annotate hgext/split.py @ 46472:98e39f04d60e

upgrade: implement partial upgrade for upgrading persistent-nodemap

Upgrading repositories to use persistent nodemap should be fast and easy as it
requires only two things:

1) Updating the requirements
2) Writing a persistent-nodemap on disk

For both of the steps above, we don't need to edit existing revlogs.

This patch makes upgrade only do the above mentioned two steps if we are
only upgarding to use persistent-nodemap feature.

Since `nodemap.persist_nodemap()` assumes that there exists a nodemap file for
the given revlog if we are trying to call it, this patch adds `force` argument
to create a file if does not exist which is true in our upgrade case.

The test changes demonstrate that we no longer write nodemap files for manifest
after upgrade which I think is desirable.

Differential Revision: https://phab.mercurial-scm.org/D9936

# split.py - split a changeset into smaller ones
#
# Copyright 2015 Laurent Charignon <[e-mail]>
# Copyright 2017 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.
"""command to split a changeset into smaller ones (EXPERIMENTAL)"""

from __future__ import absolute_import

from mercurial.i18n import _

from mercurial.node import (
    nullid,
    short,
)

from mercurial import (
    bookmarks,
    cmdutil,
    commands,
    error,
    hg,
    pycompat,
    registrar,
    revsetlang,
    rewriteutil,
    scmutil,
)

# allow people to use split without explicitly enabling rebase extension
from . import rebase

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'split',
    [
        (b'r', b'rev', b'', _(b"revision to split"), _(b'REV')),
        (b'', b'rebase', True, _(b'rebase descendants after split')),
    ]
    + cmdutil.commitopts2,
    _(b'hg split [--no-rebase] [[-r] REV]'),
    helpcategory=command.CATEGORY_CHANGE_MANAGEMENT,
    helpbasic=True,
)
def split(ui, repo, *revs, **opts):
    """split a changeset into smaller ones

    Repeatedly prompt changes and commit message for new changesets until there
    is nothing left in the original changeset.

    If --rev was not given, split the working directory parent.

    By default, rebase connected non-obsoleted descendants onto the new
    changeset. Use --no-rebase to avoid the rebase.
    """
    opts = pycompat.byteskwargs(opts)
    revlist = []
    if opts.get(b'rev'):
        revlist.append(opts.get(b'rev'))
    revlist.extend(revs)
    with repo.wlock(), repo.lock(), repo.transaction(b'split') as tr:
        revs = scmutil.revrange(repo, revlist or [b'.'])
        if len(revs) > 1:
            raise error.InputError(_(b'cannot split multiple revisions'))

        rev = revs.first()
        ctx = repo[rev]
        # Handle nullid specially here (instead of leaving for precheck()
        # below) so we get a nicer message and error code.
        if rev is None or ctx.node() == nullid:
            ui.status(_(b'nothing to split\n'))
            return 1
        if ctx.node() is None:
            raise error.InputError(_(b'cannot split working directory'))

        if opts.get(b'rebase'):
            # Skip obsoleted descendants and their descendants so the rebase
            # won't cause conflicts for sure.
            descendants = list(repo.revs(b'(%d::) - (%d)', rev, rev))
            torebase = list(
                repo.revs(
                    b'%ld - (%ld & obsolete())::', descendants, descendants
                )
            )
        else:
            torebase = []
        rewriteutil.precheck(repo, [rev] + torebase, b'split')

        if len(ctx.parents()) > 1:
            raise error.InputError(_(b'cannot split a merge changeset'))

        cmdutil.bailifchanged(repo)

        # Deactivate bookmark temporarily so it won't get moved unintentionally
        bname = repo._activebookmark
        if bname and repo._bookmarks[bname] != ctx.node():
            bookmarks.deactivate(repo)

        wnode = repo[b'.'].node()
        top = None
        try:
            top = dosplit(ui, repo, tr, ctx, opts)
        finally:
            # top is None: split failed, need update --clean recovery.
            # wnode == ctx.node(): wnode split, no need to update.
            if top is None or wnode != ctx.node():
                hg.clean(repo, wnode, show_stats=False)
            if bname:
                bookmarks.activate(repo, bname)
        if torebase and top:
            dorebase(ui, repo, torebase, top)


def dosplit(ui, repo, tr, ctx, opts):
    committed = []  # [ctx]

    # Set working parent to ctx.p1(), and keep working copy as ctx's content
    if ctx.node() != repo.dirstate.p1():
        hg.clean(repo, ctx.node(), show_stats=False)
    with repo.dirstate.parentchange():
        scmutil.movedirstate(repo, ctx.p1())

    # Any modified, added, removed, deleted result means split is incomplete
    def incomplete(repo):
        st = repo.status()
        return any((st.modified, st.added, st.removed, st.deleted))

    # Main split loop
    while incomplete(repo):
        if committed:
            header = _(
                b'HG: Splitting %s. So far it has been split into:\n'
            ) % short(ctx.node())
            # We don't want color codes in the commit message template, so
            # disable the label() template function while we render it.
            with ui.configoverride(
                {(b'templatealias', b'label(l,x)'): b"x"}, b'split'
            ):
                for c in committed:
                    summary = cmdutil.format_changeset_summary(ui, c, b'split')
                    header += _(b'HG: - %s\n') % summary
            header += _(
                b'HG: Write commit message for the next split changeset.\n'
            )
        else:
            header = _(
                b'HG: Splitting %s. Write commit message for the '
                b'first split changeset.\n'
            ) % short(ctx.node())
        opts.update(
            {
                b'edit': True,
                b'interactive': True,
                b'message': header + ctx.description(),
            }
        )
        commands.commit(ui, repo, **pycompat.strkwargs(opts))
        newctx = repo[b'.']
        committed.append(newctx)

    if not committed:
        raise error.InputError(_(b'cannot split an empty revision'))

    scmutil.cleanupnodes(
        repo,
        {ctx.node(): [c.node() for c in committed]},
        operation=b'split',
        fixphase=True,
    )

    return committed[-1]


def dorebase(ui, repo, src, destctx):
    rebase.rebase(
        ui,
        repo,
        rev=[revsetlang.formatspec(b'%ld', src)],
        dest=revsetlang.formatspec(b'%d', destctx.rev()),
    )