MAPREDUCE-6055. native-task: findbugs, interface annotations, and other misc cleanup

hadoop-mapreduce-project/CHANGES.MAPREDUCE-2841.txt

@@ -19,3 +19,4 @@ MAPREDUCE-5977. Fix or suppress native-task gcc warnings (Manu Zhang via todd)
 MAPREDUCE-6054. native-task: Speed up tests (todd)
 MAPREDUCE-6058. native-task: KVTest and LargeKVTest should check mr job is sucessful (Binglin Chang)
 MAPREDUCE-6056. native-task: move system test working dir to target dir and cleanup test config xml files (Manu Zhang via bchang)
+MAPREDUCE-6055. native-task: findbugs, interface annotations, and other misc cleanup (todd)

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/Command.java

@@ -17,6 +17,9 @@
  */
 package org.apache.hadoop.mapred.nativetask;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+
+@InterfaceAudience.Private
 public class Command {
 
   private int id;
@@ -46,4 +49,9 @@ public class Command {
     }
     return false;
   }
+  
+  @Override
+  public int hashCode() {
+    return id;
+  }
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/CommandDispatcher.java

@@ -19,20 +19,15 @@
 package org.apache.hadoop.mapred.nativetask;
 
 import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.nativetask.util.ReadWriteBuffer;
 
 /**
  * a CommandDispatcher receives {@link Command} from upstream
  * and performs corresponding operations
  */
+@InterfaceAudience.Private
 public interface CommandDispatcher {
-
-  /**
-   *
-   * @param command
-   * @param parameter
-   * @return
-   * @throws IOException
-   */
   public ReadWriteBuffer onCall(Command command, ReadWriteBuffer parameter) throws IOException;
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/Constants.java

@@ -15,9 +15,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.apache.hadoop.mapred.nativetask;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+
+@InterfaceAudience.Private
 public class Constants {
 
   public static final String MAP_SORT_CLASS = "map.sort.class";
@@ -40,17 +42,17 @@ public class Constants {
   public static final String NATIVE_OUTPUT_FILE_NAME = "native.output.file.name";
 
   public static final String NATIVE_PROCESSOR_BUFFER_KB = "native.processor.buffer.kb";
-  public static int NATIVE_PROCESSOR_BUFFER_KB_DEFAULT = 64;
-  public static int NATIVE_ASYNC_PROCESSOR_BUFFER_KB_DEFAULT = 1024;
+  public static final int NATIVE_PROCESSOR_BUFFER_KB_DEFAULT = 64;
+  public static final int NATIVE_ASYNC_PROCESSOR_BUFFER_KB_DEFAULT = 1024;
 
   public static final String NATIVE_STATUS_UPDATE_INTERVAL = "native.update.interval";
-  public static int NATIVE_STATUS_UPDATE_INTERVAL_DEFVAL = 3000;
+  public static final int NATIVE_STATUS_UPDATE_INTERVAL_DEFVAL = 3000;
 
   public static final String SERIALIZATION_FRAMEWORK = "SerializationFramework";
-  public static int SIZEOF_PARTITION_LENGTH = 4;
-  public static int SIZEOF_KEY_LENGTH = 4;
-  public static int SIZEOF_VALUE_LENGTH = 4;
-  public static int SIZEOF_KV_LENGTH = SIZEOF_KEY_LENGTH + SIZEOF_VALUE_LENGTH;
+  public static final int SIZEOF_PARTITION_LENGTH = 4;
+  public static final int SIZEOF_KEY_LENGTH = 4;
+  public static final int SIZEOF_VALUE_LENGTH = 4;
+  public static final int SIZEOF_KV_LENGTH = SIZEOF_KEY_LENGTH + SIZEOF_VALUE_LENGTH;
   
   public static final String NATIVE_CLASS_LIBRARY = "native.class.library";
   public static final String NATIVE_CLASS_LIBRARY_CUSTOM = "native.class.library.custom";

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/DataChannel.java

@@ -18,6 +18,9 @@
 
 package org.apache.hadoop.mapred.nativetask;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+
+@InterfaceAudience.Private
 public enum DataChannel {
   /**
    * We will only read data from this channel

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/DataReceiver.java

@@ -20,10 +20,13 @@ package org.apache.hadoop.mapred.nativetask;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+
 /**
  * a DataReceiver pulls in arriving data, an example
  * is {@link org.apache.hadoop.mapred.nativetask.handlers.BufferPuller}
  */
+@InterfaceAudience.Private
 public interface DataReceiver {
 
   /**

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/HadoopPlatform.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.BooleanWritable;
 import org.apache.hadoop.io.ByteWritable;
 import org.apache.hadoop.io.BytesWritable;
@@ -36,6 +37,7 @@ import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.JobConf;
 import org.apache.hadoop.mapred.nativetask.serde.*;
 
+@InterfaceAudience.Private
 public class HadoopPlatform extends Platform {
   private static final Log LOG = LogFactory.getLog(HadoopPlatform.class);
 
@@ -61,7 +63,7 @@ public class HadoopPlatform extends Platform {
   }
 
   @Override
-  public boolean support(String keyClassName, INativeSerializer serializer, JobConf job) {
+  public boolean support(String keyClassName, INativeSerializer<?> serializer, JobConf job) {
     if (keyClassNames.contains(keyClassName)
       && serializer instanceof INativeComparable) {
       return true;
@@ -71,7 +73,7 @@ public class HadoopPlatform extends Platform {
   }
 
   @Override
-  public boolean define(Class comparatorClass) {
+  public boolean define(Class<?> comparatorClass) {
     return false;
   }
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/ICombineHandler.java

@@ -19,9 +19,12 @@ package org.apache.hadoop.mapred.nativetask;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+
 /**
  * interacts with native side to support Java Combiner
  */
+@InterfaceAudience.Private
 public interface ICombineHandler {
 
   /**

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/INativeComparable.java

@@ -18,6 +18,9 @@
 
 package org.apache.hadoop.mapred.nativetask;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+
 /**
  *
  * Any key type that is comparable at native side must implement this interface
@@ -45,6 +48,8 @@ package org.apache.hadoop.mapred.nativetask;
  *     return NativeObjectFactory::BytesComparator(src + 4, sl, dest + 4, dl);
  *   }
  */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
 public interface INativeComparable {
 
