1# Copyright (C) 2005-2010 Canonical Ltd
2#
3# This program is free software; you can redistribute it and/or modify
4# it under the terms of the GNU General Public License as published by
5# the Free Software Foundation; either version 2 of the License, or
6# (at your option) any later version.
7#
8# This program is distributed in the hope that it will be useful,
9# but WITHOUT ANY WARRANTY; without even the implied warranty of
10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11# GNU General Public License for more details.
12#
13# You should have received a copy of the GNU General Public License
14# along with this program; if not, write to the Free Software
15# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16
17from io import BytesIO
18
19from .lazy_import import lazy_import
20lazy_import(globals(), """
21from breezy import (
22    transport as _mod_transport,
23    urlutils,
24    )
25from breezy.bzr.bundle import serializer as _serializer
26from breezy.merge_directive import MergeDirective
27from breezy.i18n import gettext
28""")
29
30from . import (
31    errors,
32    )
33from .trace import note
34
35
36class Mergeable(object):
37    """A mergeable object."""
38
39    def install_revisions(self, repository):
40        """Install the data from this mergeable into the specified repository.
41
42        :param repository: Repository
43        """
44        raise NotImplementedError(self.install_revisions)
45
46    def get_merge_request(self, repository):
47        """Extract merge request data.
48
49        :return: tuple with (base_revision_id, target_revision_id, verified)
50        """
51        raise NotImplementedError(self.get_merge_request)
52
53
54def read_mergeable_from_url(url, _do_directive=True, possible_transports=None):
55    """Read mergable object from a given URL.
56
57    :return: An object supporting get_target_revision.  Raises NotABundle if
58        the target is not a mergeable type.
59    """
60    child_transport = _mod_transport.get_transport(
61        url, possible_transports=possible_transports)
62    transport = child_transport.clone('..')
63    filename = transport.relpath(child_transport.base)
64    mergeable, transport = read_mergeable_from_transport(transport, filename,
65                                                         _do_directive)
66    return mergeable
67
68
69def read_mergeable_from_transport(transport, filename, _do_directive=True):
70    def get_bundle(transport):
71        return BytesIO(transport.get_bytes(filename)), transport
72
73    def redirected_transport(transport, exception, redirection_notice):
74        note(redirection_notice)
75        url, filename = urlutils.split(exception.target,
76                                       exclude_trailing_slash=False)
77        if not filename:
78            raise errors.NotABundle(gettext('A directory cannot be a bundle'))
79        return _mod_transport.get_transport_from_url(url)
80
81    try:
82        bytef, transport = _mod_transport.do_catching_redirections(
83            get_bundle, transport, redirected_transport)
84    except errors.TooManyRedirections:
85        raise errors.NotABundle(transport.clone(filename).base)
86    except (errors.ConnectionReset, errors.ConnectionError) as e:
87        raise
88    except (errors.TransportError, errors.PathError) as e:
89        raise errors.NotABundle(str(e))
90    except (IOError,) as e:
91        # jam 20060707
92        # Abstraction leakage, SFTPTransport.get('directory')
93        # doesn't always fail at get() time. Sometimes it fails
94        # during read. And that raises a generic IOError with
95        # just the string 'Failure'
96        # StubSFTPServer does fail during get() (because of prefetch)
97        # so it has an opportunity to translate the error.
98        raise errors.NotABundle(str(e))
99
100    if _do_directive:
101        try:
102            return MergeDirective.from_lines(bytef), transport
103        except errors.NotAMergeDirective:
104            bytef.seek(0)
105
106    return _serializer.read_bundle(bytef), transport
107