| /* |
| * 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.db.aggregation; |
| |
| import java.io.IOException; |
| |
| import org.apache.cassandra.db.ClusteringComparator; |
| import org.apache.cassandra.db.TypeSizes; |
| import org.apache.cassandra.io.util.DataInputPlus; |
| import org.apache.cassandra.io.util.DataOutputPlus; |
| |
| /** |
| * Defines how rows should be grouped for creating aggregates. |
| */ |
| public abstract class AggregationSpecification |
| { |
| public static final Serializer serializer = new Serializer(); |
| |
| /** |
| * <code>AggregationSpecification</code> that group all the row together. |
| */ |
| public static final AggregationSpecification AGGREGATE_EVERYTHING = new AggregationSpecification(Kind.AGGREGATE_EVERYTHING) |
| { |
| @Override |
| public GroupMaker newGroupMaker(GroupingState state) |
| { |
| return GroupMaker.GROUP_EVERYTHING; |
| } |
| }; |
| |
| /** |
| * The <code>AggregationSpecification</code> kind. |
| */ |
| private final Kind kind; |
| |
| /** |
| * The <code>AggregationSpecification</code> kinds. |
| */ |
| public static enum Kind |
| { |
| AGGREGATE_EVERYTHING, AGGREGATE_BY_PK_PREFIX |
| } |
| |
| /** |
| * Returns the <code>AggregationSpecification</code> kind. |
| * @return the <code>AggregationSpecification</code> kind |
| */ |
| public Kind kind() |
| { |
| return kind; |
| } |
| |
| private AggregationSpecification(Kind kind) |
| { |
| this.kind = kind; |
| } |
| |
| /** |
| * Creates a new <code>GroupMaker</code> instance. |
| * |
| * @return a new <code>GroupMaker</code> instance |
| */ |
| public final GroupMaker newGroupMaker() |
| { |
| return newGroupMaker(GroupingState.EMPTY_STATE); |
| } |
| |
| /** |
| * Creates a new <code>GroupMaker</code> instance. |
| * |
| * @param state <code>GroupMaker</code> state |
| * @return a new <code>GroupMaker</code> instance |
| */ |
| public abstract GroupMaker newGroupMaker(GroupingState state); |
| |
| /** |
| * Creates a new <code>AggregationSpecification</code> instance that will build aggregates based on primary key |
| * columns. |
| * |
| * @param comparator the comparator used to compare the clustering prefixes |
| * @param clusteringPrefixSize the number of clustering columns used to create the aggregates |
| * @return a new <code>AggregationSpecification</code> instance that will build aggregates based on primary key |
| * columns |
| */ |
| public static AggregationSpecification aggregatePkPrefix(ClusteringComparator comparator, int clusteringPrefixSize) |
| { |
| return new AggregateByPkPrefix(comparator, clusteringPrefixSize); |
| } |
| |
| /** |
| * <code>AggregationSpecification</code> that build aggregates based on primary key columns |
| */ |
| private static final class AggregateByPkPrefix extends AggregationSpecification |
| { |
| /** |
| * The number of clustering component to compare. |
| */ |
| private final int clusteringPrefixSize; |
| |
| /** |
| * The comparator used to compare the clustering prefixes. |
| */ |
| private final ClusteringComparator comparator; |
| |
| public AggregateByPkPrefix(ClusteringComparator comparator, int clusteringPrefixSize) |
| { |
| super(Kind.AGGREGATE_BY_PK_PREFIX); |
| this.comparator = comparator; |
| this.clusteringPrefixSize = clusteringPrefixSize; |
| } |
| |
| @Override |
| public GroupMaker newGroupMaker(GroupingState state) |
| { |
| return GroupMaker.newInstance(comparator, clusteringPrefixSize, state); |
| } |
| } |
| |
| public static class Serializer |
| { |
| public void serialize(AggregationSpecification aggregationSpec, DataOutputPlus out, int version) throws IOException |
| { |
| out.writeByte(aggregationSpec.kind().ordinal()); |
| switch (aggregationSpec.kind()) |
| { |
| case AGGREGATE_EVERYTHING: |
| break; |
| case AGGREGATE_BY_PK_PREFIX: |
| out.writeUnsignedVInt(((AggregateByPkPrefix) aggregationSpec).clusteringPrefixSize); |
| break; |
| default: |
| throw new AssertionError(); |
| } |
| } |
| |
| public AggregationSpecification deserialize(DataInputPlus in, int version, ClusteringComparator comparator) throws IOException |
| { |
| Kind kind = Kind.values()[in.readUnsignedByte()]; |
| switch (kind) |
| { |
| case AGGREGATE_EVERYTHING: |
| return AggregationSpecification.AGGREGATE_EVERYTHING; |
| case AGGREGATE_BY_PK_PREFIX: |
| int clusteringPrefixSize = (int) in.readUnsignedVInt(); |
| return AggregationSpecification.aggregatePkPrefix(comparator, clusteringPrefixSize); |
| default: |
| throw new AssertionError(); |
| } |
| } |
| |
| public long serializedSize(AggregationSpecification aggregationSpec, int version) |
| { |
| long size = TypeSizes.sizeof((byte) aggregationSpec.kind().ordinal()); |
| switch (aggregationSpec.kind()) |
| { |
| case AGGREGATE_EVERYTHING: |
| break; |
| case AGGREGATE_BY_PK_PREFIX: |
| size += TypeSizes.sizeofUnsignedVInt(((AggregateByPkPrefix) aggregationSpec).clusteringPrefixSize); |
| break; |
| default: |
| throw new AssertionError(); |
| } |
| return size; |
| } |
| } |
| } |