parsed_request = self.parse_request(environ)

            if parsed_request is None:

                return self.application(environ, start_response)

            # skip passing error to error controller

            environ['pylons.status_code_redirect'] = True

            # quick check if repo exists...

            if not is_valid_repo(parsed_request.repo_name, self.basepath, self.scm_alias):

                raise webob.exc.HTTPNotFound()

            if parsed_request.action is None:

                # Note: the client doesn't get the helpful error message

                raise webob.exc.HTTPBadRequest('Unable to detect pull/push action for %r! Are you using a nonstandard command or client?' % parsed_request.repo_name)

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

            # CHECK PERMISSIONS

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

            ip_addr = self._get_ip_addr(environ)

            user, response_app = self._authorize(environ, parsed_request.action, parsed_request.repo_name, ip_addr)

            if response_app is not None:

                return response_app(environ, start_response)

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

            # REQUEST HANDLING

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

            set_hook_environment(user.username, ip_addr,

                parsed_request.repo_name, self.scm_alias, parsed_request.action)

            try:

                log.info('%s action on %s repo "%s" by "%s" from %s',

                         parsed_request.action, self.scm_alias, parsed_request.repo_name, safe_str(user.username), ip_addr)

                app = self._make_app(parsed_request)

                return app(environ, start_response)

            except Exception:

                log.error(traceback.format_exc())

                raise webob.exc.HTTPInternalServerError()

        except webob.exc.HTTPException as e:

            return e(environ, start_response)

        finally:

            log_ = logging.getLogger('kallithea.' + self.__class__.__name__)

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

            meta.Session.remove()

class BaseController(TGController):

    def _before(self, *args, **kwargs):

        """

        _before is called before controller methods and after __call__

        """

        if request.needs_csrf_check:

            # CSRF protection: Whenever a request has ambient authority (whether

            # through a session cookie or its origin IP address), it must include

            # the correct token, unless the HTTP method is GET or HEAD (and thus

            # guaranteed to be side effect free. In practice, the only situation

            # where we allow side effects without ambient authority is when the

            # authority comes from an API key; and that is handled above.

            token = request.POST.get(secure_form.token_key)

            if not token or token != secure_form.authentication_token():

                log.error('CSRF check failed')

                raise webob.exc.HTTPForbidden()

        c.kallithea_version = __version__

        rc_config = Setting.get_app_settings()

        # Visual options

        c.visual = AttributeDict({})

        ## DB stored

        c.visual.show_public_icon = str2bool(rc_config.get('show_public_icon'))

        c.visual.show_private_icon = str2bool(rc_config.get('show_private_icon'))

        c.visual.stylify_metalabels = str2bool(rc_config.get('stylify_metalabels'))

        c.visual.page_size = safe_int(rc_config.get('dashboard_items', 100))

        c.visual.admin_grid_items = safe_int(rc_config.get('admin_grid_items', 100))

        c.visual.repository_fields = str2bool(rc_config.get('repository_fields'))

        c.visual.show_version = str2bool(rc_config.get('show_version'))

        c.visual.use_gravatar = str2bool(rc_config.get('use_gravatar'))

        c.visual.gravatar_url = rc_config.get('gravatar_url')

        c.ga_code = rc_config.get('ga_code')

        # TODO: replace undocumented backwards compatibility hack with db upgrade and rename ga_code

        if c.ga_code and '<' not in c.ga_code:

            c.ga_code = '''<script type="text/javascript">

                var _gaq = _gaq || [];

                _gaq.push(['_setAccount', '%s']);

                _gaq.push(['_trackPageview']);

                (function() {

                    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;

                    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';

                    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);

                    })();

            </script>''' % c.ga_code

        c.site_name = rc_config.get('title')

        ## INI stored

        c.visual.allow_repo_location_change = str2bool(config.get('allow_repo_location_change', True))

        c.visual.allow_custom_hooks_settings = str2bool(config.get('allow_custom_hooks_settings', True))

        c.instance_id = config.get('instance_id')

        c.issues_url = config.get('bugtracker', url('issues_url'))

        # END CONFIG VARS

        c.repo_name = get_repo_slug(request)  # can be empty

        c.backends = BACKENDS.keys()

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

        c.my_pr_count = PullRequest.query(reviewer_id=request.authuser.user_id, include_closed=False).count()

        self.scm_model = ScmModel()

    @staticmethod

    def _determine_auth_user(session_authuser, ip_addr):

        """

        Create an `AuthUser` object given the API key/bearer token

        (if any) and the value of the authuser session cookie.

