AllTokenStream.java

/*
 * Licensed to ElasticSearch and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. ElasticSearch 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.elasticsearch.common.lucene.all;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.PayloadAttribute;
import org.apache.lucene.index.Payload;

import java.io.IOException;

import static org.apache.lucene.analysis.payloads.PayloadHelper.encodeFloat;

/**
 *
 */
public final class AllTokenStream extends TokenFilter {

    public static TokenStream allTokenStream(String allFieldName, AllEntries allEntries, Analyzer analyzer) throws IOException {
        return new AllTokenStream(analyzer.reusableTokenStream(allFieldName, allEntries), allEntries);
    }

    private final AllEntries allEntries;

    private final PayloadAttribute payloadAttribute;

    AllTokenStream(TokenStream input, AllEntries allEntries) {
        super(input);
        this.allEntries = allEntries;
        payloadAttribute = addAttribute(PayloadAttribute.class);
    }

    public AllEntries allEntries() {
        return allEntries;
    }

    @Override
    public final boolean incrementToken() throws IOException {
        if (!input.incrementToken()) {
            return false;
        }
        if (allEntries.current() != null) {
            float boost = allEntries.current().boost();
            if (boost != 1.0f) {
                payloadAttribute.setPayload(new Payload(encodeFloat(boost)));
            } else {
                payloadAttribute.setPayload(null);
            }
        }
        return true;
    }

    @Override
    public String toString() {
        return allEntries.toString();
    }
}