pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / facet / src / java / org / apache / lucene / facet / taxonomy / writercache / lru / NameHashIntCacheLRU.java

diff --git a/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/taxonomy/writercache/lru/NameHashIntCacheLRU.java b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/taxonomy/writercache/lru/NameHashIntCacheLRU.java
new file mode 100644 (file)
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+++ b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/taxonomy/writercache/lru/NameHashIntCacheLRU.java
@@ -0,0 +1,46 @@
+package org.apache.lucene.facet.taxonomy.writercache.lru;
+
+import org.apache.lucene.facet.taxonomy.CategoryPath;
+
+/**
+ * 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.
+ */
+
+/**
+ * An an LRU cache of mapping from name to int.
+ * Used to cache Ordinals of category paths.
+ * It uses as key, hash of the path instead of the path.
+ * This way the cahce takes less RAM, but correctness depends on
+ * assuming no collisions. 
+ * 
+ * @lucene.experimental
+ */
+public class NameHashIntCacheLRU extends NameIntCacheLRU {
+
+  NameHashIntCacheLRU(int maxCacheSize) {
+    super(maxCacheSize);
+  }
+
+  @Override
+  Object key(CategoryPath name) {
+    return new Long(name.longHashCode());
+  }
+
+  @Override
+  Object key(CategoryPath name, int prefixLen) {
+    return new Long(name.longHashCode(prefixLen));
+  }
+}