hgext/convert/transport.py

convert: allow the sink object to be wrapped when the extension isn't loaded

The next patch will wrap the conversion code, in order to write out a
requirement for 'lfs' when appropriate.  Wrapping convcmd.convertsink() in an
afterloaded callback works fine when the convert extension is enabled by the
user.  The problem here is that lfconvert uses the convert extension, whether or
not it was formally enabled by the user.

My first attempt was to have lfs install an afterloaded callback that would wrap
the convert sink if convert was loaded, or wrap lfconvert if it wasn't.  Then
the lfconvert override could install an afterloaded callback to try wrapping the
convert sink again, before calling the original lfconvert.  But that breaks down
if largefiles can't load the convert extension on the fly. [1]  Further, some
tests were failing with an error indicating that the size of the afterloaded
list changed while iterating it.

Yuya mentioned that maybe some bits of convert could be moved into core, but I'm
not sure where to draw that line.  The convertsink() method depends on the list
of sinks, which in turn depends on the sink classes.

[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-November/108038.html

# -*- 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))