com.greplin.interval.NumericIntervalTokenStream.java Source code

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Here is the source code for com.greplin.interval.NumericIntervalTokenStream.java

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/*
 * Copyright 2010 The Lucene Interval Field Authors.
 *
 * Licensed 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 com.greplin.interval;

import com.google.common.collect.ImmutableList;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.TermAttribute;
import org.apache.lucene.util.NumericUtils;

import java.io.Serializable;

/**
 * Token stream for a numeric interval.
 */
final class NumericIntervalTokenStream extends TokenStream implements Serializable {
    /**
     * Segments that make up the interval.
     */
    private final ImmutableList<IntervalSegment> segments;

    /**
     * The term attribute.
     */
    private final TermAttribute termAtt = addAttribute(TermAttribute.class);

    /**
     * Current segment number.
     */
    private int i = 0;

    /**
     * Creates a token stream for a numeric interval.
     * @param segments The segments.
     */
    public NumericIntervalTokenStream(final ImmutableList<IntervalSegment> segments) {
        super();
        this.segments = segments;
    }

    @Override
    public void reset() {
        this.i = 0;
    }

    @Override
    public boolean incrementToken() {
        if (this.i >= this.segments.size()) {
            return false;
        }

        clearAttributes();
        IntervalSegment interval = this.segments.get(this.i);
        long value = interval.getStart();
        int shift = interval.getShift();
        final char[] buffer = this.termAtt.resizeTermBuffer(NumericUtils.BUF_SIZE_LONG);
        this.termAtt.setTermLength(NumericUtils.longToPrefixCoded(value, shift, buffer));
        this.i++;

        return true;
    }

    @Override
    public String toString() {
        return "(interval,parts=" + this.segments + ')';
    }

    @Override
    public int hashCode() {
        return this.segments.hashCode();
    }

    @Override
    public boolean equals(final Object obj) {
        return obj != null && obj.getClass() == this.getClass()
                && this.segments.equals(((NumericIntervalTokenStream) obj).segments);
    }
}