Refactor nova.volume.cinder.API to reduce roundtrips with Cinder

Make cinder.API methods accept volume_id instead of the whole volume object.
This will remove redundant roundtrip to get the volume before
passing it to other methods as in fact they only need the id.

Fixes bug 1172297

Change-Id: I5e7f944c1c29b2f211ece2ef86c0959c81e806df

1 files changed, 89 insertions, 69 deletions

diff --git a/nova/volume/cinder.py b/nova/volume/cinder.py
index 0d2666038..d08d4ef09 100644
--- a/nova/volume/cinder.py
+++ b/nova/volume/cinder.py
@@ -168,41 +168,46 @@ def _untranslate_snapshot_summary_view(context, snapshot):
     return d
 
 
+def translate_volume_exception(method):
+    """Transforms the exception for the volume but keeps its traceback intact.
+    """
+    def wrapper(self, ctx, volume_id, *args, **kwargs):
+        try:
+            res = method(self, ctx, volume_id, *args, **kwargs)
+        except cinder_exception.ClientException:
+            exc_type, exc_value, exc_trace = sys.exc_info()
+            if isinstance(exc_value, cinder_exception.NotFound):
+                exc_value = exception.VolumeNotFound(volume_id=volume_id)
+            elif isinstance(exc_value, cinder_exception.BadRequest):
+                exc_value = exception.InvalidInput(reason=exc_value.message)
+            raise exc_value, None, exc_trace
+        return res
+    return wrapper
+
+
+def translate_snapshot_exception(method):
+    """Transforms the exception for the snapshot but keeps its traceback
+       intact.
+    """
+    def wrapper(self, ctx, snapshot_id, *args, **kwargs):
+        try:
+            res = method(self, ctx, snapshot_id, *args, **kwargs)
+        except cinder_exception.ClientException:
+            exc_type, exc_value, exc_trace = sys.exc_info()
+            if isinstance(exc_value, cinder_exception.NotFound):
+                exc_value = exception.SnapshotNotFound(snapshot_id=snapshot_id)
+            raise exc_value, None, exc_trace
+        return res
+    return wrapper
+
+
 class API(base.Base):
     """API for interacting with the volume manager."""
 
-    def _reraise_translated_volume_exception(self, volume_id=None):
-        """Transform the exception for the volume but keep its traceback
-        intact."""
-        exc_type, exc_value, exc_trace = sys.exc_info()
-        new_exc = self._translate_volume_exception(volume_id, exc_value)
-        raise new_exc, None, exc_trace
-
-    def _translate_volume_exception(self, volume_id, exc_value):
-        if isinstance(exc_value, cinder_exception.NotFound):
-            return exception.VolumeNotFound(volume_id=volume_id)
-        elif isinstance(exc_value, cinder_exception.BadRequest):
-            return exception.InvalidInput(reason=exc_value.message)
-        return exc_value
-
-    def _reraise_translated_snapshot_exception(self, snapshot_id=None):
-        """Transform the exception for the snapshot but keep its traceback
-        intact."""
-        exc_type, exc_value, exc_trace = sys.exc_info()
-        new_exc = self._translate_snapshot_exception(snapshot_id, exc_value)
-        raise new_exc, None, exc_trace
-
-    def _translate_snapshot_exception(self, snapshot_id, exc_value):
-        if isinstance(exc_value, cinder_exception.NotFound):
-            return exception.SnapshotNotFound(snapshot_id=snapshot_id)
-        return exc_value
-
+    @translate_volume_exception
     def get(self, context, volume_id):
-        try:
-            item = cinderclient(context).volumes.get(volume_id)
-            return _untranslate_volume_summary_view(context, item)
-        except Exception:
-            self._reraise_translated_volume_exception(volume_id)
+        item = cinderclient(context).volumes.get(volume_id)
+        return _untranslate_volume_summary_view(context, item)
 
     def get_all(self, context, search_opts={}):
         items = cinderclient(context).volumes.list(detailed=True)
@@ -232,33 +237,40 @@ class API(base.Base):
             msg = _("already detached")
             raise exception.InvalidVolume(reason=msg)
 
-    def reserve_volume(self, context, volume):
-        cinderclient(context).volumes.reserve(volume['id'])
+    @translate_volume_exception
+    def reserve_volume(self, context, volume_id):
+        cinderclient(context).volumes.reserve(volume_id)
 
-    def unreserve_volume(self, context, volume):
-        cinderclient(context).volumes.unreserve(volume['id'])
+    @translate_volume_exception
+    def unreserve_volume(self, context, volume_id):
+        cinderclient(context).volumes.unreserve(volume_id)
 
-    def begin_detaching(self, context, volume):
-        cinderclient(context).volumes.begin_detaching(volume['id'])
+    @translate_volume_exception
+    def begin_detaching(self, context, volume_id):
+        cinderclient(context).volumes.begin_detaching(volume_id)
 
