/*
* 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;
using IndexReader = Lucene.Net.Index.IndexReader;
using FieldCache = Lucene.Net.Search.FieldCache;
namespace Lucene.Net.Search.Function
{
/// Expert: obtains the ordinal of the field value from the default Lucene
/// {@link Lucene.Net.Search.FieldCache Fieldcache} using getStringIndex().
///
/// The native lucene index order is used to assign an ordinal value for each field value.
///
/// Field values (terms) are lexicographically ordered by unicode value, and numbered starting at 1.
///
/// Example:
///
If there were only three field values: "apple","banana","pear"
///
then ord("apple")=1, ord("banana")=2, ord("pear")=3
///
/// WARNING:
/// ord() depends on the position in an index and can thus change
/// when other documents are inserted or deleted,
/// or if a MultiSearcher is used.
///
///
/// WARNING: The status of the Search.Function package is experimental.
/// The APIs introduced here might change in the future and will not be
/// supported anymore in such a case.
///
/// NOTE: with the switch in 2.9 to segment-based
/// searching, if {@link #getValues} is invoked with a
/// composite (multi-segment) reader, this can easily cause
/// double RAM usage for the values in the FieldCache. It's
/// best to switch your application to pass only atomic
/// (single segment) readers to this API. Alternatively, for
/// a short-term fix, you could wrap your ValueSource using
/// {@link MultiValueSource}, which costs more CPU per lookup
/// but will not consume double the FieldCache RAM.
///
[Serializable]
public class OrdFieldSource:ValueSource
{
private class AnonymousClassDocValues:DocValues
{
public AnonymousClassDocValues(int[] arr, OrdFieldSource enclosingInstance)
{
InitBlock(arr, enclosingInstance);
}
private void InitBlock(int[] arr, OrdFieldSource enclosingInstance)
{
this.arr = arr;
this.enclosingInstance = enclosingInstance;
}
private int[] arr;
private OrdFieldSource enclosingInstance;
public OrdFieldSource Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
/*(non-Javadoc) @see Lucene.Net.Search.Function.DocValues#floatVal(int) */
public override float FloatVal(int doc)
{
return (float) arr[doc];
}
/*(non-Javadoc) @see Lucene.Net.Search.Function.DocValues#strVal(int) */
public override System.String StrVal(int doc)
{
// the string value of the ordinal, not the string itself
return System.Convert.ToString(arr[doc]);
}
/*(non-Javadoc) @see Lucene.Net.Search.Function.DocValues#toString(int) */
public override System.String ToString(int doc)
{
return Enclosing_Instance.Description() + '=' + IntVal(doc);
}
/*(non-Javadoc) @see Lucene.Net.Search.Function.DocValues#getInnerArray() */
public /*internal*/ override System.Object GetInnerArray()
{
return arr;
}
}
protected internal System.String field;
/// Constructor for a certain field.
/// field whose values order is used.
///
public OrdFieldSource(System.String field)
{
this.field = field;
}
/*(non-Javadoc) @see Lucene.Net.Search.Function.ValueSource#description() */
public override System.String Description()
{
return "ord(" + field + ')';
}
/*(non-Javadoc) @see Lucene.Net.Search.Function.ValueSource#getValues(Lucene.Net.Index.IndexReader) */
public override DocValues GetValues(IndexReader reader)
{
int[] arr = Lucene.Net.Search.FieldCache_Fields.DEFAULT.GetStringIndex(reader, field).order;
return new AnonymousClassDocValues(arr, this);
}
/*(non-Javadoc) @see java.lang.Object#equals(java.lang.Object) */
public override bool Equals(System.Object o)
{
if (o.GetType() != typeof(OrdFieldSource))
return false;
OrdFieldSource other = (OrdFieldSource) o;
return this.field.Equals(other.field);
}
private static readonly int hcode;
/*(non-Javadoc) @see java.lang.Object#hashCode() */
public override int GetHashCode()
{
return hcode + field.GetHashCode();
}
static OrdFieldSource()
{
hcode = typeof(OrdFieldSource).GetHashCode();
}
}
}