annotate mercurial/upgrade.py @ 46236:eec47efe219d

sharesafe: add functionality to automatically downgrade shares

Reasoning is same as previous patch which adds automatic upgrade support.

Downgrade is required as if automatic upgrade is enabled, all shares upgrade and
then source repository downgrades, shares won't work. We need to downgrade them.

Differential Revision: https://phab.mercurial-scm.org/D9680

# upgrade.py - functions for in place upgrade of Mercurial repository
#
# Copyright (c) 2016-present, Gregory Szorc
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

from .i18n import _
from . import (
    error,
    hg,
    localrepo,
    lock as lockmod,
    pycompat,
    requirements as requirementsmod,
    scmutil,
)

from .upgrade_utils import (
    actions as upgrade_actions,
    engine as upgrade_engine,
)

from .utils import (
    stringutil,
)

allformatvariant = upgrade_actions.allformatvariant


def upgraderepo(
    ui,
    repo,
    run=False,
    optimize=None,
    backup=True,
    manifest=None,
    changelog=None,
    filelogs=None,
):
    """Upgrade a repository in place."""
    if optimize is None:
        optimize = {}
    repo = repo.unfiltered()

    revlogs = set(upgrade_engine.UPGRADE_ALL_REVLOGS)
    specentries = (
        (upgrade_engine.UPGRADE_CHANGELOG, changelog),
        (upgrade_engine.UPGRADE_MANIFEST, manifest),
        (upgrade_engine.UPGRADE_FILELOGS, filelogs),
    )
    specified = [(y, x) for (y, x) in specentries if x is not None]
    if specified:
        # we have some limitation on revlogs to be recloned
        if any(x for y, x in specified):
            revlogs = set()
            for upgrade, enabled in specified:
                if enabled:
                    revlogs.add(upgrade)
        else:
            # none are enabled
            for upgrade, __ in specified:
                revlogs.discard(upgrade)

    # Ensure the repository can be upgraded.
    upgrade_actions.check_source_requirements(repo)

    default_options = localrepo.defaultcreateopts(repo.ui)
    newreqs = localrepo.newreporequirements(repo.ui, default_options)
    newreqs.update(upgrade_actions.preservedrequirements(repo))

    upgrade_actions.check_requirements_changes(repo, newreqs)

    # Find and validate all improvements that can be made.
    alloptimizations = upgrade_actions.findoptimizations(repo)

    # Apply and Validate arguments.
    optimizations = []
    for o in alloptimizations:
        if o.name in optimize:
            optimizations.append(o)
            optimize.discard(o.name)

    if optimize:  # anything left is unknown
        raise error.Abort(
            _(b'unknown optimization action requested: %s')
            % b', '.join(sorted(optimize)),
            hint=_(b'run without arguments to see valid optimizations'),
        )

    format_upgrades = upgrade_actions.find_format_upgrades(repo)
    up_actions = upgrade_actions.determine_upgrade_actions(
        repo, format_upgrades, optimizations, repo.requirements, newreqs
    )
    removed_actions = upgrade_actions.find_format_downgrades(repo)

    removedreqs = repo.requirements - newreqs
    addedreqs = newreqs - repo.requirements

    if revlogs != upgrade_engine.UPGRADE_ALL_REVLOGS:
        incompatible = upgrade_actions.RECLONES_REQUIREMENTS & (
            removedreqs | addedreqs
        )
        if incompatible:
            msg = _(
                b'ignoring revlogs selection flags, format requirements '
                b'change: %s\n'
            )
            ui.warn(msg % b', '.join(sorted(incompatible)))
            revlogs = upgrade_engine.UPGRADE_ALL_REVLOGS

    upgrade_op = upgrade_actions.UpgradeOperation(
        ui,
        newreqs,
        repo.requirements,
        up_actions,
        removed_actions,
        revlogs,
    )

    if not run:
        fromconfig = []
        onlydefault = []

        for d in format_upgrades:
            if d.fromconfig(repo):
                fromconfig.append(d)
            elif d.default:
                onlydefault.append(d)

        if fromconfig or onlydefault:

            if fromconfig:
                ui.status(
                    _(
                        b'repository lacks features recommended by '
                        b'current config options:\n\n'
                    )
                )
                for i in fromconfig:
                    ui.status(b'%s\n   %s\n\n' % (i.name, i.description))

            if onlydefault:
                ui.status(
                    _(
                        b'repository lacks features used by the default '
                        b'config options:\n\n'
                    )
                )
                for i in onlydefault:
                    ui.status(b'%s\n   %s\n\n' % (i.name, i.description))

            ui.status(b'\n')
        else:
            ui.status(_(b'(no format upgrades found in existing repository)\n'))

        ui.status(
            _(
                b'performing an upgrade with "--run" will make the following '
                b'changes:\n\n'
            )
        )