-    def roll_detaching(self, context, volume):
-        cinderclient(context).volumes.roll_detaching(volume['id'])
+    @translate_volume_exception
+    def roll_detaching(self, context, volume_id):
+        cinderclient(context).volumes.roll_detaching(volume_id)
 
-    def attach(self, context, volume, instance_uuid, mountpoint):
-        cinderclient(context).volumes.attach(volume['id'],
-                                             instance_uuid,
+    @translate_volume_exception
+    def attach(self, context, volume_id, instance_uuid, mountpoint):
+        cinderclient(context).volumes.attach(volume_id, instance_uuid,
                                              mountpoint)
 
-    def detach(self, context, volume):
-        cinderclient(context).volumes.detach(volume['id'])
+    @translate_volume_exception
+    def detach(self, context, volume_id):
+        cinderclient(context).volumes.detach(volume_id)
 
-    def initialize_connection(self, context, volume, connector):
-        return cinderclient(context).\
-                 volumes.initialize_connection(volume['id'], connector)
+    @translate_volume_exception
+    def initialize_connection(self, context, volume_id, connector):
+        return cinderclient(context).volumes.initialize_connection(volume_id,
+                                                                   connector)
 
-    def terminate_connection(self, context, volume, connector):
-        return cinderclient(context).\
-                 volumes.terminate_connection(volume['id'], connector)
+    @translate_volume_exception
+    def terminate_connection(self, context, volume_id, connector):
+        return cinderclient(context).volumes.terminate_connection(volume_id,
+                                                                  connector)
 
     def create(self, context, size, name, description, snapshot=None,
                image_id=None, volume_type=None, metadata=None,
@@ -282,20 +294,20 @@ class API(base.Base):
         try:
             item = cinderclient(context).volumes.create(size, **kwargs)
             return _untranslate_volume_summary_view(context, item)
-        except Exception:
-            self._reraise_translated_volume_exception()
+        except cinder_exception.BadRequest as e:
+            raise exception.InvalidInput(reason=e.message)
 
-    def delete(self, context, volume):
-        cinderclient(context).volumes.delete(volume['id'])
+    @translate_volume_exception
+    def delete(self, context, volume_id):
+        cinderclient(context).volumes.delete(volume_id)
 
-    def update(self, context, volume, fields):
+    @translate_volume_exception
+    def update(self, context, volume_id, fields):
         raise NotImplementedError()
 
+    @translate_snapshot_exception
     def get_snapshot(self, context, snapshot_id):
-        try:
-            item = cinderclient(context).volume_snapshots.get(snapshot_id)
-        except Exception:
-            self._reraise_translated_snapshot_exception(snapshot_id)
+        item = cinderclient(context).volume_snapshots.get(snapshot_id)
         return _untranslate_snapshot_summary_view(context, item)
 
     def get_all_snapshots(self, context):
@@ -307,32 +319,40 @@ class API(base.Base):
 
         return rvals
 
-    def create_snapshot(self, context, volume, name, description):
-        item = cinderclient(context).volume_snapshots.create(volume['id'],
+    @translate_volume_exception
+    def create_snapshot(self, context, volume_id, name, description):
+        item = cinderclient(context).volume_snapshots.create(volume_id,
                                                              False,
                                                              name,
                                                              description)
         return _untranslate_snapshot_summary_view(context, item)
 
-    def create_snapshot_force(self, context, volume, name, description):
-        item = cinderclient(context).volume_snapshots.create(volume['id'],
+    @translate_volume_exception
+    def create_snapshot_force(self, context, volume_id, name, description):
+        item = cinderclient(context).volume_snapshots.create(volume_id,
                                                              True,
                                                              name,
                                                              description)
 
         return _untranslate_snapshot_summary_view(context, item)
 
-    def delete_snapshot(self, context, snapshot):
-        cinderclient(context).volume_snapshots.delete(snapshot['id'])
+    @translate_snapshot_exception
+    def delete_snapshot(self, context, snapshot_id):
+        cinderclient(context).volume_snapshots.delete(snapshot_id)
 
-    def get_volume_metadata(self, context, volume):
+    @translate_volume_exception
+    def get_volume_metadata(self, context, volume_id):
         raise NotImplementedError()
 
-    def delete_volume_metadata(self, context, volume, key):
+    @translate_volume_exception
+    def delete_volume_metadata(self, context, volume_id, key):
         raise NotImplementedError()
 
-    def update_volume_metadata(self, context, volume, metadata, delete=False):
+    @translate_volume_exception
+    def update_volume_metadata(self, context, volume_id,
+                               metadata, delete=False):
         raise NotImplementedError()
 
-    def get_volume_metadata_value(self, volume, key):
+    @translate_volume_exception
+    def get_volume_metadata_value(self, volume_id, key):
         raise NotImplementedError()