pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.4.0 / lucene / contrib / xml-query-parser / src / java / org / apache / lucene / xmlparser / builders / CachedFilterBuilder.java

diff --git a/lucene-java-3.4.0/lucene/contrib/xml-query-parser/src/java/org/apache/lucene/xmlparser/builders/CachedFilterBuilder.java b/lucene-java-3.4.0/lucene/contrib/xml-query-parser/src/java/org/apache/lucene/xmlparser/builders/CachedFilterBuilder.java
deleted file mode 100644 (file)
index a88bc4d..0000000
--- a/lucene-java-3.4.0/lucene/contrib/xml-query-parser/src/java/org/apache/lucene/xmlparser/builders/CachedFilterBuilder.java
+++ /dev/null
@@ -1,130 +0,0 @@
-/*
- * Created on 25-Jan-2006
- */
-package org.apache.lucene.xmlparser.builders;
-
-import java.util.Map.Entry;
-
-import org.apache.lucene.search.CachingWrapperFilter;
-import org.apache.lucene.search.Filter;
-import org.apache.lucene.search.Query;
-import org.apache.lucene.search.QueryWrapperFilter;
-import org.apache.lucene.xmlparser.DOMUtils;
-import org.apache.lucene.xmlparser.FilterBuilder;
-import org.apache.lucene.xmlparser.FilterBuilderFactory;
-import org.apache.lucene.xmlparser.ParserException;
-import org.apache.lucene.xmlparser.QueryBuilder;
-import org.apache.lucene.xmlparser.QueryBuilderFactory;
-import org.w3c.dom.Element;
-/**
- * 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.
- */
-/**
- * Filters are cached in an LRU Cache keyed on the contained query or filter object. Using this will 
- * speed up overall performance for repeated uses of the same expensive query/filter. The sorts of 
- * queries/filters likely to benefit from caching need not necessarily be complex - e.g. simple 
- * TermQuerys with a large DF (document frequency) can be expensive    on large indexes. 
- * A good example of this might be a term query on a field with only 2 possible        values - 
- * "true" or "false". In a large index, querying or filtering on this field requires reading 
- * millions    of document ids from disk which can more usefully be cached as a filter bitset.
- * 
- * For Queries/Filters to be cached and reused the object must implement hashcode and
- * equals methods correctly so that duplicate queries/filters can be detected in the cache.
- * 
- * The CoreParser.maxNumCachedFilters property can be used to control the size of the LRU 
- * Cache established during the construction of CoreParser instances.
- *
- */
-public class CachedFilterBuilder implements FilterBuilder {
-
-       private QueryBuilderFactory queryFactory;
-       private FilterBuilderFactory filterFactory;
-       
-    private  LRUCache<Object,Filter> filterCache = null;
-
-       private int cacheSize;
-
-       public CachedFilterBuilder(QueryBuilderFactory queryFactory, 
-                       FilterBuilderFactory filterFactory,int cacheSize)
-       {
-               this.queryFactory=queryFactory;
-               this.filterFactory=filterFactory;
-               this.cacheSize=cacheSize;
-       }
-
-       public synchronized Filter getFilter(Element e) throws ParserException
-       {
-
-               Element childElement = DOMUtils.getFirstChildOrFail(e);
-
-               if (filterCache == null)
-               {
-                       filterCache = new LRUCache<Object,Filter>(cacheSize);
-               }
-
-               // Test to see if child Element is a query or filter that needs to be
-               // cached
-               QueryBuilder qb = queryFactory.getQueryBuilder(childElement.getNodeName());
-               Object cacheKey = null;
-               Query q = null;
-               Filter f = null;
-               if (qb != null)
-               {
-                       q = qb.getQuery(childElement);
-                       cacheKey = q;
-               } else
-               {
-                       f = filterFactory.getFilter(childElement);
-                       cacheKey = f;
-               }
-               Filter cachedFilter = filterCache.get(cacheKey);
-               if (cachedFilter != null)
-               {
-                       return cachedFilter; // cache hit
-               }
-               
-               //cache miss
-               if (qb != null)
-               {
-                       cachedFilter = new QueryWrapperFilter(q);
-               } else
-               {
-                       cachedFilter = new CachingWrapperFilter(f);
-               }
-
-               filterCache.put(cacheKey, cachedFilter);
-               return cachedFilter;
-       }
-       
-       static class LRUCache<K,V> extends java.util.LinkedHashMap<K,V>
-       {
-           public LRUCache(int maxsize)
-           {
-               super(maxsize * 4 / 3 + 1, 0.75f, true);
-               this.maxsize = maxsize;
-           }
-
-           protected int maxsize;
-
-           @Override
-           protected boolean removeEldestEntry(Entry<K,V> eldest)
-           {
-               return size() > maxsize;
-           }
-
-       }
-
-}