example::

        class Task(object):

            def __init__(self, name, value):

                self.name = name

                self.value = value

            def __json__(self):

                return dict(name=self.name,

                            value=self.value)

    """

    def default(self, obj):

        if hasattr(obj, '__json__'):

            return obj.__json__()

        else:

            return json.JSONEncoder.default(self, obj)

class BaseModel(object):

    """

    Base Model for all classess

    """

    @classmethod

    def _get_keys(cls):

        """return column names for this model """

        return class_mapper(cls).c.keys()

    def get_dict(self):

        """

        return dict with keys and values corresponding

        to this model data """

        d = {}

        for k in self._get_keys():

            d[k] = getattr(self, k)

        # also use __json__() if present to get additional fields

        for k, val in getattr(self, '__json__', lambda: {})().iteritems():

            d[k] = val

        return d

    def get_appstruct(self):

        """return list with keys and values tupples corresponding

        to this model data """

        l = []

        for k in self._get_keys():

            l.append((k, getattr(self, k),))

        return l

    def populate_obj(self, populate_dict):

        """populate model with data from given populate_dict"""

        for k in self._get_keys():

            if k in populate_dict:

                setattr(self, k, populate_dict[k])

    @classmethod

    def query(cls):

        return Session.query(cls)

    @classmethod

    def get(cls, id_):

        if id_:

            return cls.query().get(id_)

    @classmethod

    def getAll(cls):

        return cls.query().all()

    @classmethod

    def delete(cls, id_):

        obj = cls.query().get(id_)

        Session.delete(obj)

class RhodeCodeSetting(Base, BaseModel):

    __tablename__ = 'rhodecode_settings'

    __table_args__ = (

        UniqueConstraint('app_settings_name'),

        {'extend_existing': True}

    )

    app_settings_id = Column("app_settings_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    app_settings_name = Column("app_settings_name", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    _app_settings_value = Column("app_settings_value", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    def __init__(self, k='', v=''):

        self.app_settings_name = k

        self.app_settings_value = v

    @validates('_app_settings_value')

    def validate_settings_value(self, key, val):

        assert type(val) == unicode

        return val

    @hybrid_property

    def app_settings_value(self):

        v = self._app_settings_value

        if v == 'ldap_active':

            v = str2bool(v)

        return v

    @app_settings_value.setter

    def app_settings_value(self, val):

        """

        Setter that will always make sure we use unicode in app_settings_value

        :param val:

        """

        self._app_settings_value = safe_unicode(val)

    def __repr__(self):

        return "<%s('%s:%s')>" % (

            self.__class__.__name__,

            self.app_settings_name, self.app_settings_value

        )

    @classmethod

    def get_by_name(cls, ldap_key):

        return cls.query()\

            .filter(cls.app_settings_name == ldap_key).scalar()

    @classmethod

    def get_app_settings(cls, cache=False):

        ret = cls.query()

        if cache:

            ret = ret.options(FromCache("sql_cache_short", "get_hg_settings"))

        if not ret:

            raise Exception('Could not get application settings !')

        settings = {}

        for each in ret:

            settings['rhodecode_' + each.app_settings_name] = \

                each.app_settings_value

        return settings

    @classmethod

    def get_ldap_settings(cls, cache=False):

        ret = cls.query()\

                .filter(cls.app_settings_name.startswith('ldap_')).all()

        fd = {}

        for row in ret:

            fd.update({row.app_settings_name:row.app_settings_value})

        return fd

class RhodeCodeUi(Base, BaseModel):

    __tablename__ = 'rhodecode_ui'

    __table_args__ = (

        UniqueConstraint('ui_key'),

        {'extend_existing': True}

    )

    HOOK_UPDATE = 'changegroup.update'

    HOOK_REPO_SIZE = 'changegroup.repo_size'

    HOOK_PUSH = 'pretxnchangegroup.push_logger'

