org.apache.lucene.queries.function.valuesource.FloatFieldSource.java Source code

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Here is the source code for org.apache.lucene.queries.function.valuesource.FloatFieldSource.java

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/*
 * 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.lucene.queries.function.valuesource;

import java.io.IOException;
import java.util.Map;

import org.apache.lucene.index.DocValues;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.NumericDocValues;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.docvalues.FloatDocValues;
import org.apache.lucene.search.SortField.Type;
import org.apache.lucene.search.SortField;
import org.apache.lucene.util.mutable.MutableValue;
import org.apache.lucene.util.mutable.MutableValueFloat;

/**
 * Obtains float field values from {@link org.apache.lucene.index.LeafReader#getNumericDocValues} and makes those
 * values available as other numeric types, casting as needed.
 */
public class FloatFieldSource extends FieldCacheSource {

    public FloatFieldSource(String field) {
        super(field);
    }

    @Override
    public String description() {
        return "float(" + field + ')';
    }

    @Override
    public SortField getSortField(boolean reverse) {
        return new SortField(field, Type.FLOAT, reverse);
    }

    @Override
    public FunctionValues getValues(Map context, LeafReaderContext readerContext) throws IOException {

        final NumericDocValues arr = getNumericDocValues(context, readerContext);

        return new FloatDocValues(this) {
            int lastDocID;

            private float getValueForDoc(int doc) throws IOException {
                if (doc < lastDocID) {
                    throw new IllegalArgumentException(
                            "docs were sent out-of-order: lastDocID=" + lastDocID + " vs docID=" + doc);
                }
                lastDocID = doc;
                int curDocID = arr.docID();
                if (doc > curDocID) {
                    curDocID = arr.advance(doc);
                }
                if (doc == curDocID) {
                    return Float.intBitsToFloat((int) arr.longValue());
                } else {
                    return 0f;
                }
            }

            @Override
            public float floatVal(int doc) throws IOException {
                return getValueForDoc(doc);
            }

            @Override
            public boolean exists(int doc) throws IOException {
                getValueForDoc(doc);
                return arr.docID() == doc;
            }

            @Override
            public ValueFiller getValueFiller() {
                return new ValueFiller() {
                    private final MutableValueFloat mval = new MutableValueFloat();

                    @Override
                    public MutableValue getValue() {
                        return mval;
                    }

                    @Override
                    public void fillValue(int doc) throws IOException {
                        mval.value = floatVal(doc);
                        mval.exists = arr.docID() == doc;
                    }
                };
            }

        };
    }

    protected NumericDocValues getNumericDocValues(Map context, LeafReaderContext readerContext)
            throws IOException {
        return DocValues.getNumeric(readerContext.reader(), field);
    }

    @Override
    public boolean equals(Object o) {
        if (o.getClass() != FloatFieldSource.class)
            return false;
        FloatFieldSource other = (FloatFieldSource) o;
        return super.equals(other);
    }

    @Override
    public int hashCode() {
        int h = Float.class.hashCode();
        h += super.hashCode();
        return h;
    }
}