MatchAllDocsQuery.cs :  » Search-Engines » dotLucene » Lucene » Net » Search » C# / CSharp Open Source

/*
 * Copyright 2005 The Apache Software Foundation
 * 
 * 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.
 */

using System;
using IndexReaderLucene.Net.Index.IndexReader;
using ToStringUtilsLucene.Net.Util.ToStringUtils;

namespace Lucene.Net.Search{
  
  /// <summary> A query that matches all documents.
  /// 
  /// </summary>
  /// <author>  John Wang
  /// </author>
  [Serializable]
  public class MatchAllDocsQuery : Query
  {
    
    public MatchAllDocsQuery()
    {
    }
    
    private class MatchAllScorer:Scorer
    {
      private void  InitBlock(MatchAllDocsQuery enclosingInstance)
      {
        this.enclosingInstance = enclosingInstance;
      }
      private MatchAllDocsQuery enclosingInstance;
      public MatchAllDocsQuery Enclosing_Instance
      {
        get
        {
          return enclosingInstance;
        }
        
      }
      
      internal IndexReader reader;
      internal int count;
      internal int maxDoc;
      
      internal MatchAllScorer(MatchAllDocsQuery enclosingInstance, IndexReader reader, Similarity similarity) : base(similarity)
      {
        InitBlock(enclosingInstance);
        this.reader = reader;
        count = - 1;
        maxDoc = reader.MaxDoc();
      }
      
      public override int Doc()
      {
        return count;
      }
      
      public override Explanation Explain(int doc)
      {
        Explanation explanation = new Explanation();
        explanation.SetValue(1.0f);
        explanation.SetDescription("MatchAllDocsQuery");
        return explanation;
      }
      
      public override bool Next()
      {
        while (count < (maxDoc - 1))
        {
          count++;
          if (!reader.IsDeleted(count))
          {
            return true;
          }
        }
        return false;
      }
      
      public override float Score()
      {
        return 1.0f;
      }
      
      public override bool SkipTo(int target)
      {
        count = target - 1;
        return Next();
      }
    }
    
    [Serializable]
    private class MatchAllDocsWeight : Weight
    {
      private void  InitBlock(MatchAllDocsQuery enclosingInstance)
      {
        this.enclosingInstance = enclosingInstance;
      }
      private MatchAllDocsQuery enclosingInstance;
      public MatchAllDocsQuery Enclosing_Instance
      {
        get
        {
          return enclosingInstance;
        }
        
      }
      private Searcher searcher;
      
      public MatchAllDocsWeight(MatchAllDocsQuery enclosingInstance, Searcher searcher)
      {
        InitBlock(enclosingInstance);
        this.searcher = searcher;
      }
      
      public override System.String ToString()
      {
        return "weight(" + Enclosing_Instance + ")";
      }
      
      public virtual Query GetQuery()
      {
        return Enclosing_Instance;
      }
      
      public virtual float GetValue()
      {
        return 1.0f;
      }
      
      public virtual float SumOfSquaredWeights()
      {
        return 1.0f;
      }
      
      public virtual void  Normalize(float queryNorm)
      {
      }
      
      public virtual Scorer Scorer(IndexReader reader)
      {
        return new MatchAllScorer(enclosingInstance, reader, Enclosing_Instance.GetSimilarity(searcher));
      }
      
      public virtual Explanation Explain(IndexReader reader, int doc)
      {
        // explain query weight
        Explanation queryExpl = new Explanation();
        queryExpl.SetDescription("MatchAllDocsQuery:");
        
        Explanation boostExpl = new Explanation(Enclosing_Instance.GetBoost(), "boost");
        if (Enclosing_Instance.GetBoost() != 1.0f)
          queryExpl.AddDetail(boostExpl);
        queryExpl.SetValue(boostExpl.GetValue());
        
        return queryExpl;
      }
    }
    
    protected internal override Weight CreateWeight(Searcher searcher)
    {
      return new MatchAllDocsWeight(this, searcher);
    }
    
    public override System.String ToString(System.String field)
    {
      System.Text.StringBuilder buffer = new System.Text.StringBuilder();
      buffer.Append("MatchAllDocsQuery");
      buffer.Append(ToStringUtils.Boost(GetBoost()));
      return buffer.ToString();
    }
    
    public  override bool Equals(System.Object o)
    {
      if (!(o is MatchAllDocsQuery))
        return false;
      MatchAllDocsQuery other = (MatchAllDocsQuery) o;
      return this.GetBoost() == other.GetBoost();
    }
    
    public override int GetHashCode()
    {
      return BitConverter.ToInt32(BitConverter.GetBytes(GetBoost()), 0);
    }

        // {{Aroush-1.9}} Do we need this?!
        override public System.Object Clone()
    {
      return null;
    }
  }
}