hadoop FixedBlockResolver 源码
haddop FixedBlockResolver 代码
文件路径：/hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/FixedBlockResolver.java
/**
* 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.namenode;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
/**
* Resolver mapping all files to a configurable, uniform blocksize.
*/
@InterfaceAudience.Public
@InterfaceStability.Unstable
public class FixedBlockResolver extends BlockResolver implements Configurable {
public static final String BLOCKSIZE =
"hdfs.image.writer.resolver.fixed.block.size";
public static final String START_BLOCK =
"hdfs.image.writer.resolver.fixed.block.start";
public static final long BLOCKSIZE_DEFAULT = 256 * (1L << 20);
private Configuration conf;
private long blocksize = 256 * (1L << 20);
private final AtomicLong blockIds = new AtomicLong(0);
@Override
public void setConf(Configuration conf) {
this.conf = conf;
blocksize = conf.getLong(BLOCKSIZE, BLOCKSIZE_DEFAULT);
blockIds.set(conf.getLong(START_BLOCK, (1L << 30)));
}
@Override
public Configuration getConf() {
return conf;
}
@Override
protected List<Long> blockLengths(FileStatus s) {
ArrayList<Long> ret = new ArrayList<>();
if (!s.isFile()) {
return ret;
}
if (0 == s.getLen()) {
// the file has length 0; so we will have one block of size 0
ret.add(0L);
return ret;
}
int nblocks = (int)((s.getLen() - 1) / blocksize) + 1;
for (int i = 0; i < nblocks - 1; ++i) {
ret.add(blocksize);
}
long rem = s.getLen() % blocksize;
ret.add(0 == (rem % blocksize) ? blocksize : rem);
return ret;
}
@Override
public long nextId() {
return blockIds.incrementAndGet();
}
@Override
public long lastId() {
return blockIds.get();
}
@Override
public long preferredBlockSize(FileStatus s) {
return blocksize;
}
@Override
public int getReplication(FileStatus s) {
return 1;
}
}
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