com.mozilla.bagheera.util.IdUtil.java Source code

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Here is the source code for com.mozilla.bagheera.util.IdUtil.java

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/*
 * Copyright 2011 Mozilla Foundation
 *
 * 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 com.mozilla.bagheera.util;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import org.apache.commons.lang.StringUtils;

/**
 * Utility class for id generation and bucketing
 */
public class IdUtil {

    public static final SimpleDateFormat SDF = new SimpleDateFormat("yyyyMMdd");

    /**
     * @param id
     * @param timestamp
     * @return
     * @throws IOException
     */
    public static byte[] bucketizeId(String id, long timestamp) throws IOException {
        if (id == null) {
            throw new IllegalArgumentException("id cannot be null");
        }

        return nonRandByteBucketizeId(id, new Date(timestamp));
    }

    /**
     * Takes a given id and prefixes it with a byte character and the date in a non-random fashion
     * This method expects id to be something like a UUID consisting only of hex characters.  If id 
     * is something else this will produce unpredictable results.
     * @param id
     * @param d
     * @return
     * @throws IOException
     */
    public static byte[] nonRandByteBucketizeId(String id, Date d) throws IOException {
        if (StringUtils.isBlank(id)) {
            throw new IllegalArgumentException("id cannot be null or empty");
        }
        if (d == null) {
            throw new IllegalArgumentException("date cannot be null");
        }

        // bucket byte + SDF bytes + id bytes
        ByteBuffer buf = ByteBuffer.allocate(9 + id.length());
        int bucket = 0;
        if (id.length() >= 2) {
            // Munge two hex characters into the range of a single byte
            bucket = Integer.parseInt(id.substring(0, 2), 16) - 128;
        } else {
            bucket = Integer.parseInt(id, 16) - 128;
        }
        buf.put((byte) bucket);
        buf.put(SDF.format(d).getBytes());
        buf.put(id.getBytes());

        return buf.array();
    }

    /**
     * Takes a given id and gives you an hbase shell compatible string that you can
     * use for get command.
     * @param id
     * @param d
     * @return
     * @throws IOException
     */
    public static String hbaseShellId(String id, Date d) throws IOException {
        byte[] idBytes = IdUtil.nonRandByteBucketizeId(id, d);
        StringBuilder sb = new StringBuilder("\"\\x");
        sb.append(String.format("%02x", idBytes[0]));
        sb.append((new String(idBytes)).substring(1));
        sb.append("\"");
        return sb.toString();
    }

    public static String hbaseShellId(byte[] idBytes) throws IOException {
        StringBuilder sb = new StringBuilder("\"\\x");
        sb.append(String.format("%02x", idBytes[0]));
        sb.append((new String(idBytes)).substring(1));
        sb.append("\"");
        return sb.toString();
    }

    public static void main(String[] args) throws IOException {
        String id = "06b87727-2946-4b1e-b654-8bafb60bb995";
        long timestamp = 1360493115891L;
        Calendar cal = Calendar.getInstance();
        //cal.set(2013, Calendar.FEBRUARY, 10);
        cal.setTimeInMillis(timestamp);
        System.out.println(IdUtil.hbaseShellId(id, cal.getTime()));
    }
}