/*
* 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 System.Collections.Generic;
using Lucene.Net.Index;
using Lucene.Net.Support;
using IndexReader = Lucene.Net.Index.IndexReader;
using ToStringUtils = Lucene.Net.Util.ToStringUtils;
using Query = Lucene.Net.Search.Query;
namespace Lucene.Net.Search.Spans
{
/// Matches spans near the beginning of a field.
[Serializable]
public class SpanFirstQuery : SpanQuery, System.ICloneable
{
private class AnonymousClassSpans : Spans
{
public AnonymousClassSpans(Lucene.Net.Index.IndexReader reader, SpanFirstQuery enclosingInstance)
{
InitBlock(reader, enclosingInstance);
}
private void InitBlock(Lucene.Net.Index.IndexReader reader, SpanFirstQuery enclosingInstance)
{
this.reader = reader;
this.enclosingInstance = enclosingInstance;
spans = Enclosing_Instance.match.GetSpans(reader);
}
private Lucene.Net.Index.IndexReader reader;
private SpanFirstQuery enclosingInstance;
public SpanFirstQuery Enclosing_Instance
{
get
{
return enclosingInstance;
}
}
private Spans spans;
public override bool Next()
{
while (spans.Next())
{
// scan to next match
if (End() <= Enclosing_Instance.end)
return true;
}
return false;
}
public override bool SkipTo(int target)
{
if (!spans.SkipTo(target))
return false;
return spans.End() <= Enclosing_Instance.end || Next();
}
public override int Doc()
{
return spans.Doc();
}
public override int Start()
{
return spans.Start();
}
public override int End()
{
return spans.End();
}
// TODO: Remove warning after API has been finalized
public override ICollection GetPayload()
{
System.Collections.Generic.ICollection result = null;
if (spans.IsPayloadAvailable())
{
result = spans.GetPayload();
}
return result; //TODO: any way to avoid the new construction?
}
// TODO: Remove warning after API has been finalized
public override bool IsPayloadAvailable()
{
return spans.IsPayloadAvailable();
}
public override System.String ToString()
{
return "spans(" + Enclosing_Instance.ToString() + ")";
}
}
private SpanQuery match;
private int end;
/// Construct a SpanFirstQuery matching spans in match whose end
/// position is less than or equal to end.
///
public SpanFirstQuery(SpanQuery match, int end)
{
this.match = match;
this.end = end;
}
/// Return the SpanQuery whose matches are filtered.
public virtual SpanQuery Match
{
get { return match; }
}
/// Return the maximum end position permitted in a match.
public virtual int End
{
get { return end; }
}
public override string Field
{
get { return match.Field; }
}
public override System.String ToString(System.String field)
{
System.Text.StringBuilder buffer = new System.Text.StringBuilder();
buffer.Append("spanFirst(");
buffer.Append(match.ToString(field));
buffer.Append(", ");
buffer.Append(end);
buffer.Append(")");
buffer.Append(ToStringUtils.Boost(Boost));
return buffer.ToString();
}
public override System.Object Clone()
{
SpanFirstQuery spanFirstQuery = new SpanFirstQuery((SpanQuery) match.Clone(), end);
spanFirstQuery.Boost = Boost;
return spanFirstQuery;
}
public override void ExtractTerms(System.Collections.Generic.ISet terms)
{
match.ExtractTerms(terms);
}
public override Spans GetSpans(IndexReader reader)
{
return new AnonymousClassSpans(reader, this);
}
public override Query Rewrite(IndexReader reader)
{
SpanFirstQuery clone = null;
SpanQuery rewritten = (SpanQuery) match.Rewrite(reader);
if (rewritten != match)
{
clone = (SpanFirstQuery) this.Clone();
clone.match = rewritten;
}
if (clone != null)
{
return clone; // some clauses rewrote
}
else
{
return this; // no clauses rewrote
}
}
public override bool Equals(System.Object o)
{
if (this == o)
return true;
if (!(o is SpanFirstQuery))
return false;
SpanFirstQuery other = (SpanFirstQuery) o;
return this.end == other.end && this.match.Equals(other.match) && this.Boost == other.Boost;
}
public override int GetHashCode()
{
int h = match.GetHashCode();
h ^= ((h << 8) | (Number.URShift(h, 25))); // reversible
h ^= System.Convert.ToInt32(Boost) ^ end;
return h;
}
}
}