org.apache.cassandra.index.internal.composites.CollectionKeyIndexBase Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
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package org.apache.cassandra.index.internal.composites;
import java.nio.ByteBuffer;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.rows.CellPath;
import org.apache.cassandra.db.rows.Row;
import org.apache.cassandra.index.internal.CassandraIndex;
import org.apache.cassandra.index.internal.IndexEntry;
import org.apache.cassandra.schema.IndexMetadata;
/**
* Common superclass for indexes that capture collection keys, including
* indexes on such keys themselves.
*
* A cell indexed by this index will have the general form:
* ck_0 ... ck_n c_name [col_elt] : v
* where ck_i are the cluster keys, c_name the CQL3 column name, col_elt the
* collection element that we want to index (which may or may not be there depending
* on whether c_name is the collection we're indexing), and v the cell value.
*
* Such a cell is indexed if c_name is the indexed collection (in which case we are guaranteed to have
* col_elt). The index entry can be viewed in the following way:
* - the row key is determined by subclasses of this type.
* - the cell name will be 'rk ck_0 ... ck_n' where rk is the row key of the initial cell.
*/
public abstract class CollectionKeyIndexBase extends CassandraIndex
{
public CollectionKeyIndexBase(ColumnFamilyStore baseCfs, IndexMetadata indexDef)
{
super(baseCfs, indexDef);
}
public CBuilder buildIndexClusteringPrefix(ByteBuffer partitionKey,
ClusteringPrefix prefix,
CellPath path)
{
CBuilder builder = CBuilder.create(getIndexComparator());
builder.add(partitionKey);
// When indexing a static column, prefix will be empty but only the
// partition key is needed at query time.
for (int i = 0; i < prefix.size(); i++)
builder.add(prefix.get(i));
return builder;
}
public IndexEntry decodeEntry(DecoratedKey indexedValue,
Row indexEntry)
{
Clustering clustering = indexEntry.clustering();
Clustering indexedEntryClustering = null;
if (getIndexedColumn().isStatic())
indexedEntryClustering = Clustering.STATIC_CLUSTERING;
else
{
int count = 1 + baseCfs.metadata.clusteringColumns().size();
CBuilder builder = CBuilder.create(baseCfs.getComparator());
for (int i = 0; i < count - 1; i++)
builder.add(clustering.get(i + 1));
indexedEntryClustering = builder.build();
}
return new IndexEntry(indexedValue,
clustering,
indexEntry.primaryKeyLivenessInfo().timestamp(),
clustering.get(0),
indexedEntryClustering);
}
}