src/Lucene.Net/Search/Sort.cs - lucenenet - Git at Google

 /*
  * 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.
  */

 using System;

 namespace Lucene.Net.Search
 {


 	/// <summary> Encapsulates sort criteria for returned hits.
 	///
 	/// <p>The fields used to determine sort order must be carefully chosen.
 	/// Documents must contain a single term in such a field,
 	/// and the value of the term should indicate the document's relative position in
 	/// a given sort order.  The field must be indexed, but should not be tokenized,
 	/// and does not need to be stored (unless you happen to want it back with the
 	/// rest of your document data).  In other words:
 	///
 	/// <p><code>document.add (new Field ("byNumber", Integer.toString(x), Field.Store.NO, Field.Index.UN_TOKENIZED));</code></p>
 	///
 	///
 	/// <p><h3>Valid Types of Values</h3>
 	///
 	/// <p>There are four possible kinds of term values which may be put into
 	/// sorting fields: Integers, Longs, Floats, or Strings.  Unless
 	/// {@link SortField SortField} objects are specified, the type of value
 	/// in the field is determined by parsing the first term in the field.
 	///
 	/// <p>Integer term values should contain only digits and an optional
 	/// preceding negative sign.  Values must be base 10 and in the range
 	/// <code>Integer.MIN_VALUE</code> and <code>Integer.MAX_VALUE</code> inclusive.
 	/// Documents which should appear first in the sort
 	/// should have low value integers, later documents high values
 	/// (i.e. the documents should be numbered <code>1..n</code> where
 	/// <code>1</code> is the first and <code>n</code> the last).
 	///
 	/// <p>Long term values should contain only digits and an optional
 	/// preceding negative sign.  Values must be base 10 and in the range
 	/// <code>Long.MIN_VALUE</code> and <code>Long.MAX_VALUE</code> inclusive.
 	/// Documents which should appear first in the sort
 	/// should have low value integers, later documents high values.
 	///
 	/// <p>Float term values should conform to values accepted by
 	/// {@link Float Float.valueOf(String)} (except that <code>NaN</code>
 	/// and <code>Infinity</code> are not supported).
 	/// Documents which should appear first in the sort
 	/// should have low values, later documents high values.
 	///
 	/// <p>String term values can contain any valid String, but should
 	/// not be tokenized.  The values are sorted according to their
 	/// {@link Comparable natural order}.  Note that using this type
 	/// of term value has higher memory requirements than the other
 	/// two types.
 	///
 	/// <p><h3>Object Reuse</h3>
 	///
 	/// <p>One of these objects can be
 	/// used multiple times and the sort order changed between usages.
 	///
 	/// <p>This class is thread safe.
 	///
 	/// <p><h3>Memory Usage</h3>
 	///
 	/// <p>Sorting uses of caches of term values maintained by the
 	/// internal HitQueue(s).  The cache is static and contains an integer
 	/// or float array of length <code>IndexReader.maxDoc()</code> for each field
 	/// name for which a sort is performed.  In other words, the size of the
 	/// cache in bytes is:
 	///
 	/// <p><code>4 * IndexReader.maxDoc() * (# of different fields actually used to sort)</code>
 	///
 	/// <p>For String fields, the cache is larger: in addition to the
 	/// above array, the value of every term in the field is kept in memory.
 	/// If there are many unique terms in the field, this could
 	/// be quite large.
 	///
 	/// <p>Note that the size of the cache is not affected by how many
 	/// fields are in the index and <i>might</i> be used to sort - only by
 	/// the ones actually used to sort a result set.
 	///
 	/// <p>Created: Feb 12, 2004 10:53:57 AM
 	///
 	/// </summary>
 	/// <author>   Tim Jones (Nacimiento Software)
 	/// </author>
 	/// <since>   lucene 1.4
 	/// </since>
 	/// <version>  $Id: Sort.java 598376 2007-11-26 18:45:39Z dnaber $
 	/// </version>
 	[Serializable]
 	public class Sort
 	{