        Returns None if no valid user is found (like not active or no access for IP).

        """

        # Authenticate by session cookie

        # In ancient login sessions, 'authuser' may not be a dict.

        # In that case, the user will have to log in again.

        # v0.3 and earlier included an 'is_authenticated' key; if present,

        # this must be True.

        if isinstance(session_authuser, dict) and session_authuser.get('is_authenticated', True):

            return AuthUser.from_cookie(session_authuser, ip_addr=ip_addr)

        # Authenticate by auth_container plugin (if enabled)

        if any(

            plugin.is_container_auth

            for plugin in auth_modules.get_auth_plugins()

        ):

            try:

                user_info = auth_modules.authenticate('', '', request.environ)

            except UserCreationError as e:

                from kallithea.lib import helpers as h

                h.flash(e, 'error', logf=log.error)

            else:

                if user_info is not None:

                    username = user_info['username']

                    user = User.get_by_username(username, case_insensitive=True)

                    return log_in_user(user, remember=False, is_external_auth=True, ip_addr=ip_addr)

        # User is default user (if active) or anonymous

        default_user = User.get_default_user(cache=True)

        authuser = AuthUser.make(dbuser=default_user, ip_addr=ip_addr)

        if authuser is None: # fall back to anonymous

            authuser = AuthUser(dbuser=default_user) # TODO: somehow use .make?

        return authuser

    @staticmethod

    def _basic_security_checks():

        """Perform basic security/sanity checks before processing the request."""

        # Only allow the following HTTP request methods.

        if request.method not in ['GET', 'HEAD', 'POST']:

            raise webob.exc.HTTPMethodNotAllowed()

        # Also verify the _method override - no longer allowed.

        if request.params.get('_method') is None:

            pass # no override, no problem

        else:

            raise webob.exc.HTTPMethodNotAllowed()

        # Make sure CSRF token never appears in the URL. If so, invalidate it.

        if secure_form.token_key in request.GET:

            log.error('CSRF key leak detected')

            session.pop(secure_form.token_key, None)

            session.save()

            from kallithea.lib import helpers as h

            h.flash(_('CSRF token leak has been detected - all form tokens have been expired'),

                    category='error')

        # WebOb already ignores request payload parameters for anything other

        # than POST/PUT, but double-check since other Kallithea code relies on

        # this assumption.

        if request.method not in ['POST', 'PUT'] and request.POST:

            log.error('%r request with payload parameters; WebOb should have stopped this', request.method)

            raise webob.exc.HTTPBadRequest()

    def __call__(self, environ, context):

        try:

            ip_addr = _get_ip_addr(environ)

            self._basic_security_checks()

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

            try:

                # Request.authorization may raise ValueError on invalid input

                type, params = request.authorization

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

# 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/>.

"""

kallithea.model.db

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

Database Models for Kallithea

This file was forked by the Kallithea project in July 2014.

Original author and date, and relevant copyright and licensing information is below:

:created_on: Apr 08, 2010

:author: marcink

:copyright: (c) 2013 RhodeCode GmbH, and others.

:license: GPLv3, see LICENSE.md for more details.

"""

import os

import time

import logging

import datetime

import traceback

import hashlib

import collections

import functools

import sqlalchemy

from sqlalchemy import *

from sqlalchemy.ext.hybrid import hybrid_property

from sqlalchemy.orm import relationship, joinedload, class_mapper, validates

from beaker.cache import cache_region, region_invalidate

from webob.exc import HTTPNotFound

from tg.i18n import lazy_ugettext as _

from kallithea.lib.exceptions import DefaultUserException

from kallithea.lib.vcs import get_backend

from kallithea.lib.vcs.utils.helpers import get_scm

from kallithea.lib.vcs.utils.lazy import LazyProperty

from kallithea.lib.vcs.backends.base import EmptyChangeset

from kallithea.lib.utils2 import str2bool, safe_str, get_changeset_safe, \

    safe_unicode, remove_prefix, time_to_datetime, aslist, Optional, safe_int, \

    get_clone_url, urlreadable

from kallithea.lib.compat import json

from kallithea.lib.caching_query import FromCache

from kallithea.model.meta import Base, Session

URL_SEP = '/'

log = logging.getLogger(__name__)

