hadoop ErasureCodingPolicy 源码

  • 2022-10-20
  • 浏览 (19)

haddop ErasureCodingPolicy 代码

文件路径:/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/ErasureCodingPolicy.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.protocol;

import org.apache.hadoop.util.Preconditions;
import org.apache.commons.lang3.builder.EqualsBuilder;
import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.io.erasurecode.ECSchema;
import org.apache.hadoop.io.erasurecode.ErasureCodeConstants;

import java.io.Serializable;

/**
 * A policy about how to write/read/code an erasure coding file.
 * <p>
 * Note this class should be lightweight and immutable, because it's cached
 * by {@link SystemErasureCodingPolicies}, to be returned as a part of
 * {@link HdfsFileStatus}.
 */
@InterfaceAudience.Private
public final class ErasureCodingPolicy implements Serializable {

  private static final long serialVersionUID = 0x0079fe4e;

  private final String name;
  private final ECSchema schema;
  private final int cellSize;
  private final byte id;

  public ErasureCodingPolicy(String name, ECSchema schema,
      int cellSize, byte id) {
    Preconditions.checkNotNull(name);
    Preconditions.checkNotNull(schema);
    Preconditions.checkArgument(cellSize > 0, "cellSize must be positive");
    Preconditions.checkArgument(cellSize % 1024 == 0,
        "cellSize must be 1024 aligned");
    this.name = name;
    this.schema = schema;
    this.cellSize = cellSize;
    this.id = id;
  }

  public ErasureCodingPolicy(ECSchema schema, int cellSize, byte id) {
    this(composePolicyName(schema, cellSize), schema, cellSize, id);
  }

  public ErasureCodingPolicy(ECSchema schema, int cellSize) {
    this(composePolicyName(schema, cellSize), schema, cellSize, (byte) -1);
  }

  public static String composePolicyName(ECSchema schema, int cellSize) {
    Preconditions.checkNotNull(schema);
    Preconditions.checkArgument(cellSize > 0, "cellSize must be positive");
    Preconditions.checkArgument(cellSize % 1024 == 0,
        "cellSize must be 1024 aligned");
    return schema.getCodecName().toUpperCase() + "-" +
        schema.getNumDataUnits() + "-" + schema.getNumParityUnits() +
        "-" + cellSize / 1024 + "k";
  }

  public String getName() {
    return name;
  }

  public ECSchema getSchema() {
    return schema;
  }

  public int getCellSize() {
    return cellSize;
  }

  public int getNumDataUnits() {
    return schema.getNumDataUnits();
  }

  public int getNumParityUnits() {
    return schema.getNumParityUnits();
  }

  public String getCodecName() {
    return schema.getCodecName();
  }

  public byte getId() {
    return id;
  }

  public boolean isReplicationPolicy() {
    return (id == ErasureCodeConstants.REPLICATION_POLICY_ID);
  }

  public boolean isSystemPolicy() {
    return (this.id < ErasureCodeConstants.USER_DEFINED_POLICY_START_ID);
  }

  @Override
  public boolean equals(Object o) {
    if (o == null) {
      return false;
    }
    if (o == this) {
      return true;
    }
    if (o.getClass() != getClass()) {
      return false;
    }
    ErasureCodingPolicy rhs = (ErasureCodingPolicy) o;
    return new EqualsBuilder()
        .append(name, rhs.name)
        .append(schema, rhs.schema)
        .append(cellSize, rhs.cellSize)
        .append(id, rhs.id)
        .isEquals();
  }

  @Override
  public int hashCode() {
    return new HashCodeBuilder(303855623, 582626729)
        .append(name)
        .append(schema)
        .append(cellSize)
        .append(id)
        .toHashCode();
  }

  @Override
  public String toString() {
    return "ErasureCodingPolicy=[" + "Name=" + name + ", "
        + "Schema=[" + schema.toString() + "], "
        + "CellSize=" + cellSize + ", "
        + "Id=" + id
        + "]";
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AclException 源码

hadoop AddErasureCodingPolicyResponse 源码

hadoop AlreadyBeingCreatedException 源码

hadoop BatchedDirectoryListing 源码

hadoop Block 源码

hadoop BlockChecksumOptions 源码

hadoop BlockChecksumType 源码

hadoop BlockLocalPathInfo 源码

hadoop BlockStoragePolicy 源码

hadoop BlockType 源码

0  赞