hgext/convert/transport.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

# -*- coding: utf-8 -*-

# Copyright (C) 2007 Daniel Holth <[e-mail]>
# This is a stripped-down version of the original bzr-svn transport.py,
# Copyright (C) 2006 Jelmer Vernooij <[e-mail]>

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, see <http://www.gnu.org/licenses/>.
from __future__ import absolute_import

import svn.client
import svn.core
import svn.ra

Pool = svn.core.Pool
SubversionException = svn.core.SubversionException

from mercurial import (
    util,
)

# Some older versions of the Python bindings need to be
# explicitly initialized. But what we want to do probably
# won't work worth a darn against those libraries anyway!
svn.ra.initialize()

svn_config = None

def _create_auth_baton(pool):
    """Create a Subversion authentication baton. """
    import svn.client
    # Give the client context baton a suite of authentication
    # providers.h
    providers = [
        svn.client.get_simple_provider(pool),
        svn.client.get_username_provider(pool),
        svn.client.get_ssl_client_cert_file_provider(pool),
        svn.client.get_ssl_client_cert_pw_file_provider(pool),
        svn.client.get_ssl_server_trust_file_provider(pool),
        ]
    # Platform-dependent authentication methods
    getprovider = getattr(svn.core, 'svn_auth_get_platform_specific_provider',
                          None)
    if getprovider:
        # Available in svn >= 1.6
        for name in ('gnome_keyring', 'keychain', 'kwallet', 'windows'):
            for type in ('simple', 'ssl_client_cert_pw', 'ssl_server_trust'):
                p = getprovider(name, type, pool)
                if p:
                    providers.append(p)
    else:
        if util.safehasattr(svn.client, 'get_windows_simple_provider'):
            providers.append(svn.client.get_windows_simple_provider(pool))

    return svn.core.svn_auth_open(providers, pool)

class NotBranchError(SubversionException):
    pass

class SvnRaTransport(object):
    """
    Open an ra connection to a Subversion repository.
    """
    def __init__(self, url="", ra=None):
        self.pool = Pool()
        self.svn_url = url
        self.username = ''
        self.password = ''

        # Only Subversion 1.4 has reparent()
        if ra is None or not util.safehasattr(svn.ra, 'reparent'):
            self.client = svn.client.create_context(self.pool)
            ab = _create_auth_baton(self.pool)
            self.client.auth_baton = ab
            global svn_config
            if svn_config is None:
                svn_config = svn.core.svn_config_get_config(None)
            self.client.config = svn_config
            try:
                self.ra = svn.client.open_ra_session(
                    self.svn_url,
                    self.client, self.pool)
            except SubversionException as xxx_todo_changeme:
                (inst, num) = xxx_todo_changeme.args
                if num in (svn.core.SVN_ERR_RA_ILLEGAL_URL,
                           svn.core.SVN_ERR_RA_LOCAL_REPOS_OPEN_FAILED,
                           svn.core.SVN_ERR_BAD_URL):
                    raise NotBranchError(url)
                raise
        else:
            self.ra = ra
            svn.ra.reparent(self.ra, self.svn_url.encode('utf8'))

    class Reporter(object):
        def __init__(self, reporter_data):
            self._reporter, self._baton = reporter_data

        def set_path(self, path, revnum, start_empty, lock_token, pool=None):
            svn.ra.reporter2_invoke_set_path(self._reporter, self._baton,
                        path, revnum, start_empty, lock_token, pool)

        def delete_path(self, path, pool=None):
            svn.ra.reporter2_invoke_delete_path(self._reporter, self._baton,
                    path, pool)

        def link_path(self, path, url, revision, start_empty, lock_token,
                      pool=None):
            svn.ra.reporter2_invoke_link_path(self._reporter, self._baton,
                    path, url, revision, start_empty, lock_token,
                    pool)

        def finish_report(self, pool=None):
            svn.ra.reporter2_invoke_finish_report(self._reporter,
                    self._baton, pool)

        def abort_report(self, pool=None):
            svn.ra.reporter2_invoke_abort_report(self._reporter,
                    self._baton, pool)

    def do_update(self, revnum, path, *args, **kwargs):
        return self.Reporter(svn.ra.do_update(self.ra, revnum, path,
                                              *args, **kwargs))