except Exception:

            log.error(traceback.format_exc())

            h.flash(_('error occurred during update of repos group %s') \

                    % request.POST.get('group_name'), category='error')

        return redirect(url('repos_groups'))

    @HasPermissionAnyDecorator('hg.admin')

    def delete(self, id):

        """DELETE /repos_groups/id: Delete an existing item"""

        # Forms posted to this method should contain a hidden field:

        #    <input type="hidden" name="_method" value="DELETE" />

        # Or using helpers:

        #    h.form(url('repos_group', id=ID),

        #           method='delete')

        # url('repos_group', id=ID)

        gr = RepoGroup.get(id)

        repos = gr.repositories.all()

        if repos:

            h.flash(_('This group contains %s repositores and cannot be '

                      'deleted' % len(repos)),

                    category='error')

            return redirect(url('repos_groups'))

        try:

            ReposGroupModel().delete(id)

            Session.commit()

            h.flash(_('removed repos group %s' % gr.group_name), category='success')

            #TODO: in future action_logger(, '', '', '', self.sa)

        except IntegrityError, e:

            if e.message.find('groups_group_parent_id_fkey') != -1:

                log.error(traceback.format_exc())

                h.flash(_('Cannot delete this group it still contains '

                          'subgroups'),

                        category='warning')

            else:

                log.error(traceback.format_exc())

                h.flash(_('error occurred during deletion of repos '

                          'group %s' % gr.group_name), category='error')

        except Exception:

            log.error(traceback.format_exc())

            h.flash(_('error occurred during deletion of repos '

                      'group %s' % gr.group_name), category='error')

        return redirect(url('repos_groups'))

    def show_by_name(self, group_name):

        id_ = RepoGroup.get_by_group_name(group_name).group_id

        return self.show(id_)

    def show(self, id, format='html'):

        """GET /repos_groups/id: Show a specific item"""

        # url('repos_group', id=ID)

        c.group = RepoGroup.get(id)

        if c.group:

            c.group_repos = c.group.repositories.all()

        else:

            return redirect(url('home'))

        #overwrite our cached list with current filter

        gr_filter = c.group_repos

        c.cached_repo_list = self.scm_model.get_repos(all_repos=gr_filter)

        c.repos_list = c.cached_repo_list

        c.repo_cnt = 0

        c.groups = self.sa.query(RepoGroup).order_by(RepoGroup.group_name)\

            .filter(RepoGroup.group_parent_id == id).all()

        return render('admin/repos_groups/repos_groups.html')

    @HasPermissionAnyDecorator('hg.admin')

    def edit(self, id, format='html'):

        """GET /repos_groups/id/edit: Form to edit an existing item"""

        # url('edit_repos_group', id=ID)

        id_ = int(id)

        c.repos_group = RepoGroup.get(id_)

        defaults = self.__load_data(id_)

        # we need to exclude this group from the group list for editing

        c.repo_groups = filter(lambda x:x[0] != id_, c.repo_groups)

        return htmlfill.render(

            render('admin/repos_groups/repos_groups_edit.html'),

            defaults=defaults,

            encoding="UTF-8",

            force_defaults=False

        )

            return jsonrpc_error(message='This method [%s] does not support '

                                 'authentication (missing %s param)' %

                                 (self._func.__name__, USER_SESSION_ATTR))

        # get our arglist and check if we provided them as args

        for arg, default in func_kwargs.iteritems():

            if arg == USER_SESSION_ATTR:

                # USER_SESSION_ATTR is something translated from api key and

                # this is checked before so we don't need validate it

                continue

            # skip the required param check if it's default value is

            # NotImplementedType (default_empty)

            if (default == default_empty and arg not in self._request_params):

                return jsonrpc_error(

                    message=(

                        'Missing non optional `%s` arg in JSON DATA' % arg

                    )

                )

        self._rpc_args = {USER_SESSION_ATTR: u}

        self._rpc_args.update(self._request_params)

        self._rpc_args['action'] = self._req_method

        self._rpc_args['environ'] = environ

        self._rpc_args['start_response'] = start_response

        status = []

        headers = []

        exc_info = []

        def change_content(new_status, new_headers, new_exc_info=None):

            status.append(new_status)

            headers.extend(new_headers)

            exc_info.append(new_exc_info)

        output = WSGIController.__call__(self, environ, change_content)

        output = list(output)

        headers.append(('Content-Length', str(len(output[0]))))

        replace_header(headers, 'Content-Type', 'application/json')

        start_response(status[0], headers, exc_info[0])

        return output

    def _dispatch_call(self):

