Unit tests for BackoffLimitedRetryHandler

git-svn-id: http://jclouds.googlecode.com/svn/trunk@853 3d8758e0-26b5-11de-8745-db77d3ebf521

core/src/main/java/org/jclouds/http/handlers/BackoffLimitedRetryHandler.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright (C) 2009 Adrian Cole <adrian@jclouds.org>
+ * Copyright (C) 2009 James Murty <jamurty@gmail.com>
  *
  * ====================================================================
  * Licensed to the Apache Software Foundation (ASF) under one
@@ -82,12 +82,18 @@ public class BackoffLimitedRetryHandler implements HttpRetryHandler {
                      retryCountLimit, command);
          return false;
       } else {
-         long delayMs = (long) (50L * Math.pow(command.getFailureCount(), 2));
-         logger.debug("Retry %1$d/%2$d after server error, delaying for %3$d ms: %4$s", 
-        		      command.getFailureCount(), retryCountLimit, delayMs, command);
-         Thread.sleep(delayMs);
+        imposeBackoffExponentialDelay(command.getFailureCount(), command.toString());
         return true;
       }
    }
    
+   public void imposeBackoffExponentialDelay(int failureCound, String commandDescription) 
+      throws InterruptedException 
+   {
+      long delayMs = (long) (50L * Math.pow(failureCound, 2));
+      logger.debug("Retry %1$d/%2$d after server error, delaying for %3$d ms: %4$s", 
+                   failureCound, retryCountLimit, delayMs, commandDescription);
+      Thread.sleep(delayMs);
+   }
+
 }

core/src/test/java/org/jclouds/http/handlers/BackoffLimitedRetryHandlerTest.java

@@ -0,0 +1,135 @@
+/**
+ *
+ * Copyright (C) 2009 James Murty <jamurty@gmail.com>
+ *
+ * ====================================================================
+ * 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.
+ * ====================================================================
+ */
+package org.jclouds.http.handlers;
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.jclouds.http.HttpFutureCommand;
+import org.jclouds.http.HttpResponse;
+import org.jclouds.http.commands.callables.ReturnStringIf200;
+import org.testng.annotations.Test;
+
+@Test(groups = "unit", testName = "core.BackoffLimitedRetryHandler")
+public class BackoffLimitedRetryHandlerTest {
+
+   BackoffLimitedRetryHandler handler = new BackoffLimitedRetryHandler(5);
+   
+   @Test
+   void testExponentialBackoffDelay() throws InterruptedException {
+     long startTime = System.currentTimeMillis();
+     handler.imposeBackoffExponentialDelay(1, "TEST FAILURE: 1");
+     long elapsedTime = System.currentTimeMillis() - startTime;
+     assertTrue(elapsedTime >= 50);
+     assertTrue(elapsedTime < 60);
+
+     startTime = System.currentTimeMillis();
+     handler.imposeBackoffExponentialDelay(2, "TEST FAILURE: 2");
+     elapsedTime = System.currentTimeMillis() - startTime;
+     assertTrue(elapsedTime >= 200);
+     assertTrue(elapsedTime < 210);
+
+     startTime = System.currentTimeMillis();
+     handler.imposeBackoffExponentialDelay(3, "TEST FAILURE: 3");
+     elapsedTime = System.currentTimeMillis() - startTime;
+     assertTrue(elapsedTime >= 450);
+     assertTrue(elapsedTime < 460);
+
+     startTime = System.currentTimeMillis();
+     handler.imposeBackoffExponentialDelay(4, "TEST FAILURE: 4");
+     elapsedTime = System.currentTimeMillis() - startTime;
+     assertTrue(elapsedTime >= 800);
+     assertTrue(elapsedTime < 810);
+
+     startTime = System.currentTimeMillis();
+     handler.imposeBackoffExponentialDelay(5, "TEST FAILURE: 5");
+     elapsedTime = System.currentTimeMillis() - startTime;
+     assertTrue(elapsedTime >= 1250);
+     assertTrue(elapsedTime < 1260);
+   }
+   
+   @Test
+   void testClosesInputStream() throws InterruptedException, IOException {
+      HttpFutureCommand<String> command = 
+     	 new HttpFutureCommand<String>("method", "uri", new ReturnStringIf200());
+      HttpResponse response = new HttpResponse();
+      InputStream inputStream = new InputStream() {
+    	 boolean isOpen = true;    	
+    	 @Override
+    	 public void close() { this.isOpen = false; }
+    	 @Override
+		 public int read() throws IOException { if (this.isOpen) return 1; else return -1; }
+    	 @Override
+    	 public int available() throws IOException { if (this.isOpen) return 1; else return 0; }
+      };
+      response.setContent(inputStream);
+      
+      assertEquals(response.getContent().available(), 1);
+      assertEquals(response.getContent().read(), 1);
+      
+      handler.retryRequest(command, response);
+      
+      assertEquals(response.getContent().available(), 0);
+      assertEquals(response.getContent().read(), -1);
+   }
+
+   @Test
+   void testIncrementsFailureCount() throws InterruptedException {
+      HttpFutureCommand<String> command = 
+     	 new HttpFutureCommand<String>("method", "uri", new ReturnStringIf200());
+      HttpResponse response = new HttpResponse();
+      
+      handler.retryRequest(command, response);
+      assertEquals(command.getFailureCount(), 1);
+
+      handler.retryRequest(command, response);
+      assertEquals(command.getFailureCount(), 2);
+
+      handler.retryRequest(command, response);
+      assertEquals(command.getFailureCount(), 3);
+   }
+
+   @Test
+   void testDisallowsExcessiveRetries() throws InterruptedException {
+      HttpFutureCommand<String> command = 
+    	 new HttpFutureCommand<String>("method", "uri", new ReturnStringIf200());
+      HttpResponse response = new HttpResponse();
+
+      assertEquals(handler.retryRequest(command, response), true);  // Failure 1
+
+      assertEquals(handler.retryRequest(command, response), true);  // Failure 2
+
+      assertEquals(handler.retryRequest(command, response), true);  // Failure 3
+      
+      assertEquals(handler.retryRequest(command, response), true);  // Failure 4
+      
+      assertEquals(handler.retryRequest(command, response), true);  // Failure 5
+
+      assertEquals(handler.retryRequest(command, response), false);  // Failure 6
+   }
+
+}