io.druid.segment.ColumnSelectorBitmapIndexSelector Maven / Gradle / Ivy
/*
* Licensed to Metamarkets Group Inc. (Metamarkets) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Metamarkets 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 io.druid.segment;
import com.google.common.base.Strings;
import io.druid.collections.bitmap.BitmapFactory;
import io.druid.collections.bitmap.ImmutableBitmap;
import io.druid.collections.spatial.ImmutableRTree;
import io.druid.query.filter.BitmapIndexSelector;
import io.druid.query.monomorphicprocessing.RuntimeShapeInspector;
import io.druid.segment.column.BitmapIndex;
import io.druid.segment.column.Column;
import io.druid.segment.column.DictionaryEncodedColumn;
import io.druid.segment.column.GenericColumn;
import io.druid.segment.column.ValueType;
import io.druid.segment.data.Indexed;
import io.druid.segment.data.IndexedIterable;
import io.druid.segment.filter.Filters;
import java.util.Iterator;
/**
*/
public class ColumnSelectorBitmapIndexSelector implements BitmapIndexSelector
{
private final BitmapFactory bitmapFactory;
private final VirtualColumns virtualColumns;
private final ColumnSelector index;
public ColumnSelectorBitmapIndexSelector(
final BitmapFactory bitmapFactory,
final VirtualColumns virtualColumns,
final ColumnSelector index
)
{
this.bitmapFactory = bitmapFactory;
this.virtualColumns = virtualColumns;
this.index = index;
}
@Override
public Indexed getDimensionValues(String dimension)
{
if (isVirtualColumn(dimension)) {
// Virtual columns don't have dictionaries or indexes.
return null;
}
final Column columnDesc = index.getColumn(dimension);
if (columnDesc == null || !columnDesc.getCapabilities().isDictionaryEncoded()) {
return null;
}
final DictionaryEncodedColumn column = columnDesc.getDictionaryEncoding();
return new Indexed()
{
@Override
public Class getClazz()
{
return String.class;
}
@Override
public int size()
{
return column.getCardinality();
}
@Override
public String get(int index)
{
return column.lookupName(index);
}
@Override
public int indexOf(String value)
{
return column.lookupId(value);
}
@Override
public Iterator iterator()
{
return IndexedIterable.create(this).iterator();
}
@Override
public void inspectRuntimeShape(RuntimeShapeInspector inspector)
{
inspector.visit("column", column);
}
};
}
@Override
public boolean hasMultipleValues(final String dimension)
{
if (isVirtualColumn(dimension)) {
return virtualColumns.getVirtualColumn(dimension).capabilities(dimension).hasMultipleValues();
}
final Column column = index.getColumn(dimension);
return column != null && column.getCapabilities().hasMultipleValues();
}
@Override
public int getNumRows()
{
try (final GenericColumn column = index.getColumn(Column.TIME_COLUMN_NAME).getGenericColumn()) {
return column.length();
}
}
@Override
public BitmapFactory getBitmapFactory()
{
return bitmapFactory;
}
@Override
public BitmapIndex getBitmapIndex(String dimension)
{
if (isVirtualColumn(dimension)) {
// Virtual columns don't have dictionaries or indexes.
return null;
}
final Column column = index.getColumn(dimension);
if (column == null || !columnSupportsFiltering(column)) {
// for missing columns and columns with types that do not support filtering,
// treat the column as if it were a String column full of nulls.
// Create a BitmapIndex so that filters applied to null columns can use
// bitmap indexes. Filters check for the presence of a bitmap index, this is used to determine
// whether the filter is applied in the pre or post filtering stage.
return new BitmapIndex()
{
@Override
public int getCardinality()
{
return 1;
}
@Override
public String getValue(int index)
{
return null;
}
@Override
public boolean hasNulls()
{
return true;
}
@Override
public BitmapFactory getBitmapFactory()
{
return bitmapFactory;
}
@Override
public int getIndex(String value)
{
// Return -2 for non-null values to match what the BitmapIndex implementation in BitmapIndexColumnPartSupplier
// would return for getIndex() when there is only a single index, for the null value.
// i.e., return an 'insertion point' of 1 for non-null values (see BitmapIndex interface)
return Strings.isNullOrEmpty(value) ? 0 : -2;
}
@Override
public ImmutableBitmap getBitmap(int idx)
{
if (idx == 0) {
return bitmapFactory.complement(bitmapFactory.makeEmptyImmutableBitmap(), getNumRows());
} else {
return bitmapFactory.makeEmptyImmutableBitmap();
}
}
};
} else if (column.getCapabilities().hasBitmapIndexes()) {
return column.getBitmapIndex();
} else {
return null;
}
}
@Override
public ImmutableBitmap getBitmapIndex(String dimension, String value)
{
if (isVirtualColumn(dimension)) {
// Virtual columns don't have dictionaries or indexes.
return null;
}
final Column column = index.getColumn(dimension);
if (column == null || !columnSupportsFiltering(column)) {
if (Strings.isNullOrEmpty(value)) {
return bitmapFactory.complement(bitmapFactory.makeEmptyImmutableBitmap(), getNumRows());
} else {
return bitmapFactory.makeEmptyImmutableBitmap();
}
}
if (!column.getCapabilities().hasBitmapIndexes()) {
return null;
}
final BitmapIndex bitmapIndex = column.getBitmapIndex();
return bitmapIndex.getBitmap(bitmapIndex.getIndex(value));
}
@Override
public ImmutableRTree getSpatialIndex(String dimension)
{
if (isVirtualColumn(dimension)) {
return new ImmutableRTree();
}
final Column column = index.getColumn(dimension);
if (column == null || !column.getCapabilities().hasSpatialIndexes()) {
return new ImmutableRTree();
}
return column.getSpatialIndex().getRTree();
}
private boolean isVirtualColumn(final String columnName)
{
return virtualColumns.getVirtualColumn(columnName) != null;
}
private static boolean columnSupportsFiltering(Column column)
{
ValueType columnType = column.getCapabilities().getType();
return Filters.FILTERABLE_TYPES.contains(columnType);
}
}