hgext/churn.py

copies: make mergecopies() distinguish between copies on each side

I find it confusing that most of the dicts returned from
`mergecopies()` have entries specific to one branch of the merge, but
they're still combined into dict. For example, you can't tell if `copy
= {"bar": "foo"}` means that "foo" was copied to "bar" on the first
branch or the second.

It also feels like there are bugs lurking here because we may mistake
which side the copy happened on. However, for most of the dicts, it's
not possible that there is disagreement. For example, `renamedelete`
keeps track of renames that happened on one side of the merge where
the other side deleted the file. There can't be a disagreement there
(because we record that in the `diverge` dict instead). For regular
copies/renames, there can be a disagreement. Let's say file "foo" was
copied to "bar" on one branch and file "baz" was copied to "bar" on
the other. Beacause we only return one `copy` dict, we end up
replacing the `{"bar": "foo"}` entry by `{"bar": "baz"}`. The merge
code (`manifestmerge()`) will then decide that that means "both
renamed from 'baz'". We should probably treat it as a conflict
instead.

The next few patches will make `mergecopies()` return two instances of
most of the returned copies. That will lead to a bit more code (~40
lines), but I think it makes both `copies.mergecopies()` and
`merge.manifestmerge()` clearer.

Differential Revision: https://phab.mercurial-scm.org/D7986

# 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'''

from __future__ import absolute_import, division

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,
)
from mercurial.utils import dateutil

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, fns):
    added, removed = 0, 0
    fmatch = scmutil.matchfiles(repo, fns)
    diff = b''.join(patch.diff(repo, ctx1.node(), ctx2.node(), fmatch))
    for l in diff.split(b'\n'):
        if l.startswith(b"+") and not l.startswith(b"+++ "):
            added += 1
        elif l.startswith(b"-") and not l.startswith(b"--- "):
            removed += 1
    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 = {}
    df = False
    if opts.get(b'date'):
        df = dateutil.matchdate(opts[b'date'])

    m = scmutil.match(repo[None], pats, opts)

    def prep(ctx, fns):
        rev = ctx.rev()
        if df and not df(ctx.date()[0]):  # doesn't match date format
            return

        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, fns)
            rate[key] = [r + l for r, l in zip(rate.get(key, (0, 0)), lines)]

        progress.increment()

    for ctx in cmdutil.walkchangerevs(repo, m, opts, 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

    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))