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/INativeHandler.java

@@ -19,12 +19,14 @@ package org.apache.hadoop.mapred.nativetask;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.mapred.nativetask.util.ReadWriteBuffer;
 
 /**
  * A Handler accept input, and give output can be used to transfer command and data
  */
+@InterfaceAudience.Private
 public interface INativeHandler extends NativeDataTarget, NativeDataSource {
 
   public String name();

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/NativeBatchProcessor.java

@@ -23,6 +23,7 @@ import java.nio.ByteBuffer;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.mapred.nativetask.buffer.BufferType;
@@ -30,11 +31,11 @@ import org.apache.hadoop.mapred.nativetask.buffer.InputBuffer;
 import org.apache.hadoop.mapred.nativetask.buffer.OutputBuffer;
 import org.apache.hadoop.mapred.nativetask.util.ReadWriteBuffer;
 import org.apache.hadoop.mapred.nativetask.util.ConfigUtil;
-import org.apache.hadoop.util.DirectBufferPool;
 
 /**
  * used to create channel, transfer data and command between Java and native
  */
+@InterfaceAudience.Private
 public class NativeBatchProcessor implements INativeHandler {
   private static Log LOG = LogFactory.getLog(NativeBatchProcessor.class);
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/NativeDataSource.java

@@ -20,33 +20,27 @@ package org.apache.hadoop.mapred.nativetask;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.nativetask.buffer.InputBuffer;
-import org.apache.hadoop.mapred.nativetask.util.ReadWriteBuffer;
 
 /**
  * NativeDataSource loads data from upstream
  */
+@InterfaceAudience.Private
 public interface NativeDataSource {
 
   /**
    * get input buffer
-   * 
-   * @return
    */
   public InputBuffer getInputBuffer();
 
   /**
    * set listener. When data from upstream arrives, the listener will be activated.
-   * 
-   * @param handler
    */
   void setDataReceiver(DataReceiver handler);
 
   /**
    * load data from upstream
-   * 
-   * @return
-   * @throws IOException
    */
   public void loadData() throws IOException;
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/NativeDataTarget.java

@@ -20,31 +20,27 @@ package org.apache.hadoop.mapred.nativetask;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.nativetask.buffer.OutputBuffer;
 
 /**
  * NativeDataTarge sends data to downstream
  */
+@InterfaceAudience.Private
 public interface NativeDataTarget {
 
   /**
-   * send a signal to indicate that the data has been stored in output buffer
-   * 
-   * @throws IOException
+   * Sends a signal to indicate that the data has been stored in output buffer
    */
   public void sendData() throws IOException;
 
   /**
-   * Send a signal that there is no more data
-   * 
-   * @throws IOException
+   * Sends a signal that there is no more data
    */
   public void finishSendData() throws IOException;
 
   /**
-   * get the output buffer.
-   * 
-   * @return
+   * Gets the output buffer.
    */
   public OutputBuffer getOutputBuffer();
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/NativeMapOutputCollectorDelegator.java

@@ -17,13 +17,13 @@
  */
 package org.apache.hadoop.mapred.nativetask;
 
-import java.io.File;
 import java.io.IOException;
 
 import com.google.common.base.Charsets;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.RawComparator;
 import org.apache.hadoop.mapred.InvalidJobConfException;
 import org.apache.hadoop.mapred.JobConf;
@@ -34,13 +34,12 @@ import org.apache.hadoop.mapred.nativetask.serde.INativeSerializer;
 import org.apache.hadoop.mapred.nativetask.serde.NativeSerialization;
 import org.apache.hadoop.mapreduce.MRConfig;
 import org.apache.hadoop.mapreduce.MRJobConfig;
-import org.apache.hadoop.mapreduce.server.jobtracker.JTConfig;
 import org.apache.hadoop.util.QuickSort;
-import org.apache.hadoop.util.RunJar;
 
 /**
  * native map output collector wrapped in Java interface
  */
+@InterfaceAudience.Private
 public class NativeMapOutputCollectorDelegator<K, V> implements MapOutputCollector<K, V> {
 
   private static Log LOG = LogFactory.getLog(NativeMapOutputCollectorDelegator.class);
@@ -67,6 +66,7 @@ public class NativeMapOutputCollectorDelegator<K, V> implements MapOutputCollect
     handler.flush();
   }
 
+  @SuppressWarnings("unchecked")
   @Override
   public void init(Context context) throws IOException, ClassNotFoundException {
     this.job = context.getJobConf();
@@ -79,7 +79,8 @@ public class NativeMapOutputCollectorDelegator<K, V> implements MapOutputCollect
       throw new InvalidJobConfException(message);
     }
 
-    Class comparatorClass = job.getClass(MRJobConfig.KEY_COMPARATOR, null, RawComparator.class);
+    Class<?> comparatorClass = job.getClass(MRJobConfig.KEY_COMPARATOR, null,
+        RawComparator.class);
     if (comparatorClass != null && !Platforms.define(comparatorClass)) {
       String message = "Native output collector doesn't support customized java comparator "
         + job.get(MRJobConfig.KEY_COMPARATOR);

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/NativeRuntime.java

@@ -23,6 +23,7 @@ import java.io.IOException;
 import com.google.common.base.Charsets;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.io.DataInputBuffer;
 import org.apache.hadoop.io.FloatWritable;
@@ -34,11 +35,12 @@ import org.apache.hadoop.mapred.nativetask.util.ConfigUtil;
 import org.apache.hadoop.util.VersionInfo;
 
 /**
- * This class stands for the native runtime It has three functions: 1. Create native handlers for map, reduce,
- * outputcollector, and etc 2. Configure native task with provided MR configs 3. Provide file system api to native
- * space, so that it can use File system like HDFS.
- * 
+ * This class stands for the native runtime It has three functions:
+ * 1. Create native handlers for map, reduce, outputcollector, etc
+ * 2. Configure native task with provided MR configs
+ * 3. Provide file system api to native space, so that it can use File system like HDFS.
  */
+@InterfaceAudience.Private
 public class NativeRuntime {
   private static Log LOG = LogFactory.getLog(NativeRuntime.class);
   private static boolean nativeLibraryLoaded = false;

