| /* |
| * 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.druid.segment; |
| |
| import com.google.common.base.Predicate; |
| import org.apache.druid.common.config.NullHandling; |
| import org.apache.druid.query.filter.ValueMatcher; |
| import org.apache.druid.query.monomorphicprocessing.RuntimeShapeInspector; |
| import org.apache.druid.segment.data.IndexedInts; |
| import org.apache.druid.segment.data.ZeroIndexedInts; |
| import org.apache.druid.segment.filter.BooleanValueMatcher; |
| import org.apache.druid.segment.historical.SingleValueHistoricalDimensionSelector; |
| |
| import javax.annotation.Nullable; |
| import java.util.Objects; |
| |
| public class ConstantDimensionSelector implements SingleValueHistoricalDimensionSelector, IdLookup |
| { |
| private final String value; |
| |
| public ConstantDimensionSelector(final String value) |
| { |
| if (NullHandling.isNullOrEquivalent(value)) { |
| // There's an optimized implementation for nulls that callers should use instead. |
| throw new IllegalArgumentException("Use DimensionSelector.constant(null)"); |
| } |
| |
| this.value = value; |
| } |
| |
| @Override |
| public IndexedInts getRow() |
| { |
| return ZeroIndexedInts.instance(); |
| } |
| |
| @Override |
| public int getRowValue(int offset) |
| { |
| return 0; |
| } |
| |
| @Override |
| public IndexedInts getRow(int offset) |
| { |
| return getRow(); |
| } |
| |
| @Override |
| public ValueMatcher makeValueMatcher(String matchValue) |
| { |
| return BooleanValueMatcher.of(Objects.equals(value, matchValue)); |
| } |
| |
| @Override |
| public ValueMatcher makeValueMatcher(Predicate<String> predicate) |
| { |
| return BooleanValueMatcher.of(predicate.apply(value)); |
| } |
| |
| @Override |
| public int getValueCardinality() |
| { |
| return 1; |
| } |
| |
| @Override |
| public String lookupName(int id) |
| { |
| assert id == 0 : "id = " + id; |
| return value; |
| } |
| |
| @Override |
| public boolean nameLookupPossibleInAdvance() |
| { |
| return true; |
| } |
| |
| @Nullable |
| @Override |
| public IdLookup idLookup() |
| { |
| return this; |
| } |
| |
| @Override |
| public int lookupId(String name) |
| { |
| return value.equals(name) ? 0 : -1; |
| } |
| |
| @Nullable |
| @Override |
| public Object getObject() |
| { |
| return value; |
| } |
| |
| @Override |
| public Class classOfObject() |
| { |
| return String.class; |
| } |
| |
| @Override |
| public void inspectRuntimeShape(RuntimeShapeInspector inspector) |
| { |
| inspector.visit("value", value); |
| } |
| } |