Pool
pool is a registry (dictionary object {}).
The registry is essentially a mapping between model names and model
instances. There is one registry instance per database.
server/openerp/osv/orm.py
class BaseModel(object):
def __init__(self, pool, cr):
""" Initialize a model and make it part of the given registry.
- copy the stored fields' functions in the osv_pool,
- update the _columns with the fields found in ir_model_fields,
- ensure there is a many2one for each _inherits'd parent,
- update the children's _columns,
- give a chance to each field to initialize itself.
"""
pool.add(self._name, self)
self.pool = pool
Refer /openerp/sql_db.py to see how Odoo-Postgresql connection
pool establish.
_Pool = None
def db_connect(to, allow_uri=False):
global _Pool
if _Pool is None:
_Pool = ConnectionPool(int(tools.config['db_maxconn']))
db, uri = dsn(to)
if not allow_uri and db != to:
raise ValueError('URI connections not allowed')
return Connection(_Pool, db, uri)
def close_db(db_name):
""" You might want to call openerp.modules.registry.RegistryManager.delete(db_name) along this function."""
global _Pool
if _Pool:
_Pool.close_all(dsn(db_name)[1])
def close_all():
global _Pool
if _Pool:
_Pool.close_all()
Connection class
class Connection(object):
""" A lightweight instance of a connection to postgres
"""
def __init__(self, pool, dbname, dsn):
self.dbname = dbname
self.dsn = dsn
self.__pool = pool
if you look at the /server/openerp/pooler.py file there you can find the method get_db_and_pool which is used to Create and return a database connection and a newly initialized registry, there are many other methods related to pool look at these.
def get_db_and_pool(db_name, force_demo=False, status=None, update_module=False):
"""Create and return a database connection and a newly initialized registry."""
registry = RegistryManager.get(db_name, force_demo, status, update_module)
return registry.db, registry
def restart_pool(db_name, force_demo=False, status=None, update_module=False):
"""Delete an existing registry and return a database connection and a newly initialized registry."""
registry = RegistryManager.new(db_name, force_demo, status, update_module)
return registry.db, registry
def get_db(db_name):
"""Return a database connection. The corresponding registry is initialized."""
return get_db_and_pool(db_name)[0]
def get_pool(db_name, force_demo=False, status=None, update_module=False):
"""Return a model registry."""
return get_db_and_pool(db_name, force_demo, status, update_module)[1]
And finally you call get method of dictionary to get the value of the specified key, even you can use can use self.pool['model_name'], any method of dictionary can be used with pool.
