~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005, 2006 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

from StringIO import StringIO

from bzrlib.lazy_import import lazy_import

lazy_import(globals(), """

from bzrlib import (

    errors,

    urlutils,

    )

from bzrlib.bundle import serializer as _serializer

from bzrlib.transport import (

    do_catching_redirections,

    get_transport,

    )

""")

from bzrlib.trace import note

def read_bundle_from_url(url):

    return read_mergeable_from_url(url, _do_directive=False)

def read_mergeable_from_url(url, _do_directive=True):

    """Read mergable object from a given URL.

    :return: An object supporting get_target_revision.  Raises NotABundle if

        the target is not a mergeable type.

    """

    from bzrlib.merge_directive import MergeDirective

    url = urlutils.normalize_url(url)

    url, filename = urlutils.split(url, exclude_trailing_slash=False)

    if not filename:

        # A path to a directory was passed in

        # definitely not a bundle

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

    # All of this must be in the try/except

    # Some transports cannot detect that we are trying to read a

    # directory until we actually issue read() on the handle.

    try:

        transport = get_transport(url)

        def get_bundle(transport):

            return transport.get(filename)

        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('A directory cannot be a bundle')

            return get_transport(url)

        try:

            f = do_catching_redirections(get_bundle, transport,

                                         redirected_transport)

        except errors.TooManyRedirections:

            raise errors.NotABundle(str(url))

        if _do_directive:

            directive = MergeDirective.from_lines(f.readlines())

            return directive

        else:

            return _serializer.read_bundle(f)

    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))

    except errors.NotAMergeDirective:

        f.seek(0)

        return _serializer.read_bundle(f)