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/Platform.java

@@ -18,13 +18,11 @@
 package org.apache.hadoop.mapred.nativetask;
 
 import java.io.IOException;
-import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Map;
 import java.util.Set;
 
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.mapred.InvalidJobConfException;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.mapred.JobConf;
 import org.apache.hadoop.mapred.nativetask.serde.INativeSerializer;
 import org.apache.hadoop.mapred.nativetask.serde.NativeSerialization;
@@ -39,6 +37,8 @@ import org.apache.hadoop.mapred.nativetask.serde.NativeSerialization;
  * that supports all key types of Hadoop and users could implement their custom
  * platform.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
 public abstract class Platform {
   private final NativeSerialization serialization;
   protected Set<String> keyClassNames = new HashSet<String>();
@@ -67,7 +67,7 @@ public abstract class Platform {
    * @param key          key serializer class
    * @throws IOException
    */
-  protected void registerKey(String keyClassName, Class key) throws IOException {
+  protected void registerKey(String keyClassName, Class<?> key) throws IOException {
     serialization.register(keyClassName, key);
     keyClassNames.add(keyClassName);
   }
@@ -85,7 +85,8 @@ public abstract class Platform {
    * @return             true if the platform has implemented native comparators of the key and
    *                     false otherwise
    */
-  protected abstract boolean support(String keyClassName, INativeSerializer serializer, JobConf job);
+  protected abstract boolean support(String keyClassName,
+      INativeSerializer<?> serializer, JobConf job);
 
 
   /**
@@ -98,5 +99,5 @@ public abstract class Platform {
    * @param keyComparator comparator set with mapreduce.job.output.key.comparator.class
    * @return
    */
-  protected abstract boolean define(Class keyComparator);
+  protected abstract boolean define(Class<?> keyComparator);
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/Platforms.java

@@ -22,6 +22,7 @@ import java.util.ServiceLoader;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.mapred.JobConf;
 import org.apache.hadoop.mapred.nativetask.serde.INativeSerializer;
@@ -33,6 +34,7 @@ import org.apache.hadoop.mapred.nativetask.serde.NativeSerialization;
  * it is also the facade to check for key type support and other
  * platform methods
  */
+@InterfaceAudience.Private
 public class Platforms {
 
   private static final Log LOG = LogFactory.getLog(Platforms.class);
@@ -48,7 +50,8 @@ public class Platforms {
     }
   }
 
-  public static boolean support(String keyClassName, INativeSerializer serializer, JobConf job) {
+  public static boolean support(String keyClassName,
+      INativeSerializer<?> serializer, JobConf job) {
     synchronized (platforms) {
       for (Platform platform : platforms) {
         if (platform.support(keyClassName, serializer, job)) {
@@ -61,7 +64,7 @@ public class Platforms {
     return false;
   }
 
-  public static boolean define(Class keyComparator) {
+  public static boolean define(Class<?> keyComparator) {
     synchronized (platforms) {
       for (Platform platform : platforms) {
         if (platform.define(keyComparator)) {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/StatusReportChecker.java

@@ -21,17 +21,18 @@ import java.io.IOException;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.apache.hadoop.mapred.Task.Counter;
 import org.apache.hadoop.mapred.Task.TaskReporter;
+import org.apache.hadoop.mapreduce.TaskCounter;
+import org.apache.hadoop.mapreduce.lib.input.FileInputFormatCounter;
 
 /**
  * Will periodically check status from native and report to MR framework.
  * 
  */
-public class StatusReportChecker implements Runnable {
+class StatusReportChecker implements Runnable {
 
   private static Log LOG = LogFactory.getLog(StatusReportChecker.class);
-  public static int INTERVAL = 1000; // milli-seconds
+  public static final int INTERVAL = 1000; // milliseconds
 
   private Thread checker;
   private final TaskReporter reporter;
@@ -68,19 +69,19 @@ public class StatusReportChecker implements Runnable {
   }
 
   protected void initUsedCounters() {
-    reporter.getCounter(Counter.MAP_INPUT_RECORDS);
-    reporter.getCounter(Counter.MAP_OUTPUT_RECORDS);
-    reporter.getCounter(Counter.MAP_INPUT_BYTES);
-    reporter.getCounter(Counter.MAP_OUTPUT_BYTES);
-    reporter.getCounter(Counter.MAP_OUTPUT_MATERIALIZED_BYTES);
-    reporter.getCounter(Counter.COMBINE_INPUT_RECORDS);
-    reporter.getCounter(Counter.COMBINE_OUTPUT_RECORDS);
-    reporter.getCounter(Counter.REDUCE_INPUT_RECORDS);
-    reporter.getCounter(Counter.REDUCE_OUTPUT_RECORDS);
-    reporter.getCounter(Counter.REDUCE_INPUT_GROUPS);
-    reporter.getCounter(Counter.SPILLED_RECORDS);
-    reporter.getCounter(Counter.MAP_OUTPUT_BYTES);
-    reporter.getCounter(Counter.MAP_OUTPUT_RECORDS);
+    reporter.getCounter(TaskCounter.MAP_INPUT_RECORDS);
+    reporter.getCounter(TaskCounter.MAP_OUTPUT_RECORDS);
+    reporter.getCounter(FileInputFormatCounter.BYTES_READ);
+    reporter.getCounter(TaskCounter.MAP_OUTPUT_BYTES);
+    reporter.getCounter(TaskCounter.MAP_OUTPUT_MATERIALIZED_BYTES);
+    reporter.getCounter(TaskCounter.COMBINE_INPUT_RECORDS);
+    reporter.getCounter(TaskCounter.COMBINE_OUTPUT_RECORDS);
+    reporter.getCounter(TaskCounter.REDUCE_INPUT_RECORDS);
+    reporter.getCounter(TaskCounter.REDUCE_OUTPUT_RECORDS);
+    reporter.getCounter(TaskCounter.REDUCE_INPUT_GROUPS);
+    reporter.getCounter(TaskCounter.SPILLED_RECORDS);
+    reporter.getCounter(TaskCounter.MAP_OUTPUT_BYTES);
+    reporter.getCounter(TaskCounter.MAP_OUTPUT_RECORDS);
   }
 
   public synchronized void start() {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/TaskContext.java

