HBASE-1596 Remove WatcherWrapper and have all users of Zookeeper provide a Watcher

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@790970 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -431,6 +431,8 @@ Release 0.20.0 - Unreleased
    HBASE-1385  Revamp TableInputFormat, needs updating to match hadoop 0.20.x
                AND remove bit where we can make < maps than regions
                (Lars George via Stack)
+   HBASE-1596  Remove WatcherWrapper and have all users of Zookeeper provide a
+               Watcher
 
   OPTIMIZATIONS
    HBASE-1412  Change values for delete column and column family in KeyValue

src/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -88,6 +88,8 @@ import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.ipc.RemoteException;
 import org.apache.hadoop.net.DNS;
 import org.apache.hadoop.util.StringUtils;
+import org.apache.zookeeper.WatchedEvent;
+import org.apache.zookeeper.Watcher;
 
 /**
  * HMaster is the "master server" for a HBase.
@@ -98,7 +100,7 @@ import org.apache.hadoop.util.StringUtils;
  * sleep time which is invariant.
  */
 public class HMaster extends Thread implements HConstants, HMasterInterface, 
-  HMasterRegionInterface {
+  HMasterRegionInterface, Watcher {
 
   static final Log LOG = LogFactory.getLog(HMaster.class.getName());
 
@@ -242,7 +244,7 @@ public class HMaster extends Thread implements HConstants, HMasterInterface,
 
     this.sleeper = new Sleeper(this.threadWakeFrequency, this.closed);
     
-    zooKeeperWrapper = new ZooKeeperWrapper(conf);
+    zooKeeperWrapper = new ZooKeeperWrapper(conf, this);
     zkMasterAddressWatcher = new ZKMasterAddressWatcher(this);
     serverManager = new ServerManager(this);
     regionManager = new RegionManager(this);
@@ -1168,4 +1170,12 @@ public class HMaster extends Thread implements HConstants, HMasterInterface,
   public static void main(String [] args) {
     doMain(args, HMaster.class);
   }
+
+  /**
+   * @see org.apache.zookeeper.Watcher#process(org.apache.zookeeper.WatchedEvent)
+   */
+  @Override
+  public void process(WatchedEvent event) {
+    // TODO: Write me to handle session expired events.
+  }
 }

src/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -314,7 +314,7 @@ public class HRegionServer implements HConstants, HRegionInterface,
   }
 
   private void reinitializeZooKeeper() throws IOException {
-    zooKeeperWrapper = new ZooKeeperWrapper(conf);
+    zooKeeperWrapper = new ZooKeeperWrapper(conf, this);
     watchMasterAddress();
   }
 

src/java/org/apache/hadoop/hbase/zookeeper/WatcherWrapper.java

@@ -1,49 +0,0 @@
-/**
- * Copyright 2009 The Apache Software Foundation
- *
- * 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.hbase.zookeeper;
-
-import org.apache.zookeeper.WatchedEvent;
-import org.apache.zookeeper.Watcher;
-
-/**
- * Place-holder Watcher.
- * Does nothing currently.
- */
-public class WatcherWrapper implements Watcher {
-  private final Watcher otherWatcher;
-
-  /**
-   * Construct with a Watcher to pass events to.
-   * @param otherWatcher Watcher to pass events to.
-   */
-  public WatcherWrapper(Watcher otherWatcher) {
-    this.otherWatcher = otherWatcher;
-  }
-
-  /**
-   * @param event WatchedEvent from ZooKeeper.
-   */
-  public void process(WatchedEvent event) {
-    if (otherWatcher != null) {
-      otherWatcher.process(event);
-    }
-  }
-
-}

src/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWrapper.java

@@ -62,7 +62,6 @@ public class ZooKeeperWrapper implements HConstants {
   }
 
   private final ZooKeeper zooKeeper;
-  private final WatcherWrapper watcher;
 
   private final String parentZNode;
   public final String rootRegionZNode;
@@ -71,15 +70,6 @@ public class ZooKeeperWrapper implements HConstants {
   public final String masterElectionZNode;
   public final String clusterStateZNode;
 
-  /**
-   * Create a ZooKeeperWrapper.
-   * @param conf HBaseConfiguration to read settings from.
-   * @throws IOException If a connection error occurs.
-   */
-  public ZooKeeperWrapper(HBaseConfiguration conf) throws IOException { 
-    this(conf, null);
-  }
-
   /**
    * Create a ZooKeeperWrapper.
    * @param conf HBaseConfiguration to read settings from.
@@ -94,9 +84,8 @@ public class ZooKeeperWrapper implements HConstants {
     }
 
     int sessionTimeout = conf.getInt("zookeeper.session.timeout", 10 * 1000);
-    this.watcher = new WatcherWrapper(watcher);
     try {
-      zooKeeper = new ZooKeeper(quorumServers, sessionTimeout, this.watcher);
+      zooKeeper = new ZooKeeper(quorumServers, sessionTimeout, watcher);
     } catch (IOException e) {
       LOG.error("Failed to create ZooKeeper object: " + e);
       throw new IOException(e);

src/test/org/apache/hadoop/hbase/TestZooKeeper.java

@@ -54,7 +54,7 @@ public class TestZooKeeper extends HBaseClusterTestCase {
    * @throws IOException
    */
   public void testWritesRootRegionLocation() throws IOException {
-    ZooKeeperWrapper zooKeeper = new ZooKeeperWrapper(conf);
+    ZooKeeperWrapper zooKeeper = new ZooKeeperWrapper(conf, new EmptyWatcher());
 
     boolean outOfSafeMode = zooKeeper.checkOutOfSafeMode();
     assertFalse(outOfSafeMode);
@@ -83,7 +83,7 @@ public class TestZooKeeper extends HBaseClusterTestCase {
    */
   public void testParentExists() throws IOException {
     conf.set("zookeeper.znode.safemode", "/a/b/c/d/e");
-    ZooKeeperWrapper zooKeeper = new ZooKeeperWrapper(conf);
+    ZooKeeperWrapper zooKeeper = new ZooKeeperWrapper(conf, new EmptyWatcher());
     assertTrue(zooKeeper.writeOutOfSafeMode());
   }