/*
* Copyright 2004 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 DocumentLucene.Net.Documents.Document;
using TermLucene.Net.Index.Term;
namespace Lucene.Net.Search{
/// <summary>An abstract base class for search implementations.
/// Implements the main search methods.
///
/// <p>Note that you can only access Hits from a Searcher as long as it is
/// not yet closed, otherwise an IOException will be thrown.
/// </summary>
public abstract class Searcher : Lucene.Net.Search.Searchable
{
public Searcher()
{
InitBlock();
}
private void InitBlock()
{
similarity = Similarity.GetDefault();
}
/// <summary>Returns the documents matching <code>query</code>. </summary>
/// <throws> BooleanQuery.TooManyClauses </throws>
public Hits Search(Query query)
{
return Search(query, (Filter) null);
}
/// <summary>Returns the documents matching <code>query</code> and
/// <code>filter</code>.
/// </summary>
/// <throws> BooleanQuery.TooManyClauses </throws>
public virtual Hits Search(Query query, Filter filter)
{
return new Hits(this, query, filter);
}
/// <summary>Returns documents matching <code>query</code> sorted by
/// <code>sort</code>.
/// </summary>
/// <throws> BooleanQuery.TooManyClauses </throws>
public virtual Hits Search(Query query, Sort sort)
{
return new Hits(this, query, null, sort);
}
/// <summary>Returns documents matching <code>query</code> and <code>filter</code>,
/// sorted by <code>sort</code>.
/// </summary>
/// <throws> BooleanQuery.TooManyClauses </throws>
public virtual Hits Search(Query query, Filter filter, Sort sort)
{
return new Hits(this, query, filter, sort);
}
/// <summary>Expert: Low-level search implementation with arbitrary sorting. Finds
/// the top <code>n</code> hits for <code>query</code>, applying
/// <code>filter</code> if non-null, and sorting the hits by the criteria in
/// <code>sort</code>.
///
/// <p>Applications should usually call {@link
/// Searcher#Search(Query,Filter,Sort)} instead.
/// </summary>
/// <throws> BooleanQuery.TooManyClauses </throws>
public virtual TopFieldDocs Search(Query query, Filter filter, int n, Sort sort)
{
return Search(CreateWeight(query), filter, n, sort);
}
/// <summary>Lower-level search API.
///
/// <p>{@link HitCollector#Collect(int,float)} is called for every non-zero
/// scoring document.
///
/// <p>Applications should only use this if they need <i>all</i> of the
/// matching documents. The high-level search API ({@link
/// Searcher#Search(Query)}) is usually more efficient, as it skips
/// non-high-scoring hits.
/// <p>Note: The <code>score</code> passed to this method is a raw score.
/// In other words, the score will not necessarily be a float whose value is
/// between 0 and 1.
/// </summary>
/// <throws> BooleanQuery.TooManyClauses </throws>
public virtual void Search(Query query, HitCollector results)
{
Search(query, (Filter) null, results);
}
/// <summary>Lower-level search API.
///
/// <p>{@link HitCollector#Collect(int,float)} is called for every non-zero
/// scoring document.
/// <br>HitCollector-based access to remote indexes is discouraged.
///
/// <p>Applications should only use this if they need <i>all</i> of the
/// matching documents. The high-level search API ({@link
/// Searcher#Search(Query)}) is usually more efficient, as it skips
/// non-high-scoring hits.
///
/// </summary>
/// <param name="query">to match documents
/// </param>
/// <param name="filter">if non-null, a bitset used to eliminate some documents
/// </param>
/// <param name="results">to receive hits
/// </param>
/// <throws> BooleanQuery.TooManyClauses </throws>
public virtual void Search(Query query, Filter filter, HitCollector results)
{
Search(CreateWeight(query), filter, results);
}
/// <summary>Expert: Low-level search implementation. Finds the top <code>n</code>
/// hits for <code>query</code>, applying <code>filter</code> if non-null.
///
/// <p>Called by {@link Hits}.
///
/// <p>Applications should usually call {@link Searcher#Search(Query)} or
/// {@link Searcher#Search(Query,Filter)} instead.
/// </summary>
/// <throws> BooleanQuery.TooManyClauses </throws>
public virtual TopDocs Search(Query query, Filter filter, int n)
{
return Search(CreateWeight(query), filter, n);
}
/// <summary>Returns an Explanation that describes how <code>doc</code> scored against
/// <code>query</code>.
///
/// <p>This is intended to be used in developing Similarity implementations,
/// and, for good performance, should not be displayed with every hit.
/// Computing an explanation is as expensive as executing the query over the
/// entire index.
/// </summary>
public virtual Explanation Explain(Query query, int doc)
{
return Explain(CreateWeight(query), doc);
}
/// <summary>The Similarity implementation used by this searcher. </summary>
private Similarity similarity;
/// <summary>Expert: Set the Similarity implementation used by this Searcher.
///
/// </summary>
/// <seealso cref="Similarity.SetDefault(Similarity)">
/// </seealso>
public virtual void SetSimilarity(Similarity similarity)
{
this.similarity = similarity;
}
/// <summary>Expert: Return the Similarity implementation used by this Searcher.
///
/// <p>This defaults to the current value of {@link Similarity#GetDefault()}.
/// </summary>
public virtual Similarity GetSimilarity()
{
return this.similarity;
}
/// <summary> creates a weight for <code>query</code></summary>
/// <returns> new weight
/// </returns>
protected internal virtual Weight CreateWeight(Query query)
{
return query.Weight(this);
}
// inherit javadoc
public virtual int[] DocFreqs(Term[] terms)
{
int[] result = new int[terms.Length];
for (int i = 0; i < terms.Length; i++)
{
result[i] = DocFreq(terms[i]);
}
return result;
}
/* The following abstract methods were added as a workaround for GCJ bug #15411.
* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15411
*/
abstract public void Search(Weight weight, Filter filter, HitCollector results);
abstract public void Close();
abstract public int DocFreq(Term term);
abstract public int MaxDoc();
abstract public TopDocs Search(Weight weight, Filter filter, int n);
abstract public Document Doc(int i);
abstract public Query Rewrite(Query query);
abstract public Explanation Explain(Weight weight, int doc);
abstract public TopFieldDocs Search(Weight weight, Filter filter, int n, Sort sort);
/* End patch for GCJ bug #15411. */
}
}
|