        """

        Implement dispatch interface specified by WSGIController

        """

        try:

            raw_response = self._inspect_call(self._func)

            if isinstance(raw_response, HTTPError):

                self._error = str(raw_response)

        except JSONRPCError, e:

            self._error = str(e)

        except Exception, e:

            log.error('Encountered unhandled exception: %s' \

                      % traceback.format_exc())

            json_exc = JSONRPCError('Internal server error')

            self._error = str(json_exc)

        if self._error is not None:

            raw_response = None

        response = dict(id=self._req_id, result=raw_response, 

                        error=self._error)

        try:

            return json.dumps(response)

        except TypeError, e:

            log.debug('Error encoding response: %s', e)

            return json.dumps(

                dict(

                    self._req_id,

                    result=None,

                    error="Error encoding response"

                )

            )

    def _find_method(self):

        """

        Return method named by `self._req_method` in controller if able

        """

        log.debug('Trying to find JSON-RPC method: %s', self._req_method)

        if self._req_method.startswith('_'):

            raise AttributeError("Method not allowed")

        try:

            func = getattr(self, self._req_method, None)

        except UnicodeEncodeError:

            raise AttributeError("Problem decoding unicode in requested "

                                 "method name.")

        if isinstance(func, types.MethodType):

            return func

        else:

            raise AttributeError("No such method: %s" % self._req_method)

class ChangelogController(BaseRepoController):

    @LoginRequired()

    @HasRepoPermissionAnyDecorator('repository.read', 'repository.write',

                                   'repository.admin')

    def __before__(self):

        super(ChangelogController, self).__before__()

        c.affected_files_cut_off = 60

    def index(self):

        limit = 100

        default = 20

        if request.params.get('size'):

            try:

                int_size = int(request.params.get('size'))

            except ValueError:

                int_size = default

            int_size = int_size if int_size <= limit else limit

            c.size = int_size

            session['changelog_size'] = c.size

            session.save()

        else:

            c.size = int(session.get('changelog_size', default))

        p = int(request.params.get('page', 1))

        branch_name = request.params.get('branch', None)

        try:

            if branch_name:

                collection = [z for z in 

                              c.rhodecode_repo.get_changesets(start=0, 

                                                    branch_name=branch_name)]

                c.total_cs = len(collection)

            else:

                collection = list(c.rhodecode_repo)

                c.total_cs = len(c.rhodecode_repo)

            c.pagination = RepoPage(collection, page=p, item_count=c.total_cs,

                                    items_per_page=c.size, branch=branch_name)

        except (RepositoryError, ChangesetDoesNotExistError, Exception), e:

            log.error(traceback.format_exc())

            h.flash(str(e), category='warning')

            return redirect(url('home'))        

        self._graph(c.rhodecode_repo, collection, c.total_cs, c.size, p)

        c.branch_name = branch_name

        c.branch_filters = [('',_('All Branches'))] + \

            [(k,k) for k in c.rhodecode_repo.branches.keys()]

        return render('changelog/changelog.html')

    def changelog_details(self, cs):

        if request.environ.get('HTTP_X_PARTIAL_XHR'):

            c.cs = c.rhodecode_repo.get_changeset(cs)

            return render('changelog/changelog_details.html')

    def _graph(self, repo, collection, repo_size, size, p):

        """

        Generates a DAG graph for mercurial

        :param repo: repo instance

        :param size: number of commits to show

        :param p: page number

        """

        if not collection:

            c.jsdata = json.dumps([])

            return

        revcount = min(repo_size, size)

        offset = 1 if p == 1 else  ((p - 1) * revcount + 1)

        try:

            rev_end = collection.index(collection[(-1 * offset)])

        except IndexError:

            rev_end = collection.index(collection[-1])

        rev_start = max(0, rev_end - revcount)

        data = []

        rev_end += 1

        if repo.alias == 'git':

            for _ in xrange(rev_start, rev_end):

                vtx = [0, 1]

                edges = [[0, 0, 1]]

                data.append(['', vtx, edges])

        elif repo.alias == 'hg':

