sapling/backups.py

# backups.py
#
# Copyright 2013 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.
"""display recently made backups to recover stripped commits"""

from mercurial import extensions, cmdutil, commands, error, bundlerepo
from mercurial import hg, changegroup, exchange, obsolete
from mercurial import bundle2
from mercurial import lock as lockmod
from hgext import pager
from mercurial.node import nullid, short
from mercurial.i18n import _
import os, glob, time

pager.attended.append('backups')

cmdtable = {}
command = cmdutil.command(cmdtable)
testedwith = 'internal'
msgwithcreatermarkers = """Marker creation is enabled so no commit should be
stripped unless you explicitly called hg strip. hg backups will show you the
stripped commits.  If you are trying to recover a commit hidden from a previous
command, use hg reflog to get its sha1 and you will be able to access it
directly without recovering a backup."""
verbosetemplate = "{label('status.modified', node|short)} {desc|firstline}\n"

@command('^backups', [
    ('', 'recover', '', 'brings the specified commit back into the repository')
    ] + commands.logopts, _('hg backups [--recover HASH]'))
def backups(ui, repo, *pats, **opts):
    '''lists the commits available in backup bundles

    Without any arguments, this command prints a list of the commits in each
    backup bundle.

    --recover takes a commit hash and unbundles the first bundle that contains
    that commit hash, which puts that commit back in your repository.

    --verbose will print the entire commit message and the bundle path for that
    backup.
    '''
    supportsmarkers = obsolete.isenabled(repo, obsolete.createmarkersopt)
    if supportsmarkers:
        # Warn users of obsolescence markers that they probably don't want to
        # use backups but reflog instead
        ui.warn(msgwithcreatermarkers)
    backuppath = repo.join("strip-backup")
    backups = filter(os.path.isfile, glob.glob(backuppath + "/*.hg"))
    backups.sort(key=lambda x: os.path.getmtime(x), reverse=True)

    opts['bundle'] = ''
    opts['force'] = None

    def display(other, chlist, displayer):
        limit = cmdutil.loglimit(opts)
        if opts.get('newest_first'):
            chlist.reverse()
        count = 0
        for n in chlist:
            if limit is not None and count >= limit:
                break
            parents = [p for p in other.changelog.parents(n) if p != nullid]
            if opts.get('no_merges') and len(parents) == 2:
                continue
            count += 1
            displayer.show(other[n])

    recovernode = opts.get('recover')
    if recovernode:
        if recovernode in repo:
            ui.warn("%s already exists in the repo\n" % recovernode)
            return
    else:
        msg = _("Recover commits using: hg backups --recover <commit hash>\n")
        ui.status(msg, label="status.removed")

    for backup in backups:
        # Much of this is copied from the hg incoming logic
        source = os.path.relpath(backup, os.getcwd())
        source = ui.expandpath(source)
        source, branches = hg.parseurl(source, opts.get('branch'))
        try:
            other = hg.peer(repo, opts, source)
        except error.LookupError as ex:
            msg = _("\nwarning: unable to open bundle %s") % source
            hint = _("\n(missing parent rev %s)\n") % short(ex.name)
            ui.warn(msg)
            ui.warn(hint)
            continue
        revs, checkout = hg.addbranchrevs(repo, other, branches,
                                          opts.get('rev'))

        if revs:
            revs = [other.lookup(rev) for rev in revs]

        quiet = ui.quiet
        try:
            ui.quiet = True
            other, chlist, cleanupfn = bundlerepo.getremotechanges(ui, repo,
                                        other, revs, opts["bundle"],
                                        opts["force"])
        except error.LookupError:
            continue
        finally:
            ui.quiet = quiet

        try:
            if chlist:
                if recovernode:
                    tr = lock = None
                    try:
                        lock = repo.lock()
                        if recovernode in other:
                            ui.status(_("Unbundling %s\n") % (recovernode))
                            f = hg.openpath(ui, source)
                            gen = exchange.readbundle(ui, f, source)
                            tr = repo.transaction("unbundle")
                            if not isinstance(gen, bundle2.unbundle20):
                                gen.apply(repo, 'unbundle', 'bundle:' + source)
                            if isinstance(gen, bundle2.unbundle20):
                                bundle2.applybundle(repo, gen, tr,
                                                    source='unbundle',
                                                    url='bundle:' + source)
                            tr.close()
                            break
                    finally:
                        lockmod.release(lock, tr)
                else:
                    backupdate = os.path.getmtime(source)
                    backupdate = time.strftime('%a %H:%M, %Y-%m-%d',
                                                time.localtime(backupdate))
                    ui.status("\n%s\n" % (backupdate.ljust(50)))
                    if not ui.verbose:
                        opts['template'] = verbosetemplate
                    else:
                        ui.status("%s%s\n" % ("bundle:".ljust(13), source))
                    displayer = cmdutil.show_changeset(ui, other, opts, False)
                    display(other, chlist, displayer)
                    displayer.close()
        finally:
            cleanupfn()