@@ -17,20 +17,23 @@
  */
 package org.apache.hadoop.mapred.nativetask;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.JobConf;
 import org.apache.hadoop.mapred.Task.TaskReporter;
 import org.apache.hadoop.mapred.TaskAttemptID;
 
+@InterfaceAudience.Private
 public class TaskContext {
   private final JobConf conf;
-  private Class iKClass;
-  private Class iVClass;
-  private Class oKClass;
-  private Class oVClass;
+  private Class<?> iKClass;
+  private Class<?> iVClass;
+  private Class<?> oKClass;
+  private Class<?> oVClass;
   private final TaskReporter reporter;
   private final TaskAttemptID taskAttemptID;
 
-  public TaskContext(JobConf conf, Class iKClass, Class iVClass, Class oKClass, Class oVClass, TaskReporter reporter,
+  public TaskContext(JobConf conf, Class<?> iKClass, Class<?> iVClass,
+      Class<?> oKClass, Class<?> oVClass, TaskReporter reporter,
       TaskAttemptID id) {
     this.conf = conf;
     this.iKClass = iKClass;
@@ -41,35 +44,35 @@ public class TaskContext {
     this.taskAttemptID = id;
   }
 
-  public Class getInputKeyClass() {
+  public Class<?> getInputKeyClass() {
     return iKClass;
   }
 
-  public void setInputKeyClass(Class klass) {
+  public void setInputKeyClass(Class<?> klass) {
     this.iKClass = klass;
   }
 
-  public Class getInputValueClass() {
+  public Class<?> getInputValueClass() {
     return iVClass;
   }
 
-  public void setInputValueClass(Class klass) {
+  public void setInputValueClass(Class<?> klass) {
     this.iVClass = klass;
   }
 
-  public Class getOuputKeyClass() {
+  public Class<?> getOutputKeyClass() {
     return this.oKClass;
   }
 
-  public void setOutputKeyClass(Class klass) {
+  public void setOutputKeyClass(Class<?> klass) {
     this.oKClass = klass;
   }
 
-  public Class getOutputValueClass() {
+  public Class<?> getOutputValueClass() {
     return this.oVClass;
   }
 
-  public void setOutputValueClass(Class klass) {
+  public void setOutputValueClass(Class<?> klass) {
     this.oVClass = klass;
   }
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/buffer/BufferType.java

@@ -18,9 +18,10 @@
 
 package org.apache.hadoop.mapred.nativetask.buffer;
 
-public enum BufferType {
+import org.apache.hadoop.classification.InterfaceAudience;
 
+@InterfaceAudience.Private
+public enum BufferType {
   DIRECT_BUFFER,
-
   HEAP_BUFFER
 };

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/buffer/ByteBufferDataReader.java

@@ -17,22 +17,17 @@
  */
 package org.apache.hadoop.mapred.nativetask.buffer;
 
-import com.google.common.base.Charsets;
-
-import java.io.DataInput;
 import java.io.EOFException;
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.PushbackInputStream;
-import java.io.UTFDataFormatException;
 import java.nio.ByteBuffer;
+import org.apache.hadoop.classification.InterfaceAudience;
 
 /**
  * read data from a input buffer
  */
+@InterfaceAudience.Private
 public class ByteBufferDataReader extends DataInputStream {
   private ByteBuffer byteBuffer;
-  private char lineCache[];
   private java.io.DataInputStream javaReader;
 
   public ByteBufferDataReader(InputBuffer buffer) {
@@ -130,6 +125,7 @@ public class ByteBufferDataReader extends DataInputStream {
     return byteBuffer.getDouble();
   }
 
+  @SuppressWarnings("deprecation")
   @Override
   public String readLine() throws IOException {
     return javaReader.readLine();

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/buffer/ByteBufferDataWriter.java

@@ -17,23 +17,21 @@
  */
 package org.apache.hadoop.mapred.nativetask.buffer;
 
-import java.io.DataOutput;
 import java.io.IOException;
-import java.io.UTFDataFormatException;
 import java.nio.ByteBuffer;
 
-import com.google.common.base.Charsets;
-import com.google.common.base.Preconditions;
-import com.google.common.primitives.UnsignedInteger;
-import com.google.common.primitives.UnsignedInts;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.nativetask.NativeDataTarget;
 
+import com.google.common.base.Preconditions;
+
 /**
  * DataOutputStream implementation which buffers data in a fixed-size
  * ByteBuffer.
  * When the byte buffer has filled up, synchronously passes the buffer
  * to a downstream NativeDataTarget.
  */
+@InterfaceAudience.Private
 public class ByteBufferDataWriter extends DataOutputStream {
   private final ByteBuffer buffer;
   private final NativeDataTarget target;

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/buffer/DataInputStream.java

@@ -19,7 +19,9 @@ package org.apache.hadoop.mapred.nativetask.buffer;
 
 import java.io.DataInput;
 import java.io.InputStream;
+import org.apache.hadoop.classification.InterfaceAudience;
 
+@InterfaceAudience.Private
 public abstract class DataInputStream extends InputStream implements DataInput {
   public abstract boolean hasUnReadData();
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/buffer/DataOutputStream.java

@@ -21,22 +21,19 @@ import java.io.DataOutput;
 import java.io.IOException;
 import java.io.OutputStream;
 
-public abstract class DataOutputStream extends OutputStream implements DataOutput {
+import org.apache.hadoop.classification.InterfaceAudience;
 
+@InterfaceAudience.Private
+public abstract class DataOutputStream extends OutputStream implements DataOutput {
   /**
    * Check whether this buffer has enough space to store length of bytes
    * 
-   * @param length
-   *          , length of bytes
-   * @return
-   * @throws IOException
+   * @param length length of bytes
    */
   public abstract boolean shortOfSpace(int length) throws IOException;
 