            revs = list(reversed(xrange(rev_start, rev_end)))

            c.dag = graphmod.colored(graphmod.dagwalker(repo._repo, revs))

            for (id, type, ctx, vtx, edges) in c.dag:

                if type != graphmod.CHANGESET:

                    continue

                data.append(['', vtx, edges])

        c.jsdata = json.dumps(data)

        c.no_changes = diff1 == diff2

        c.f_path = f_path

        c.big_diff = False

        c.anchor_url = anchor_url

        c.ignorews_url = _ignorews_url

        c.context_url = _context_url

        c.changes = OrderedDict()

        c.changes[diff2] = []

        try:

            if diff1 not in ['', None, 'None', '0' * 12, '0' * 40]:

                c.changeset_1 = c.rhodecode_repo.get_changeset(diff1)

                node1 = c.changeset_1.get_node(f_path)

            else:

                c.changeset_1 = EmptyChangeset(repo=c.rhodecode_repo)

                node1 = FileNode('.', '', changeset=c.changeset_1)

            if diff2 not in ['', None, 'None', '0' * 12, '0' * 40]:

                c.changeset_2 = c.rhodecode_repo.get_changeset(diff2)

                node2 = c.changeset_2.get_node(f_path)

            else:

                c.changeset_2 = EmptyChangeset(repo=c.rhodecode_repo)

                node2 = FileNode('.', '', changeset=c.changeset_2)

        except RepositoryError:

            return redirect(url('files_home', repo_name=c.repo_name, 

                                f_path=f_path))

        if c.action == 'download':

            _diff = diffs.get_gitdiff(node1, node2,

                                      ignore_whitespace=ignore_whitespace,

                                      context=line_context)

            diff = diffs.DiffProcessor(_diff, format='gitdiff')

            diff_name = '%s_vs_%s.diff' % (diff1, diff2)

            response.content_type = 'text/plain'

            response.content_disposition = 'attachment; filename=%s' \

                                                    % diff_name

            return diff.raw_diff()

        elif c.action == 'raw':

            _diff = diffs.get_gitdiff(node1, node2,

                                      ignore_whitespace=ignore_whitespace,

                                      context=line_context)

            diff = diffs.DiffProcessor(_diff, format='gitdiff')

            response.content_type = 'text/plain'

            return diff.raw_diff()

        else:

            fid = h.FID(diff2, node2.path)

            line_context_lcl = get_line_ctx(fid, request.GET)

            ign_whitespace_lcl = get_ignore_ws(fid, request.GET)

            lim = request.GET.get('fulldiff') or self.cut_off_limit

            _, cs1, cs2, diff, st = wrapped_diff(filenode_old=node1,

                                         filenode_new=node2,

                                         cut_off_limit=lim,

                                         ignore_whitespace=ign_whitespace_lcl,

                                         line_context=line_context_lcl,

                                         enable_comments=False)

            c.changes = [('', node2, diff, cs1, cs2, st,)]

        return render('files/file_diff.html')

    def _get_node_history(self, cs, f_path):

        changesets = cs.get_file_history(f_path)

        hist_l = []

        changesets_group = ([], _("Changesets"))

        branches_group = ([], _("Branches"))

        tags_group = ([], _("Tags"))

        for chs in changesets:

            n_desc = 'r%s:%s' % (chs.revision, chs.short_id)

            changesets_group[0].append((chs.raw_id, n_desc,))

        hist_l.append(changesets_group)

        for name, chs in c.rhodecode_repo.branches.items():

            branches_group[0].append((chs, name),)

        hist_l.append(branches_group)

        for name, chs in c.rhodecode_repo.tags.items():

            tags_group[0].append((chs, name),)

        hist_l.append(tags_group)

        return hist_l

    @jsonify

    @HasRepoPermissionAnyDecorator('repository.read', 'repository.write',

                                   'repository.admin')

    def nodelist(self, repo_name, revision, f_path):

        if request.environ.get('HTTP_X_PARTIAL_XHR'):

            cs = self.__get_cs_or_redirect(revision, repo_name)

            _d, _f = ScmModel().get_nodes(repo_name, cs.raw_id, f_path,

                                          flat=False)

            return _d + _f

# -*- coding: utf-8 -*-

"""

    rhodecode.controllers.home

    ~~~~~~~~~~~~~~~~~~~~~~~~~~

    Home controller for Rhodecode

    :created_on: Feb 18, 2010

    :author: marcink

    :copyright: (C) 2009-2011 Marcin Kuzminski <marcin@python-works.com>

    :license: GPLv3, see COPYING for more details.

