| /** |
| * |
| * 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.hbase.filter; |
| |
| import java.util.Objects; |
| import java.util.Random; |
| |
| import org.apache.hadoop.hbase.Cell; |
| import org.apache.yetus.audience.InterfaceAudience; |
| import org.apache.hadoop.hbase.exceptions.DeserializationException; |
| import org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos; |
| |
| import org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException; |
| |
| /** |
| * A filter that includes rows based on a chance. |
| * |
| */ |
| @InterfaceAudience.Public |
| public class RandomRowFilter extends FilterBase { |
| protected static final Random random = new Random(); |
| |
| protected float chance; |
| protected boolean filterOutRow; |
| |
| /** |
| * Create a new filter with a specified chance for a row to be included. |
| * |
| * @param chance |
| */ |
| public RandomRowFilter(float chance) { |
| this.chance = chance; |
| } |
| |
| /** |
| * @return The chance that a row gets included. |
| */ |
| public float getChance() { |
| return chance; |
| } |
| |
| /** |
| * Set the chance that a row is included. |
| * |
| * @param chance |
| */ |
| public void setChance(float chance) { |
| this.chance = chance; |
| } |
| |
| @Override |
| public boolean filterAllRemaining() { |
| return false; |
| } |
| |
| @Override |
| public ReturnCode filterCell(final Cell c) { |
| if (filterOutRow) { |
| return ReturnCode.NEXT_ROW; |
| } |
| return ReturnCode.INCLUDE; |
| } |
| |
| @Override |
| public boolean filterRow() { |
| return filterOutRow; |
| } |
| |
| @Override |
| public boolean hasFilterRow() { |
| return true; |
| } |
| |
| @Override |
| public boolean filterRowKey(Cell firstRowCell) { |
| if (chance < 0) { |
| // with a zero chance, the rows is always excluded |
| filterOutRow = true; |
| } else if (chance > 1) { |
| // always included |
| filterOutRow = false; |
| } else { |
| // roll the dice |
| filterOutRow = !(random.nextFloat() < chance); |
| } |
| return filterOutRow; |
| } |
| |
| @Override |
| public void reset() { |
| filterOutRow = false; |
| } |
| |
| /** |
| * @return The filter serialized using pb |
| */ |
| @Override |
| public byte [] toByteArray() { |
| FilterProtos.RandomRowFilter.Builder builder = |
| FilterProtos.RandomRowFilter.newBuilder(); |
| builder.setChance(this.chance); |
| return builder.build().toByteArray(); |
| } |
| |
| /** |
| * @param pbBytes A pb serialized {@link RandomRowFilter} instance |
| * @return An instance of {@link RandomRowFilter} made from <code>bytes</code> |
| * @throws DeserializationException |
| * @see #toByteArray |
| */ |
| public static RandomRowFilter parseFrom(final byte [] pbBytes) |
| throws DeserializationException { |
| FilterProtos.RandomRowFilter proto; |
| try { |
| proto = FilterProtos.RandomRowFilter.parseFrom(pbBytes); |
| } catch (InvalidProtocolBufferException e) { |
| throw new DeserializationException(e); |
| } |
| return new RandomRowFilter(proto.getChance()); |
| } |
| |
| /** |
| * @param o the other filter to compare with |
| * @return true if and only if the fields of the filter that are serialized |
| * are equal to the corresponding fields in other. Used for testing. |
| */ |
| @Override |
| boolean areSerializedFieldsEqual(Filter o) { |
| if (o == this) return true; |
| if (!(o instanceof RandomRowFilter)) return false; |
| |
| RandomRowFilter other = (RandomRowFilter)o; |
| return this.getChance() == other.getChance(); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(this.getChance()); |
| } |
| } |