From 19b54659b3203557c9ae55e51d05598cdf57f71d Mon Sep 17 00:00:00 2001
From: Robert Varga <rovarga@cisco.com>
Date: Sat, 6 Jun 2015 03:44:24 +0200
Subject: [PATCH] BUG-3157: performance tuning - Use a TrieMap as the
 ConcurrentMap implementation

TrieMap is space-optimized and has a high fanout, which means it will
reclaim space when not needed and has shallower structure than a
ConcurrentHashMap. It also re-hashes automatically and concurrently.

Change-Id: I1e40dbb5588c1e42475e12d73f7cadf46b909594
Signed-off-by: Robert Varga <rovarga@cisco.com>
(cherry picked from commit 5faeb7ea76404e4da3620e63432b6038800d4de7)
---
 openflowplugin-impl/pom.xml                                   | 4 ++++
 .../impl/registry/flow/DeviceFlowRegistryImpl.java            | 4 ++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/openflowplugin-impl/pom.xml b/openflowplugin-impl/pom.xml
index f5edb1e3e0..8b6cad7ae6 100644
--- a/openflowplugin-impl/pom.xml
+++ b/openflowplugin-impl/pom.xml
@@ -132,6 +132,10 @@
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.github.romix</groupId>
+            <artifactId>java-concurrent-hash-trie-map</artifactId>
+        </dependency>
 
         <dependency>
             <groupId>junit</groupId>
diff --git a/openflowplugin-impl/src/main/java/org/opendaylight/openflowplugin/impl/registry/flow/DeviceFlowRegistryImpl.java b/openflowplugin-impl/src/main/java/org/opendaylight/openflowplugin/impl/registry/flow/DeviceFlowRegistryImpl.java
index 16e5ce9ad5..e34b829269 100644
--- a/openflowplugin-impl/src/main/java/org/opendaylight/openflowplugin/impl/registry/flow/DeviceFlowRegistryImpl.java
+++ b/openflowplugin-impl/src/main/java/org/opendaylight/openflowplugin/impl/registry/flow/DeviceFlowRegistryImpl.java
@@ -7,11 +7,11 @@
  */
 package org.opendaylight.openflowplugin.impl.registry.flow;
 
+import com.romix.scala.collection.concurrent.TrieMap;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import javax.annotation.concurrent.GuardedBy;
 import org.opendaylight.openflowplugin.api.openflow.registry.flow.DeviceFlowRegistry;
@@ -28,7 +28,7 @@ import org.slf4j.LoggerFactory;
 public class DeviceFlowRegistryImpl implements DeviceFlowRegistry {
     private static final Logger LOG = LoggerFactory.getLogger(DeviceFlowRegistryImpl.class);
 
-    private final ConcurrentMap<FlowRegistryKey, FlowDescriptor> flowRegistry = new ConcurrentHashMap<>();
+    private final ConcurrentMap<FlowRegistryKey, FlowDescriptor> flowRegistry = new TrieMap<>();
     @GuardedBy("marks")
     private final Collection<FlowRegistryKey> marks = new HashSet<>();
 
-- 
2.36.6