/*
* 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.index.composites;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.config.ColumnDefinition;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.composites.CBuilder;
import org.apache.cassandra.db.composites.CellName;
import org.apache.cassandra.db.composites.CellNameType;
import org.apache.cassandra.db.composites.Composite;
import org.apache.cassandra.db.composites.CompoundDenseCellNameType;
import org.apache.cassandra.db.index.SecondaryIndex;
import org.apache.cassandra.db.marshal.*;
/**
* Index the value of a collection cell.
*
* This is a lot like an index on REGULAR, except that we also need to make
* the collection key part of the index entry so that:
* 1) we don't have to scan the whole collection at query time to know the
* entry is stale and if it still satisfies the query.
* 2) if a collection has multiple time the same value, we need one entry
* for each so that if we delete one of the value only we only delete the
* entry corresponding to that value.
*/
public class CompositesIndexOnCollectionValue extends CompositesIndex
{
public static CellNameType buildIndexComparator(CFMetaData baseMetadata, ColumnDefinition columnDef)
{
int prefixSize = columnDef.position();
List<AbstractType<?>> types = new ArrayList<>(prefixSize + 2);
types.add(SecondaryIndex.keyComparator);
for (int i = 0; i < prefixSize; i++)
types.add(baseMetadata.comparator.subtype(i));
types.add(((CollectionType)columnDef.type).nameComparator()); // collection key
return new CompoundDenseCellNameType(types);
}
@Override
protected AbstractType<?> getIndexKeyComparator()
{
return ((CollectionType)columnDef.type).valueComparator();
}
protected ByteBuffer getIndexedValue(ByteBuffer rowKey, Cell cell)
{
return cell.value();
}
protected Composite makeIndexColumnPrefix(ByteBuffer rowKey, Composite cellName)
{
CBuilder builder = getIndexComparator().prefixBuilder();
builder.add(rowKey);
for (int i = 0; i < Math.min(columnDef.position(), cellName.size()); i++)
builder.add(cellName.get(i));
// When indexing, cellName is a full name including the collection
// key. When searching, restricted clustering columns are included
// but the collection key is not. In this case, don't try to add an
// element to the builder for it, as it will just end up null and
// error out when retrieving cells from the index cf (CASSANDRA-7525)
if (cellName.size() >= columnDef.position() + 1)
builder.add(cellName.get(columnDef.position() + 1));
return builder.build();
}
public IndexedEntry decodeEntry(DecoratedKey indexedValue, Cell indexEntry)
{
int prefixSize = columnDef.position();
CellName name = indexEntry.name();
CBuilder builder = baseCfs.getComparator().builder();
for (int i = 0; i < prefixSize; i++)
builder.add(name.get(i + 1));
return new IndexedEntry(indexedValue, name, indexEntry.timestamp(), name.get(0), builder.build(), name.get(prefixSize + 1));
}
@Override
public boolean indexes(CellName name)
{
AbstractType<?> comp = baseCfs.metadata.getColumnDefinitionComparator(columnDef);
return name.size() > columnDef.position()
&& comp.compare(name.get(columnDef.position()), columnDef.name.bytes) == 0;
}
public boolean isStale(IndexedEntry entry, ColumnFamily data, long now)
{
CellName name = data.getComparator().create(entry.indexedEntryPrefix, columnDef, entry.indexedEntryCollectionKey);
Cell cell = data.getColumn(name);
return cell == null || !cell.isLive(now) || ((CollectionType) columnDef.type).valueComparator().compare(entry.indexValue.getKey(), cell.value()) != 0;
}
}