odoo/openerp/modules/registry.py

# -*- coding: utf-8 -*-
##############################################################################
#
#    OpenERP, Open Source Management Solution
#    Copyright (C) 2004-2009 Tiny SPRL (<http://tiny.be>).
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################

""" Models registries.

"""

import openerp.sql_db
import openerp.osv.orm
import openerp.netsvc
import openerp.tools


class Registry(object):
    """ Model registry for a particular database.

    The registry is essentially a mapping between model names and model
    instances. There is one registry instance per database.

    """

    def __init__(self, db_name):
        self.models = {} # model name/model instance mapping
        self._sql_error = {}
        self._store_function = {}
        self._init = True
        self._init_parent = {}
        self.db_name = db_name
        self.db = openerp.sql_db.db_connect(db_name)

    def do_parent_store(self, cr):
        for o in self._init_parent:
            self.get(o)._parent_store_compute(cr)
        self._init = False

    def obj_list(self):
        """ Return the list of model names in this registry."""
        return self.models.keys()

    def add(self, model_name, model):
        """ Add or replace a model in the registry."""
        self.models[model_name] = model

    def get(self, model_name):
        """ Return a model for a given name or None if it doesn't exist."""
        return self.models.get(model_name)

    def __getitem__(self, model_name):
        """ Return a model for a given name or raise KeyError if it doesn't exist."""
        return self.models[model_name]

    def instanciate(self, module, cr):
        """ Instanciate all the classes of a given module for a particular db."""

        res = []

        # Instanciate classes registered through their constructor and
        # add them to the pool.
        for klass in openerp.osv.orm.module_class_list.get(module, []):
            res.append(klass.createInstance(self, cr))

        # Instanciate classes automatically discovered.
        for cls in openerp.osv.orm.MetaModel.module_to_models.get(module, []):
            if cls not in openerp.osv.orm.module_class_list.get(module, []):
                res.append(cls.createInstance(self, cr))

        return res

    def start_cron_thread(self):
        self.get('ir.cron').restart(self.db.dbname)


class RegistryManager(object):
    """ Model registries manager.

        The manager is responsible for creation and deletion of model
        registries (essentially database connection/model registry pairs).

    """

    # Mapping between db name and model registry.
    # Accessed through the methods below.
    registries = {}


    @classmethod
    def get(cls, db_name, force_demo=False, status=None, update_module=False,
            pooljobs=True):
        """ Return a registry for a given database name."""

        if db_name in cls.registries:
            registry = cls.registries[db_name]
        else:
            registry = cls.new(db_name, force_demo, status,
                update_module, pooljobs)
        return registry


    @classmethod
    def new(cls, db_name, force_demo=False, status=None,
            update_module=False, pooljobs=True):
        """ Create and return a new registry for a given database name.

        The (possibly) previous registry for that database name is discarded.

        """

        import openerp.modules
        registry = Registry(db_name)

        # Initializing a registry will call general code which will in turn
        # call registries.get (this object) to obtain the registry being
        # initialized. Make it available in the registries dictionary then
        # remove it if an exception is raised.
        cls.delete(db_name)
        cls.registries[db_name] = registry
        try:
            # This should be a method on Registry
            openerp.modules.load_modules(registry.db, force_demo, status, update_module)
        except Exception:
            del cls.registries[db_name]
            raise

        cr = registry.db.cursor()
        try:
            registry.do_parent_store(cr)
            registry.get('ir.actions.report.xml').register_all(cr)
            cr.commit()
        finally:
            cr.close()

        if pooljobs:
            registry.start_cron_thread()

        return registry


    @classmethod
    def delete(cls, db_name):
        """ Delete the registry linked to a given database.

        This also cleans the associated caches. For good measure this also
        cancels the associated cron job. But please note that the cron job can
        be running and take some time before ending, and that you should not
        remove a registry if it can still be used by some thread. So it might
        be necessary to call yourself openerp.netsvc.Agent.cancel(db_name) and
        and join (i.e. wait for) the thread.

        """
        if db_name in cls.registries:
            del cls.registries[db_name]
        openerp.tools.cache.clean_caches_for_db(db_name)
        openerp.netsvc.Agent.cancel(db_name)


    @classmethod
    def delete_all(cls):
        """ Delete all the registries. """
        for db_name in cls.registries.keys():
            cls.delete(db_name)


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