        upgrade_op.print_requirements()
        upgrade_op.print_optimisations()
        upgrade_op.print_upgrade_actions()
        upgrade_op.print_affected_revlogs()

        if upgrade_op.unused_optimizations:
            ui.status(
                _(
                    b'additional optimizations are available by specifying '
                    b'"--optimize <name>":\n\n'
                )
            )
            upgrade_op.print_unused_optimizations()
        return

    if not (upgrade_op.upgrade_actions or upgrade_op.removed_actions):
        ui.status(_(b'nothing to do\n'))
        return
    # Else we're in the run=true case.
    ui.write(_(b'upgrade will perform the following actions:\n\n'))
    upgrade_op.print_requirements()
    upgrade_op.print_optimisations()
    upgrade_op.print_upgrade_actions()
    upgrade_op.print_affected_revlogs()

    ui.status(_(b'beginning upgrade...\n'))
    with repo.wlock(), repo.lock():
        ui.status(_(b'repository locked and read-only\n'))
        # Our strategy for upgrading the repository is to create a new,
        # temporary repository, write data to it, then do a swap of the
        # data. There are less heavyweight ways to do this, but it is easier
        # to create a new repo object than to instantiate all the components
        # (like the store) separately.
        tmppath = pycompat.mkdtemp(prefix=b'upgrade.', dir=repo.path)
        backuppath = None
        try:
            ui.status(
                _(
                    b'creating temporary repository to stage upgraded '
                    b'data: %s\n'
                )
                % tmppath
            )

            # clone ui without using ui.copy because repo.ui is protected
            repoui = repo.ui.__class__(repo.ui)
            dstrepo = hg.repository(repoui, path=tmppath, create=True)

            with dstrepo.wlock(), dstrepo.lock():
                backuppath = upgrade_engine.upgrade(
                    ui, repo, dstrepo, upgrade_op
                )
            if not backup:
                ui.status(
                    _(b'removing old repository content %s\n') % backuppath
                )
                repo.vfs.rmtree(backuppath, forcibly=True)
                backuppath = None

        finally:
            ui.status(_(b'removing temporary repository %s\n') % tmppath)
            repo.vfs.rmtree(tmppath, forcibly=True)

            if backuppath and not ui.quiet:
                ui.warn(
                    _(b'copy of old repository backed up at %s\n') % backuppath
                )
                ui.warn(
                    _(
                        b'the old repository will not be deleted; remove '
                        b'it to free up disk space once the upgraded '
                        b'repository is verified\n'
                    )
                )

            upgrade_op.print_post_op_messages()


def upgrade_share_to_safe(ui, hgvfs, storevfs, current_requirements):
    """Upgrades a share to use share-safe mechanism"""
    wlock = None
    try:
        wlock = lockmod.trylock(ui, hgvfs, b'wlock', 0, 0)
        store_requirements = localrepo._readrequires(storevfs, False)
        # after upgrade, store requires will be shared, so lets find
        # the requirements which are not present in store and
        # write them to share's .hg/requires
        diffrequires = current_requirements - store_requirements
        # add share-safe requirement as it will mark the share as share-safe
        diffrequires.add(requirementsmod.SHARESAFE_REQUIREMENT)
        scmutil.writerequires(hgvfs, diffrequires)
        current_requirements.add(requirementsmod.SHARESAFE_REQUIREMENT)
        ui.warn(_(b'repository upgraded to use share-safe mode\n'))
    except error.LockError as e:
        ui.warn(
            _(b'failed to upgrade share, got error: %s\n')
            % stringutil.forcebytestr(e.strerror)
        )
    finally:
        if wlock:
            wlock.release()


def downgrade_share_to_non_safe(
    ui,
    hgvfs,
    sharedvfs,
    current_requirements,
):
    """Downgrades a share which use share-safe to not use it"""
    wlock = None
    try:
        wlock = lockmod.trylock(ui, hgvfs, b'wlock', 0, 0)
        source_requirements = localrepo._readrequires(sharedvfs, True)
        # we cannot be 100% sure on which requirements were present in store when
        # the source supported share-safe. However, we do know that working
        # directory requirements were not there. Hence we remove them
        source_requirements -= requirementsmod.WORKING_DIR_REQUIREMENTS
        current_requirements |= source_requirements
        current_requirements.remove(requirementsmod.SHARESAFE_REQUIREMENT)
        scmutil.writerequires(hgvfs, current_requirements)
        ui.warn(_(b'repository downgraded to not use share-safe mode\n'))
    except error.LockError as e:
        # raise error right away because if downgrade failed, we cannot load
        # the repository because it does not have complete set of requirements
        raise error.Abort(
            _(b'failed to downgrade share, got error: %s')
            % stringutil.forcebytestr(e.strerror)
        )
    finally:
        if wlock:
            wlock.release()