001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs.protocol;
019
020import org.apache.hadoop.classification.InterfaceAudience;
021import org.apache.hadoop.classification.InterfaceStability;
022import org.apache.hadoop.io.erasurecode.ECSchema;
023
024/**
025 * A policy about how to write/read/code an erasure coding file.
026 */
027@InterfaceAudience.Public
028@InterfaceStability.Evolving
029public final class ErasureCodingPolicy {
030
031  private final String name;
032  private final ECSchema schema;
033  private final int cellSize;
034
035  public ErasureCodingPolicy(String name, ECSchema schema, int cellSize){
036    this.name = name;
037    this.schema = schema;
038    this.cellSize = cellSize;
039  }
040
041  public String getName() {
042    return name;
043  }
044
045  public ECSchema getSchema() {
046    return schema;
047  }
048
049  public int getCellSize() {
050    return cellSize;
051  }
052
053  public int getNumDataUnits() {
054    return schema.getNumDataUnits();
055  }
056
057  public int getNumParityUnits() {
058    return schema.getNumParityUnits();
059  }
060
061  @Override
062  public boolean equals(Object o) {
063    if (this == o) {
064      return true;
065    }
066    if (o == null || getClass() != o.getClass()) {
067      return false;
068    }
069    ErasureCodingPolicy that = (ErasureCodingPolicy) o;
070
071    return that.getName().equals(name) &&
072        that.getCellSize() == cellSize &&
073        that.getSchema().equals(schema);
074  }
075
076  @Override
077  public int hashCode() {
078    int result = name.hashCode();
079    result = 31 * result + schema.hashCode();
080    result = 31 * result + cellSize;
081    return result;
082  }
083
084  @Override
085  public String toString() {
086    return "ErasureCodingPolicy=[" + "Name=" + name + ", "
087        + "Schema=[" + schema.toString() + "], "
088        + "CellSize=" + cellSize + " " + "]";
089  }
090}