content: /**
   * 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.solr.search.function;
  
  import org.apache.lucene.index.IndexReader;
  import org.apache.lucene.search.Explanation;
  import org.apache.lucene.search.Scorer;
  
  import java.io.IOException;
  
  /** @lucene.internal */
  public class ValueSourceScorer extends Scorer {
    protected IndexReader reader;
    private int doc = -1;
    protected final int maxDoc;
    protected final DocValues values;
    protected boolean checkDeletes;
  
    protected ValueSourceScorer(IndexReader reader, DocValues values) {
      super(null, null);
      this.reader = reader;
      this.maxDoc = reader.maxDoc();
      this.values = values;
      setCheckDeletes(true);
    }
  
    public IndexReader getReader() {
      return reader;
    }
  
    public void setCheckDeletes(boolean checkDeletes) {
      this.checkDeletes = checkDeletes && reader.hasDeletions();
    }
  
    public boolean matches(int doc) {
      return (!checkDeletes || !reader.isDeleted(doc)) && matchesValue(doc);
    }
  
    public boolean matchesValue(int doc) {
      return true;
    }
  
    @Override
    public int docID() {
      return doc;
    }
  
    @Override
    public int nextDoc() throws IOException {
      for (; ;) {
        doc++;
        if (doc >= maxDoc) return doc = NO_MORE_DOCS;
        if (matches(doc)) return doc;
      }
    }
  
    @Override
    public int advance(int target) throws IOException {
      // also works fine when target==NO_MORE_DOCS
      doc = target - 1;
      return nextDoc();
    }
  
    public int doc() {
      return doc;
    }
  
    public boolean next() {
      for (; ;) {
        doc++;
        if (doc >= maxDoc) return false;
        if (matches(doc)) return true;
      }
    }
  
    public boolean skipTo(int target) {
      doc = target - 1;
      return next();
    }
  
  
    @Override
    public float score() throws IOException {
      return values.floatVal(doc);
    }
  
    public Explanation explain(int doc) throws IOException {
      return values.explain(doc);
    }
  }
  
  