From 26e03a5173b62c66f114bb03b90eb1831ec0810d Mon Sep 17 00:00:00 2001
From: Chris Behrens <cbehrens@codestud.com>
Date: Mon, 13 Aug 2012 07:33:15 +0000
Subject: [PATCH] Improve bw_usage_update() performance

Fixes bug 1036084

bw_usage_update() most commonly updates rows vs creates rows.  New rows
are only created on the 1st bandwidth update for an instance or when
the audit period rolls over.  This cuts down DB queries to 1 for the
'update' case.

Added bonus:
Remove unused 'import inspect' in compute manager.

Change-Id: Ie5f6c919676046d817b842138dc9d17d1115d3c0
---
 nova/tests/test_db_api.py | 59 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/nova/tests/test_db_api.py b/nova/tests/test_db_api.py
index 9acc964c..93e0edfb 100644
--- a/nova/tests/test_db_api.py
+++ b/nova/tests/test_db_api.py
@@ -459,6 +459,65 @@ class DbApiTestCase(test.TestCase):
         ec2_id = db.get_ec2_snapshot_id_by_uuid(self.context, 'fake-uuid')
         self.assertEqual(ref['id'], ec2_id)
 
+    def test_bw_usage_calls(self):
+        ctxt = context.get_admin_context()
+        now = timeutils.utcnow()
+        timeutils.set_time_override(now)
+        start_period = now - datetime.timedelta(seconds=10)
+        uuid3_refreshed = now - datetime.timedelta(seconds=5)
+
+        expected_bw_usages = [{'uuid': 'fake_uuid1',
+                               'mac': 'fake_mac1',
+                               'start_period': start_period,
+                               'bw_in': 100,
+                               'bw_out': 200,
+                               'last_refreshed': now},
+                              {'uuid': 'fake_uuid2',
+                               'mac': 'fake_mac2',
+                               'start_period': start_period,
+                               'bw_in': 200,
+                               'bw_out': 300,
+                               'last_refreshed': now},
+                              {'uuid': 'fake_uuid3',
+                               'mac': 'fake_mac3',
+                               'start_period': start_period,
+                               'bw_in': 400,
+                               'bw_out': 500,
+                               'last_refreshed': uuid3_refreshed}]
+
+        def _compare(bw_usage, expected):
+            for key, value in expected.items():
+                self.assertEqual(bw_usage[key], value)
+
+        bw_usages = db.bw_usage_get_by_uuids(ctxt,
+                ['fake_uuid1', 'fake_uuid2'], start_period)
+        # No matches
+        self.assertEqual(len(bw_usages), 0)
+
+        # Add 3 entries
+        db.bw_usage_update(ctxt, 'fake_uuid1',
+                'fake_mac1', start_period,
+                100, 200)
+        db.bw_usage_update(ctxt, 'fake_uuid2',
+                'fake_mac2', start_period,
+                100, 200)
+        # Test explicit refreshed time
+        db.bw_usage_update(ctxt, 'fake_uuid3',
+                'fake_mac3', start_period,
+                400, 500, last_refreshed=uuid3_refreshed)
+        # Update 2nd entry
+        db.bw_usage_update(ctxt, 'fake_uuid2',
+                'fake_mac2', start_period,
+                200, 300)
+
+        bw_usages = db.bw_usage_get_by_uuids(ctxt,
+                ['fake_uuid1', 'fake_uuid2', 'fake_uuid3'], start_period)
+        self.assertEqual(len(bw_usages), 3)
+        _compare(bw_usages[0], expected_bw_usages[0])
+        _compare(bw_usages[1], expected_bw_usages[1])
+        _compare(bw_usages[2], expected_bw_usages[2])
+        timeutils.clear_time_override()
+
 
 def _get_fake_aggr_values():
     return {'name': 'fake_aggregate',