diff options
Diffstat (limited to 'nova/hooks.py')
| -rw-r--r-- | nova/hooks.py | 84 |
1 files changed, 51 insertions, 33 deletions
diff --git a/nova/hooks.py b/nova/hooks.py index 735b89338b..15c2d8c490 100644 --- a/nova/hooks.py +++ b/nova/hooks.py @@ -46,7 +46,7 @@ import functools import stevedore -from nova.i18n import _LE +from nova.i18n import _, _LE from nova.openstack.common import log as logging LOG = logging.getLogger(__name__) @@ -65,50 +65,68 @@ class FatalHookException(Exception): class HookManager(stevedore.hook.HookManager): def __init__(self, name): - # invoke_on_load creates an instance of the Hook class + """Invoke_on_load creates an instance of the Hook class + + :param name: The name of the hooks to load. + :type name: str + """ super(HookManager, self).__init__(NS, name, invoke_on_load=True) - def run_pre(self, name, args, kwargs, f=None): + def _run(self, name, method_type, args, kwargs, func=None): + if method_type not in ('pre', 'post'): + msg = _("Wrong type of hook method. " + "Only 'pre' and 'post' type allowed") + raise ValueError(msg) + for e in self.extensions: obj = e.obj - pre = getattr(obj, 'pre', None) - if pre: - LOG.debug("Running %(name)s pre-hook: %(obj)s", - {'name': name, 'obj': obj}) + hook_method = getattr(obj, method_type, None) + if hook_method: + LOG.debug("Running %(name)s %(type)s-hook: %(obj)s", + {'name': name, 'type': method_type, 'obj': obj}) try: - if f: - pre(f, *args, **kwargs) + if func: + hook_method(func, *args, **kwargs) else: - pre(*args, **kwargs) + hook_method(*args, **kwargs) except FatalHookException: msg = _LE("Fatal Exception running %(name)s " - "pre-hook: %(obj)s") - LOG.exception(msg, {'name': name, 'obj': obj}) + "%(type)s-hook: %(obj)s") + LOG.exception(msg, {'name': name, 'type': method_type, + 'obj': obj}) raise except Exception: - msg = _LE("Exception running %(name)s pre-hook: %(obj)s") - LOG.exception(msg, {'name': name, 'obj': obj}) + msg = _LE("Exception running %(name)s " + "%(type)s-hook: %(obj)s") + LOG.exception(msg, {'name': name, 'type': method_type, + 'obj': obj}) + + def run_pre(self, name, args, kwargs, f=None): + """Execute optional pre methods of loaded hooks. + + :param name: The name of the loaded hooks. + :param args: Positional arguments which would be transmitted into + all pre methods of loaded hooks. + :param kwargs: Keyword args which would be transmitted into all pre + methods of loaded hooks. + :param f: Target function. + """ + self._run(name=name, method_type='pre', args=args, kwargs=kwargs, + func=f) def run_post(self, name, rv, args, kwargs, f=None): - for e in reversed(self.extensions): - obj = e.obj - post = getattr(obj, 'post', None) - if post: - LOG.debug("Running %(name)s post-hook: %(obj)s", - {'name': name, 'obj': obj}) - try: - if f: - post(f, rv, *args, **kwargs) - else: - post(rv, *args, **kwargs) - except FatalHookException: - msg = _LE("Fatal Exception running %(name)s " - "post-hook: %(obj)s") - LOG.exception(msg, {'name': name, 'obj': obj}) - raise - except Exception: - msg = _LE("Exception running %(name)s post-hook: %(obj)s") - LOG.exception(msg, {'name': name, 'obj': obj}) + """Execute optional post methods of loaded hooks. + + :param name: The name of the loaded hooks. + :param rv: Return values of target method call. + :param args: Positional arguments which would be transmitted into + all post methods of loaded hooks. + :param kwargs: Keyword args which would be transmitted into all post + methods of loaded hooks. + :param f: Target function. + """ + self._run(name=name, method_type='post', args=(rv,) + args, + kwargs=kwargs, func=f) def add_hook(name, pass_function=False): |