mercurial/upgrade.py

upgrade: take lock only for part where it's required

The final config calculation code does not require a lock, only writing it back
does require one.

Differential Revision: https://phab.mercurial-scm.org/D9783

# 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
    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)
    current_requirements.add(requirementsmod.SHARESAFE_REQUIREMENT)
    try:
        wlock = lockmod.trylock(ui, hgvfs, b'wlock', 0, 0)
        scmutil.writerequires(hgvfs, diffrequires)
        ui.warn(_(b'repository upgraded to use share-safe mode\n'))
    except error.LockError as e:
        if ui.configbool(b'experimental', b'sharesafe-auto-upgrade-fail-error'):
            raise error.Abort(
                _(b'failed to upgrade share, got error: %s')
                % stringutil.forcebytestr(e.strerror)
            )
        elif ui.configbool(b'experimental', b'sharesafe-warn-outdated-shares'):
            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
    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)

    try:
        wlock = lockmod.trylock(ui, hgvfs, b'wlock', 0, 0)
        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()