allowed response parsing to be logged

git-svn-id: http://jclouds.googlecode.com/svn/trunk@1954 3d8758e0-26b5-11de-8745-db77d3ebf521

concurrent/src/main/java/org/jclouds/concurrent/FutureExceptionParser.java

@@ -28,6 +28,8 @@ import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
+import org.jclouds.logging.Logger;
+
 import com.google.common.base.Function;
 
 /**
@@ -39,10 +41,16 @@ public class FutureExceptionParser<T> implements Future<T> {
 
    private final Future<T> delegate;
    private final Function<Exception, T> function;
+   private final Logger logger;
 
    public FutureExceptionParser(Future<T> delegate, Function<Exception, T> function) {
+      this(delegate, function, Logger.NULL);
+   }
+
+   public FutureExceptionParser(Future<T> delegate, Function<Exception, T> function, Logger logger) {
       this.delegate = delegate;
       this.function = function;
+      this.logger = logger;
    }
 
    public boolean cancel(boolean mayInterruptIfRunning) {
@@ -59,7 +67,10 @@ public class FutureExceptionParser<T> implements Future<T> {
 
    private T attemptConvert(ExecutionException e) throws ExecutionException {
       if (e.getCause() instanceof Exception) {
+
+         logger.debug("Processing exception for: %s", e.getCause());
          T returnVal = function.apply((Exception) e.getCause());
+         logger.debug("Processed exception for: %s", e.getCause());
          if (returnVal != null)
             return returnVal;
       }

concurrent/src/main/java/org/jclouds/concurrent/FutureFunctionCallable.java

@@ -27,6 +27,8 @@ import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 
+import org.jclouds.logging.Logger;
+
 import com.google.common.base.Function;
 
 /**
@@ -38,15 +40,25 @@ public class FutureFunctionCallable<F, T> implements Callable<T> {
 
    private final Future<F> future;
    private final Function<F, T> function;
+   private final Logger logger;
 
    public FutureFunctionCallable(Future<F> future, Function<F, T> function) {
+      this(future, function, Logger.NULL);
+   }
+
+   public FutureFunctionCallable(Future<F> future, Function<F, T> function, Logger logger) {
       this.future = future;
       this.function = function;
+      this.logger = logger;
    }
 
    public T call() throws Exception {
       try {
-         return function.apply(future.get());
+         F input = future.get();
+         logger.debug("Processing intermediate result for: %s", input);
+         T result = function.apply(input);
+         logger.debug("Processed intermediate result for: %s", input);
+         return result;
       } catch (ExecutionException e) {
          throw (Exception) e.getCause();
       }

concurrent/src/main/java/org/jclouds/concurrent/WithinThreadExecutor.java

@@ -32,6 +32,7 @@ import java.util.concurrent.Executor;
  * @author Adrian Cole
  */
 @SingleThreadCompatible
+@SingleThreaded
 public class WithinThreadExecutor implements Executor {
 
    public void execute(Runnable command) {

concurrent/src/main/java/org/jclouds/logging/Logger.java

@@ -0,0 +1,89 @@
+/**
+ *
+ * Copyright (C) 2009 Global Cloud Specialists, Inc. <info@globalcloudspecialists.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.logging;
+
+/**
+ * JCloud log abstraction layer.
+ * <p/>
+ * Implementations of logging are optional and injected if they are configured.
+ * <p/>
+ * <code> @Resource Logger logger = Logger.NULL;</code> The above will get you a
+ * null-safe instance of <tt>Logger</tt>. If configured, this logger will be
+ * swapped with a real Logger implementation with category set to the current
+ * class name. This is done post-object construction, so do not attempt to use
+ * these loggers in your constructor.
+ * <p/>
+ * If you wish to initialize loggers like these yourself, do not use the @Resource
+ * annotation.
+ * <p/>
+ * This implementation first checks to see if the level is enabled before
+ * issuing the log command. In other words, don't do the following
+ * <code>if (logger.isTraceEnabled()) logger.trace("message");.
+ * <p/>
+ * 
+ * @author Adrian Cole
+ */
+public interface Logger {
+
+    /**
+     * Assign to member to avoid NPE when no logging module is configured.
+     */
+    public static final Logger NULL = new NullLogger();
+
+    String getCategory();
+
+    void trace(String message, Object... args);
+
+    boolean isTraceEnabled();
+
+    void debug(String message, Object... args);
+
+    boolean isDebugEnabled();
+
+    void info(String message, Object... args);
+
+    boolean isInfoEnabled();
+
+    void warn(String message, Object... args);
+
+    void warn(Throwable throwable, String message, Object... args);
+
+    boolean isWarnEnabled();
+
+    void error(String message, Object... args);
+
+    void error(Throwable throwable, String message, Object... args);
+
+    boolean isErrorEnabled();
+
+    /**
+     * Produces instances of {@link Logger} relevant to the specified category
+     * 
+     * @author Adrian Cole
+     * 
+     */
+    public static interface LoggerFactory {
+	public Logger getLogger(String category);
+    }
+}

concurrent/src/main/java/org/jclouds/logging/NullLogger.java

@@ -0,0 +1,93 @@
+/**
+ *
+ * Copyright (C) 2009 Global Cloud Specialists, Inc. <info@globalcloudspecialists.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.logging;
+
+/**
+ * <tt>Logger</tt> that doesn't do anything.
+ * <p />
+ * Useful to get baseline performance unaffected by logging.
+ * 
+ * @author Adrian Cole
+ * 
+ */
+public class NullLogger implements Logger {
+
+    public void debug(String message, Object... args) {
+
+    }
+
+    public void error(String message, Object... args) {
+
+    }
+
+    public void error(Throwable throwable, String message, Object... args) {
+
+    }
+
+    public String getCategory() {
+
+	return null;
+    }
+
+    public void info(String message, Object... args) {
+
+    }
+
+    public boolean isDebugEnabled() {
+
+	return false;
+    }
+
+    public boolean isErrorEnabled() {
+
+	return false;
+    }
+
+    public boolean isInfoEnabled() {
+
+	return false;
+    }
+
+    public boolean isTraceEnabled() {
+
+	return false;
+    }
+
+    public boolean isWarnEnabled() {
+
+	return false;
+    }
+
+    public void trace(String message, Object... args) {
+
+    }
+
+    public void warn(String message, Object... args) {
+
+    }
+
+    public void warn(Throwable throwable, String message, Object... args) {
+
+    }
+}