org.apache.phoenix.mapreduce.util.ColumnInfoToStringEncoderDecoder.java Source code

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Here is the source code for org.apache.phoenix.mapreduce.util.ColumnInfoToStringEncoderDecoder.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.phoenix.mapreduce.util;

import java.util.List;

import org.apache.hadoop.conf.Configuration;
import org.apache.phoenix.util.ColumnInfo;

import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;

/**
 * A codec to transform a {@link ColumnInfo} to a {@link String} and decode back.
 */
public class ColumnInfoToStringEncoderDecoder {

    static final String CONFIGURATION_VALUE_PREFIX = "phoenix.colinfo.encoder.decoeder.value";
    static final String CONFIGURATION_COUNT = "phoenix.colinfo.encoder.decoder.count";

    private ColumnInfoToStringEncoderDecoder() {

    }

    public static void encode(Configuration configuration, List<ColumnInfo> columnInfos) {
        Preconditions.checkNotNull(configuration);
        Preconditions.checkNotNull(columnInfos);
        int count = 0;
        for (int i = 0; i < columnInfos.size(); ++i) {
            if (columnInfos.get(i) != null) {
                configuration.set(String.format("%s_%d", CONFIGURATION_VALUE_PREFIX, i),
                        columnInfos.get(i).toString());
                ++count;
            }
        }
        configuration.setInt(CONFIGURATION_COUNT, count);
    }

    public static List<ColumnInfo> decode(Configuration configuration) {
        Preconditions.checkNotNull(configuration);
        int numCols = configuration.getInt(CONFIGURATION_COUNT, 0);
        List<ColumnInfo> columnInfos = Lists.newArrayListWithExpectedSize(numCols);
        for (int i = 0; i < numCols; ++i) {
            columnInfos.add(ColumnInfo
                    .fromString(configuration.get(String.format("%s_%d", CONFIGURATION_VALUE_PREFIX, i))));
        }
        return columnInfos;
    }

}