stevedore/stevedore/driver.py
2012-07-22 16:54:13 -04:00

41 lines
1.6 KiB
Python

from .hook import HookManager
class DriverManager(HookManager):
"""Load a single plugin with a given name from the namespace.
:param namespace: The namespace for the entry points.
:type namespace: str
:param name: The name of the driver to load.
:type name: str
:param invoke_on_load: Boolean controlling whether to invoke the
object returned by the entry point after the driver is loaded.
:type invoke_on_load: bool
:param invoke_args: Positional arguments to pass when invoking
the object returned by the entry point. Only used if invoke_on_load
is True.
:type invoke_args: tuple
:param invoke_kwds: Named arguments to pass when invoking
the object returned by the entry point. Only used if invoke_on_load
is True.
:type invoke_kwds: dict
"""
def __init__(self, namespace, name,
invoke_on_load=False, invoke_args=(), invoke_kwds={}):
super(HookManager, self).__init__(
namespace,
[name],
invoke_on_load=invoke_on_load,
invoke_args=invoke_args,
invoke_kwds=invoke_kwds,
)
if not self.extensions:
raise RuntimeError('No %r driver found' % namespace)
if len(self.extensions) > 1:
raise RuntimeError('Multiple %r drivers found: %s' %
(namespace,
','.join('%s:%s' % (e.module_name, e.attrs[0])
for e in self.extensions))
)