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

# BASE CLASSES

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

_hash_key = lambda k: hashlib.md5(safe_str(k)).hexdigest()

class BaseDbModel(object):

    """

    Base Model for all classes

    """

    @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

        _json_attr = getattr(self, '__json__', None)

        if _json_attr:

            # update with attributes from __json__

            if callable(_json_attr):

                _json_attr = _json_attr()

            for k, val in _json_attr.iteritems():

                d[k] = val

        return d

    def get_appstruct(self):

        """return list with keys and values tuples corresponding

        to this model data """

        return [

            (k, getattr(self, k))

            for k in self._get_keys()

        ]

    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 guess_instance(cls, value, callback=None):

        """Haphazardly attempt to convert `value` to a `cls` instance.

        If `value` is None or already a `cls` instance, return it. If `value`

        is a number (or looks like one if you squint just right), assume it's

        a database primary key and let SQLAlchemy sort things out. Otherwise,

        fall back to resolving it using `callback` (if specified); this could

        e.g. be a function that looks up instances by name (though that won't

        work if the name begins with a digit). Otherwise, raise Exception.

        """

        if value is None:

            return None

        if isinstance(value, cls):

            return value

        if isinstance(value, (int, long)) or safe_str(value).isdigit():

            return cls.get(value)

    @app_settings_type.setter

    def app_settings_type(self, val):

        if val not in self.SETTINGS_TYPES:

            raise Exception('type must be one of %s got %s'

                            % (self.SETTINGS_TYPES.keys(), val))

        self._app_settings_type = val

    def __unicode__(self):

        return u"<%s('%s:%s[%s]')>" % (

            self.__class__.__name__,

            self.app_settings_name, self.app_settings_value, self.app_settings_type

        )

    @classmethod

    def get_by_name(cls, key):

        return cls.query() \

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

    @classmethod

    def get_by_name_or_create(cls, key, val='', type='unicode'):

        res = cls.get_by_name(key)

        if res is None:

            res = cls(key, val, type)

        return res

    @classmethod

    def create_or_update(cls, key, val=Optional(''), type=Optional('unicode')):

        """

        Creates or updates Kallithea setting. If updates are triggered, it will only

        update parameters that are explicitly set. Optional instance will be skipped.

        :param key:

        :param val:

        :param type:

        :return:

        """

        res = cls.get_by_name(key)

        if res is None:

            val = Optional.extract(val)

            type = Optional.extract(type)

            res = cls(key, val, type)

            Session().add(res)

        else:

            res.app_settings_name = key

            if not isinstance(val, Optional):

                # update if set

                res.app_settings_value = val

            if not isinstance(type, Optional):

                # update if set

                res.app_settings_type = type

        return res

    @classmethod

    def get_app_settings(cls, cache=False):

        ret = cls.query()

        if cache:

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

        if ret is None:

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

        settings = {}

        for each in ret:

            settings[each.app_settings_name] = \

                each.app_settings_value

        return settings

    @classmethod

    def get_auth_settings(cls, cache=False):

        ret = cls.query() \

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

        fd = {}

        for row in ret:

            fd[row.app_settings_name] = row.app_settings_value

        return fd

    @classmethod

    def get_default_repo_settings(cls, cache=False, strip_prefix=False):

        ret = cls.query() \

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

        fd = {}

        for row in ret:

            key = row.app_settings_name

            if strip_prefix:

                key = remove_prefix(key, prefix='default_')

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

        return fd

    @classmethod

    def get_server_info(cls):

        import pkg_resources

        import platform

        from kallithea.lib.utils import check_git_version

        mods = [(p.project_name, p.version) for p in pkg_resources.working_set]

        info = {

            'modules': sorted(mods, key=lambda k: k[0].lower()),

            'py_version': platform.python_version(),

            'platform': safe_unicode(platform.platform()),

            'kallithea_version': kallithea.__version__,

            'git_version': safe_unicode(check_git_version()),

            'git_path': kallithea.CONFIG.get('git_path')

