/*
* 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.Runtime.InteropServices;
using IndexReader = Lucene.Net.Index.IndexReader;
namespace Lucene.Net.Search
{
/// Wraps another SpanFilter's result and caches it. The purpose is to allow
/// filters to simply filter, and then wrap with this class to add caching.
///
[Serializable]
public class CachingSpanFilter:SpanFilter
{
private SpanFilter filter;
/// A transient Filter cache (internal because of test)
[NonSerialized]
internal CachingWrapperFilter.FilterCache cache;
///
/// New deletions always result in a cache miss, by default
/// (.
/// Filter to cache results of
///
///
public CachingSpanFilter(SpanFilter filter): this(filter, CachingWrapperFilter.DeletesMode.RECACHE)
{
}
/// New deletions always result in a cache miss, specify the
/// Filter to cache results of
/// See
public CachingSpanFilter(SpanFilter filter, CachingWrapperFilter.DeletesMode deletesMode)
{
this.filter = filter;
if (deletesMode == CachingWrapperFilter.DeletesMode.DYNAMIC)
{
throw new System.ArgumentException("DeletesMode.DYNAMIC is not supported");
}
this.cache = new AnonymousFilterCache(deletesMode);
}
class AnonymousFilterCache : CachingWrapperFilter.FilterCache
{
public AnonymousFilterCache(CachingWrapperFilter.DeletesMode deletesMode) : base(deletesMode)
{
}
protected override SpanFilterResult MergeDeletes(IndexReader reader, SpanFilterResult docIdSet)
{
throw new System.ArgumentException("DeletesMode.DYNAMIC is not supported");
}
}
public override DocIdSet GetDocIdSet(IndexReader reader)
{
SpanFilterResult result = GetCachedResult(reader);
return result != null?result.DocIdSet:null;
}
// for testing
public int hitCount, missCount;
private SpanFilterResult GetCachedResult(IndexReader reader)
{
object coreKey = reader.FieldCacheKey;
object delCoreKey = reader.HasDeletions ? reader.DeletesCacheKey : coreKey;
SpanFilterResult result = cache.Get(reader, coreKey, delCoreKey);
if (result != null) {
hitCount++;
return result;
}
missCount++;
result = filter.BitSpans(reader);
cache.Put(coreKey, delCoreKey, result);
return result;
}
public override SpanFilterResult BitSpans(IndexReader reader)
{
return GetCachedResult(reader);
}
public override System.String ToString()
{
return "CachingSpanFilter(" + filter + ")";
}
public override bool Equals(System.Object o)
{
if (!(o is CachingSpanFilter))
return false;
return this.filter.Equals(((CachingSpanFilter) o).filter);
}
public override int GetHashCode()
{
return filter.GetHashCode() ^ 0x1117BF25;
}
}
}