org.apache.hadoop.hbase.index.IndexedHTableDescriptor.java Source code

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Here is the source code for org.apache.hadoop.hbase.index.IndexedHTableDescriptor.java

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/**
 * Copyright 2011 The Apache Software 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 org.apache.hadoop.hbase.index;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.EOFException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.HTableDescriptor;

/**
 * IndexedHTabledDescriptor is extension of HTableDescriptor. This contains indices to specify index
 * name and column details. There can be one or more indices on one table. For each of the index on
 * the table and IndexSpecification is to be created and added to the indices.
 */
public class IndexedHTableDescriptor extends HTableDescriptor {

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

    private List<IndexSpecification> indices = new ArrayList<IndexSpecification>(1);

    public IndexedHTableDescriptor() {

    }

    public IndexedHTableDescriptor(String tableName) {
        super(tableName);
    }

    public IndexedHTableDescriptor(byte[] tableName) {
        super(tableName);
    }

    /**
     * @param IndexSpecification to be added to indices
     * @throws IllegalArgumentException if duplicate indexes for same table
     */
    public void addIndex(IndexSpecification iSpec) throws IllegalArgumentException {
        String indexName = iSpec.getName();
        if (null == indexName) {
            String message = "Index name should not be null in Index Specification.";
            LOG.error(message);
            throw new IllegalArgumentException(message);
        }
        if (true == StringUtils.isBlank(indexName)) {
            String message = "Index name should not be blank in Index Specification.";
            LOG.error(message);
            throw new IllegalArgumentException(message);
        }
        if (indexName.length() > Constants.DEF_MAX_INDEX_NAME_LENGTH) {
            String message = "Index name length should not more than " + Constants.DEF_MAX_INDEX_NAME_LENGTH + '.';
            LOG.error(message);
            throw new IllegalArgumentException(message);
        }
        for (IndexSpecification is : indices) {
            if (is.getName().equals(indexName)) {
                String message = "Duplicate index names should not be present for same table.";
                LOG.error(message);
                throw new IllegalArgumentException(message);
            }
        }
        indices.add(iSpec);
    }

    /**
     * @return IndexSpecification list
     */
    public List<IndexSpecification> getIndices() {
        return (new ArrayList<IndexSpecification>(this.indices));
    }

    /**
     * @param DataOutput stream
     */
    public void write(DataOutput out) throws IOException {
        super.write(out);
        out.writeInt(this.indices.size());
        for (IndexSpecification index : indices) {
            index.write(out);
        }
    }

    /**
     * @param DataInput stream
     * @throws IOException
     */
    public void readFields(DataInput in) throws IOException {
        try {
            super.readFields(in);
            int indicesSize = in.readInt();
            indices.clear();
            for (int i = 0; i < indicesSize; i++) {
                IndexSpecification is = new IndexSpecification();
                is.readFields(in);
                this.indices.add(is);
            }
        } catch (EOFException e) {
            LOG.warn("Error reading feilds from the descriptor " + this.getNameAsString());
            throw e;
        }

    }

}