    HOOK_PULL = 'preoutgoing.pull_logger'

    ui_id = Column("ui_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    ui_section = Column("ui_section", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    ui_key = Column("ui_key", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    ui_value = Column("ui_value", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    ui_active = Column("ui_active", Boolean(), nullable=True, unique=None, default=True)

    @classmethod

    def get_by_key(cls, key):

        return cls.query().filter(cls.ui_key == key)

    @classmethod

    def get_builtin_hooks(cls):

        q = cls.query()

        q = q.filter(cls.ui_key.in_([cls.HOOK_UPDATE,

                                    cls.HOOK_REPO_SIZE,

                                    cls.HOOK_PUSH, cls.HOOK_PULL]))

        return q.all()

    @classmethod

    def get_custom_hooks(cls):

        q = cls.query()

        q = q.filter(~cls.ui_key.in_([cls.HOOK_UPDATE,

                                    cls.HOOK_REPO_SIZE,

                                    cls.HOOK_PUSH, cls.HOOK_PULL]))

        q = q.filter(cls.ui_section == 'hooks')

        return q.all()

    @classmethod

    def create_or_update_hook(cls, key, val):

        new_ui = cls.get_by_key(key).scalar() or cls()

        new_ui.ui_section = 'hooks'

        new_ui.ui_active = True

        new_ui.ui_key = key

        new_ui.ui_value = val

        Session.add(new_ui)

class User(Base, BaseModel):

    __tablename__ = 'users'

    __table_args__ = (

        UniqueConstraint('username'), UniqueConstraint('email'),

        {'extend_existing': True}

    )

    user_id = Column("user_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    username = Column("username", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    password = Column("password", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    active = Column("active", Boolean(), nullable=True, unique=None, default=None)

    admin = Column("admin", Boolean(), nullable=True, unique=None, default=False)

    name = Column("name", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    lastname = Column("lastname", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    _email = Column("email", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    last_login = Column("last_login", DateTime(timezone=False), nullable=True, unique=None, default=None)

    ldap_dn = Column("ldap_dn", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    api_key = Column("api_key", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    user_log = relationship('UserLog', cascade='all')

    user_perms = relationship('UserToPerm', primaryjoin="User.user_id==UserToPerm.user_id", cascade='all')

    repositories = relationship('Repository')

    user_followers = relationship('UserFollowing', primaryjoin='UserFollowing.follows_user_id==User.user_id', cascade='all')

    repo_to_perm = relationship('UserRepoToPerm', primaryjoin='UserRepoToPerm.user_id==User.user_id', cascade='all')

    group_member = relationship('UsersGroupMember', cascade='all')

    notifications = relationship('UserNotification',)

    @hybrid_property

    def email(self):

        return self._email

    @email.setter

    def email(self, val):

        self._email = val.lower() if val else None

    @property

    def full_name(self):

        return '%s %s' % (self.name, self.lastname)

    @property

    def full_name_or_username(self):

        return ('%s %s' % (self.name, self.lastname)

                if (self.name and self.lastname) else self.username)

    @property

    def full_contact(self):

        return '%s %s <%s>' % (self.name, self.lastname, self.email)

    @property

    def short_contact(self):

        return '%s %s' % (self.name, self.lastname)

    @property

    def is_admin(self):

        return self.admin

    def __repr__(self):

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

                                     self.user_id, self.username)

    @classmethod

    def get_by_username(cls, username, case_insensitive=False, cache=False):

        if case_insensitive:

            q = cls.query().filter(cls.username.ilike(username))

        else:

            q = cls.query().filter(cls.username == username)

        if cache:

            q = q.options(FromCache("sql_cache_short",

                                    "get_user_%s" % username))

        return q.scalar()

    @classmethod

    def get_by_api_key(cls, api_key, cache=False):

        q = cls.query().filter(cls.api_key == api_key)

        if cache:

            q = q.options(FromCache("sql_cache_short",

                                    "get_api_key_%s" % api_key))

        return q.scalar()

