NativeCodeLoader.java
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上传日期:2018-01-08
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- /**
- * 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.util;
- import org.apache.commons.logging.Log;
- import org.apache.commons.logging.LogFactory;
- import org.apache.hadoop.conf.Configuration;
- /**
- * A helper to load the native hadoop code i.e. libhadoop.so.
- * This handles the fallback to either the bundled libhadoop-Linux-i386-32.so
- * or the default java implementations where appropriate.
- *
- */
- public class NativeCodeLoader {
- private static final Log LOG =
- LogFactory.getLog(NativeCodeLoader.class);
-
- private static boolean nativeCodeLoaded = false;
-
- static {
- // Try to load native hadoop library and set fallback flag appropriately
- LOG.debug("Trying to load the custom-built native-hadoop library...");
- try {
- System.loadLibrary("hadoop");
- LOG.info("Loaded the native-hadoop library");
- nativeCodeLoaded = true;
- } catch (Throwable t) {
- // Ignore failure to load
- LOG.debug("Failed to load native-hadoop with error: " + t);
- LOG.debug("java.library.path=" + System.getProperty("java.library.path"));
- }
-
- if (!nativeCodeLoaded) {
- LOG.warn("Unable to load native-hadoop library for your platform... " +
- "using builtin-java classes where applicable");
- }
- }
- /**
- * Check if native-hadoop code is loaded for this platform.
- *
- * @return <code>true</code> if native-hadoop is loaded,
- * else <code>false</code>
- */
- public static boolean isNativeCodeLoaded() {
- return nativeCodeLoaded;
- }
- /**
- * Return if native hadoop libraries, if present, can be used for this job.
- * @param conf configuration
- *
- * @return <code>true</code> if native hadoop libraries, if present, can be
- * used for this job; <code>false</code> otherwise.
- */
- public boolean getLoadNativeLibraries(Configuration conf) {
- return conf.getBoolean("hadoop.native.lib", true);
- }
-
- /**
- * Set if native hadoop libraries, if present, can be used for this job.
- *
- * @param conf configuration
- * @param loadNativeLibraries can native hadoop libraries be loaded
- */
- public void setLoadNativeLibraries(Configuration conf,
- boolean loadNativeLibraries) {
- conf.setBoolean("hadoop.native.lib", loadNativeLibraries);
- }
- }