LUCENE-4836: Fix SimpleRateLimiter#pause to return the actual time spent sleeping

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1457154 13f79535-47bb-0310-9956-ffa450edef68

lucene/CHANGES.txt

@@ -109,6 +109,9 @@ Bug Fixes
 * LUCENE-4828: BooleanQuery no longer extracts terms from its MUST_NOT
   clauses.  (Mike McCandless)
 
+* LUCENE-4836: Fix SimpleRateLimiter#pause to return the actual time spent
+  sleeping instead of the wakeup timestamp in nano seconds. (Simon Willnauer)
+
 ======================= Lucene 4.2.0 =======================
 
 Changes in backwards compatibility policy

lucene/core/src/java/org/apache/lucene/store/RateLimiter.java

@@ -97,7 +97,8 @@ public abstract class RateLimiter {
       // TODO: this is purely instantaneous rate; maybe we
       // should also offer decayed recent history one?
       final long targetNS = lastNS = lastNS + ((long) (bytes * nsPerByte));
-      long curNS = System.nanoTime();
+      final long startNS;
+      long curNS = startNS = System.nanoTime();
       if (lastNS < curNS) {
         lastNS = curNS;
       }
@@ -117,7 +118,7 @@ public abstract class RateLimiter {
         }
         break;
       }
-      return targetNS;
+      return curNS - startNS;
     }
   }
 }

lucene/core/src/test/org/apache/lucene/store/TestRateLimiter.java

@@ -0,0 +1,40 @@
+package org.apache.lucene.store;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+import java.util.concurrent.TimeUnit;
+
+import org.apache.lucene.store.RateLimiter.SimpleRateLimiter;
+import org.apache.lucene.util.LuceneTestCase;
+
+/**
+ * Simple testcase for RateLimiter.SimpleRateLimiter
+ */
+public final class TestRateLimiter extends LuceneTestCase {
+
+  public void testPause() {
+    SimpleRateLimiter limiter = new SimpleRateLimiter(10); // 10 MB / Sec
+    limiter.pause(2);//init
+    long pause = 0;
+    for (int i = 0; i < 3; i++) {
+      pause += limiter.pause(4 * 1024 * 1024); // fire up 3 * 4 MB 
+    }
+    final long convert = TimeUnit.MILLISECONDS.convert(pause, TimeUnit.NANOSECONDS);
+    assertTrue("we should sleep less than 2 seconds but did: " + convert + " millis", convert < 2000l); 
+    assertTrue("we should sleep at least 1 second but did only: " + convert + " millis", convert > 1000l); 
+  }
+}