    @classmethod

    def get_by_email(cls, email, case_insensitive=False, cache=False):

        if case_insensitive:

            q = cls.query().filter(cls.email.ilike(email))

        else:

            q = cls.query().filter(cls.email == email)

        if cache:

            q = q.options(FromCache("sql_cache_short",

                                    "get_api_key_%s" % email))

        return q.scalar()

    def update_lastlogin(self):

        """Update user lastlogin"""

        self.last_login = datetime.datetime.now()

        Session.add(self)

        log.debug('updated user %s lastlogin' % self.username)

    def __json__(self):

        return dict(

            email=self.email,

            full_name=self.full_name,

            full_name_or_username=self.full_name_or_username,

            short_contact=self.short_contact,

            full_contact=self.full_contact

        )

class UserLog(Base, BaseModel):

    __tablename__ = 'user_logs'

    __table_args__ = {'extend_existing': True}

    user_log_id = Column("user_log_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

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

    repository_id = Column("repository_id", Integer(), ForeignKey('repositories.repo_id'), nullable=True)

    repository_name = Column("repository_name", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    user_ip = Column("user_ip", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    action = Column("action", UnicodeText(length=1200000, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    action_date = Column("action_date", DateTime(timezone=False), nullable=True, unique=None, default=None)

    @property

    def action_as_day(self):

        return datetime.date(*self.action_date.timetuple()[:3])

    user = relationship('User')

    repository = relationship('Repository',cascade='')

class UsersGroup(Base, BaseModel):

    __tablename__ = 'users_groups'

    __table_args__ = {'extend_existing': True}

    users_group_id = Column("users_group_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    users_group_name = Column("users_group_name", String(length=255, convert_unicode=False, assert_unicode=None), nullable=False, unique=True, default=None)

    users_group_active = Column("users_group_active", Boolean(), nullable=True, unique=None, default=None)

    members = relationship('UsersGroupMember', cascade="all, delete, delete-orphan", lazy="joined")

    def __repr__(self):

        return '<userGroup(%s)>' % (self.users_group_name)

    @classmethod

    def get_by_group_name(cls, group_name, cache=False,

                          case_insensitive=False):

        if case_insensitive:

            q = cls.query().filter(cls.users_group_name.ilike(group_name))

        else:

            q = cls.query().filter(cls.users_group_name == group_name)

        if cache:

            q = q.options(FromCache("sql_cache_short",

                                    "get_user_%s" % group_name))

        return q.scalar()

    @classmethod

    def get(cls, users_group_id, cache=False):

        users_group = cls.query()

        if cache:

            users_group = users_group.options(FromCache("sql_cache_short",

                                    "get_users_group_%s" % users_group_id))

        return users_group.get(users_group_id)

class UsersGroupMember(Base, BaseModel):

    __tablename__ = 'users_groups_members'

    __table_args__ = {'extend_existing': True}

    users_group_member_id = Column("users_group_member_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    users_group_id = Column("users_group_id", Integer(), ForeignKey('users_groups.users_group_id'), nullable=False, unique=None, default=None)

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

    user = relationship('User', lazy='joined')

    users_group = relationship('UsersGroup')

    def __init__(self, gr_id='', u_id=''):

        self.users_group_id = gr_id

        self.user_id = u_id

class Repository(Base, BaseModel):

    __tablename__ = 'repositories'

    __table_args__ = (

        UniqueConstraint('repo_name'),

        {'extend_existing': True},

    )

    repo_id = Column("repo_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    repo_name = Column("repo_name", String(length=255, convert_unicode=False, assert_unicode=None), nullable=False, unique=True, default=None)

    clone_uri = Column("clone_uri", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=False, default=None)

    repo_type = Column("repo_type", String(length=255, convert_unicode=False, assert_unicode=None), nullable=False, unique=False, default='hg')

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

    private = Column("private", Boolean(), nullable=True, unique=None, default=None)

    enable_statistics = Column("statistics", Boolean(), nullable=True, unique=None, default=True)

    enable_downloads = Column("downloads", Boolean(), nullable=True, unique=None, default=True)

    description = Column("description", String(length=10000, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    created_on = Column('created_on', DateTime(timezone=False), nullable=True, unique=None, default=datetime.datetime.now)

    fork_id = Column("fork_id", Integer(), ForeignKey('repositories.repo_id'), nullable=True, unique=False, default=None)

