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

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Here is the source code for org.apache.lucene.queries.function.valuesource.LiteralValueSource.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 org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.queries.function.docvalues.StrDocValues;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.BytesRefBuilder;

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

/**
 * Pass a the field value through as a String, no matter the type // Q: doesn't this mean it's a "string"?
 *
 **/
public class LiteralValueSource extends ValueSource {
    protected final String string;
    protected final BytesRef bytesRef;

    public LiteralValueSource(String string) {
        this.string = string;
        this.bytesRef = new BytesRef(string);
    }

    /** returns the literal value */
    public String getValue() {
        return string;
    }

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

        return new StrDocValues(this) {
            @Override
            public String strVal(int doc) {
                return string;
            }

            @Override
            public boolean bytesVal(int doc, BytesRefBuilder target) {
                target.copyBytes(bytesRef);
                return true;
            }

            @Override
            public String toString(int doc) {
                return string;
            }
        };
    }

    @Override
    public String description() {
        return "literal(" + string + ")";
    }

    @Override
    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (!(o instanceof LiteralValueSource))
            return false;

        LiteralValueSource that = (LiteralValueSource) o;

        return string.equals(that.string);

    }

    public static final int hash = LiteralValueSource.class.hashCode();

    @Override
    public int hashCode() {
        return hash + string.hashCode();
    }
}