   /**
    * Check whether there is unflushed data stored in the stream
-   * 
-   * @return
    */
   public abstract boolean hasUnFlushedData();
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/buffer/InputBuffer.java

@@ -19,12 +19,14 @@
 package org.apache.hadoop.mapred.nativetask.buffer;
 
 import org.apache.hadoop.util.DirectBufferPool;
+import org.apache.hadoop.classification.InterfaceAudience;
 
 import java.io.Closeable;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
+@InterfaceAudience.Private
 public class InputBuffer implements Closeable {
 
   static DirectBufferPool bufferPool = new DirectBufferPool();

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/buffer/OutputBuffer.java

@@ -20,7 +20,9 @@ package org.apache.hadoop.mapred.nativetask.buffer;
 
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
+import org.apache.hadoop.classification.InterfaceAudience;
 
+@InterfaceAudience.Private
 public class OutputBuffer {
   protected ByteBuffer byteBuffer;
   private final BufferType type;

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/handlers/BufferPullee.java

@@ -19,6 +19,7 @@ package org.apache.hadoop.mapred.nativetask.handlers;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.RawKeyValueIterator;
 import org.apache.hadoop.mapred.nativetask.Constants;
 import org.apache.hadoop.mapred.nativetask.NativeDataTarget;
@@ -30,9 +31,10 @@ import org.apache.hadoop.mapred.nativetask.util.SizedWritable;
 /**
  * load data into a buffer signaled by a {@link BufferPuller}
  */
+@InterfaceAudience.Private
 public class BufferPullee<IK, IV> implements IDataLoader {
 
-  public static int KV_HEADER_LENGTH = Constants.SIZEOF_KV_LENGTH;
+  public static final int KV_HEADER_LENGTH = Constants.SIZEOF_KV_LENGTH;
 
   private final SizedWritable<IK> tmpInputKey;
   private final SizedWritable<IV> tmpInputValue;

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/handlers/BufferPuller.java

@@ -1,10 +1,29 @@
+/**
+ * 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.apache.hadoop.mapred.nativetask.handlers;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
+import org.apache.commons.io.IOUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.DataInputBuffer;
 import org.apache.hadoop.mapred.RawKeyValueIterator;
 import org.apache.hadoop.mapred.nativetask.Constants;
@@ -13,13 +32,12 @@ import org.apache.hadoop.mapred.nativetask.NativeDataSource;
 import org.apache.hadoop.mapred.nativetask.buffer.BufferType;
 import org.apache.hadoop.mapred.nativetask.buffer.ByteBufferDataReader;
 import org.apache.hadoop.mapred.nativetask.buffer.InputBuffer;
-import org.apache.hadoop.mapred.nativetask.serde.SerializationFramework;
-import org.apache.hadoop.mapred.nativetask.util.ReadWriteBuffer;
 import org.apache.hadoop.util.Progress;
 
 /**
  * actively signal a {@link BufferPullee} to load data into buffer and receive
  */
+@InterfaceAudience.Private
 public class BufferPuller implements RawKeyValueIterator, DataReceiver {
   
   private static Log LOG = LogFactory.getLog(BufferPuller.class);
@@ -108,8 +126,8 @@ public class BufferPuller implements RawKeyValueIterator, DataReceiver {
       valueBytes = new byte[valueLength];
     }
     
-    nativeReader.read(keyBytes, 0, keyLength);
-    nativeReader.read(valueBytes, 0, valueLength);
+    IOUtils.readFully(nativeReader, keyBytes, 0, keyLength);
+    IOUtils.readFully(nativeReader, valueBytes, 0, valueLength);
 
     keyBuffer.reset(keyBytes, keyLength);
     valueBuffer.reset(valueBytes, valueLength);

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/handlers/BufferPushee.java

@@ -23,6 +23,7 @@ import java.nio.ByteBuffer;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.RecordWriter;
 import org.apache.hadoop.mapred.nativetask.Constants;
 import org.apache.hadoop.mapred.nativetask.buffer.BufferType;
@@ -34,6 +35,7 @@ import org.apache.hadoop.mapred.nativetask.util.SizedWritable;
 /**
  * collect data when signaled
  */
+@InterfaceAudience.Private
 public class BufferPushee<OK, OV> implements Closeable {
 
   private static Log LOG = LogFactory.getLog(BufferPushee.class);

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/handlers/BufferPusher.java

@@ -22,7 +22,7 @@ import java.io.IOException;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.apache.hadoop.io.Text;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.OutputCollector;
 import org.apache.hadoop.mapred.nativetask.NativeDataTarget;
 import org.apache.hadoop.mapred.nativetask.buffer.ByteBufferDataWriter;
@@ -33,6 +33,7 @@ import org.apache.hadoop.mapred.nativetask.util.SizedWritable;
 /**
  * actively push data into a buffer and signal a {@link BufferPushee} to collect it
  */
+@InterfaceAudience.Private
 public class BufferPusher<K, V> implements OutputCollector<K, V> {
   
   private static Log LOG = LogFactory.getLog(BufferPusher.class);

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/handlers/CombinerHandler.java

@@ -17,8 +17,6 @@
  */
 package org.apache.hadoop.mapred.nativetask.handlers;
 
-import static org.apache.hadoop.mapred.Task.Counter.COMBINE_INPUT_RECORDS;
-
 import java.io.IOException;
 
 import org.apache.commons.logging.Log;
@@ -37,13 +35,13 @@ import org.apache.hadoop.mapred.nativetask.TaskContext;
 import org.apache.hadoop.mapred.nativetask.serde.SerializationFramework;
 import org.apache.hadoop.mapred.nativetask.util.ReadWriteBuffer;
 import org.apache.hadoop.mapreduce.MRJobConfig;
+import org.apache.hadoop.mapreduce.TaskCounter;
 