 		/// <summary> Represents sorting by computed relevance. Using this sort criteria returns
 		/// the same results as calling
 		/// {@link Searcher#Search(Query) Searcher#search()}without a sort criteria,
 		/// only with slightly more overhead.
 		/// </summary>
 		public static readonly Sort RELEVANCE = new Sort();

 		/// <summary>Represents sorting by index order. </summary>
 		public static readonly Sort INDEXORDER;

 		// internal representation of the sort criteria
 		internal SortField[] fields;

 		/// <summary> Sorts by computed relevance. This is the same sort criteria as calling
 		/// {@link Searcher#Search(Query) Searcher#search()}without a sort criteria,
 		/// only with slightly more overhead.
 		/// </summary>
 		public Sort() : this(new SortField[] {SortField.FIELD_SCORE, SortField.FIELD_DOC})
 		{
 		}

 		/// <summary> Sorts by the terms in <code>field</code> then by index order (document
 		/// number). The type of value in <code>field</code> is determined
 		/// automatically.
 		///
 		/// </summary>
 		/// <seealso cref="SortField#AUTO">
 		/// </seealso>
 		public Sort(System.String field)
 		{
 			SetSort(field, false);
 		}

 		/// <summary> Sorts possibly in reverse by the terms in <code>field</code> then by
 		/// index order (document number). The type of value in <code>field</code> is
 		/// determined automatically.
 		///
 		/// </summary>
 		/// <seealso cref="SortField#AUTO">
 		/// </seealso>
 		public Sort(System.String field, bool reverse)
 		{
 			SetSort(field, reverse);
 		}

 		/// <summary> Sorts in succession by the terms in each field. The type of value in
 		/// <code>field</code> is determined automatically.
 		///
 		/// </summary>
 		/// <seealso cref="SortField#AUTO">
 		/// </seealso>
 		public Sort(System.String[] fields)
 		{
 			SetSort(fields);
 		}

 		/// <summary>Sorts by the criteria in the given SortField. </summary>
 		public Sort(SortField field)
 		{
 			SetSort(field);
 		}

 		/// <summary>Sorts in succession by the criteria in each SortField. </summary>
 		public Sort(SortField[] fields)
 		{
 			SetSort(fields);
 		}

 		/// <summary> Sets the sort to the terms in <code>field</code> then by index order
 		/// (document number).
 		/// </summary>
 		public void  SetSort(System.String field)
 		{
 			SetSort(field, false);
 		}

 		/// <summary> Sets the sort to the terms in <code>field</code> possibly in reverse,
 		/// then by index order (document number).
 		/// </summary>
 		public virtual void  SetSort(System.String field, bool reverse)
 		{
 			SortField[] nfields = new SortField[]{new SortField(field, SortField.AUTO, reverse), SortField.FIELD_DOC};
 			fields = nfields;
 		}

 		/// <summary>Sets the sort to the terms in each field in succession. </summary>
 		public virtual void  SetSort(System.String[] fieldnames)
 		{
 			int n = fieldnames.Length;
 			SortField[] nfields = new SortField[n];
 			for (int i = 0; i < n; ++i)
 			{
 				nfields[i] = new SortField(fieldnames[i], SortField.AUTO);
 			}
 			fields = nfields;
 		}

 		/// <summary>Sets the sort to the given criteria. </summary>
 		public virtual void  SetSort(SortField field)
 		{
 			this.fields = new SortField[]{field};
 		}

 		/// <summary>Sets the sort to the given criteria in succession. </summary>
 		public virtual void  SetSort(SortField[] fields)
 		{
 			this.fields = fields;
 		}

