Remove unnecessary wrapping of transformer ExtentionManager

Currently, the TransformerExtensionManager is used to wrap the
ExtentionManager of stevedore.extension just to provide getting extension
by name functionality, this is naturally supported by stevedore. This
change remove the unnecessary code.

Change-Id: I0b7bfa40e4131236b4adedc8b4bdcd70c14d5680

ceilometer/cmd/eventlet/sample.py

@@ -23,11 +23,11 @@ import sys
 from oslo_config import cfg
 from oslo_context import context
 from oslo_utils import timeutils
+from stevedore import extension
 
 from ceilometer import pipeline
 from ceilometer import sample
 from ceilometer import service
-from ceilometer import transformer
 
 
 def send_sample():
@@ -79,10 +79,7 @@ def send_sample():
     root_logger.setLevel(logging.DEBUG)
 
     pipeline_manager = pipeline.setup_pipeline(
-        transformer.TransformerExtensionManager(
-            'ceilometer.transformer',
-        ),
-    )
+        extension.ExtensionManager('ceilometer.transformer'))
 
     with pipeline_manager.publisher(context.get_admin_context()) as p:
         p([sample.Sample(

ceilometer/notifier.py

@@ -19,7 +19,6 @@ from stevedore import extension
 
 from ceilometer.i18n import _
 from ceilometer import pipeline
-from ceilometer import transformer
 
 
 LOG = logging.getLogger(__name__)
@@ -51,7 +50,7 @@ def _load_pipeline_manager():
     global _pipeline_manager
 
     _pipeline_manager = pipeline.setup_pipeline(
-        transformer.TransformerExtensionManager(
+        extension.ExtensionManager(
             'ceilometer.transformer',
         ),
     )

ceilometer/pipeline.py

@@ -25,14 +25,15 @@ from oslo_config import cfg
 from oslo_log import log
 from oslo_utils import timeutils
 import six
+from stevedore import extension
 import yaml
 
+
 from ceilometer.event.storage import models
 from ceilometer.i18n import _
 from ceilometer import publisher
 from ceilometer.publisher import utils as publisher_utils
 from ceilometer import sample as sample_util
-from ceilometer import transformer as xformer
 
 
 OPTS = [
@@ -376,7 +377,7 @@ class Sink(object):
         for transformer in self.transformer_cfg:
             parameter = transformer['parameters'] or {}
             try:
-                ext = transformer_manager.get_ext(transformer['name'])
+                ext = transformer_manager[transformer['name']]
             except KeyError:
                 raise PipelineException(
                     "No transformer named %s loaded" % transformer['name'],
@@ -732,7 +733,7 @@ def _setup_pipeline_manager(cfg_file, transformer_manager, p_type=SAMPLE_TYPE):
 
     return PipelineManager(pipeline_cfg,
                            transformer_manager or
-                           xformer.TransformerExtensionManager(
+                           extension.ExtensionManager(
                                'ceilometer.transformer',
                            ), p_type)
 

ceilometer/tests/agent/agentbase.py

@@ -37,7 +37,6 @@ from ceilometer import publisher
 from ceilometer.publisher import test as test_publisher
 from ceilometer import sample
 from ceilometer.tests import base
-from ceilometer import transformer
 from ceilometer import utils
 
 
@@ -173,7 +172,7 @@ class BaseAgentManagerTestCase(base.BaseTestCase):
         params = []
 
     def setup_pipeline(self):
-        self.transformer_manager = transformer.TransformerExtensionManager(
+        self.transformer_manager = extension.ExtensionManager(
             'ceilometer.transformer',
         )
         self.mgr.pipeline_manager = pipeline.PipelineManager(

ceilometer/tests/pipeline_base.py

@@ -138,18 +138,12 @@ class BasePipelineTestCase(base.BaseTestCase):
             resource_metadata={}
         )
 
-        self.useFixture(mockpatch.PatchObject(
-            transformer.TransformerExtensionManager, "__init__",
-            side_effect=self.fake_tem_init))
-
-        self.useFixture(mockpatch.PatchObject(
-            transformer.TransformerExtensionManager, "get_ext",
-            side_effect=self.fake_tem_get_ext))
-
         self.useFixture(mockpatch.PatchObject(
             publisher, 'get_publisher', side_effect=self.get_publisher))
 
-        self.transformer_manager = transformer.TransformerExtensionManager()
+        self.transformer_manager = mock.MagicMock()
+        self.transformer_manager.__getitem__.side_effect = \
+            self.fake_tem_get_ext
 
         self._setup_pipeline_cfg()
 

ceilometer/tests/test_notifier.py

@@ -15,10 +15,10 @@
 """Tests for ceilometer/notifier.py
 """
 from oslotest import base
+from stevedore import extension
 
 from ceilometer import notifier
 from ceilometer import pipeline
-from ceilometer import transformer
 
 
 MESSAGE = {
@@ -64,7 +64,7 @@ MESSAGE = {
 class TestNotifier(base.BaseTestCase):
 
     def test_process_notification(self):
-        transformer_manager = transformer.TransformerExtensionManager(
+        transformer_manager = extension.ExtensionManager(
             'ceilometer.transformer',
         )
         notifier._pipeline_manager = pipeline.PipelineManager(

ceilometer/transformer/__init__.py

@@ -17,22 +17,6 @@ import abc
 import collections
 
 import six
-from stevedore import extension
-
-
-class TransformerExtensionManager(extension.ExtensionManager):
-
-    def __init__(self, namespace):
-        super(TransformerExtensionManager, self).__init__(
-            namespace=namespace,
-            invoke_on_load=False,
-            invoke_args=(),
-            invoke_kwds={}
-        )
-        self.by_name = dict((e.name, e) for e in self.extensions)
-
-    def get_ext(self, name):
-        return self.by_name[name]
 
 
 @six.add_metaclass(abc.ABCMeta)