pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / facet / src / java / org / apache / lucene / facet / search / aggregator / Aggregator.java

diff --git a/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/search/aggregator/Aggregator.java b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/search/aggregator/Aggregator.java
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+package org.apache.lucene.facet.search.aggregator;
+
+import java.io.IOException;
+
+/**
+ * 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 Aggregator is the analogue of Lucene's Collector (see
+ * {@link org.apache.lucene.search.Collector}), for processing the categories
+ * belonging to a certain document. The Aggregator is responsible for doing
+ * whatever it wishes with the categories it is fed, e.g., counting the number
+ * of times that each category appears, or performing some computation on their
+ * association values.
+ * <P>
+ * Much of the function of an Aggregator implementation is not described by this
+ * interface. This includes the constructor and getter methods to retrieve the
+ * results of the aggregation.
+ * 
+ * @lucene.experimental
+ */
+public interface Aggregator {
+
+  /**
+   * Specify the document (and its score in the search) that the following
+   * {@link #aggregate(int)} calls will pertain to.
+   */
+  void setNextDoc(int docid, float score) throws IOException;
+
+  /**
+   * Collect (and do whatever an implementation deems appropriate) the
+   * category given by its ordinal. This category belongs to a document
+   * given earlier by {@link #setNextDoc(int, float)}.
+   */
+  void aggregate(int ordinal);
+
+}