org.apache.hadoop.dfs.AppendTestUtil.java Source code

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Here is the source code for org.apache.hadoop.dfs.AppendTestUtil.java

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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.dfs;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Random;

import junit.framework.TestCase;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.security.UnixUserGroupInformation;
import org.apache.hadoop.security.UserGroupInformation;

/** Utilities for append-related tests */
class AppendTestUtil {
    /** For specifying the random number generator seed,
     *  change the following value:
     */
    static final Long RANDOM_NUMBER_GENERATOR_SEED = null;

    static final Log LOG = LogFactory.getLog(AppendTestUtil.class);

    private static final Random SEED = new Random();
    static {
        final long seed = RANDOM_NUMBER_GENERATOR_SEED == null ? SEED.nextLong() : RANDOM_NUMBER_GENERATOR_SEED;
        LOG.info("seed=" + seed);
        SEED.setSeed(seed);
    }

    private static final ThreadLocal<Random> RANDOM = new ThreadLocal<Random>() {
        protected Random initialValue() {
            final Random r = new Random();
            synchronized (SEED) {
                final long seed = SEED.nextLong();
                r.setSeed(seed);
                LOG.info(Thread.currentThread().getName() + ": seed=" + seed);
            }
            return r;
        }
    };

    static int nextInt() {
        return RANDOM.get().nextInt();
    }

    static int nextInt(int n) {
        return RANDOM.get().nextInt(n);
    }

    static int nextLong() {
        return RANDOM.get().nextInt();
    }

    static byte[] randomBytes(long seed, int size) {
        LOG.info("seed=" + seed + ", size=" + size);
        final byte[] b = new byte[size];
        final Random rand = new Random(seed);
        rand.nextBytes(b);
        return b;
    }

    static void sleep(long ms) {
        try {
            Thread.sleep(ms);
        } catch (InterruptedException e) {
            LOG.info("ms=" + ms, e);
        }
    }

    static FileSystem createHdfsWithDifferentUsername(Configuration conf) throws IOException {
        Configuration conf2 = new Configuration(conf);
        String username = UserGroupInformation.getCurrentUGI().getUserName() + "_XXX";
        UnixUserGroupInformation.saveToConf(conf2, UnixUserGroupInformation.UGI_PROPERTY_NAME,
                new UnixUserGroupInformation(username, new String[] { "supergroup" }));
        return FileSystem.get(conf2);
    }

    static void write(OutputStream out, int offset, int length) throws IOException {
        final byte[] bytes = new byte[length];
        for (int i = 0; i < length; i++) {
            bytes[i] = (byte) (offset + i);
        }
        out.write(bytes);
    }

    static void check(FileSystem fs, Path p, long length) throws IOException {
        int i = -1;
        try {
            final FileStatus status = fs.getFileStatus(p);
            TestCase.assertEquals(length, status.getLen());
            InputStream in = fs.open(p);
            for (i++; i < length; i++) {
                TestCase.assertEquals((byte) i, (byte) in.read());
            }
            i = -(int) length;
            TestCase.assertEquals(-1, in.read()); //EOF  
            in.close();
        } catch (IOException ioe) {
            throw (IOException) new IOException("p=" + p + ", length=" + length + ", i=" + i).initCause(ioe);
        }
    }
}