test untested class

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1334738 13f79535-47bb-0310-9956-ffa450edef68

lucene/misc/src/java/org/apache/lucene/index/BalancedSegmentMergePolicy.java

@@ -45,11 +45,12 @@ public class BalancedSegmentMergePolicy extends LogByteSizeMergePolicy {
 
   public void setMergePolicyParams(MergePolicyParams params) {
     if (params!=null) {
+      // note: this order is important!
+      setMergeFactor(params._mergeFactor);
       setPartialExpunge(params._doPartialExpunge);
       setNumLargeSegments(params._numLargeSegments);
       setMaxSmallSegments(params._maxSmallSegments);
       setPartialExpunge(params._doPartialExpunge);
-      setMergeFactor(params._mergeFactor);
       setUseCompoundFile(params._useCompoundFile);
       setMaxMergeDocs(params._maxMergeDocs);
     }

lucene/misc/src/test/org/apache/lucene/index/TestBalancedSegmentMergePolicy.java

@@ -0,0 +1,87 @@
+package org.apache.lucene.index;
+
+/**
+ * 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.util.Random;
+
+import org.apache.lucene.analysis.MockAnalyzer;
+import org.apache.lucene.codecs.Codec;
+import org.apache.lucene.index.BalancedSegmentMergePolicy.MergePolicyParams;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.util.LineFileDocs;
+import org.apache.lucene.util.LuceneTestCase;
+import org.apache.lucene.util._TestUtil;
+
+/**
+ * Simple tests for {@link BalancedSegmentMergePolicy}
+ * doesn't actually test that this thing does what it says it should,
+ * just merges with it!
+ */
+public class TestBalancedSegmentMergePolicy extends LuceneTestCase {
+  Directory dir;
+  RandomIndexWriter iw;
+  
+  public void setUp() throws Exception {
+    super.setUp();
+    dir = newDirectory();
+    IndexWriterConfig iwc = newIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random()));
+    BalancedSegmentMergePolicy mp = new BalancedSegmentMergePolicy();
+    mp.setMergePolicyParams(newMergePolicyParams(random()));
+    iwc.setMergePolicy(mp);
+    iw = new RandomIndexWriter(random(), dir, iwc);
+    LineFileDocs docs = new LineFileDocs(random(), !Codec.getDefault().getName().equals("Lucene3x"));
+    int numDocs = atLeast(200);
+    for (int i = 0; i < numDocs; i++) {
+      iw.addDocument(docs.nextDoc());
+      if (random().nextInt(6) == 0) {
+        iw.deleteDocuments(new Term("docid", Integer.toString(i)));
+      }
+      if (random().nextInt(10) == 0) {
+        iw.commit();
+      }
+    }
+  }
+  
+  public void tearDown() throws Exception {
+    iw.close();
+    dir.close();
+    super.tearDown();
+  }
+  
+  public void testForceMerge() throws Exception {
+    int numSegments = _TestUtil.nextInt(random(), 1, 4);
+    iw.forceMerge(numSegments);
+    DirectoryReader ir = iw.getReader();
+    assertTrue(ir.getSequentialSubReaders().length <= numSegments);
+    ir.close();
+  }
+  
+  private static MergePolicyParams newMergePolicyParams(Random random) {
+    MergePolicyParams params = new MergePolicyParams();
+    if (rarely(random)) {
+      params.setMergeFactor(_TestUtil.nextInt(random, 2, 9));
+    } else {
+      params.setMergeFactor(_TestUtil.nextInt(random, 10, 50));
+    }
+    int mergeFactor = params.getMergeFactor();
+    params.setMaxSmallSegments(_TestUtil.nextInt(random, mergeFactor, mergeFactor*2));
+    params.setNumLargeSegments(_TestUtil.nextInt(random, 2, 3));
+    params.setUseCompoundFile(random.nextBoolean());
+    return params;
+  }
+}