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

    # SCM CACHE INSTANCE

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

    def set_invalidate(self):

        """

        Mark caches of this repo as invalid.

        """

        CacheInvalidation.set_invalidate(self.repo_name)

    def scm_instance_no_cache(self):

        return self.__get_instance()

    @property

    def scm_instance(self):

        import kallithea

        full_cache = str2bool(kallithea.CONFIG.get('vcs_full_cache'))

        if full_cache:

            return self.scm_instance_cached()

        return self.__get_instance()

    def scm_instance_cached(self, valid_cache_keys=None):

        @cache_region('long_term')

        def _c(repo_name):

            return self.__get_instance()

        rn = self.repo_name

        valid = CacheInvalidation.test_and_set_valid(rn, None, valid_cache_keys=valid_cache_keys)

        if not valid:

            log.debug('Cache for %s invalidated, getting new object' % (rn))

            region_invalidate(_c, None, rn)

        else:

            log.debug('Getting scm_instance of %s from cache' % (rn))

        return _c(rn)

    def __get_instance(self):

        repo_full_path = self.repo_full_path

        alias = get_scm(repo_full_path)[0]

        log.debug('Creating instance of %s repository from %s'

                  % (alias, repo_full_path))

        backend = get_backend(alias)

        if alias == 'hg':

            repo = backend(safe_str(repo_full_path), create=False,

                           baseui=self._ui)

        else:

            repo = backend(repo_full_path, create=False)

        return repo

    def __json__(self):

        return dict(landing_rev = self.landing_rev)

class RepoGroup(Base, BaseModel):

    __tablename__ = 'groups'

    __table_args__ = (

        UniqueConstraint('group_name', 'group_parent_id'),

        CheckConstraint('group_id != group_parent_id'),

        {'extend_existing': True, 'mysql_engine': 'InnoDB',

         'mysql_charset': 'utf8', 'sqlite_autoincrement': True},

    )

    __mapper_args__ = {'order_by': 'group_name'}

    SEP = ' » '

    group_id = Column(Integer(), nullable=False, unique=True, primary_key=True)

    group_name = Column(String(255, convert_unicode=False), nullable=False, unique=True, default=None)

    group_parent_id = Column(Integer(), ForeignKey('groups.group_id'), nullable=True, unique=None, default=None)

    group_description = Column(String(10000, convert_unicode=False), nullable=True, unique=None, default=None)

    enable_locking = Column(Boolean(), nullable=False, unique=None, default=False)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=False, unique=False, default=None)

    created_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    repo_group_to_perm = relationship('UserRepoGroupToPerm', cascade='all', order_by='UserRepoGroupToPerm.group_to_perm_id')

    users_group_to_perm = relationship('UserGroupRepoGroupToPerm', cascade='all')

    parent_group = relationship('RepoGroup', remote_side=group_id)

    user = relationship('User')

    def __init__(self, group_name='', parent_group=None):

        self.group_name = group_name

        self.parent_group = parent_group

    def __unicode__(self):

        return u"<%s('id:%s:%s')>" % (self.__class__.__name__, self.group_id,

                                      self.group_name)

    @classmethod

    def _generate_choice(cls, repo_group):

        """Return tuple with group_id and name as html literal"""

        from webhelpers.html import literal

        if repo_group is None:

            return (-1, u'-- %s --' % _('top level'))

        return repo_group.group_id, literal(cls.SEP.join(repo_group.full_path_splitted))

    @classmethod

        """Return tuples with group_id and name as html literal."""

    @classmethod

    def url_sep(cls):

        return URL_SEP

    @classmethod

    def get_by_group_name(cls, group_name, cache=False, case_insensitive=False):

        if case_insensitive:

            gr = cls.query()\

                .filter(cls.group_name.ilike(group_name))

        else:

            gr = cls.query()\

                .filter(cls.group_name == group_name)

        if cache:

            gr = gr.options(FromCache(

                            "sql_cache_short",

                            "get_group_%s" % _hash_key(group_name)

                            )

            )

        return gr.scalar()

    @property

    def parents(self):

        parents_recursion_limit = 10

        groups = []

        if self.parent_group is None:

            return groups

        cur_gr = self.parent_group

        groups.insert(0, cur_gr)

        cnt = 0

        while 1:

            cnt += 1

            gr = getattr(cur_gr, 'parent_group', None)

            cur_gr = cur_gr.parent_group

            if gr is None:

                break

            if cnt == parents_recursion_limit:

                # this will prevent accidental infinite loops

                log.error(('more than %s parents found for group %s, stopping '

                           'recursive parent fetching' % (parents_recursion_limit, self)))

                break

            groups.insert(0, gr)

        return groups

    @property

    def children(self):

        return RepoGroup.query().filter(RepoGroup.parent_group == self)

    @property

    def name(self):

        return self.group_name.split(RepoGroup.url_sep())[-1]

    @property

    def full_path(self):

        return self.group_name

    @property

    def full_path_splitted(self):

        return self.group_name.split(RepoGroup.url_sep())

    @property

    def repositories(self):

        return Repository.query()\

                .filter(Repository.group == self)\

                .order_by(Repository.repo_name)

    @property

    def repositories_recursive_count(self):

        cnt = self.repositories.count()

        def children_count(group):

            cnt = 0

            for child in group.children:

                cnt += child.repositories.count()

                cnt += children_count(child)

            return cnt

        return cnt + children_count(self)

    def _recursive_objects(self, include_repos=True):

        all_ = []

        def _get_members(root_gr):

            if include_repos:

                for r in root_gr.repositories:

                    all_.append(r)

            childs = root_gr.children.all()

            if childs:

                for gr in childs:

                    all_.append(gr)

                    _get_members(gr)

        _get_members(self)

        return [self] + all_

        hist_l.append(['rev:tip', _('latest tip')])

        choices.append('rev:tip')

        if not repo:

            return choices, hist_l

        repo = repo.scm_instance

        branches_group = ([(u'branch:%s' % k, k) for k, v in

                           repo.branches.iteritems()], _("Branches"))

        hist_l.append(branches_group)

        choices.extend([x[0] for x in branches_group[0]])

        if repo.alias == 'hg':

            bookmarks_group = ([(u'book:%s' % k, k) for k, v in

                                repo.bookmarks.iteritems()], _("Bookmarks"))

            hist_l.append(bookmarks_group)

            choices.extend([x[0] for x in bookmarks_group[0]])

        tags_group = ([(u'tag:%s' % k, k) for k, v in

                       repo.tags.iteritems()], _("Tags"))

        hist_l.append(tags_group)

        choices.extend([x[0] for x in tags_group[0]])

        return choices, hist_l

    def install_git_hook(self, repo, force_create=False):

        """

        Creates a kallithea hook inside a git repository

        :param repo: Instance of VCS repo

        :param force_create: Create even if same name hook exists

        """

        loc = jn(repo.path, 'hooks')

        if not repo.bare:

            loc = jn(repo.path, '.git', 'hooks')

        if not os.path.isdir(loc):

            os.makedirs(loc)

        tmpl_post = pkg_resources.resource_string(

            'kallithea', jn('config', 'post_receive_tmpl.py')

        )

        tmpl_pre = pkg_resources.resource_string(

            'kallithea', jn('config', 'pre_receive_tmpl.py')

        )

        for h_type, tmpl in [('pre', tmpl_pre), ('post', tmpl_post)]:

            _hook_file = jn(loc, '%s-receive' % h_type)

            has_hook = False

            log.debug('Installing git hook in repo %s' % repo)

            if os.path.exists(_hook_file):

                # let's take a look at this hook, maybe it's kallithea ?

                log.debug('hook exists, checking if it is from kallithea')

                with open(_hook_file, 'rb') as f:

                    data = f.read()

                    matches = re.compile(r'(?:%s)\s*=\s*(.*)'

                                         % 'KALLITHEA_HOOK_VER').search(data)

                    if matches:

                        try:

                            ver = matches.groups()[0]

                            log.debug('got %s it is kallithea' % (ver))

                            has_hook = True

                        except Exception:

                            log.error(traceback.format_exc())

            else:

                # there is no hook in this dir, so we want to create one

                has_hook = True

            if has_hook or force_create:

                log.debug('writing %s hook file !' % (h_type,))

                try:

                    with open(_hook_file, 'wb') as f:

                        tmpl = tmpl.replace('_TMPL_', kallithea.__version__)

                        f.write(tmpl)

                    os.chmod(_hook_file, 0755)

                except IOError, e:

                    log.error('error writing %s: %s' % (_hook_file, e))

            else:

                log.debug('skipping writing hook file')

def AvailableRepoGroupChoices(top_perms, repo_group_perms, extras=()):

    """Return group_id,string tuples with choices for all the repo groups where

    the user has the necessary permissions.

    Top level is -1.

    """

    groups = RepoGroup.query().all()

    if HasPermissionAll('hg.admin')('available repo groups'):

        groups.append(None)

    else:

        groups = list(RepoGroupList(groups, perm_set=repo_group_perms))

        if top_perms and HasPermissionAny(*top_perms)('available repo groups'):

            groups.append(None)

        for extra in extras:

            if not any(rg == extra for rg in groups):

                groups.append(extra)