-public class CombinerHandler<K, V> implements ICombineHandler, CommandDispatcher {
-
-  public static String NAME = "NativeTask.CombineHandler";
+class CombinerHandler<K, V> implements ICombineHandler, CommandDispatcher {
+  public static final String NAME = "NativeTask.CombineHandler";
   private static Log LOG = LogFactory.getLog(NativeCollectorOnlyHandler.class);
-  public static Command LOAD = new Command(1, "Load");
-  public static Command COMBINE = new Command(4, "Combine");
+  public static final Command LOAD = new Command(1, "Load");
+  public static final Command COMBINE = new Command(4, "Combine");
   public final CombinerRunner<K, V> combinerRunner;
 
   private final INativeHandler nativeHandler;
@@ -66,13 +64,16 @@ public class CombinerHandler<K, V> implements ICombineHandler, CommandDispatcher
       LOG.info("NativeTask Combiner is enabled, class = " + combinerClazz);
     }
 
-    final Counter combineInputCounter = context.getTaskReporter().getCounter(COMBINE_INPUT_RECORDS);
+    final Counter combineInputCounter = context.getTaskReporter().getCounter(
+        TaskCounter.COMBINE_INPUT_RECORDS);
     
     final CombinerRunner<K, V> combinerRunner = CombinerRunner.create(conf, context.getTaskAttemptId(),
         combineInputCounter, context.getTaskReporter(), null);
 
     final INativeHandler nativeHandler = NativeBatchProcessor.create(NAME, conf, DataChannel.INOUT);
-    final BufferPusher<K, V> pusher = new BufferPusher<K, V>(context.getInputKeyClass(), context.getInputValueClass(),
+    @SuppressWarnings("unchecked")
+    final BufferPusher<K, V> pusher = new BufferPusher<K, V>((Class<K>)context.getInputKeyClass(),
+        (Class<V>)context.getInputValueClass(),
         nativeHandler);
     final BufferPuller puller = new BufferPuller(nativeHandler);
     return new CombinerHandler<K, V>(nativeHandler, combinerRunner, puller, pusher);

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/handlers/IDataLoader.java

@@ -20,9 +20,12 @@ package org.apache.hadoop.mapred.nativetask.handlers;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+
 /**
  * an IDataLoader loads data on demand
  */
+@InterfaceAudience.Private
 public interface IDataLoader {
 
   /**

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/handlers/NativeCollectorOnlyHandler.java

@@ -23,6 +23,7 @@ import java.io.IOException;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.mapred.TaskAttemptID;
@@ -41,14 +42,19 @@ import org.apache.hadoop.mapred.nativetask.util.ReadWriteBuffer;
  * Java Record Reader + Java Mapper + Native Collector
  */
 @SuppressWarnings("unchecked")
+@InterfaceAudience.Private
 public class NativeCollectorOnlyHandler<K, V> implements CommandDispatcher, Closeable {
 
-  public static String NAME = "NativeTask.MCollectorOutputHandler";
+  public static final String NAME = "NativeTask.MCollectorOutputHandler";
   private static Log LOG = LogFactory.getLog(NativeCollectorOnlyHandler.class);
-  public static Command GET_OUTPUT_PATH = new Command(100, "GET_OUTPUT_PATH");
-  public static Command GET_OUTPUT_INDEX_PATH = new Command(101, "GET_OUTPUT_INDEX_PATH");
-  public static Command GET_SPILL_PATH = new Command(102, "GET_SPILL_PATH");
-  public static Command GET_COMBINE_HANDLER = new Command(103, "GET_COMBINE_HANDLER");
+  public static final Command GET_OUTPUT_PATH =
+      new Command(100, "GET_OUTPUT_PATH");
+  public static final Command GET_OUTPUT_INDEX_PATH =
+      new Command(101, "GET_OUTPUT_INDEX_PATH");
+  public static final Command GET_SPILL_PATH =
+      new Command(102, "GET_SPILL_PATH");
+  public static final Command GET_COMBINE_HANDLER =
+      new Command(103, "GET_COMBINE_HANDLER");
   
   private NativeTaskOutput output;
   private int spillNumber = 0;
@@ -63,7 +69,7 @@ public class NativeCollectorOnlyHandler<K, V> implements CommandDispatcher, Clos
     ICombineHandler combinerHandler = null;
     try {
       final TaskContext combineContext = context.copyOf();
-      combineContext.setInputKeyClass(context.getOuputKeyClass());
+      combineContext.setInputKeyClass(context.getOutputKeyClass());
       combineContext.setInputValueClass(context.getOutputValueClass());
 
       combinerHandler = CombinerHandler.create(combineContext);
@@ -76,7 +82,9 @@ public class NativeCollectorOnlyHandler<K, V> implements CommandDispatcher, Clos
     }
 
     final INativeHandler nativeHandler = NativeBatchProcessor.create(NAME, context.getConf(), DataChannel.OUT);
-    final BufferPusher<K, V> kvPusher = new BufferPusher<K, V>(context.getOuputKeyClass(), context.getOutputValueClass(),
+    final BufferPusher<K, V> kvPusher = new BufferPusher<K, V>(
+        (Class<K>)context.getOutputKeyClass(),
+        (Class<V>)context.getOutputValueClass(),
         nativeHandler);
 
     return new NativeCollectorOnlyHandler<K, V>(context, nativeHandler, kvPusher, combinerHandler);

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/BoolWritableSerializer.java

@@ -20,9 +20,11 @@ package org.apache.hadoop.mapred.nativetask.serde;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class BoolWritableSerializer extends DefaultSerializer implements
     INativeComparable {
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/ByteWritableSerializer.java

@@ -20,9 +20,11 @@ package org.apache.hadoop.mapred.nativetask.serde;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class ByteWritableSerializer extends DefaultSerializer implements
     INativeComparable {
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/BytesWritableSerializer.java

@@ -22,9 +22,11 @@ import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.BytesWritable;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class BytesWritableSerializer implements INativeComparable, INativeSerializer<BytesWritable> {
 
   @Override

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/DefaultSerializer.java

@@ -24,8 +24,12 @@ import java.io.DataOutput;
 import java.io.DataOutputStream;
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.io.Writable;
 
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
 public class DefaultSerializer implements INativeSerializer<Writable> {
 
   static class ModifiedByteArrayOutputStream extends ByteArrayOutputStream {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/DoubleWritableSerializer.java

@@ -20,9 +20,11 @@ package org.apache.hadoop.mapred.nativetask.serde;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class DoubleWritableSerializer extends DefaultSerializer implements
     INativeComparable {
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/FloatWritableSerializer.java

