org.trend.hgraph.mapreduce.pagerank.Utils.java Source code

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Here is the source code for org.trend.hgraph.mapreduce.pagerank.Utils.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.trend.hgraph.mapreduce.pagerank;

import java.io.IOException;

import org.apache.commons.lang.Validate;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.security.User;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.mapreduce.Job;
import org.slf4j.Logger;
import org.trend.hgraph.HBaseGraphConstants;

/**
 * A Utility class
 * @author scott_miao
 */
class Utils {

    static void writePageRank(HTable table, String rowkey, String columnQualifer, double pageRank) {
        Put put = null;

        put = new Put(Bytes.toBytes(rowkey));
        put.add(Bytes.toBytes(HBaseGraphConstants.HBASE_GRAPH_TABLE_COLFAM_PROPERTY_NAME), Bytes.toBytes(
                columnQualifer + HBaseGraphConstants.HBASE_GRAPH_TABLE_COLFAM_PROPERTY_NAME_DELIMITER + "String"),
                Bytes.toBytes(("" + pageRank)));
        try {
            table.put(put);
        } catch (IOException e) {
            System.err.println("writePageRank failed");
            e.printStackTrace(System.err);
        }
    }

    static double getPageRank(HTable table, String rowkey, String columnQualifer) throws IOException {
        Get get = null;
        Result r = null;
        try {
            get = new Get(Bytes.toBytes(rowkey));
            r = table.get(get);
        } catch (IOException e) {
            System.err.println("access HTable failed");
            e.printStackTrace(System.err);
            throw e;
        }
        return getPageRank(r, columnQualifer);
    }

    static double getPageRank(Result value, String columnQualifer) {
        byte[] colValue = value.getValue(Bytes.toBytes(HBaseGraphConstants.HBASE_GRAPH_TABLE_COLFAM_PROPERTY_NAME),
                Bytes.toBytes(columnQualifer + HBaseGraphConstants.HBASE_GRAPH_TABLE_COLFAM_PROPERTY_NAME_DELIMITER
                        + "String"));
        double pageRank = 0.0D;
        if (null != colValue) {
            try {
                pageRank = Double.parseDouble(Bytes.toString(colValue));
            } catch (NumberFormatException e) {
                String rowkey = Bytes.toString(value.getRow());
                System.err.println("parse pageRank failed for row:" + rowkey);
            }
        }
        return pageRank;
    }

    static HTable initTable(Configuration conf, String tableKey, @SuppressWarnings("rawtypes") Class clazz)
            throws IOException {
        HTable table = null;
        String tableName = conf.get(tableKey);
        Validate.notEmpty(tableName,
                tableKey + " shall be set before running this task:" + clazz.getClass().getName());
        try {
            table = new HTable(conf, tableName);
        } catch (IOException e) {
            System.err.println("initial table:" + tableName + " failed");
            e.printStackTrace(System.err);
            throw e;
        }
        return table;
    }

    /**
     * Set token if authentication enabled.
     * @param job
     */
    static void setAuthenticationToken(Job job, Logger logger) {
        if (User.isSecurityEnabled()) {
            try {
                User.getCurrent().obtainAuthTokenForJob(job.getConfiguration(), job);
            } catch (IOException e) {
                String msg = job.getJobName() + ": Failed to obtain current user.";
                logger.error(msg);
                throw new IllegalStateException(msg, e);
            } catch (InterruptedException ie) {
                logger.warn(job.getJobName() + ": Interrupted obtaining user authentication token");
            }
        }
    }

}