 		/// <summary> Representation of the sort criteria.</summary>
 		/// <returns> Array of SortField objects used in this sort criteria
 		/// </returns>
 		public virtual SortField[] GetSort()
 		{
 			return fields;
 		}

 		public override System.String ToString()
 		{
 			System.Text.StringBuilder buffer = new System.Text.StringBuilder();

 			for (int i = 0; i < fields.Length; i++)
 			{
 				buffer.Append(fields[i].ToString());
 				if ((i + 1) < fields.Length)
 					buffer.Append(',');
 			}

 			return buffer.ToString();
 		}
 		static Sort()
 		{
 			INDEXORDER = new Sort(SortField.FIELD_DOC);
 		}
 	}
 }
	/*
	* 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.
	*/

	using System;

	namespace Lucene.Net.Search
	{


	/// <summary> Encapsulates sort criteria for returned hits.
	///
	/// <p>The fields used to determine sort order must be carefully chosen.
	/// Documents must contain a single term in such a field,
	/// and the value of the term should indicate the document's relative position in
	/// a given sort order. The field must be indexed, but should not be tokenized,
	/// and does not need to be stored (unless you happen to want it back with the
	/// rest of your document data). In other words:
	///
	/// <p><code>document.add (new Field ("byNumber", Integer.toString(x), Field.Store.NO, Field.Index.UN_TOKENIZED));</code></p>
	///
	///
	/// <p><h3>Valid Types of Values</h3>
	///
	/// <p>There are four possible kinds of term values which may be put into
	/// sorting fields: Integers, Longs, Floats, or Strings. Unless
	/// {@link SortField SortField} objects are specified, the type of value
	/// in the field is determined by parsing the first term in the field.
	///
	/// <p>Integer term values should contain only digits and an optional
	/// preceding negative sign. Values must be base 10 and in the range
	/// <code>Integer.MIN_VALUE</code> and <code>Integer.MAX_VALUE</code> inclusive.
	/// Documents which should appear first in the sort
	/// should have low value integers, later documents high values
	/// (i.e. the documents should be numbered <code>1..n</code> where
	/// <code>1</code> is the first and <code>n</code> the last).
	///
	/// <p>Long term values should contain only digits and an optional
	/// preceding negative sign. Values must be base 10 and in the range
	/// <code>Long.MIN_VALUE</code> and <code>Long.MAX_VALUE</code> inclusive.
	/// Documents which should appear first in the sort
	/// should have low value integers, later documents high values.
	///
	/// <p>Float term values should conform to values accepted by
	/// {@link Float Float.valueOf(String)} (except that <code>NaN</code>
	/// and <code>Infinity</code> are not supported).
	/// Documents which should appear first in the sort
	/// should have low values, later documents high values.
	///
	/// <p>String term values can contain any valid String, but should
	/// not be tokenized. The values are sorted according to their
	/// {@link Comparable natural order}. Note that using this type
	/// of term value has higher memory requirements than the other
	/// two types.
	///
	/// <p><h3>Object Reuse</h3>
	///
	/// <p>One of these objects can be
	/// used multiple times and the sort order changed between usages.
	///
	/// <p>This class is thread safe.
	///
	/// <p><h3>Memory Usage</h3>
	///
	/// <p>Sorting uses of caches of term values maintained by the
	/// internal HitQueue(s). The cache is static and contains an integer
	/// or float array of length <code>IndexReader.maxDoc()</code> for each field
	/// name for which a sort is performed. In other words, the size of the
	/// cache in bytes is:
	///
	/// <p><code>4 * IndexReader.maxDoc() * (# of different fields actually used to sort)</code>
	///
	/// <p>For String fields, the cache is larger: in addition to the
	/// above array, the value of every term in the field is kept in memory.
	/// If there are many unique terms in the field, this could
	/// be quite large.
	///
	/// <p>Note that the size of the cache is not affected by how many
	/// fields are in the index and <i>might</i> be used to sort - only by
	/// the ones actually used to sort a result set.
	///
	/// <p>Created: Feb 12, 2004 10:53:57 AM
	///
	/// </summary>
	/// <author> Tim Jones (Nacimiento Software)
	/// </author>
	/// <since> lucene 1.4
	/// </since>
	/// <version> $Id: Sort.java 598376 2007-11-26 18:45:39Z dnaber $
	/// </version>
	[Serializable]
	public class Sort
	{

