| /* |
| * 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.cassandra.io.sstable.metadata; |
| |
| import java.io.IOException; |
| |
| import com.clearspring.analytics.stream.cardinality.HyperLogLogPlus; |
| import com.clearspring.analytics.stream.cardinality.ICardinality; |
| |
| import org.apache.cassandra.db.TypeSizes; |
| import org.apache.cassandra.io.sstable.format.Version; |
| import org.apache.cassandra.io.util.DataInputPlus; |
| import org.apache.cassandra.io.util.DataOutputPlus; |
| import org.apache.cassandra.utils.ByteBufferUtil; |
| |
| /** |
| * Compaction related SSTable metadata. |
| * |
| * Only loaded for <b>compacting</b> SSTables at the time of compaction. |
| */ |
| public class CompactionMetadata extends MetadataComponent |
| { |
| public static final IMetadataComponentSerializer serializer = new CompactionMetadataSerializer(); |
| |
| public final ICardinality cardinalityEstimator; |
| |
| public CompactionMetadata(ICardinality cardinalityEstimator) |
| { |
| this.cardinalityEstimator = cardinalityEstimator; |
| } |
| |
| public MetadataType getType() |
| { |
| return MetadataType.COMPACTION; |
| } |
| |
| @Override |
| public boolean equals(Object o) |
| { |
| if (this == o) |
| return true; |
| |
| if (o == null || getClass() != o.getClass()) |
| return false; |
| |
| // keeping equals and hashCode as all classes inheriting from MetadataComponent |
| // implement them but we have really nothing to compare |
| return true; |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| // see comment in equals |
| return 31; |
| } |
| |
| public static class CompactionMetadataSerializer implements IMetadataComponentSerializer<CompactionMetadata> |
| { |
| public int serializedSize(Version version, CompactionMetadata component) throws IOException |
| { |
| int sz = 0; |
| if (version.hasCompactionAncestors()) |
| { // write empty ancestor marker |
| sz = 4; |
| } |
| byte[] serializedCardinality = component.cardinalityEstimator.getBytes(); |
| return TypeSizes.sizeof(serializedCardinality.length) + serializedCardinality.length + sz; |
| } |
| |
| public void serialize(Version version, CompactionMetadata component, DataOutputPlus out) throws IOException |
| { |
| if (version.hasCompactionAncestors()) |
| { // write empty ancestor marker |
| out.writeInt(0); |
| } |
| ByteBufferUtil.writeWithLength(component.cardinalityEstimator.getBytes(), out); |
| } |
| |
| public CompactionMetadata deserialize(Version version, DataInputPlus in) throws IOException |
| { |
| if (version.hasCompactionAncestors()) |
| { // skip ancestors |
| int nbAncestors = in.readInt(); |
| in.skipBytes(nbAncestors * TypeSizes.sizeof(nbAncestors)); |
| } |
| ICardinality cardinality = HyperLogLogPlus.Builder.build(ByteBufferUtil.readBytes(in, in.readInt())); |
| return new CompactionMetadata(cardinality); |
| } |
| } |
| } |