hgext/automv.py
author Pierre-Yves David <pierre-yves.david@octobus.net>
Tue, 13 Dec 2022 09:59:22 +0100
changeset 50057 cf8b9c80d67c
parent 50043 5cfc48354d0f
child 50124 18149ecb5122
permissions -rw-r--r--
dirstate: issue a developer warning on implicit write on wlock release Our goal is to get rid of all these to clarify the writing pattern, so it is time to warn about this (and later, forbid it).

# automv.py
#
# Copyright 2013-2016 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""check for unrecorded moves at commit time (EXPERIMENTAL)

This extension checks at commit/amend time if any of the committed files
comes from an unrecorded mv.

The threshold at which a file is considered a move can be set with the
``automv.similarity`` config option. This option takes a percentage between 0
(disabled) and 100 (files must be identical), the default is 95.

"""

# Using 95 as a default similarity is based on an analysis of the mercurial
# repositories of the cpython, mozilla-central & mercurial repositories, as
# well as 2 very large facebook repositories. At 95 50% of all potential
# missed moves would be caught, as well as correspond with 87% of all
# explicitly marked moves.  Together, 80% of moved files are 95% similar or
# more.
#
# See http://markmail.org/thread/5pxnljesvufvom57 for context.


from mercurial.i18n import _
from mercurial import (
    commands,
    copies,
    error,
    extensions,
    pycompat,
    registrar,
    scmutil,
    similar,
)

configtable = {}
configitem = registrar.configitem(configtable)

configitem(
    b'automv',
    b'similarity',
    default=95,
)


def extsetup(ui):
    entry = extensions.wrapcommand(commands.table, b'commit', mvcheck)
    entry[1].append(
        (b'', b'no-automv', None, _(b'disable automatic file move detection'))
    )


def mvcheck(orig, ui, repo, *pats, **opts):
    """Hook to check for moves at commit time"""
    opts = pycompat.byteskwargs(opts)
    renames = None
    disabled = opts.pop(b'no_automv', False)
    if not disabled:
        threshold = ui.configint(b'automv', b'similarity')
        if not 0 <= threshold <= 100:
            raise error.Abort(_(b'automv.similarity must be between 0 and 100'))
        if threshold > 0:
            match = scmutil.match(repo[None], pats, opts)
            added, removed = _interestingfiles(repo, match)
            uipathfn = scmutil.getuipathfn(repo, legacyrelativevalue=True)
            renames = _findrenames(
                repo, uipathfn, added, removed, threshold / 100.0
            )

    with repo.wlock():
        if renames is not None:
            with repo.dirstate.changing_files(repo):
                # XXX this should be wider and integrated with the commit
                # transaction. At the same time as we do the `addremove` logic
                # for commit.  However we can't really do better with the
                # current extension structure, and this is not worse than what
                # happened before.
                scmutil._markchanges(repo, (), (), renames)
        return orig(ui, repo, *pats, **pycompat.strkwargs(opts))


def _interestingfiles(repo, matcher):
    """Find what files were added or removed in this commit.

    Returns a tuple of two lists: (added, removed). Only files not *already*
    marked as moved are included in the added list.

    """
    stat = repo.status(match=matcher)
    added = stat.added
    removed = stat.removed

    copy = copies.pathcopies(repo[b'.'], repo[None], matcher)
    # remove the copy files for which we already have copy info
    added = [f for f in added if f not in copy]

    return added, removed


def _findrenames(repo, uipathfn, added, removed, similarity):
    """Find what files in added are really moved files.

    Any file named in removed that is at least similarity% similar to a file
    in added is seen as a rename.

    """
    renames = {}
    if similarity > 0:
        for src, dst, score in similar.findrenames(
            repo, added, removed, similarity
        ):
            if repo.ui.verbose:
                repo.ui.status(
                    _(b'detected move of %s as %s (%d%% similar)\n')
                    % (uipathfn(src), uipathfn(dst), score * 100)
                )
            renames[dst] = src
    if renames:
        repo.ui.status(_(b'detected move of %d files\n') % len(renames))
    return renames