From: Ivan Kolodyazhny <e0ne@e0ne.info>
Date: Tue, 16 Dec 2014 23:04:33 +0000 (+0200)
Subject: Remove custom lazy loading
X-Git-Url: https://review.fuel-infra.org/gitweb?a=commitdiff_plain;h=2146c18c4abc7675b768008133b27ec3c2927943;p=openstack-build%2Fcinder-build.git

Remove custom lazy loading

We are using stevedore for database migration backend loading

Closes-Bug: #1420321
Change-Id: I281d631f9fd72d9d6938ffd2945fbeea8099dff5
---

diff --git a/cinder/db/api.py b/cinder/db/api.py
index 4a393e60d..7cd45a34a 100644
--- a/cinder/db/api.py
+++ b/cinder/db/api.py
@@ -17,8 +17,6 @@
 
 """Defines interface for DB access.
 
-The underlying driver is loaded as a :class:`LazyPluggable`.
-
 Functions in this module are imported into the cinder.db namespace. Call these
 functions from cinder.db namespace, not the cinder.db.api namespace.
 
@@ -30,9 +28,6 @@ these objects be simple dictionaries.
 
 **Related Flags**
 
-:backend:  string to lookup in the list of LazyPluggable backends.
-           `sqlalchemy` is the only supported backend right now.
-
 :connection:  string specifying the sqlalchemy connection to use, like:
               `sqlite:///var/lib/cinder/cinder.sqlite`.
 
@@ -47,14 +42,6 @@ from oslo.db import options as db_options
 
 
 db_opts = [
-    # TODO(rpodolyaka): this option is deprecated but still passed to
-    #                   LazyPluggable class which doesn't support retrieving
-    #                   of options put into groups. Nova's version of this
-    #                   class supports this. Perhaps, we should put it to Oslo
-    #                   and then reuse here.
-    cfg.StrOpt('db_backend',
-               default='sqlalchemy',
-               help='The backend to use for db'),
     cfg.BoolOpt('enable_new_services',
                 default=True,
                 help='Services to be added to the available pool on create'),
diff --git a/cinder/utils.py b/cinder/utils.py
index aa6fadcc9..0ad14dd5b 100644
--- a/cinder/utils.py
+++ b/cinder/utils.py
@@ -276,37 +276,6 @@ def last_completed_audit_period(unit=None):
     return (begin, end)
 
 
-class LazyPluggable(object):
-    """A pluggable backend loaded lazily based on some value."""
-
-    def __init__(self, pivot, **backends):
-        self.__backends = backends
-        self.__pivot = pivot
-        self.__backend = None
-
-    def __get_backend(self):
-        if not self.__backend:
-            backend_name = CONF[self.__pivot]
-            if backend_name not in self.__backends:
-                raise exception.Error(_('Invalid backend: %s') % backend_name)
-
-            backend = self.__backends[backend_name]
-            if isinstance(backend, tuple):
-                name = backend[0]
-                fromlist = backend[1]
-            else:
-                name = backend
-                fromlist = backend
-
-            self.__backend = __import__(name, None, None, fromlist)
-            LOG.debug('backend %s', self.__backend)
-        return self.__backend
-
-    def __getattr__(self, key):
-        backend = self.__get_backend()
-        return getattr(backend, key)
-
-
 class ProtectedExpatParser(expatreader.ExpatParser):
     """An expat parser which disables DTD's and entities by default."""