/* * 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; import java.io.IOException; import java.nio.ByteBuffer; import java.util.*; import org.apache.cassandra.config.CFMetaData; import org.apache.cassandra.config.ColumnDefinition; import org.apache.cassandra.db.marshal.AbstractType; import org.apache.cassandra.io.util.*; import org.apache.cassandra.utils.memory.AbstractAllocator; /** * The clustering column values for a row. * <p> * A {@code Clustering} is a {@code ClusteringPrefix} that must always be "complete", i.e. have * as many values as there is clustering columns in the table it is part of. It is the clustering * prefix used by rows. * <p> * Note however that while it's size must be equal to the table clustering size, a clustering can have * {@code null} values, and this mostly for thrift backward compatibility (in practice, if a value is null, * all of the following ones will be too because that's what thrift allows, but it's never assumed by the * code so we could start generally allowing nulls for clustering columns if we wanted to). */ public class Clustering extends AbstractClusteringPrefix { public static final Serializer serializer = new Serializer(); /** * The special cased clustering used by all static rows. It is a special case in the * sense that it's always empty, no matter how many clustering columns the table has. */ public static final Clustering STATIC_CLUSTERING = new Clustering(EMPTY_VALUES_ARRAY) { @Override public Kind kind() { return Kind.STATIC_CLUSTERING; } @Override public String toString() { return "STATIC"; } @Override public String toString(CFMetaData metadata) { return toString(); } }; /** Empty clustering for tables having no clustering columns. */ public static final Clustering EMPTY = new Clustering(EMPTY_VALUES_ARRAY) { @Override public String toString(CFMetaData metadata) { return "EMPTY"; } }; public Clustering(ByteBuffer... values) { super(Kind.CLUSTERING, values); } public Kind kind() { return Kind.CLUSTERING; } public Clustering copy(AbstractAllocator allocator) { // Important for STATIC_CLUSTERING (but no point in being wasteful in general). if (size() == 0) return this; ByteBuffer[] newValues = new ByteBuffer[size()]; for (int i = 0; i < size(); i++) newValues[i] = values[i] == null ? null : allocator.clone(values[i]); return new Clustering(newValues); } public String toString(CFMetaData metadata) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < size(); i++) { ColumnDefinition c = metadata.clusteringColumns().get(i); sb.append(i == 0 ? "" : ", ").append(c.name).append('=').append(get(i) == null ? "null" : c.type.getString(get(i))); } return sb.toString(); } public String toCQLString(CFMetaData metadata) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < size(); i++) { ColumnDefinition c = metadata.clusteringColumns().get(i); sb.append(i == 0 ? "" : ", ").append(c.type.getString(get(i))); } return sb.toString(); } /** * Serializer for Clustering object. * <p> * Because every clustering in a given table must have the same size (ant that size cannot actually change once the table * has been defined), we don't record that size. */ public static class Serializer { public void serialize(Clustering clustering, DataOutputPlus out, int version, List<AbstractType<?>> types) throws IOException { assert clustering != STATIC_CLUSTERING : "We should never serialize a static clustering"; assert clustering.size() == types.size() : "Invalid clustering for the table: " + clustering; ClusteringPrefix.serializer.serializeValuesWithoutSize(clustering, out, version, types); } public ByteBuffer serialize(Clustering clustering, int version, List<AbstractType<?>> types) { try (DataOutputBuffer buffer = new DataOutputBuffer((int)serializedSize(clustering, version, types))) { serialize(clustering, buffer, version, types); return buffer.buffer(); } catch (IOException e) { throw new RuntimeException("Writting to an in-memory buffer shouldn't trigger an IOException", e); } } public long serializedSize(Clustering clustering, int version, List<AbstractType<?>> types) { return ClusteringPrefix.serializer.valuesWithoutSizeSerializedSize(clustering, version, types); } public Clustering deserialize(DataInputPlus in, int version, List<AbstractType<?>> types) throws IOException { if (types.isEmpty()) return EMPTY; ByteBuffer[] values = ClusteringPrefix.serializer.deserializeValuesWithoutSize(in, types.size(), version, types); return new Clustering(values); } public Clustering deserialize(ByteBuffer in, int version, List<AbstractType<?>> types) { try (DataInputBuffer buffer = new DataInputBuffer(in, true)) { return deserialize(buffer, version, types); } catch (IOException e) { throw new RuntimeException("Reading from an in-memory buffer shouldn't trigger an IOException", e); } } } }