pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / highlighter / src / java / org / apache / lucene / search / highlight / OffsetLimitTokenFilter.java

diff --git a/lucene-java-3.5.0/lucene/contrib/highlighter/src/java/org/apache/lucene/search/highlight/OffsetLimitTokenFilter.java b/lucene-java-3.5.0/lucene/contrib/highlighter/src/java/org/apache/lucene/search/highlight/OffsetLimitTokenFilter.java
new file mode 100644 (file)
index 0000000..2102c28
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/contrib/highlighter/src/java/org/apache/lucene/search/highlight/OffsetLimitTokenFilter.java
@@ -0,0 +1,57 @@
+package org.apache.lucene.search.highlight;
+
+/**
+ * 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.
+ */
+
+import java.io.IOException;
+
+import org.apache.lucene.analysis.TokenFilter;
+import org.apache.lucene.analysis.TokenStream;
+import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
+
+/**
+ * This TokenFilter limits the number of tokens while indexing by adding up the
+ * current offset.
+ */
+public final class OffsetLimitTokenFilter extends TokenFilter {
+  
+  private int offsetCount;
+  private OffsetAttribute offsetAttrib = getAttribute(OffsetAttribute.class);
+  private int offsetLimit;
+  
+  public OffsetLimitTokenFilter(TokenStream input, int offsetLimit) {
+    super(input);
+    this.offsetLimit = offsetLimit;
+  }
+  
+  @Override
+  public boolean incrementToken() throws IOException {
+    if (offsetCount < offsetLimit && input.incrementToken()) {
+      int offsetLength = offsetAttrib.endOffset() - offsetAttrib.startOffset();
+      offsetCount += offsetLength;
+      return true;
+    }
+    return false;
+  }
+  
+  @Override
+  public void reset() throws IOException {
+    super.reset();
+    offsetCount = 0;
+  }
+  
+}