@@ -20,9 +20,12 @@ package org.apache.hadoop.mapred.nativetask.serde;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+
+@InterfaceAudience.Private
 public class FloatWritableSerializer extends DefaultSerializer implements
     INativeComparable {
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/IKVSerializer.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.mapred.nativetask.serde;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.nativetask.buffer.DataInputStream;
 import org.apache.hadoop.mapred.nativetask.buffer.DataOutputStream;
 import org.apache.hadoop.mapred.nativetask.util.SizedWritable;
@@ -27,6 +28,7 @@ import org.apache.hadoop.mapred.nativetask.util.SizedWritable;
 /**
  * serializes key-value pair
  */
+@InterfaceAudience.Private
 public interface IKVSerializer {
 
   /**
@@ -35,7 +37,7 @@ public interface IKVSerializer {
    * @param value
    * @throws IOException
    */
-  public void updateLength(SizedWritable key, SizedWritable value) throws IOException;
+  public void updateLength(SizedWritable<?> key, SizedWritable<?> value) throws IOException;
 
   /**
    *
@@ -45,7 +47,8 @@ public interface IKVSerializer {
    * @return       bytes written
    * @throws IOException
    */
-  public int serializeKV(DataOutputStream out, SizedWritable key, SizedWritable value) throws IOException;
+  public int serializeKV(DataOutputStream out, SizedWritable<?> key,
+      SizedWritable<?> value) throws IOException;
 
   /**
    * serialize partitionId as well
@@ -56,7 +59,8 @@ public interface IKVSerializer {
    * @return
    * @throws IOException
    */
-  public int serializePartitionKV(DataOutputStream out, int partitionId, SizedWritable key, SizedWritable value)
+  public int serializePartitionKV(DataOutputStream out, int partitionId,
+      SizedWritable<?> key, SizedWritable<?> value)
       throws IOException;
 
   /**
@@ -67,5 +71,5 @@ public interface IKVSerializer {
    * @return      bytes read
    * @throws IOException
    */
-  public int deserializeKV(DataInputStream in, SizedWritable key, SizedWritable value) throws IOException;
+  public int deserializeKV(DataInputStream in, SizedWritable<?> key, SizedWritable<?> value) throws IOException;
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/INativeSerializer.java

@@ -21,6 +21,8 @@ package org.apache.hadoop.mapred.nativetask.serde;
 import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 
 /**
  * an INativeSerializer serializes and deserializes data transferred between
@@ -30,6 +32,8 @@ import java.io.IOException;
  * you have to make sure the native side can serialize it correctly.
  * 
  */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
 public interface INativeSerializer<T> {
 
   /**

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/IntWritableSerializer.java

@@ -20,9 +20,11 @@ package org.apache.hadoop.mapred.nativetask.serde;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class IntWritableSerializer extends DefaultSerializer implements
     INativeComparable {
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/KVSerializer.java

@@ -22,18 +22,21 @@ import java.io.IOException;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.nativetask.Constants;
 import org.apache.hadoop.mapred.nativetask.buffer.DataInputStream;
 import org.apache.hadoop.mapred.nativetask.buffer.DataOutputStream;
 import org.apache.hadoop.mapred.nativetask.util.SizedWritable;
 
-public class KVSerializer<K, V> implements IKVSerializer {
 
 
+@InterfaceAudience.Private
+public class KVSerializer<K, V> implements IKVSerializer {
+
   private static final Log LOG = LogFactory.getLog(KVSerializer.class);
   
-  public static int KV_HEAD_LENGTH = Constants.SIZEOF_KV_LENGTH;
+  public static final int KV_HEAD_LENGTH = Constants.SIZEOF_KV_LENGTH;
 
   private final INativeSerializer<Writable> keySerializer;
   private final INativeSerializer<Writable> valueSerializer;
@@ -45,19 +48,20 @@ public class KVSerializer<K, V> implements IKVSerializer {
   }
 
   @Override
-  public void updateLength(SizedWritable key, SizedWritable value) throws IOException {
+  public void updateLength(SizedWritable<?> key, SizedWritable<?> value) throws IOException {
     key.length = keySerializer.getLength(key.v);
     value.length = valueSerializer.getLength(value.v);
     return;
   }
 
   @Override
-  public int serializeKV(DataOutputStream out, SizedWritable key, SizedWritable value) throws IOException {
+  public int serializeKV(DataOutputStream out, SizedWritable<?> key, SizedWritable<?> value) throws IOException {
     return serializePartitionKV(out, -1, key, value);
   }
 
   @Override
-  public int serializePartitionKV(DataOutputStream out, int partitionId, SizedWritable key, SizedWritable value)
+  public int serializePartitionKV(DataOutputStream out, int partitionId,
+      SizedWritable<?> key, SizedWritable<?> value)
       throws IOException {
 
     if (key.length == SizedWritable.INVALID_LENGTH || value.length == SizedWritable.INVALID_LENGTH) {
@@ -90,7 +94,8 @@ public class KVSerializer<K, V> implements IKVSerializer {
   }
 
   @Override
-  public int deserializeKV(DataInputStream in, SizedWritable key, SizedWritable value) throws IOException {
+  public int deserializeKV(DataInputStream in, SizedWritable<?> key,
+      SizedWritable<?> value) throws IOException {
 
     if (!in.hasUnReadData()) {
       return 0;

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/LongWritableSerializer.java

@@ -20,9 +20,11 @@ package org.apache.hadoop.mapred.nativetask.serde;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class LongWritableSerializer extends DefaultSerializer implements
     INativeComparable {
   @Override

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/NativeSerialization.java

@@ -21,8 +21,10 @@ package org.apache.hadoop.mapred.nativetask.serde;
 import java.io.IOException;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 
+@InterfaceAudience.Private
 public class NativeSerialization {
 
   private final ConcurrentHashMap<String, Class<?>> map = new ConcurrentHashMap<String, Class<?>>();

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/NullWritableSerializer.java

