pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / index / LogDocMergePolicy.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/index/LogDocMergePolicy.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/index/LogDocMergePolicy.java
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+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/index/LogDocMergePolicy.java
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+package org.apache.lucene.index;
+
+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.
+ */
+
+/** This is a {@link LogMergePolicy} that measures size of a
+ *  segment as the number of documents (not taking deletions
+ *  into account). */
+
+public class LogDocMergePolicy extends LogMergePolicy {
+
+  /** Default minimum segment size.  @see setMinMergeDocs */
+  public static final int DEFAULT_MIN_MERGE_DOCS = 1000;
+
+  public LogDocMergePolicy() {
+    minMergeSize = DEFAULT_MIN_MERGE_DOCS;
+    
+    // maxMergeSize(ForForcedMerge) are never used by LogDocMergePolicy; set
+    // it to Long.MAX_VALUE to disable it
+    maxMergeSize = Long.MAX_VALUE;
+    maxMergeSizeForForcedMerge = Long.MAX_VALUE;
+  }
+
+  @Override
+  protected long size(SegmentInfo info) throws IOException {
+    return sizeDocs(info);
+  }
+
+  /** Sets the minimum size for the lowest level segments.
+   * Any segments below this size are considered to be on
+   * the same level (even if they vary drastically in size)
+   * and will be merged whenever there are mergeFactor of
+   * them.  This effectively truncates the "long tail" of
+   * small segments that would otherwise be created into a
+   * single level.  If you set this too large, it could
+   * greatly increase the merging cost during indexing (if
+   * you flush many small segments). */
+  public void setMinMergeDocs(int minMergeDocs) {
+    minMergeSize = minMergeDocs;
+  }
+
+  /** Get the minimum size for a segment to remain
+   *  un-merged.
+   *  @see #setMinMergeDocs **/
+  public int getMinMergeDocs() {
+    return (int) minMergeSize;
+  }
+}