X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=yardstick%2Fbenchmark%2Fscenarios%2Fbase.py;h=10a72882887fe6d808d9666ccd81efab237b2bf4;hb=caa5354c05e567ee4c6753ed77c819dfa4e2a37e;hp=3cb138dd85fd25ab8ce2de6cdd6285b3e3cf3278;hpb=fd0a88140f7114ef90fabdfb5436cff42ec0cd2c;p=yardstick.git

diff --git a/yardstick/benchmark/scenarios/base.py b/yardstick/benchmark/scenarios/base.py
index 3cb138dd8..10a728828 100644
--- a/yardstick/benchmark/scenarios/base.py
+++ b/yardstick/benchmark/scenarios/base.py
@@ -16,20 +16,34 @@
 # yardstick comment: this is a modified copy of
 # rally/rally/benchmark/scenarios/base.py
 
-""" Scenario base class
-"""
+from stevedore import extension
 
-from __future__ import absolute_import
 import yardstick.common.utils as utils
 
 
+def _iter_scenario_classes(scenario_type=None):
+    """Generator over all 'Scenario' subclasses
+
+    This function will iterate over all 'Scenario' subclasses defined in this
+    project and will load any class introduced by any installed plugin project,
+    defined in 'entry_points' section, under 'yardstick.scenarios' subsection.
+    """
+    extension.ExtensionManager(namespace='yardstick.scenarios',
+                               invoke_on_load=False)
+    for scenario in utils.itersubclasses(Scenario):
+        if not scenario_type:
+            yield scenario
+        elif getattr(scenario, '__scenario_type__', None) == scenario_type:
+            yield scenario
+
+
 class Scenario(object):
 
     def setup(self):
         """ default impl for scenario setup """
         pass
 
-    def run(self, args):
+    def run(self, *args):
         """ catcher for not implemented run methods in subclasses """
         raise RuntimeError("run method not implemented")
 
@@ -41,16 +55,15 @@ class Scenario(object):
     def get_types():
         """return a list of known runner type (class) names"""
         scenarios = []
-        for scenario in utils.itersubclasses(Scenario):
+        for scenario in _iter_scenario_classes():
             scenarios.append(scenario)
         return scenarios
 
     @staticmethod
     def get_cls(scenario_type):
         """return class of specified type"""
-        for scenario in utils.itersubclasses(Scenario):
-            if scenario_type == scenario.__scenario_type__:
-                return scenario
+        for scenario in _iter_scenario_classes(scenario_type):
+            return scenario
 
         raise RuntimeError("No such scenario type %s" % scenario_type)
 
@@ -58,11 +71,22 @@ class Scenario(object):
     def get(scenario_type):
         """Returns instance of a scenario runner for execution type.
         """
-        for scenario in utils.itersubclasses(Scenario):
-            if scenario_type == scenario.__scenario_type__:
-                return scenario.__module__ + "." + scenario.__name__
+        scenario = Scenario.get_cls(scenario_type)
+        return scenario.__module__ + "." + scenario.__name__
 
-        raise RuntimeError("No such scenario type %s" % scenario_type)
+    @classmethod
+    def get_scenario_type(cls):
+        """Return a string with the scenario type, if defined"""
+        return str(getattr(cls, '__scenario_type__', None))
+
+    @classmethod
+    def get_description(cls):
+        """Return a single line string with the class description
+
+        This function will retrieve the class docstring and return the first
+        line, or 'None' if it's empty.
+        """
+        return cls.__doc__.splitlines()[0] if cls.__doc__ else str(None)
 
     def _push_to_outputs(self, keys, values):
         return dict(zip(keys, values))