@@ -20,9 +20,11 @@ package org.apache.hadoop.mapred.nativetask.serde;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class NullWritableSerializer extends DefaultSerializer implements
     INativeComparable {
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/SerializationFramework.java

@@ -17,6 +17,9 @@
  */
 package org.apache.hadoop.mapred.nativetask.serde;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+
+@InterfaceAudience.Private
 public enum SerializationFramework {
   WRITABLE_SERIALIZATION(0), NATIVE_SERIALIZATION(1);
 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/TextSerializer.java

@@ -22,9 +22,11 @@ import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class TextSerializer implements INativeSerializer<Text>, INativeComparable {
 
   public TextSerializer() throws SecurityException, NoSuchMethodException {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/VIntWritableSerializer.java

@@ -18,9 +18,10 @@
 
 package org.apache.hadoop.mapred.nativetask.serde;
 
-import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class VIntWritableSerializer extends DefaultSerializer implements
     INativeComparable {
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/VLongWritableSerializer.java

@@ -18,9 +18,10 @@
 
 package org.apache.hadoop.mapred.nativetask.serde;
 
-import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.mapred.nativetask.INativeComparable;
 
+@InterfaceAudience.Private
 public class VLongWritableSerializer extends DefaultSerializer implements
     INativeComparable {
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/util/BytesUtil.java

@@ -20,7 +20,9 @@ package org.apache.hadoop.mapred.nativetask.util;
 
 import com.google.common.primitives.Ints;
 import com.google.common.primitives.Longs;
+import org.apache.hadoop.classification.InterfaceAudience;
 
+@InterfaceAudience.Private
 public class BytesUtil {
 
   private static final char[] HEX_CHARS =

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/util/ConfigUtil.java

@@ -24,7 +24,10 @@ import java.util.Map;
 import com.google.common.base.Charsets;
 import org.apache.hadoop.conf.Configuration;
 
-public class ConfigUtil {
+import org.apache.hadoop.classification.InterfaceAudience;
+
+@InterfaceAudience.Private
+public abstract class ConfigUtil {
   public static byte[][] toBytes(Configuration conf) {
     List<byte[]> nativeConfigs = new ArrayList<byte[]>();
     for (Map.Entry<String, String> e : conf) {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/util/LocalJobOutputFiles.java

@@ -19,12 +19,14 @@ package org.apache.hadoop.mapred.nativetask.util;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.LocalDirAllocator;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.mapred.JobConf;
 import org.apache.hadoop.mapred.TaskID;
 
+@InterfaceAudience.Private
 public class LocalJobOutputFiles implements NativeTaskOutput {
 
   static final String TASKTRACKER_OUTPUT = "output";

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/util/NativeTaskOutput.java

@@ -19,6 +19,7 @@ package org.apache.hadoop.mapred.nativetask.util;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.mapred.TaskID;
@@ -26,6 +27,7 @@ import org.apache.hadoop.mapred.TaskID;
 /**
  * base class of output files manager.
  */
+@InterfaceAudience.Private
 public interface NativeTaskOutput {
 
   /**

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/util/NativeTaskOutputFiles.java

@@ -19,6 +19,7 @@ package org.apache.hadoop.mapred.nativetask.util;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.LocalDirAllocator;
 import org.apache.hadoop.fs.Path;
@@ -33,7 +34,7 @@ import org.apache.hadoop.mapred.TaskID;
  * mapreduce.cluster.local.dir as taskTracker/jobCache/jobId/attemptId This class should not be used
  * from TaskTracker space.
  */
-
+@InterfaceAudience.Private
 public class NativeTaskOutputFiles implements NativeTaskOutput {
 
   static final String TASKTRACKER_OUTPUT = "output";

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/util/OutputUtil.java

@@ -22,9 +22,10 @@ import java.lang.reflect.Constructor;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 
-
+@InterfaceAudience.Private
 public class OutputUtil {
 
   private static Log LOG = LogFactory.getLog(OutputUtil.class);
@@ -40,7 +41,7 @@ public class OutputUtil {
       NativeTaskOutput instance = (NativeTaskOutput) ctor.newInstance(conf, id);
       return instance;
     } catch (Exception e) {
-      return null;
+      throw new RuntimeException(e);
     }
   }
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/util/ReadWriteBuffer.java

@@ -15,16 +15,17 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.apache.hadoop.mapred.nativetask.util;
 
 import com.google.common.base.Charsets;
+import org.apache.hadoop.classification.InterfaceAudience;
 
+@InterfaceAudience.Private
 public class ReadWriteBuffer {
   private byte[] _buff;
   private int _writePoint;
   private int _readPoint;
-  final int CACHE_LINE_SIZE = 16;
+  final static int CACHE_LINE_SIZE = 16;
 
   public ReadWriteBuffer(int length) {
     if (length > 0) {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/util/SizedWritable.java

@@ -19,12 +19,14 @@ package org.apache.hadoop.mapred.nativetask.util;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.DataInputBuffer;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.util.ReflectionUtils;
 
+@InterfaceAudience.Private
 public class SizedWritable<T> {
-  public static int INVALID_LENGTH = -1;
+  public static final int INVALID_LENGTH = -1;
 
   public int length = INVALID_LENGTH;
   public Writable v;

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/test/java/org/apache/hadoop/mapred/nativetask/TestTaskContext.java

@@ -30,13 +30,13 @@ public class TestTaskContext extends TestCase {
     TaskContext context = new TaskContext(null, null, null, null, null, null, null);
     
     context.setInputKeyClass(IntWritable.class);
-    assertEquals(IntWritable.class.getName(), context.getInputKeyClass().getName()); 
+    assertEquals(IntWritable.class.getName(), context.getInputKeyClass().getName());
  
     context.setInputValueClass(Text.class);
     assertEquals(Text.class.getName(), context.getInputValueClass().getName()); 
    
     context.setOutputKeyClass(LongWritable.class);
-    assertEquals(LongWritable.class.getName(), context.getOuputKeyClass().getName()); 
+    assertEquals(LongWritable.class.getName(), context.getOutputKeyClass().getName()); 
 
     context.setOutputValueClass(FloatWritable.class);
     assertEquals(FloatWritable.class.getName(), context.getOutputValueClass().getName());