org.apache.lucene.index.SingletonSortedSetDocValues.java Source code

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Here is the source code for org.apache.lucene.index.SingletonSortedSetDocValues.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.index;

import java.io.IOException;

import org.apache.lucene.util.BytesRef;

/** 
 * Exposes multi-valued iterator view over a single-valued iterator.
 * <p>
 * This can be used if you want to have one multi-valued implementation
 * that works for single or multi-valued types.
 */
final class SingletonSortedSetDocValues extends SortedSetDocValues {
    private final SortedDocValues in;
    private long ord;

    /** Creates a multi-valued view over the provided SortedDocValues */
    public SingletonSortedSetDocValues(SortedDocValues in) {
        if (in.docID() != -1) {
            throw new IllegalStateException("iterator has already been used: docID=" + in.docID());
        }
        this.in = in;
    }

    /** Return the wrapped {@link SortedDocValues} */
    public SortedDocValues getSortedDocValues() {
        if (in.docID() != -1) {
            throw new IllegalStateException("iterator has already been used: docID=" + in.docID());
        }
        return in;
    }

    @Override
    public int docID() {
        return in.docID();
    }

    @Override
    public long nextOrd() {
        long v = ord;
        ord = NO_MORE_ORDS;
        return v;
    }

    @Override
    public int nextDoc() throws IOException {
        int docID = in.nextDoc();
        if (docID != NO_MORE_DOCS) {
            ord = in.ordValue();
        }
        return docID;
    }

    @Override
    public int advance(int target) throws IOException {
        int docID = in.advance(target);
        if (docID != NO_MORE_DOCS) {
            ord = in.ordValue();
        }
        return docID;
    }

    @Override
    public boolean advanceExact(int target) throws IOException {
        if (in.advanceExact(target)) {
            ord = in.ordValue();
            return true;
        }
        return false;
    }

    @Override
    public BytesRef lookupOrd(long ord) throws IOException {
        // cast is ok: single-valued cannot exceed Integer.MAX_VALUE
        return in.lookupOrd((int) ord);
    }

    @Override
    public long getValueCount() {
        return in.getValueCount();
    }

    @Override
    public long lookupTerm(BytesRef key) throws IOException {
        return in.lookupTerm(key);
    }

    @Override
    public TermsEnum termsEnum() throws IOException {
        return in.termsEnum();
    }

    @Override
    public long cost() {
        return in.cost();
    }
}