"""

# 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 3 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/>.

import logging

from pylons import tmpl_context as c, request

from paste.httpexceptions import HTTPBadRequest

from rhodecode.lib.auth import LoginRequired

from rhodecode.lib.base import BaseController, render

from rhodecode.model.db import RepoGroup, Repository

log = logging.getLogger(__name__)

class HomeController(BaseController):

    @LoginRequired()

    def __before__(self):

        super(HomeController, self).__before__()

    def index(self):

        c.repos_list = self.scm_model.get_repos()

        c.groups = RepoGroup.query()\

            .filter(RepoGroup.group_parent_id == None).all()

        return render('/index.html')

    def repo_switcher(self):

        if request.is_xhr:

            all_repos = Repository.query().order_by(Repository.repo_name).all()

            c.repos_list = self.scm_model.get_repos(all_repos,

                                                    sort_key='name_sort')

            return render('/repo_switcher_list.html')

        else:

            return HTTPBadRequest()

    def branch_tag_switcher(self, repo_name):

        if request.is_xhr:

            c.rhodecode_db_repo = Repository.get_by_repo_name(c.repo_name)

            c.rhodecode_repo = c.rhodecode_db_repo.scm_instance

            return render('/switch_to_list.html')

        else:

            return HTTPBadRequest()

        stats = self.sa.query(Statistics)\

            .filter(Statistics.repository == dbrepo)\

            .scalar()

        c.stats_percentage = 0

        if stats and stats.languages:

            c.no_data = False is dbrepo.enable_statistics

            lang_stats_d = json.loads(stats.languages)

            c.commit_data = stats.commit_activity

            c.overview_data = stats.commit_activity_combined

            lang_stats = ((x, {"count": y,

                               "desc": LANGUAGES_EXTENSIONS_MAP.get(x)})

                          for x, y in lang_stats_d.items())

            c.trending_languages = json.dumps(OrderedDict(

                                       sorted(lang_stats, reverse=True,

                                            key=lambda k: k[1])[:10]

                                        )

                                    )

            last_rev = stats.stat_on_revision + 1

            c.repo_last_rev = c.rhodecode_repo.count()\

                if c.rhodecode_repo.revisions else 0

            if last_rev == 0 or c.repo_last_rev == 0:

                pass

            else:

                c.stats_percentage = '%.2f' % ((float((last_rev)) /

                                                c.repo_last_rev) * 100)

        else:

            c.commit_data = json.dumps({})

            c.overview_data = json.dumps([[ts_min_y, 0], [ts_max_y, 10]])

            c.trending_languages = json.dumps({})

            c.no_data = True

        c.enable_downloads = dbrepo.enable_downloads

        if c.enable_downloads:

            c.download_options = self._get_download_links(c.rhodecode_repo)

        c.readme_data, c.readme_file = self.__get_readme_data(c.rhodecode_repo)

        return render('summary/summary.html')

    def __get_readme_data(self, repo):

        @cache_region('long_term')

        def _get_readme_from_cache(key):

            readme_data = None

            readme_file = None

            log.debug('Fetching readme file')

            try:

                cs = repo.get_changeset('tip')

                renderer = MarkupRenderer()

                for f in README_FILES:

                    try:

                        readme = cs.get_node(f)

                        readme_file = f

                        readme_data = renderer.render(readme.content, f)

                        log.debug('Found readme %s' % readme_file)

                        break

                    except NodeDoesNotExistError:

                        continue

            except ChangesetError:

                pass

            except EmptyRepositoryError:

                pass

            except Exception:

                log.error(traceback.format_exc())

            return readme_data, readme_file

        key = repo.name + '_README'

        inv = CacheInvalidation.invalidate(key)

        if inv is not None:

            region_invalidate(_get_readme_from_cache, None, key)

            CacheInvalidation.set_valid(inv.cache_key)

        return _get_readme_from_cache(key)

    def _get_download_links(self, repo):

        download_l = []

        branches_group = ([], _("Branches"))

        tags_group = ([], _("Tags"))

        for name, chs in c.rhodecode_repo.branches.items():

