XenAPI: get_info was very expensive

Getting the whole VM record is expensive and slowed down Tempest tests
significantly.  Replaced with getting each required item.

When getting power state, only need that specific value, so reduce the
calls to get_info too.

Change-Id: I93bcef5b692a531aac41518dc29d5d4f46cded65

nova/tests/virt/xenapi/test_vm_utils.py

@@ -25,6 +25,7 @@ import mox
 from oslo.config import cfg
 
 from nova.compute import flavors
+from nova.compute import power_state
 from nova.compute import vm_mode
 from nova import context
 from nova import exception
@@ -2030,3 +2031,58 @@ class ResizeFunctionTestCase(test.NoDBTestCase):
 
     def test_bad_version(self):
         self._test_is_resize("XenServer", "asdf")
+
+
+class VMInfoTests(VMUtilsTestBase):
+    def setUp(self):
+        super(VMInfoTests, self).setUp()
+        self.session = mock.Mock()
+
+    def test_get_power_state_valid(self):
+        # Save on test setup calls by having these simple tests in one method
+        self.session.call_xenapi.return_value = "Running"
+        self.assertEqual(vm_utils.get_power_state(self.session, "ref"),
+                         power_state.RUNNING)
+
+        self.session.call_xenapi.return_value = "Halted"
+        self.assertEqual(vm_utils.get_power_state(self.session, "ref"),
+                         power_state.SHUTDOWN)
+
+        self.session.call_xenapi.return_value = "Paused"
+        self.assertEqual(vm_utils.get_power_state(self.session, "ref"),
+                         power_state.PAUSED)
+
+        self.session.call_xenapi.return_value = "Suspended"
+        self.assertEqual(vm_utils.get_power_state(self.session, "ref"),
+                         power_state.SUSPENDED)
+
+        self.session.call_xenapi.return_value = "Crashed"
+        self.assertEqual(vm_utils.get_power_state(self.session, "ref"),
+                         power_state.CRASHED)
+
+    def test_get_power_state_invalid(self):
+        self.session.call_xenapi.return_value = "Invalid"
+        self.assertRaises(KeyError,
+                          vm_utils.get_power_state, self.session, "ref")
+
+    _XAPI_record = {'power_state': 'Running',
+                    'memory_static_max': str(10 << 10),
+                    'memory_dynamic_max': str(9 << 10),
+                    'VCPUs_max': '5'}
+
+    def test_compile_info(self):
+
+        def call_xenapi(method, *args):
+            if method.startswith('VM.get_') and args[0] == 'dummy':
+                return self._XAPI_record[method[7:]]
+
+        self.session.call_xenapi.side_effect = call_xenapi
+
+        expected = {'state': power_state.RUNNING,
+                    'max_mem': 10L,
+                    'mem': 9L,
+                    'num_cpu': '5',
+                    'cpu_time': 0}
+
+        self.assertEqual(vm_utils.compile_info(self.session, "dummy"),
+                         expected)

nova/tests/virt/xenapi/test_vmops.py

@@ -523,12 +523,13 @@ class SpawnTestCase(VMOpsTestBase):
         instance = {"uuid": "uuid"}
         vm_ref = "vm_ref"
 
-        self.mox.StubOutWithMock(self.vmops, 'get_info')
+        self.mox.StubOutWithMock(vm_utils, 'get_power_state')
         self.mox.StubOutWithMock(greenthread, 'sleep')
-        self.vmops.get_info(instance, vm_ref).AndReturn({"state": "asdf"})
+        vm_utils.get_power_state(self._session, vm_ref).AndReturn(
+                                             power_state.SHUTDOWN)
         greenthread.sleep(0.5)
-        self.vmops.get_info(instance, vm_ref).AndReturn({
-                                            "state": power_state.RUNNING})
+        vm_utils.get_power_state(self._session, vm_ref).AndReturn(
+                                            power_state.RUNNING)
 
         self.mox.ReplayAll()
         self.vmops._wait_for_instance_to_start(instance, vm_ref)