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

    user = relationship('User')

    fork = relationship('Repository', remote_side=repo_id)

    group = relationship('RepoGroup')

    repo_to_perm = relationship('UserRepoToPerm', cascade='all', order_by='UserRepoToPerm.repo_to_perm_id')

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

    stats = relationship('Statistics', cascade='all', uselist=False)

    followers = relationship('UserFollowing', primaryjoin='UserFollowing.follows_repo_id==Repository.repo_id', cascade='all')

    logs = relationship('UserLog')

    def __repr__(self):

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

                                  self.repo_id, self.repo_name)

    @classmethod

    def url_sep(cls):

        return '/'

    @classmethod

    def get_by_repo_name(cls, repo_name):

        q = Session.query(cls).filter(cls.repo_name == repo_name)

        q = q.options(joinedload(Repository.fork))\

                .options(joinedload(Repository.user))\

                .options(joinedload(Repository.group))

        return q.scalar()

    @classmethod

    def get_repo_forks(cls, repo_id):

        return cls.query().filter(Repository.fork_id == repo_id)

    @classmethod

    def base_path(cls):

        """

        Returns base path when all repos are stored

        :param cls:

        """

        q = Session.query(RhodeCodeUi)\

            .filter(RhodeCodeUi.ui_key == cls.url_sep())

        q = q.options(FromCache("sql_cache_short", "repository_repo_path"))

        return q.one().ui_value

    @property

    def just_name(self):

        return self.repo_name.split(Repository.url_sep())[-1]

    @property

    def groups_with_parents(self):

        groups = []

        if self.group is None:

            return groups

        cur_gr = self.group

        groups.insert(0, cur_gr)

        while 1:

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

            cur_gr = cur_gr.parent_group

            if gr is None:

                break

            groups.insert(0, gr)

        return groups

    @property

    def groups_and_repo(self):

        return self.groups_with_parents, self.just_name

    @LazyProperty

    def repo_path(self):

        """

        Returns base full path for that repository means where it actually

        exists on a filesystem

        """

        q = Session.query(RhodeCodeUi).filter(RhodeCodeUi.ui_key ==

                                              Repository.url_sep())

        q = q.options(FromCache("sql_cache_short", "repository_repo_path"))

        return q.one().ui_value

    @property

    def repo_full_path(self):

        p = [self.repo_path]

        # we need to split the name by / since this is how we store the

        # names in the database, but that eventually needs to be converted

        # into a valid system path

        p += self.repo_name.split(Repository.url_sep())

        return os.path.join(*p)

    def get_new_name(self, repo_name):

        """

        returns new full repository name based on assigned group and new new

        :param group_name:

        """

        path_prefix = self.group.full_path_splitted if self.group else []

        return Repository.url_sep().join(path_prefix + [repo_name])

    @property

    def _ui(self):

        """

        Creates an db based ui object for this repository

        """

        from mercurial import ui

        from mercurial import config

        baseui = ui.ui()

        #clean the baseui object

        baseui._ocfg = config.config()

        baseui._ucfg = config.config()

        baseui._tcfg = config.config()

        ret = RhodeCodeUi.query()\

            .options(FromCache("sql_cache_short", "repository_repo_ui")).all()

        hg_ui = ret

        for ui_ in hg_ui:

            if ui_.ui_active:

                log.debug('settings ui from db[%s]%s:%s', ui_.ui_section,

                          ui_.ui_key, ui_.ui_value)

                baseui.setconfig(ui_.ui_section, ui_.ui_key, ui_.ui_value)

        return baseui

    @classmethod

    def is_valid(cls, repo_name):

        """

        returns True if given repo name is a valid filesystem repository

        :param cls:

        :param repo_name:

        """

        from rhodecode.lib.utils import is_valid_repo

        return is_valid_repo(repo_name, cls.base_path())

