lucene/codecs/src/java/org/apache/lucene/codecs/memory/LegacySortedNumericDocValuesWrapper.java

/*
 * 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.codecs.memory;

import java.io.IOException;
import org.apache.lucene.index.SortedNumericDocValues;

/**
 * Wraps a {@link LegacySortedNumericDocValues} into a {@link SortedNumericDocValues}.
 *
 * @deprecated Implement {@link SortedNumericDocValues} directly.
 */
@Deprecated
final class LegacySortedNumericDocValuesWrapper extends SortedNumericDocValues {
  private final LegacySortedNumericDocValues values;
  private final int maxDoc;
  private int docID = -1;
  private int upto;

  public LegacySortedNumericDocValuesWrapper(LegacySortedNumericDocValues values, int maxDoc) {
    this.values = values;
    this.maxDoc = maxDoc;
  }

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

  @Override
  public int nextDoc() {
    assert docID != NO_MORE_DOCS;
    while (true) {
      docID++;
      if (docID == maxDoc) {
        docID = NO_MORE_DOCS;
        break;
      }
      values.setDocument(docID);
      if (values.count() != 0) {
        break;
      }
    }
    upto = 0;
    return docID;
  }

  @Override
  public int advance(int target) {
    if (target < docID) {
      throw new IllegalArgumentException(
          "cannot advance backwards: docID=" + docID + " target=" + target);
    }
    if (target >= maxDoc) {
      docID = NO_MORE_DOCS;
    } else {
      docID = target - 1;
      nextDoc();
    }
    return docID;
  }

  @Override
  public boolean advanceExact(int target) throws IOException {
    docID = target;
    values.setDocument(docID);
    upto = 0;
    return values.count() != 0;
  }

  @Override
  public long cost() {
    return 0;
  }

  @Override
  public long nextValue() {
    return values.valueAt(upto++);
  }

  @Override
  public int docValueCount() {
    return values.count();
  }
}