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;
  
  import org.apache.lucene.search.Query;
  import org.apache.lucene.search.Sort;
  import org.apache.lucene.search.SortField;
  import java.io.IOException;
  import java.util.List;
  
  /** A hash key encapsulating a query, a list of filters, and a sort
   * @version $Id: QueryResultKey.java 1065312 2011-01-30 16:08:25Z rmuir $
   */
  public final class QueryResultKey {
    final Query query;
    final Sort sort;
    final SortField[] sfields;
    final List<Query> filters;
    final int nc_flags;  // non-comparable flags... ignored by hashCode and equals
  
    private final int hc;  // cached hashCode
  
    private static SortField[] defaultSort = new SortField[0];
  
  
    public QueryResultKey(Query query, List<Query> filters, Sort sort, int nc_flags) throws IOException {
      this.query = query;
      this.sort = sort;
      this.filters = filters;
      this.nc_flags = nc_flags;
  
      int h = query.hashCode();
  
      if (filters != null) h ^= filters.hashCode();
  
      sfields = (this.sort !=null) ? this.sort.getSort() : defaultSort;
      for (SortField sf : sfields) {
        h = h*29 + sf.hashCode();
      }
  
      hc = h;
    }
  
    @Override
    public int hashCode() {
      return hc;
    }
  
    @Override
    public boolean equals(Object o) {
      if (o==this) return true;
      if (!(o instanceof QueryResultKey)) return false;
      QueryResultKey other = (QueryResultKey)o;
  
      // fast check of the whole hash code... most hash tables will only use
      // some of the bits, so if this is a hash collision, it's still likely
      // that the full cached hash code will be different.
      if (this.hc != other.hc) return false;
  
      // check for the thing most likely to be different (and the fastest things)
      // first.
      if (this.sfields.length != other.sfields.length) return false;
      if (!this.query.equals(other.query)) return false;
      if (!isEqual(this.filters, other.filters)) return false;
  
      for (int i=0; i<sfields.length; i++) {
        SortField sf1 = this.sfields[i];
        SortField sf2 = other.sfields[i];
        if (!sf1.equals(sf2)) return false;
      }
  
      return true;
    }
  
  
    private static boolean isEqual(Object o1, Object o2) {
      if (o1==o2) return true;  // takes care of identity and null cases
      if (o1==null || o2==null) return false;
      return o1.equals(o2);
    }
  }
  