Reduce map reads

hystrix-core/build.gradle

@@ -37,7 +37,7 @@ jar {
 jmh {
 	fork = 10
 	iterations = 3
-	jmhVersion = '1.11.1'
+	jmhVersion = '1.11.2'
 	profilers = ['gc']
 	threads = 8
 	warmup = '1s'

hystrix-core/src/jmh/java/com/netflix/hystrix/perf/CommandConstructionPerfTest.java

@@ -0,0 +1,42 @@
+/**
+ * Copyright 2014 Netflix, Inc.
+ * <p/>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p/>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p/>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.netflix.hystrix.perf;
+
+import com.netflix.hystrix.HystrixCommand;
+import com.netflix.hystrix.HystrixCommandGroupKey;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+
+import java.util.concurrent.TimeUnit;
+
+public class CommandConstructionPerfTest {
+
+    static HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey("Group");
+
+    @Benchmark
+    @BenchmarkMode({Mode.SampleTime})
+    @OutputTimeUnit(TimeUnit.MICROSECONDS)
+    public HystrixCommand constructHystrixCommandByGroupKeyOnly() {
+        return new HystrixCommand<Integer>(groupKey) {
+            @Override
+            protected Integer run() throws Exception {
+                return 1;
+            }
+        };
+    }
+}

hystrix-core/src/main/java/com/netflix/hystrix/HystrixCommandGroupKey.java

@@ -50,9 +50,10 @@ private Factory() {
         public static HystrixCommandGroupKey asKey(String name) {
             HystrixCommandGroupKey k = intern.get(name);
             if (k == null) {
-                intern.putIfAbsent(name, new HystrixCommandGroupDefault(name));
+                k = new HystrixCommandGroupDefault(name);
+                intern.putIfAbsent(name, k);
             }
-            return intern.get(name);
+            return k;
         }
 
         private static class HystrixCommandGroupDefault implements HystrixCommandGroupKey {

hystrix-core/src/main/java/com/netflix/hystrix/HystrixCommandKey.java

@@ -48,9 +48,10 @@ private Factory() {
         public static HystrixCommandKey asKey(String name) {
             HystrixCommandKey k = intern.get(name);
             if (k == null) {
-                intern.putIfAbsent(name, new HystrixCommandKeyDefault(name));
+                k = new HystrixCommandKeyDefault(name);
+                intern.putIfAbsent(name, k);
             }
-            return intern.get(name);
+            return k;
         }
 
         private static class HystrixCommandKeyDefault implements HystrixCommandKey {

hystrix-core/src/main/java/com/netflix/hystrix/HystrixThreadPoolKey.java

@@ -50,9 +50,10 @@ private Factory() {
         public static HystrixThreadPoolKey asKey(String name) {
             HystrixThreadPoolKey k = intern.get(name);
             if (k == null) {
-                intern.putIfAbsent(name, new HystrixThreadPoolKeyDefault(name));
+                k = new HystrixThreadPoolKeyDefault(name);
+                intern.putIfAbsent(name, k);
             }
-            return intern.get(name);
+            return k;
         }
 
         private static class HystrixThreadPoolKeyDefault implements HystrixThreadPoolKey {