(b'revision %d is a merge, ignoring...\n') % (rev,))
                return

            ctx1 = parents[0]
            lines = changedlines(ui, repo, ctx1, ctx, fmatch)
            rate[key] = [r + l for r, l in zip(rate.get(key, (0, 0)), lines)]

        progress.increment()

    wopts = logcmdutil.walkopts(
        pats=pats,
        opts=opts,
        revspec=opts[b'rev'],
        date=opts[b'date'],
        include_pats=opts[b'include'],
        exclude_pats=opts[b'exclude'],
    )
    revs, makefilematcher = logcmdutil.makewalker(repo, wopts)
    for ctx in scmutil.walkchangerevs(repo, revs, makefilematcher, prep):
        continue

    progress.complete()

    return rate


@command(
    b'churn',
    [
        (
            b'r',
            b'rev',
            [],
            _(b'count rate for the specified revision or revset'),
            _(b'REV'),
        ),
        (
            b'd',
            b'date',
            b'',
            _(b'count rate for revisions matching date spec'),
            _(b'DATE'),
        ),
        (
            b't',
            b'oldtemplate',
            b'',
            _(b'template to group changesets (DEPRECATED)'),
            _(b'TEMPLATE'),
        ),
        (
            b'T',
            b'template',
            b'{author|email}',
            _(b'template to group changesets'),
            _(b'TEMPLATE'),
        ),
        (
            b'f',
            b'dateformat',
            b'',
            _(b'strftime-compatible format for grouping by date'),
            _(b'FORMAT'),
        ),
        (b'c', b'changesets', False, _(b'count rate by number of changesets')),
        (b's', b'sort', False, _(b'sort by key (default: sort by count)')),
        (b'', b'diffstat', False, _(b'display added/removed lines separately')),
        (b'', b'aliases', b'', _(b'file with email aliases'), _(b'FILE')),
    ]
    + cmdutil.walkopts,
    _(b"hg churn [-d DATE] [-r REV] [--aliases FILE] [FILE]"),
    helpcategory=command.CATEGORY_MAINTENANCE,
    inferrepo=True,
)
def churn(ui, repo, *pats, **opts):
    """histogram of changes to the repository

    This command will display a histogram representing the number
    of changed lines or revisions, grouped according to the given
    template. The default template will group changes by author.
    The --dateformat option may be used to group the results by
    date instead.

    Statistics are based on the number of changed lines, or
    alternatively the number of matching revisions if the
    --changesets option is specified.

    Examples::

      # display count of changed lines for every committer
      hg churn -T "{author|email}"

      # display daily activity graph
      hg churn -f "%H" -s -c

      # display activity of developers by month
      hg churn -f "%Y-%m" -s -c

      # display count of lines changed in every year
      hg churn -f "%Y" -s

      # display count of lines changed in a time range
      hg churn -d "2020-04 to 2020-09"

    It is possible to map alternate email addresses to a main address
    by providing a file using the following format::

      <alias email> = <actual email>

    Such a file may be specified with the --aliases option, otherwise
    a .hgchurn file will be looked for in the working directory root.
    Aliases will be split from the rightmost "=".
    """

    def pad(s, l):
        return s + b" " * (l - encoding.colwidth(s))

    amap = {}
    aliases = opts.get('aliases')
    if not aliases and os.path.exists(repo.wjoin(b'.hgchurn')):
        aliases = repo.wjoin(b'.hgchurn')
    if aliases:
        for l in open(aliases, b"rb"):
            try:
                alias, actual = l.rsplit(b'=' in l and b'=' or None, 1)
                amap[alias.strip()] = actual.strip()
            except ValueError:
                l = l.strip()
                if l:
                    ui.warn(_(b"skipping malformed alias: %s\n") % l)
                continue

    rate = list(countrate(ui, repo, amap, *pats, **opts).items())
    if not rate:
        return

    if opts.get('sort'):
        rate.sort()
    else:
        rate.sort(key=lambda x: (-sum(x[1]), x))

    # Be careful not to have a zero maxcount (issue833)
    maxcount = float(max(sum(v) for k, v in rate)) or 1.0
    maxname = max(len(k) for k, v in rate)

    ttywidth = ui.termwidth()
    ui.debug(b"assuming %i character terminal\n" % ttywidth)
    width = ttywidth - maxname - 2 - 2 - 2

    if opts.get('diffstat'):
        width -= 15

        def format(name, diffstat):
            added, removed = diffstat
            return b"%s %15s %s%s\n" % (
                pad(name, maxname),
                b'+%d/-%d' % (added, removed),
                ui.label(b'+' * charnum(added), b'diffstat.inserted'),
                ui.label(b'-' * charnum(removed), b'diffstat.deleted'),
            )

    else:
        width -= 6

        def format(name, count):
            return b"%s %6d %s\n" % (
                pad(name, maxname),
                sum(count),
                b'*' * charnum(sum(count)),
            )

    def charnum(count):
        return int(count * width // maxcount)

    for name, count in rate:
        ui.write(format(name, count))