        }

        return info

class Ui(Base, BaseDbModel):

    __tablename__ = 'ui'

    __table_args__ = (

        # FIXME: ui_key as key is wrong and should be removed when the corresponding

        # Ui.get_by_key has been replaced by the composite key

        UniqueConstraint('ui_key'),

        UniqueConstraint('ui_section', 'ui_key'),

        _table_args_default_dict,

    )

    HOOK_UPDATE = 'changegroup.update'

    HOOK_REPO_SIZE = 'changegroup.repo_size'

    ui_id = Column(Integer(), primary_key=True)

    ui_section = Column(String(255), nullable=False)

    ui_key = Column(String(255), nullable=False)

    ui_value = Column(String(255), nullable=True) # FIXME: not nullable?

    ui_active = Column(Boolean(), nullable=False, default=True)

    @classmethod

    def get_by_key(cls, section, key):

        """ Return specified Ui object, or None if not found. """

        return cls.query().filter_by(ui_section=section, ui_key=key).scalar()

    @classmethod

    def get_or_create(cls, section, key):

        """ Return specified Ui object, creating it if necessary. """

        setting = cls.get_by_key(section, key)

        if setting is None:

            setting = cls(ui_section=section, ui_key=key)

            Session().add(setting)

        return setting

    @classmethod

    def get_builtin_hooks(cls):

        q = cls.query()

        q = q.filter(cls.ui_key.in_([cls.HOOK_UPDATE, cls.HOOK_REPO_SIZE]))

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

        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]))

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

        return q.all()

    @classmethod

    def get_repos_location(cls):

        return cls.get_by_key('paths', '/').ui_value

    @classmethod

    def create_or_update_hook(cls, key, val):

        new_ui = cls.get_or_create('hooks', key)

        new_ui.ui_active = True

        new_ui.ui_value = val

    def __repr__(self):

        return '<%s[%s]%s=>%s]>' % (self.__class__.__name__, self.ui_section,

                                    self.ui_key, self.ui_value)

class User(Base, BaseDbModel):

    __tablename__ = 'users'

    __table_args__ = (

        Index('u_username_idx', 'username'),

        Index('u_email_idx', 'email'),

        _table_args_default_dict,

    )

    DEFAULT_USER = 'default'

    DEFAULT_GRAVATAR_URL = 'https://secure.gravatar.com/avatar/{md5email}?d=identicon&s={size}'

    # The name of the default auth type in extern_type, 'internal' lives in auth_internal.py

    DEFAULT_AUTH_TYPE = 'internal'

    user_id = Column(Integer(), primary_key=True)

    username = Column(String(255), nullable=False, unique=True)

    password = Column(String(255), nullable=False)

    active = Column(Boolean(), nullable=False, default=True)

    admin = Column(Boolean(), nullable=False, default=False)

    name = Column("firstname", Unicode(255), nullable=False)

    lastname = Column(Unicode(255), nullable=False)

    _email = Column("email", String(255), nullable=True, unique=True) # FIXME: not nullable?

            .filter(CacheInvalidation.cache_args == self.repo_name) \

            .order_by(CacheInvalidation.cache_key) \

            .all()

    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 kallithea.lib.utils import make_ui

        return make_ui(clear_session=False)

    @classmethod

    def is_valid(cls, repo_name):

        """

        returns True if given repo name is a valid filesystem repository

        :param cls:

        :param repo_name:

        """

        from kallithea.lib.utils import is_valid_repo

        return is_valid_repo(repo_name, cls.base_path())

    def get_api_data(self, with_revision_names=False,

                           with_pullrequests=False):

        """

        Common function for generating repo api data.

        Optionally, also return tags, branches, bookmarks and PRs.

