~launchpad-pqm/launchpad/devel

#!/usr/bin/python -S

#

# Copyright 2009 Canonical Ltd.  This software is licensed under the

# GNU Affero General Public License version 3 (see the file LICENSE).

# pylint: disable-msg=W0403

"""Update stacked_on_location for all Bazaar branches.

Expects standard input of:

    '<id> <branch_type> <unique_name> <stacked_on_unique_name>\n'.

Such input can be provided using "get-stacked-on-branches.py".

This script makes the stacked_on_location variables in all Bazaar branches

match the stacked_on column in the Launchpad database. This is useful for

updating stacked branches when their stacked-on branch has been moved or

renamed.

"""

__metaclass__ = type

import _pythonpath

import sys

from bzrlib.bzrdir import BzrDir

from bzrlib.config import TransportConfig

from bzrlib import errors

from lp.codehosting.vfs import get_rw_server, get_ro_server

from lp.codehosting.bzrutils import get_branch_stacked_on_url

from lp.services.scripts.base import LaunchpadScript

def set_branch_stacked_on_url(bzrdir, stacked_on_url):

    """Set the stacked_on_location for the branch at 'bzrdir'.

    We cannot use Branch.set_stacked_on, since that requires us to first open

    the branch. Opening the branch requires a working stacked_on_url:

    something we don't yet have.

    """

    branch_transport = bzrdir.get_branch_transport(None)

    branch_config = TransportConfig(branch_transport, 'branch.conf')

    stacked_on_url = branch_config.set_option(

        stacked_on_url, 'stacked_on_location')

class UpdateStackedBranches(LaunchpadScript):

    """Update stacked branches so their stacked_on_location matches the db."""

    def __init__(self):

        super(UpdateStackedBranches, self).__init__('update-stacked-on')

    def add_my_options(self):

        self.parser.add_option(

            '-n', '--dry-run', default=False, action="store_true",

            dest="dry_run",

            help=("Don't change anything on disk, just go through the "

                  "motions."))

    def main(self):

        if self.options.dry_run:

            server = get_ro_server()

        else:

            server = get_rw_server()

        server.start_server()

        if self.options.dry_run:

            self.logger.debug('Running read-only')

        self.logger.debug('Beginning processing')

        try:

            self.updateBranches(self.parseFromStream(sys.stdin))

        finally:

            server.stop_server()

        self.logger.info('Done')

    def updateStackedOn(self, branch_id, bzr_branch_url, stacked_on_location):

        """Stack the Bazaar branch at 'bzr_branch_url' on the given URL.

        :param branch_id: The database ID of the branch. This is only used for

            logging.

        :param bzr_branch_url: The lp-internal:/// URL of the Bazaar branch.

        :param stacked_on_location: The location to store in the branch's

            stacked_on_location configuration variable.

        """

        try:

            bzrdir = BzrDir.open(bzr_branch_url)

        except errors.NotBranchError:

            self.logger.warn(

                "No bzrdir for %r at %r" % (branch_id, bzr_branch_url))

            return

        try:

            current_stacked_on_location = get_branch_stacked_on_url(bzrdir)

        except errors.NotBranchError:

            self.logger.warn(

                "No branch for %r at %r" % (branch_id, bzr_branch_url))

        except errors.NotStacked:

            self.logger.warn(

                "Branch for %r at %r is not stacked at all. Giving up."

                % (branch_id, bzr_branch_url))

        except errors.UnstackableBranchFormat:

            self.logger.error(

                "Branch for %r at %r is unstackable. Giving up."

                % (branch_id, bzr_branch_url))

        else:

            if current_stacked_on_location != stacked_on_location:

                self.logger.info(

                    'Branch for %r at %r stacked on %r, should be on %r.'

                    % (branch_id, bzr_branch_url, current_stacked_on_location,

                       stacked_on_location))

                if not self.options.dry_run:

                    set_branch_stacked_on_url(bzrdir, stacked_on_location)

    def parseFromStream(self, stream):

        """Parse branch input from the given stream.

        Expects the stream to be populated only by blank lines or by lines

        with whitespace-separated fields. Such lines are yielded as tuples.

        Blank lines are ignored.

        """

        for line in stream.readlines():

            if not line.strip():

                continue

            yield line.split()

    def updateBranches(self, branches):

        """Update the stacked_on_location for all branches in 'branches'.

        :param branches: An iterator yielding (branch_id, branch_type,

            unique_name, stacked_on_unique_name).

        """

        for branch_info in branches:

            (branch_id, branch_type, unique_name,

             stacked_on_name) = branch_info

            stacked_on_location = '/' + stacked_on_name

            self.updateStackedOn(

                branch_id, 'lp-internal:///' + unique_name,

                stacked_on_location)

if __name__ == '__main__':

    UpdateStackedBranches().lock_and_run()