com.xiaomi.linden.lucene.query.flexiblequery.TermDocsEnum.java Source code

Introduction

Here is the source code for com.xiaomi.linden.lucene.query.flexiblequery.TermDocsEnum.java

Source

// Copyright 2016 Xiaomi, Inc.
//
// 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.xiaomi.linden.lucene.query.flexiblequery;

import java.io.IOException;

import org.apache.lucene.index.DocsAndPositionsEnum;
import org.apache.lucene.search.ComplexExplanation;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.similarities.Similarity;

public class TermDocsEnum {

    protected DocsAndPositionsEnum postings;
    protected FlexibleQuery.FlexibleTerm term;
    protected Similarity.SimScorer docScorer;

    protected int doc;
    private int position;
    private int[] positions;
    private int freq;
    protected int termPos = -1;
    protected int docFreq = -1;

    private int matchedDoc = -1;
    private int matchedPosition = -1;
    private int[] matchedPositions;
    private int matchedFreq = -1;
    private int field;
    private int initPositionSize = 5;

    public TermDocsEnum(FlexibleQuery.FlexibleTerm term, int docFreq, DocsAndPositionsEnum postings,
            Similarity.SimScorer docScorer, int field, int termPos) throws IOException {
        this.doc = -1;
        this.term = term;
        this.postings = postings;
        this.docFreq = docFreq;
        this.docScorer = docScorer;
        this.field = field;
        this.termPos = termPos;
        this.positions = new int[initPositionSize];
        this.matchedPositions = new int[initPositionSize];
    }

    public FlexibleQuery.FlexibleTerm term() {
        return term;
    }

    public float score(int doc) throws IOException {
        if (isMatched(doc)) {
            return docScorer.score(matchedDoc, matchedFreq);
        } else {
            return 0f;
        }
    }

    public boolean next() throws IOException {
        if (postings == null) {
            doc = DocIdSetIterator.NO_MORE_DOCS;
            return false;
        }
        doc = postings.nextDoc();
        if (doc == DocIdSetIterator.NO_MORE_DOCS) {
            return false;
        }
        freq = postings.freq();
        if (freq > initPositionSize) {
            int newSize = 2 * freq;
            positions = new int[newSize];
            matchedPositions = new int[newSize];
            initPositionSize = newSize;
        }
        for (int i = 0; i < freq; i++) {
            positions[i] = postings.nextPosition();
        }
        position = positions[0];
        return true;
    }

    public int doc() {
        return doc;
    }

    public int freq(int doc) {
        return doc == matchedDoc ? matchedFreq : -1;
    }

    public int position(int doc) {
        return doc == matchedDoc ? matchedPosition : -1;
    }

    public int[] positions(int doc) {
        if (doc == matchedDoc) {
            int[] matchedPositionsData = new int[matchedFreq];
            System.arraycopy(matchedPositions, 0, matchedPositionsData, 0, matchedFreq);
            return matchedPositionsData;
        }
        return new int[0];
    }

    public String toString() {
        if (postings != null) {
            return "MatchedDocs(" + term.toString() + ")@"
                    + (doc == -1 ? "START" : (doc == Integer.MAX_VALUE) ? "END" : doc + "-" + position);
        } else {
            return term + "NotMatched";
        }
    }

    public Explanation explain(Similarity similarity, Query query, int doc) {
        if (!isMatched(doc)) {
            return null;
        }
        ComplexExplanation result = new ComplexExplanation();
        result.setDescription(
                "weight(" + query + " in " + doc + ") [" + similarity.getClass().getSimpleName() + "], result of:");
        Explanation scoreExplanation = docScorer.explain(doc,
                new Explanation(matchedFreq, "termFreq=" + matchedFreq));
        result.addDetail(scoreExplanation);
        result.setValue(scoreExplanation.getValue());
        result.setMatch(true);
        return result;
    }

    public boolean isMatched(int doc) {
        return matchedDoc == doc;
    }

    public void saveMatchedInfo() {
        this.matchedDoc = doc;
        this.matchedPosition = position;
        this.matchedFreq = freq;
        for (int i = 0; i < matchedFreq; i++) {
            matchedPositions[i] = positions[i];
        }
    }

    public int getField() {
        return field;
    }

}