        """

        repo = self

        data = dict(

            repo_id=repo.repo_id,

            repo_name=repo.repo_name,

            repo_type=repo.repo_type,

            clone_uri=repo.clone_uri,

            private=repo.private,

            created_on=repo.created_on,

            description=repo.description,

            landing_rev=repo.landing_rev,

            owner=repo.owner.username,

            fork_of=repo.fork.repo_name if repo.fork else None,

            enable_statistics=repo.enable_statistics,

            enable_downloads=repo.enable_downloads,

            last_changeset=repo.changeset_cache,

        )

        if with_revision_names:

            scm_repo = repo.scm_instance_no_cache()

            data.update(dict(

                tags=scm_repo.tags,

                branches=scm_repo.branches,

                bookmarks=scm_repo.bookmarks,

            ))

        if with_pullrequests:

            data['pull_requests'] = repo.pull_requests_other

        rc_config = Setting.get_app_settings()

        repository_fields = str2bool(rc_config.get('repository_fields'))

        if repository_fields:

            for f in self.extra_fields:

                data[f.field_key_prefixed] = f.field_value

        return data

    @property

    def last_db_change(self):

        return self.updated_on

    @property

    def clone_uri_hidden(self):

        clone_uri = self.clone_uri

        if clone_uri:

            import urlobject

            url_obj = urlobject.URLObject(self.clone_uri)

            if url_obj.password:

                clone_uri = url_obj.with_password('*****')

        return clone_uri

    def clone_url(self, **override):

        clone_uri_tmpl = None

        if 'with_id' in override:

            clone_uri_tmpl = self.DEFAULT_CLONE_URI_ID

            del override['with_id']

        if 'clone_uri_tmpl' in override:

            clone_uri_tmpl = override['clone_uri_tmpl']

            del override['clone_uri_tmpl']

        import kallithea.lib.helpers as h

        prefix_url = h.canonical_url('home')

        return get_clone_url(clone_uri_tmpl=clone_uri_tmpl,

                             prefix_url=prefix_url,

                             repo_name=self.repo_name,

                             repo_id=self.repo_id, **override)

    def set_state(self, state):

        self.repo_state = state

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

    # SCM PROPERTIES

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

    def get_changeset(self, rev=None):

        return get_changeset_safe(self.scm_instance, rev)

    def get_landing_changeset(self):

        """

        Returns landing changeset, or if that doesn't exist returns the tip

        """

        _rev_type, _rev = self.landing_rev

        cs = self.get_changeset(_rev)

        if isinstance(cs, EmptyChangeset):

            return self.get_changeset()

        return cs

    def update_changeset_cache(self, cs_cache=None):

        """

        Update cache of last changeset for repository, keys should be::

            short_id

            raw_id

            revision

            message

            date

            author

        :param cs_cache:

        """

        from kallithea.lib.vcs.backends.base import BaseChangeset

        if cs_cache is None:

            cs_cache = EmptyChangeset()

            # use no-cache version here

            scm_repo = self.scm_instance_no_cache()

            if scm_repo:

                cs_cache = scm_repo.get_changeset()

        if isinstance(cs_cache, BaseChangeset):

            cs_cache = cs_cache.__json__()

        if (not self.changeset_cache or cs_cache['raw_id'] != self.changeset_cache['raw_id']):

            _default = datetime.datetime.fromtimestamp(0)

            last_change = cs_cache.get('date') or _default

            log.debug('updated repo %s with new cs cache %s',

                      self.repo_name, cs_cache)

            self.updated_on = last_change

            self.changeset_cache = cs_cache

            Session().commit()

        else:

            log.debug('changeset_cache for %s already up to date with %s',

                      self.repo_name, cs_cache['raw_id'])

    @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 get_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 is not None:

            if not revisions:

                return {} # don't use sql 'in' on empty set

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

        grouped = collections.defaultdict(list)

        for cmt in cmts.all():

            grouped[cmt.revision].append(cmt)

        return grouped

    def statuses(self, revisions):

        """

        Returns statuses for this repository.

    stat_on_revision = Column(Integer(), nullable=False)

    commit_activity = Column(LargeBinary(1000000), nullable=False) # JSON data

    commit_activity_combined = Column(LargeBinary(), nullable=False) # JSON data

    languages = Column(LargeBinary(1000000), nullable=False) # JSON data

    repository = relationship('Repository', single_parent=True)

class UserFollowing(Base, BaseDbModel):