            #chs = chs.split(':')[-1]

            branches_group[0].append((chs, name),)

        download_l.append(branches_group)

        for name, chs in c.rhodecode_repo.tags.items():

            #chs = chs.split(':')[-1]

            tags_group[0].append((chs, name),)

        download_l.append(tags_group)

        return download_l

                      check_Location or 'unspecified location')

            return True

        else:

            log.warning('Permission denied for %s @ %s', self.granted_for,

                        check_Location or 'unspecified location')

            return False

    def check_permissions(self):

        """Dummy function for overriding"""

        raise Exception('You have to write this function in child class')

class HasPermissionAll(PermsFunction):

    def check_permissions(self):

        if self.required_perms.issubset(self.user_perms.get('global')):

            return True

        return False

class HasPermissionAny(PermsFunction):

    def check_permissions(self):

        if self.required_perms.intersection(self.user_perms.get('global')):

            return True

        return False

class HasRepoPermissionAll(PermsFunction):

    def __call__(self, repo_name=None, check_Location=''):

        self.repo_name = repo_name

        return super(HasRepoPermissionAll, self).__call__(check_Location)

    def check_permissions(self):

        if not self.repo_name:

            self.repo_name = get_repo_slug(request)

        try:

            self.user_perms = set([self.user_perms['reposit'

                                                   'ories'][self.repo_name]])

        except KeyError:

            return False

        self.granted_for = self.repo_name

        if self.required_perms.issubset(self.user_perms):

            return True

        return False

class HasRepoPermissionAny(PermsFunction):

    def __call__(self, repo_name=None, check_Location=''):

        self.repo_name = repo_name

        return super(HasRepoPermissionAny, self).__call__(check_Location)

    def check_permissions(self):

        if not self.repo_name:

            self.repo_name = get_repo_slug(request)

        try:

            self.user_perms = set([self.user_perms['reposi'

                                                   'tories'][self.repo_name]])

        except KeyError:

            return False

        self.granted_for = self.repo_name

        if self.required_perms.intersection(self.user_perms):

            return True

        return False

#==============================================================================

# SPECIAL VERSION TO HANDLE MIDDLEWARE AUTH

#==============================================================================

class HasPermissionAnyMiddleware(object):

    def __init__(self, *perms):

        self.required_perms = set(perms)

    def __call__(self, user, repo_name):

        usr = AuthUser(user.user_id)

        try:

            self.user_perms = set([usr.permissions['repositories'][repo_name]])

        except:

            self.user_perms = set()

        self.granted_for = ''

        self.username = user.username

        self.repo_name = repo_name

        return self.check_permissions()

    def check_permissions(self):

        log.debug('checking mercurial protocol '

                  'permissions %s for user:%s repository:%s', self.user_perms,

                                                self.username, self.repo_name)

        if self.required_perms.intersection(self.user_perms):

            log.debug('permission granted')

            return True

        log.debug('permission denied')

        return False

            if not HasPermissionAnyMiddleware('repository.write',

                                              'repository.admin')(user,

                                                                  repo_name):

                return False

        else:

            #any other action need at least read permission

            if not HasPermissionAnyMiddleware('repository.read',

                                              'repository.write',

                                              'repository.admin')(user,

                                                                  repo_name):

                return False

        return True

    def __call__(self, environ, start_response):

        start = time.time()

        try:

            return self._handle_request(environ, start_response)

        finally:

            log = logging.getLogger('rhodecode.' + self.__class__.__name__)

            log.debug('Request time: %.3fs' % (time.time() - start))

            meta.Session.remove()

class BaseController(WSGIController):

    def __before__(self):

        c.rhodecode_version = __version__

        c.rhodecode_name = config.get('rhodecode_title')

        c.use_gravatar = str2bool(config.get('use_gravatar'))

        c.ga_code = config.get('rhodecode_ga_code')

        c.repo_name = get_repo_slug(request)

        c.backends = BACKENDS.keys()

        c.unread_notifications = NotificationModel()\

                        .get_unread_cnt_for_user(c.rhodecode_user.user_id)

        self.cut_off_limit = int(config.get('cut_off_limit'))

        self.sa = meta.Session

        self.scm_model = ScmModel(self.sa)

    def __call__(self, environ, start_response):

        """Invoke the Controller"""