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

    # SCM PROPERTIES

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

    def get_changeset(self, rev):

        return get_changeset_safe(self.scm_instance, rev)

    @property

    def tip(self):

        return self.get_changeset('tip')

    @property

    def author(self):

        return self.tip.author

    @property

    def last_change(self):

        return self.scm_instance.last_change

    def comments(self, revisions=None):

        """

        Returns comments for this repository grouped by revisions

        :param revisions: filter query by revisions only

        """

        cmts = ChangesetComment.query()\

            .filter(ChangesetComment.repo == self)

        if revisions:

            cmts = cmts.filter(ChangesetComment.revision.in_(revisions))

        grouped = defaultdict(list)

        for cmt in cmts.all():

            grouped[cmt.revision].append(cmt)

        return grouped

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

    # SCM CACHE INSTANCE

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

    @property

    def invalidate(self):

        return CacheInvalidation.invalidate(self.repo_name)

    def set_invalidate(self):

        """

        set a cache for invalidation for this instance

        """

        CacheInvalidation.set_invalidate(self.repo_name)

    @LazyProperty

    def scm_instance(self):

        return self.__get_instance()

    @property

    def scm_instance_cached(self):

        @cache_region('long_term')

        def _c(repo_name):

            return self.__get_instance()

        rn = self.repo_name

        log.debug('Getting cached instance of repo')

        inv = self.invalidate

        if inv is not None:

            region_invalidate(_c, None, rn)

            # update our cache

            CacheInvalidation.set_valid(inv.cache_key)

        return _c(rn)

    def __get_instance(self):

        repo_full_path = self.repo_full_path

        try:

            alias = get_scm(repo_full_path)[0]

            log.debug('Creating instance of %s repository' % alias)

            backend = get_backend(alias)

        except VCSError:

            log.error(traceback.format_exc())

            log.error('Perhaps this repository is in db and not in '

                      'filesystem run rescan repositories with '

                      '"destroy old data " option from admin panel')

            return

        if alias == 'hg':

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

                           baseui=self._ui)

            # skip hidden web repository

            if repo._get_hidden():

                return

        else:

            repo = backend(repo_full_path, create=False)

        return repo

class RepoGroup(Base, BaseModel):

    __tablename__ = 'groups'

    __table_args__ = (

        UniqueConstraint('group_name', 'group_parent_id'),

        CheckConstraint('group_id != group_parent_id'),

        {'extend_existing': True},

    )

    __mapper_args__ = {'order_by': 'group_name'}

    group_id = Column("group_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

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

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

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

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

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

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

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

        self.group_name = group_name

        self.parent_group = parent_group

    def __repr__(self):

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

                                  self.group_name)

    @classmethod

    def groups_choices(cls):

        from webhelpers.html import literal as _literal

        repo_groups = [('', '')]

        sep = ' » '

        _name = lambda k: _literal(sep.join(k))

        repo_groups.extend([(x.group_id, _name(x.full_path_splitted))

                              for x in cls.query().all()])

        repo_groups = sorted(repo_groups, key=lambda t: t[1].split(sep)[0])

        return repo_groups

    @classmethod

    def url_sep(cls):

        return '/'

    @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" % group_name))

        return gr.scalar()

    @property

    def parents(self):

        parents_recursion_limit = 5

        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 infinit loops

                log.error('group nested more than %s' %

                          parents_recursion_limit)

                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)

    @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 get_new_name(self, group_name):

        """

        returns new full group name based on parent and new name

        :param group_name:

        """

        path_prefix = (self.parent_group.full_path_splitted if

                       self.parent_group else [])

        return RepoGroup.url_sep().join(path_prefix + [group_name])

class Permission(Base, BaseModel):

    __tablename__ = 'permissions'

    __table_args__ = {'extend_existing': True}

    permission_id = Column("permission_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    permission_name = Column("permission_name", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    permission_longname = Column("permission_longname", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    def __repr__(self):

        return "<%s('%s:%s')>" % (

            self.__class__.__name__, self.permission_id, self.permission_name

        )