    __tablename__ = 'user_followings'

    __table_args__ = (

        UniqueConstraint('user_id', 'follows_repository_id', name='uq_user_followings_user_repo'),

        UniqueConstraint('user_id', 'follows_user_id', name='uq_user_followings_user_user'),

        _table_args_default_dict,

    )

    user_following_id = Column(Integer(), primary_key=True)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=False)

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

    follows_user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=True)

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

    user = relationship('User', primaryjoin='User.user_id==UserFollowing.user_id')

    follows_user = relationship('User', primaryjoin='User.user_id==UserFollowing.follows_user_id')

    follows_repository = relationship('Repository', order_by=lambda: func.lower(Repository.repo_name))

    @classmethod

    def get_repo_followers(cls, repo_id):

        return cls.query().filter(cls.follows_repository_id == repo_id)

class CacheInvalidation(Base, BaseDbModel):

    __tablename__ = 'cache_invalidation'

    __table_args__ = (

        Index('key_idx', 'cache_key'),

        _table_args_default_dict,

    )

    # cache_id, not used

    cache_id = Column(Integer(), primary_key=True)

    # cache_key as created by _get_cache_key

    cache_key = Column(Unicode(255), nullable=False, unique=True)

    # cache_args is a repo_name

    cache_args = Column(Unicode(255), nullable=False)

    # instance sets cache_active True when it is caching, other instances set

    # cache_active to False to indicate that this cache is invalid

    cache_active = Column(Boolean(), nullable=False, default=False)

    def __init__(self, cache_key, repo_name=''):

        self.cache_key = cache_key

        self.cache_args = repo_name

        self.cache_active = False

    def __unicode__(self):

        return u"<%s('%s:%s[%s]')>" % (

            self.__class__.__name__,

            self.cache_id, self.cache_key, self.cache_active)

    def _cache_key_partition(self):

        prefix, repo_name, suffix = self.cache_key.partition(self.cache_args)

        return prefix, repo_name, suffix

    def get_prefix(self):

        """

        get prefix that might have been used in _get_cache_key to

        generate self.cache_key. Only used for informational purposes

        in repo_edit.html.

        """

        # prefix, repo_name, suffix

        return self._cache_key_partition()[0]

    def get_suffix(self):

        """

        get suffix that might have been used in _get_cache_key to

        generate self.cache_key. Only used for informational purposes

        in repo_edit.html.

        """

        # prefix, repo_name, suffix

        return self._cache_key_partition()[2]

    @classmethod

    def clear_cache(cls):

        """

        Delete all cache keys from database.

        Should only be run when all instances are down and all entries thus stale.

        """

        cls.query().delete()

        Session().commit()

    @classmethod

    def _get_cache_key(cls, key):

        """

        Wrapper for generating a unique cache key for this instance and "key".

        key must / will start with a repo_name which will be stored in .cache_args .

        """

        prefix = kallithea.CONFIG.get('instance_id', '')

        return "%s%s" % (prefix, key)

    @classmethod

    def set_invalidate(cls, repo_name):

        """

        Mark all caches of a repo as invalid in the database.

        """

        inv_objs = Session().query(cls).filter(cls.cache_args == repo_name).all()

        log.debug('for repo %s got %s invalidation objects',

                  safe_str(repo_name), inv_objs)

        for inv_obj in inv_objs:

            log.debug('marking %s key for invalidation based on repo_name=%s',

                      inv_obj, safe_str(repo_name))

            Session().delete(inv_obj)

        Session().commit()

    @classmethod

    def test_and_set_valid(cls, repo_name, kind, valid_cache_keys=None):

        """

        Mark this cache key as active and currently cached.

        Return True if the existing cache registration still was valid.

        Return False to indicate that it had been invalidated and caches should be refreshed.

        """

        key = (repo_name + '_' + kind) if kind else repo_name

        cache_key = cls._get_cache_key(key)

        if valid_cache_keys and cache_key in valid_cache_keys:

            return True

        inv_obj = cls.query().filter(cls.cache_key == cache_key).scalar()

        if inv_obj is None:

            inv_obj = cls(cache_key, repo_name)

            Session().add(inv_obj)

        elif inv_obj.cache_active:

            return True

        inv_obj.cache_active = True

        try: