try:

                self.sa.delete(f)

                action_logger(UserTemp(user_id),

                              'stopped_following_repo',

                              RepoTemp(follow_repo_id))

                return

            except:

                log.error(traceback.format_exc())

                raise

        try:

            f = UserFollowing()

            f.user_id = user_id

            f.follows_repo_id = follow_repo_id

            self.sa.add(f)

            action_logger(UserTemp(user_id),

                          'started_following_repo',

                          RepoTemp(follow_repo_id))

        except:

            log.error(traceback.format_exc())

            raise

    def toggle_following_user(self, follow_user_id, user_id):

        f = self.sa.query(UserFollowing)\

            .filter(UserFollowing.follows_user_id == follow_user_id)\

            .filter(UserFollowing.user_id == user_id).scalar()

        if f is not None:

            try:

                self.sa.delete(f)

                return

            except:

                log.error(traceback.format_exc())

                raise

        try:

            f = UserFollowing()

            f.user_id = user_id

            f.follows_user_id = follow_user_id

            self.sa.add(f)

        except:

            log.error(traceback.format_exc())

            raise

    def is_following_repo(self, repo_name, user_id, cache=False):

        r = self.sa.query(Repository)\

            .filter(Repository.repo_name == repo_name).scalar()

        f = self.sa.query(UserFollowing)\

            .filter(UserFollowing.follows_repository == r)\

            .filter(UserFollowing.user_id == user_id).scalar()

        return f is not None

    def is_following_user(self, username, user_id, cache=False):

        u = User.get_by_username(username)

        f = self.sa.query(UserFollowing)\

            .filter(UserFollowing.follows_user == u)\

            .filter(UserFollowing.user_id == user_id).scalar()

        return f is not None

    def get_followers(self, repo):

        repo = self._get_repo(repo)

        return self.sa.query(UserFollowing)\

                .filter(UserFollowing.follows_repository == repo).count()

    def get_forks(self, repo):

        repo = self._get_repo(repo)

        return self.sa.query(Repository)\

                .filter(Repository.fork == repo).count()

    def get_pull_requests(self, repo):

        repo = self._get_repo(repo)

        return self.sa.query(PullRequest)\

                .filter(PullRequest.other_repo == repo).count()

    def mark_as_fork(self, repo, fork, user):

        repo = self.__get_repo(repo)

        fork = self.__get_repo(fork)

        if fork and repo.repo_id == fork.repo_id:

            raise Exception("Cannot set repository as fork of itself")

        repo.fork = fork

        self.sa.add(repo)

        return repo

    def pull_changes(self, repo, username):

        dbrepo = self.__get_repo(repo)

        clone_uri = dbrepo.clone_uri

        if not clone_uri:

            raise Exception("This repository doesn't have a clone uri")

        repo = dbrepo.scm_instance

        try:

            extras = {

                'ip': '',

                'username': username,

                'action': 'push_remote',

                'repository': dbrepo.repo_name,

                'scm': repo.alias,

            }

            Repository.inject_ui(repo, extras=extras)

            if repo.alias == 'git':

                repo.fetch(clone_uri)

            else:

                repo.pull(clone_uri)

            self.mark_for_invalidation(dbrepo.repo_name)

        except:

            log.error(traceback.format_exc())

            raise

    def commit_change(self, repo, repo_name, cs, user, author, message,

                      content, f_path):

        """

        Commits changes

        :param repo: SCM instance

        """

        if repo.alias == 'hg':

            from rhodecode.lib.vcs.backends.hg import \

                MercurialInMemoryChangeset as IMC

        elif repo.alias == 'git':

            from rhodecode.lib.vcs.backends.git import \

                GitInMemoryChangeset as IMC

        # decoding here will force that we have proper encoded values

        # in any other case this will throw exceptions and deny commit

        content = safe_str(content)

        path = safe_str(f_path)

        # message and author needs to be unicode

        # proper backend should then translate that into required type

        message = safe_unicode(message)

        author = safe_unicode(author)

        m = IMC(repo)

        m.change(FileNode(path, content))

        tip = m.commit(message=message,

                       author=author,

                       parents=[cs], branch=cs.branch)

        action = 'push_local:%s' % tip.raw_id

        action_logger(user, action, repo_name)

        self.mark_for_invalidation(repo_name)

        return tip

    def create_node(self, repo, repo_name, cs, user, author, message, content,

                      f_path):

        if repo.alias == 'hg':

            from rhodecode.lib.vcs.backends.hg import MercurialInMemoryChangeset as IMC

        elif repo.alias == 'git':

            from rhodecode.lib.vcs.backends.git import GitInMemoryChangeset as IMC

        # decoding here will force that we have proper encoded values

        # in any other case this will throw exceptions and deny commit

        if isinstance(content, (basestring,)):

            content = safe_str(content)

        elif isinstance(content, (file, cStringIO.OutputType,)):

            content = content.read()

        else:

            raise Exception('Content is of unrecognized type %s' % (

                type(content)

            ))

        message = safe_unicode(message)

        author = safe_unicode(author)

        path = safe_str(f_path)

        m = IMC(repo)

        if isinstance(cs, EmptyChangeset):

            # EmptyChangeset means we we're editing empty repository

            parents = None

        else:

            parents = [cs]

        m.add(FileNode(path, content=content))

        tip = m.commit(message=message,

                       author=author,

                       parents=parents, branch=cs.branch)

        action = 'push_local:%s' % tip.raw_id

        action_logger(user, action, repo_name)

        self.mark_for_invalidation(repo_name)

        return tip

    def get_nodes(self, repo_name, revision, root_path='/', flat=True):

        """

        recursive walk in root dir and return a set of all path in that dir

        based on repository walk function

        :param repo_name: name of repository

        :param revision: revision for which to list nodes

        :param root_path: root path to list

        :param flat: return as a list, if False returns a dict with decription

        """