From bd7055daf23f03fe2e939e6d585885341422978c Mon Sep 17 00:00:00 2001
From: Kevin Benton <kevin@benton.pub>
Date: Thu, 6 Apr 2017 05:01:30 -0700
Subject: [PATCH] Allow offloading lookups in driver contexts

This allows segments looked up ahead of time to be passed
into NetworkContext objects and NetworkContext objects to
be passed into PortContext objects. This allows us to avoid
doing segments lookups for every PortContext construction
when handling a bunch of ports (e.g. in RPC handler).

Conflicts:
	neutron/plugins/ml2/driver_context.py

Change-Id: Ib4c43a7894fe1285ecf4bdf9af5e5f1b93b0b39b
Partial-Bug: #1665215
(cherry picked from commit 604e598a7d43b8b3a260969de84af737a4988c4e)
(cherry picked from commit a2ae48c2cee71d8a27f44c5d5cfbfbdacc1fee00)
---
 neutron/plugins/ml2/driver_context.py | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/neutron/plugins/ml2/driver_context.py b/neutron/plugins/ml2/driver_context.py
index f0503138e68..d18bb25d6c2 100644
--- a/neutron/plugins/ml2/driver_context.py
+++ b/neutron/plugins/ml2/driver_context.py
@@ -38,12 +38,15 @@ class MechanismDriverContext(object):
 class NetworkContext(MechanismDriverContext, api.NetworkContext):
 
     def __init__(self, plugin, plugin_context, network,
-                 original_network=None):
+                 original_network=None, segments=None):
         super(NetworkContext, self).__init__(plugin, plugin_context)
         self._network = network
         self._original_network = original_network
-        self._segments = segments_db.get_network_segments(
-            plugin_context.session, network['id'])
+        if segments is None:
+            self._segments = segments_db.get_network_segments(
+                plugin_context.session, network['id'])
+        else:
+            self._segments = segments
 
     @property
     def current(self):
@@ -88,8 +91,11 @@ class PortContext(MechanismDriverContext, api.PortContext):
         super(PortContext, self).__init__(plugin, plugin_context)
         self._port = port
         self._original_port = original_port
-        self._network_context = NetworkContext(plugin, plugin_context,
-                                               network) if network else None
+        if isinstance(network, NetworkContext):
+            self._network_context = network
+        else:
+            self._network_context = NetworkContext(
+                plugin, plugin_context, network) if network else None
         self._binding = binding
         self._binding_levels = binding_levels
         self._segments_to_bind = None