| /** |
| * 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.protocol; |
| |
| import java.io.*; |
| |
| import org.apache.hadoop.hdfs.server.common.GenerationStamp; |
| import org.apache.hadoop.io.*; |
| |
| /************************************************** |
| * A Block is a Hadoop FS primitive, identified by a |
| * long. |
| * |
| **************************************************/ |
| public class Block implements Writable, Comparable<Block> { |
| |
| static { // register a ctor |
| WritableFactories.setFactory |
| (Block.class, |
| new WritableFactory() { |
| public Writable newInstance() { return new Block(); } |
| }); |
| } |
| |
| // generation stamp of blocks that pre-date the introduction of |
| // a generation stamp. |
| public static final long GRANDFATHER_GENERATION_STAMP = 0; |
| |
| /** |
| */ |
| public static boolean isBlockFilename(File f) { |
| String name = f.getName(); |
| if ( name.startsWith( "blk_" ) && |
| name.indexOf( '.' ) < 0 ) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| static long filename2id(String name) { |
| return Long.parseLong(name.substring("blk_".length())); |
| } |
| |
| private long blockId; |
| private long numBytes; |
| private long generationStamp; |
| |
| public Block() {this(0, 0, 0);} |
| |
| public Block(final long blkid, final long len, final long generationStamp) { |
| set(blkid, len, generationStamp); |
| } |
| |
| public Block(final long blkid) {this(blkid, 0, GenerationStamp.WILDCARD_STAMP);} |
| |
| public Block(Block blk) {this(blk.blockId, blk.numBytes, blk.generationStamp);} |
| |
| /** |
| * Find the blockid from the given filename |
| */ |
| public Block(File f, long len, long genstamp) { |
| this(filename2id(f.getName()), len, genstamp); |
| } |
| |
| public void set(long blkid, long len, long genStamp) { |
| this.blockId = blkid; |
| this.numBytes = len; |
| this.generationStamp = genStamp; |
| } |
| /** |
| */ |
| public long getBlockId() { |
| return blockId; |
| } |
| |
| public void setBlockId(long bid) { |
| blockId = bid; |
| } |
| |
| /** |
| */ |
| public String getBlockName() { |
| return "blk_" + String.valueOf(blockId); |
| } |
| |
| /** |
| */ |
| public long getNumBytes() { |
| return numBytes; |
| } |
| public void setNumBytes(long len) { |
| this.numBytes = len; |
| } |
| |
| public long getGenerationStamp() { |
| return generationStamp; |
| } |
| |
| public void setGenerationStamp(long stamp) { |
| generationStamp = stamp; |
| } |
| |
| /** |
| */ |
| public String toString() { |
| return getBlockName() + "_" + getGenerationStamp(); |
| } |
| |
| ///////////////////////////////////// |
| // Writable |
| ///////////////////////////////////// |
| public void write(DataOutput out) throws IOException { |
| out.writeLong(blockId); |
| out.writeLong(numBytes); |
| out.writeLong(generationStamp); |
| } |
| |
| public void readFields(DataInput in) throws IOException { |
| this.blockId = in.readLong(); |
| this.numBytes = in.readLong(); |
| this.generationStamp = in.readLong(); |
| if (numBytes < 0) { |
| throw new IOException("Unexpected block size: " + numBytes); |
| } |
| } |
| |
| ///////////////////////////////////// |
| // Comparable |
| ///////////////////////////////////// |
| static void validateGenerationStamp(long generationstamp) { |
| if (generationstamp == GenerationStamp.WILDCARD_STAMP) { |
| throw new IllegalStateException("generationStamp (=" + generationstamp |
| + ") == GenerationStamp.WILDCARD_STAMP"); |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| public int compareTo(Block b) { |
| //Wildcard generationStamp is NOT ALLOWED here |
| validateGenerationStamp(this.generationStamp); |
| validateGenerationStamp(b.generationStamp); |
| |
| if (blockId < b.blockId) { |
| return -1; |
| } else if (blockId == b.blockId) { |
| return GenerationStamp.compare(generationStamp, b.generationStamp); |
| } else { |
| return 1; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| public boolean equals(Object o) { |
| if (!(o instanceof Block)) { |
| return false; |
| } |
| final Block that = (Block)o; |
| //Wildcard generationStamp is ALLOWED here |
| return this.blockId == that.blockId |
| && GenerationStamp.equalsWithWildcard( |
| this.generationStamp, that.generationStamp); |
| } |
| |
| /** {@inheritDoc} */ |
| public int hashCode() { |
| //GenerationStamp is IRRELEVANT and should not be used here |
| return 37 * 17 + (int) (blockId^(blockId>>>32)); |
| } |
| } |