org.apache.hadoop.hdfs.server.protocol.BlocksWithLocations.java Source code

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Here is the source code for org.apache.hadoop.hdfs.server.protocol.BlocksWithLocations.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.hdfs.server.protocol;

import com.google.common.base.Preconditions;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.StorageType;
import org.apache.hadoop.hdfs.protocol.Block;

/**
 * Maintains an array of blocks and their corresponding storage IDs.
 */
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class BlocksWithLocations {

    /**
     * A class to keep track of a block and its locations
     */
    @InterfaceAudience.Private
    @InterfaceStability.Evolving
    public static class BlockWithLocations {
        final Block block;
        final String[] datanodeUuids;
        final String[] storageIDs;
        final StorageType[] storageTypes;

        /** constructor */
        public BlockWithLocations(Block block, String[] datanodeUuids, String[] storageIDs,
                StorageType[] storageTypes) {
            this.block = block;
            this.datanodeUuids = datanodeUuids;
            this.storageIDs = storageIDs;
            this.storageTypes = storageTypes;
        }

        /** get the block */
        public Block getBlock() {
            return block;
        }

        /** get the block's datanode locations */
        public String[] getDatanodeUuids() {
            return datanodeUuids;
        }

        /** get the block's storage locations */
        public String[] getStorageIDs() {
            return storageIDs;
        }

        /** @return the storage types */
        public StorageType[] getStorageTypes() {
            return storageTypes;
        }

        @Override
        public String toString() {
            final StringBuilder b = new StringBuilder();
            b.append(block);
            if (datanodeUuids.length == 0) {
                return b.append("[]").toString();
            }

            appendString(0, b.append("["));
            for (int i = 1; i < datanodeUuids.length; i++) {
                appendString(i, b.append(","));
            }
            return b.append("]").toString();
        }

        private StringBuilder appendString(int i, StringBuilder b) {
            return b.append("[").append(storageTypes[i]).append("]").append(storageIDs[i]).append("@")
                    .append(datanodeUuids[i]);
        }
    }

    public static class StripedBlockWithLocations extends BlockWithLocations {
        final byte[] indices;
        final short dataBlockNum;
        final int cellSize;

        public StripedBlockWithLocations(BlockWithLocations blk, byte[] indices, short dataBlockNum, int cellSize) {
            super(blk.getBlock(), blk.getDatanodeUuids(), blk.getStorageIDs(), blk.getStorageTypes());
            Preconditions.checkArgument(blk.getDatanodeUuids().length == indices.length);
            this.indices = indices;
            this.dataBlockNum = dataBlockNum;
            this.cellSize = cellSize;
        }

        public byte[] getIndices() {
            return indices;
        }

        public short getDataBlockNum() {
            return dataBlockNum;
        }

        public int getCellSize() {
            return cellSize;
        }
    }

    private final BlockWithLocations[] blocks;

    /** Constructor with one parameter */
    public BlocksWithLocations(BlockWithLocations[] blocks) {
        this.blocks = blocks;
    }

    /** getter */
    public BlockWithLocations[] getBlocks() {
        return blocks;
    }
}