/**
* 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.hive.shims;
import java.lang.IllegalArgumentException;
import java.util.HashMap;
import java.util.Map;
import org.apache.hadoop.hive.thrift.HadoopThriftAuthBridge;
import org.apache.hadoop.util.VersionInfo;
import org.apache.log4j.AppenderSkeleton;
/**
* ShimLoader.
*
*/
public abstract class ShimLoader {
private static HadoopShims hadoopShims;
private static JettyShims jettyShims;
private static AppenderSkeleton eventCounter;
/**
* The names of the classes for shimming Hadoop for each major version.
*/
private static final HashMap<String, String> HADOOP_SHIM_CLASSES =
new HashMap<String, String>();
static {
HADOOP_SHIM_CLASSES.put("0.20", "org.apache.hadoop.hive.shims.Hadoop20Shims");
HADOOP_SHIM_CLASSES.put("0.20S", "org.apache.hadoop.hive.shims.Hadoop20SShims");
HADOOP_SHIM_CLASSES.put("0.23", "org.apache.hadoop.hive.shims.Hadoop23Shims");
}
/**
* The names of the classes for shimming Jetty for each major version of
* Hadoop.
*/
private static final HashMap<String, String> JETTY_SHIM_CLASSES =
new HashMap<String, String>();
static {
JETTY_SHIM_CLASSES.put("0.20", "org.apache.hadoop.hive.shims.Jetty20Shims");
JETTY_SHIM_CLASSES.put("0.20S", "org.apache.hadoop.hive.shims.Jetty20SShims");
JETTY_SHIM_CLASSES.put("0.23", "org.apache.hadoop.hive.shims.Jetty23Shims");
}
/**
* The names of the classes for shimming Hadoop's event counter
*/
private static final HashMap<String, String> EVENT_COUNTER_SHIM_CLASSES =
new HashMap<String, String>();
static {
EVENT_COUNTER_SHIM_CLASSES.put("0.20", "org.apache.hadoop.metrics.jvm.EventCounter");
EVENT_COUNTER_SHIM_CLASSES.put("0.20S", "org.apache.hadoop.log.metrics.EventCounter");
EVENT_COUNTER_SHIM_CLASSES.put("0.23", "org.apache.hadoop.log.metrics.EventCounter");
}
/**
* Factory method to get an instance of HadoopShims based on the
* version of Hadoop on the classpath.
*/
public static synchronized HadoopShims getHadoopShims() {
if (hadoopShims == null) {
hadoopShims = loadShims(HADOOP_SHIM_CLASSES, HadoopShims.class);
}
return hadoopShims;
}
/**
* Factory method to get an instance of JettyShims based on the version
* of Hadoop on the classpath.
*/
public static synchronized JettyShims getJettyShims() {
if (jettyShims == null) {
jettyShims = loadShims(JETTY_SHIM_CLASSES, JettyShims.class);
}
return jettyShims;
}
public static synchronized AppenderSkeleton getEventCounter() {
if (eventCounter == null) {
eventCounter = loadShims(EVENT_COUNTER_SHIM_CLASSES, AppenderSkeleton.class);
}
return eventCounter;
}
public static synchronized HadoopThriftAuthBridge getHadoopThriftAuthBridge() {
if (getHadoopShims().isSecureShimImpl()) {
return createShim("org.apache.hadoop.hive.thrift.HadoopThriftAuthBridge20S",
HadoopThriftAuthBridge.class);
} else {
return new HadoopThriftAuthBridge();
}
}
private static <T> T loadShims(Map<String, String> classMap, Class<T> xface) {
String vers = getMajorVersion();
String className = classMap.get(vers);
return createShim(className, xface);
}
private static <T> T createShim(String className, Class<T> xface) {
try {
Class<?> clazz = Class.forName(className);
return xface.cast(clazz.newInstance());
} catch (Exception e) {
throw new RuntimeException("Could not load shims in class " +
className, e);
}
}
/**
* Return the "major" version of Hadoop currently on the classpath.
* For releases in the 0.x series this is simply the first two
* components of the version, e.g. "0.20" or "0.23". Releases in
* the 1.x and 2.x series are mapped to the appropriate
* 0.x release series, e.g. 1.x is mapped to "0.20S" and 2.x
* is mapped to "0.23".
*/
public static String getMajorVersion() {
String vers = VersionInfo.getVersion();
String[] parts = vers.split("\\.");
if (parts.length < 2) {
throw new RuntimeException("Illegal Hadoop Version: " + vers +
" (expected A.B.* format)");
}
// Special handling for Hadoop 1.x and 2.x
switch (Integer.parseInt(parts[0])) {
case 0:
break;
case 1:
return "0.20S";
case 2:
return "0.23";
default:
throw new IllegalArgumentException("Unrecognized Hadoop major version number: " + vers);
}
String majorVersion = parts[0] + "." + parts[1];
// If we are running a security release, we won't have UnixUserGroupInformation
// (removed by HADOOP-6299 when switching to JAAS for Login)
try {
Class.forName("org.apache.hadoop.security.UnixUserGroupInformation");
} catch (ClassNotFoundException cnf) {
if ("0.20".equals(majorVersion)) {
majorVersion += "S";
}
}
return majorVersion;
}
private ShimLoader() {
// prevent instantiation
}
}