~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005-2010 Canonical Ltd

#

# 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, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

from cStringIO import StringIO

from bzrlib.lazy_import import lazy_import

lazy_import(globals(), """

from bzrlib import (

    errors,

    transport as _mod_transport,

    urlutils,

    )

from bzrlib.bundle import serializer as _serializer

from bzrlib.merge_directive import MergeDirective

from bzrlib.i18n import gettext

""")

from bzrlib.trace import note

def read_mergeable_from_url(url, _do_directive=True, possible_transports=None):

    """Read mergable object from a given URL.

    :return: An object supporting get_target_revision.  Raises NotABundle if

        the target is not a mergeable type.

    """

    child_transport = _mod_transport.get_transport(url,

        possible_transports=possible_transports)

    transport = child_transport.clone('..')

    filename = transport.relpath(child_transport.base)

    mergeable, transport = read_mergeable_from_transport(transport, filename,

                                                         _do_directive)

    return mergeable

def read_mergeable_from_transport(transport, filename, _do_directive=True):

    def get_bundle(transport):

        return StringIO(transport.get_bytes(filename)), transport

    def redirected_transport(transport, exception, redirection_notice):

        note(redirection_notice)

        url, filename = urlutils.split(exception.target,

                                       exclude_trailing_slash=False)

        if not filename:

            raise errors.NotABundle(gettext('A directory cannot be a bundle'))

        return _mod_transport.get_transport_from_url(url)

    try:

        bytef, transport = _mod_transport.do_catching_redirections(

            get_bundle, transport, redirected_transport)

    except errors.TooManyRedirections:

        raise errors.NotABundle(transport.clone(filename).base)

    except (errors.ConnectionReset, errors.ConnectionError), e:

        raise

    except (errors.TransportError, errors.PathError), e:

        raise errors.NotABundle(str(e))

    except (IOError,), e:

        # jam 20060707

        # Abstraction leakage, SFTPTransport.get('directory')

        # doesn't always fail at get() time. Sometimes it fails

        # during read. And that raises a generic IOError with

        # just the string 'Failure'

        # StubSFTPServer does fail during get() (because of prefetch)

        # so it has an opportunity to translate the error.

        raise errors.NotABundle(str(e))

    if _do_directive:

        try:

            return MergeDirective.from_lines(bytef), transport

        except errors.NotAMergeDirective:

            bytef.seek(0)

    return _serializer.read_bundle(bytef), transport