hgext/commitextras.py

verify: start to abstract file verification

Currently, the file storage interface has a handful of attributes
that are exclusively or near-exclusively used by repo verification
code. In order to support verification on non-revlog/alternate
storage backends, we'll need to abstract verification so it can
be performed in a storage-agnostic way.

This commit starts that process.

We establish a new verifyintegrity() method on revlogs and expose
it to the file storage interface. Most of verify.verifier.checklog()
has been ported to this new method.

We need a way to represent verification problems. So we invent an
interface to represent a verification problem, invent a revlog type
to implement that interface, and use it.

The arguments to verifyintegrity() will almost certainly change in
the future, once more functionality is ported from the verify code.
And the "revlogv1" version check is very hacky. (The code in verify
is actually buggy because it is comparing the full 32-bit header
integer instead of just the revlog version short. I'll likely fix
this in a subsequent commit.)

Differential Revision: https://phab.mercurial-scm.org/D4701

# commitextras.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.

'''adds a new flag extras to commit (ADVANCED)'''

from __future__ import absolute_import

import re

from mercurial.i18n import _
from mercurial import (
    commands,
    error,
    extensions,
    registrar,
    util,
)

cmdtable = {}
command = registrar.command(cmdtable)
testedwith = 'ships-with-hg-core'

usedinternally = {
    'amend_source',
    'branch',
    'close',
    'histedit_source',
    'topic',
    'rebase_source',
    'intermediate-source',
    '__touch-noise__',
    'source',
    'transplant_source',
}

def extsetup(ui):
    entry = extensions.wrapcommand(commands.table, 'commit', _commit)
    options = entry[1]
    options.append(('', 'extra', [],
        _('set a changeset\'s extra values'), _("KEY=VALUE")))

def _commit(orig, ui, repo, *pats, **opts):
    if util.safehasattr(repo, 'unfiltered'):
        repo = repo.unfiltered()
    class repoextra(repo.__class__):
        def commit(self, *innerpats, **inneropts):
            extras = opts.get(r'extra')
            for raw in extras:
                if '=' not in raw:
                    msg = _("unable to parse '%s', should follow "
                            "KEY=VALUE format")
                    raise error.Abort(msg % raw)
                k, v = raw.split('=', 1)
                if not k:
                    msg = _("unable to parse '%s', keys can't be empty")
                    raise error.Abort(msg % raw)
                if re.search('[^\w-]', k):
                    msg = _("keys can only contain ascii letters, digits,"
                            " '_' and '-'")
                    raise error.Abort(msg)
                if k in usedinternally:
                    msg = _("key '%s' is used internally, can't be set "
                            "manually")
                    raise error.Abort(msg % k)
                inneropts[r'extra'][k] = v
            return super(repoextra, self).commit(*innerpats, **inneropts)
    repo.__class__ = repoextra
    return orig(ui, repo, *pats, **opts)