org.apache.hadoop.mapred.FileAllocationStore.java Source code

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Here is the source code for org.apache.hadoop.mapred.FileAllocationStore.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.mapred;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;

import java.io.FileReader;
import java.io.BufferedReader;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.Closeable;

/**
 * Implements persistent storage for queue budget and spending
 * information in a file.
 */
public class FileAllocationStore extends AllocationStore {
    private static final Log LOG = LogFactory.getLog(FileAllocationStore.class);
    private String fileName = "";
    private boolean loaded = false;

    /** {@inheritDoc} */
    public void init(Configuration conf) {
        fileName = conf.get(PrioritySchedulerOptions.DYNAMIC_SCHEDULER_BUDGET_FILE, "/etc/hadoop.budget");
    }

    /** {@inheritDoc} */
    public void save() {
        PrintWriter out = null;
        try {
            out = new PrintWriter(new BufferedWriter(new FileWriter(fileName)));
            for (BudgetQueue queue : getQueues()) {
                out.printf("%s %.20f %.20f\n", queue.name, queue.budget, queue.spending);
            }
        } catch (Exception e) {
            LOG.error("Error writing to file: " + fileName, e);
        } finally {
            close(out);
        }
    }

    private void close(Closeable closeable) {
        if (closeable != null) {
            try {
                closeable.close();
            } catch (Exception ce) {
                LOG.error("Error closing file: " + fileName, ce);
            }
        }
    }

    /** {@inheritDoc} */
    public void load() {
        if (loaded) {
            return;
        }
        BufferedReader in = null;
        try {
            in = new BufferedReader(new FileReader(fileName));
            String line = in.readLine();
            while (line != null) {
                String[] nameValue = line.split(" ");
                if (nameValue.length != 3) {
                    continue;
                }
                queueCache.put(nameValue[0], new BudgetQueue(nameValue[0], Float.parseFloat(nameValue[1]),
                        Float.parseFloat(nameValue[2])));
                line = in.readLine();
            }
            loaded = true;
        } catch (Exception e) {
            LOG.error("Error reading file: " + fileName, e);
        } finally {
            close(in);
        }
    }
}