        # WSGIController.__call__ dispatches to the Controller method

        # the request is routed to. This routing information is

        # available in environ['pylons.routes_dict']

        start = time.time()

        try:

            # make sure that we update permissions each time we call controller

            api_key = request.GET.get('api_key')

            cookie_store = session.get('rhodecode_user') or {}

            user_id = cookie_store.get('user_id', None)

            username = get_container_username(environ, config)

            auth_user = AuthUser(user_id, api_key, username)

            request.user = auth_user

            self.rhodecode_user = c.rhodecode_user = auth_user

            if not self.rhodecode_user.is_authenticated and \

                       self.rhodecode_user.user_id is not None:

                self.rhodecode_user\

                    .set_authenticated(cookie_store.get('is_authenticated'))

            session['rhodecode_user'] = self.rhodecode_user.get_cookie_store()

            session.save()

            return WSGIController.__call__(self, environ, start_response)

        finally:

            log.debug('Request time: %.3fs' % (time.time() - start))

            meta.Session.remove()

class BaseRepoController(BaseController):

    """

    Base class for controllers responsible for loading all needed data for

    repository loaded items are

    c.rhodecode_repo: instance of scm repository

    c.rhodecode_db_repo: instance of db

    c.repository_followers: number of followers

    c.repository_forks: number of forks

    """

    def __before__(self):

        super(BaseRepoController, self).__before__()

        if c.repo_name:

            c.rhodecode_db_repo = Repository.get_by_repo_name(c.repo_name)

            c.rhodecode_repo = c.rhodecode_db_repo.scm_instance

            if c.rhodecode_repo is None:

                log.error('%s this repository is present in database but it '

                          'cannot be created as an scm instance', c.repo_name)

                redirect(url('home'))

            c.repository_followers = self.scm_model.get_followers(c.repo_name)

            c.repository_forks = self.scm_model.get_forks(c.repo_name)

"""

   SQLAlchemy migrate provides two APIs :mod:`migrate.versioning` for

   database schema version and repository management and

   :mod:`migrate.changeset` that allows to define database schema changes

   using Python.

"""

from rhodecode.lib.dbmigrate.migrate.versioning import *

from rhodecode.lib.dbmigrate.migrate.changeset import *

                    'pre_meta.tables[%r].columns[%r].drop()' % (tn, col))

                downgradeCommands.append(

                    'pre_meta.tables[%r].columns[%r].create()' % (tn, col))

            for col in td.columns_missing_from_B:

                upgradeCommands.append(

                    'post_meta.tables[%r].columns[%r].create()' % (tn, col))

                downgradeCommands.append(

                    'post_meta.tables[%r].columns[%r].drop()' % (tn, col))

            for modelCol, databaseCol, modelDecl, databaseDecl in td.columns_different:

                upgradeCommands.append(

                    'assert False, "Can\'t alter columns: %s:%s=>%s"' % (

                    tn, modelCol.name, databaseCol.name))

                downgradeCommands.append(

                    'assert False, "Can\'t alter columns: %s:%s=>%s"' % (

                    tn, modelCol.name, databaseCol.name))

        return (

            '\n'.join(decls),

            '\n'.join('%s%s' % (indent, line) for line in upgradeCommands),

            '\n'.join('%s%s' % (indent, line) for line in downgradeCommands))

    def _db_can_handle_this_change(self,td):

        """Check if the database can handle going from B to A."""

        if (td.columns_missing_from_B

            and not td.columns_missing_from_A

            and not td.columns_different):

            # Even sqlite can handle column additions.

            return True

        else:

            return not self.engine.url.drivername.startswith('sqlite')

    def runB2A(self):

        """Goes from B to A.

        Was: applyModel. Apply model (A) to current database (B).

        """

        meta = sqlalchemy.MetaData(self.engine)

        for table in self._get_tables(missingA=True):

            table = table.tometadata(meta)

            table.drop()

        for table in self._get_tables(missingB=True):

            table = table.tometadata(meta)

            table.create()

        for modelTable in self._get_tables(modified=True):

            tableName = modelTable.name

            modelTable = modelTable.tometadata(meta)

            dbTable = self.diff.metadataB.tables[tableName]

            td = self.diff.tables_different[tableName]

            if self._db_can_handle_this_change(td):

                for col in td.columns_missing_from_B:

                    modelTable.columns[col].create()