	/// <summary> Represents sorting by computed relevance. Using this sort criteria returns
	/// the same results as calling
	/// {@link Searcher#Search(Query) Searcher#search()}without a sort criteria,
	/// only with slightly more overhead.
	/// </summary>
	public static readonly Sort RELEVANCE = new Sort();

	/// <summary>Represents sorting by index order. </summary>
	public static readonly Sort INDEXORDER;

	// internal representation of the sort criteria
	internal SortField[] fields;

	/// <summary> Sorts by computed relevance. This is the same sort criteria as calling
	/// {@link Searcher#Search(Query) Searcher#search()}without a sort criteria,
	/// only with slightly more overhead.
	/// </summary>
	public Sort() : this(new SortField[] {SortField.FIELD_SCORE, SortField.FIELD_DOC})
	{
	}

	/// <summary> Sorts by the terms in <code>field</code> then by index order (document
	/// number). The type of value in <code>field</code> is determined
	/// automatically.
	///
	/// </summary>
	/// <seealso cref="SortField#AUTO">
	/// </seealso>
	public Sort(System.String field)
	{
	SetSort(field, false);
	}

	/// <summary> Sorts possibly in reverse by the terms in <code>field</code> then by
	/// index order (document number). The type of value in <code>field</code> is
	/// determined automatically.
	///
	/// </summary>
	/// <seealso cref="SortField#AUTO">
	/// </seealso>
	public Sort(System.String field, bool reverse)
	{
	SetSort(field, reverse);
	}

	/// <summary> Sorts in succession by the terms in each field. The type of value in
	/// <code>field</code> is determined automatically.
	///
	/// </summary>
	/// <seealso cref="SortField#AUTO">
	/// </seealso>
	public Sort(System.String[] fields)
	{
	SetSort(fields);
	}

	/// <summary>Sorts by the criteria in the given SortField. </summary>
	public Sort(SortField field)
	{
	SetSort(field);
	}

	/// <summary>Sorts in succession by the criteria in each SortField. </summary>
	public Sort(SortField[] fields)
	{
	SetSort(fields);
	}

	/// <summary> Sets the sort to the terms in <code>field</code> then by index order
	/// (document number).
	/// </summary>
	public void SetSort(System.String field)
	{
	SetSort(field, false);
	}

	/// <summary> Sets the sort to the terms in <code>field</code> possibly in reverse,
	/// then by index order (document number).
	/// </summary>
	public virtual void SetSort(System.String field, bool reverse)
	{
	SortField[] nfields = new SortField[]{new SortField(field, SortField.AUTO, reverse), SortField.FIELD_DOC};
	fields = nfields;
	}

	/// <summary>Sets the sort to the terms in each field in succession. </summary>
	public virtual void SetSort(System.String[] fieldnames)
	{
	int n = fieldnames.Length;
	SortField[] nfields = new SortField[n];
	for (int i = 0; i < n; ++i)
	{
	nfields[i] = new SortField(fieldnames[i], SortField.AUTO);
	}
	fields = nfields;
	}

	/// <summary>Sets the sort to the given criteria. </summary>
	public virtual void SetSort(SortField field)
	{
	this.fields = new SortField[]{field};
	}

	/// <summary>Sets the sort to the given criteria in succession. </summary>
	public virtual void SetSort(SortField[] fields)
	{
	this.fields = fields;
	}

	/// <summary> Representation of the sort criteria.</summary>
	/// <returns> Array of SortField objects used in this sort criteria
	/// </returns>
	public virtual SortField[] GetSort()
	{
	return fields;
	}

	public override System.String ToString()
	{
	System.Text.StringBuilder buffer = new System.Text.StringBuilder();

	for (int i = 0; i < fields.Length; i++)
	{
	buffer.Append(fields[i].ToString());
	if ((i + 1) < fields.Length)
	buffer.Append(',');
	}

	return buffer.ToString();
	}
	static Sort()
	{
	INDEXORDER = new Sort(SortField.FIELD_DOC);
	}
	}
	}