LUCENE-6533: don't cache live docs in SlowCompositeReaderWrapper

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1684615 13f79535-47bb-0310-9956-ffa450edef68

lucene/CHANGES.txt

@@ -95,6 +95,10 @@ Bug fixes
 * LUCENE-6527: Queries now get a dummy Similarity when scores are not needed
   in order to not load unnecessary information like norms. (Adrien Grand)
 
+* LUCENE-6533: SlowCompositeReaderWrapper no longer caches its live docs
+  instance since this can prevent future improvements like a
+  disk-backed live docs (Adrien Grand, Mike McCandless)
+
 Changes in Runtime Behavior
 
 * LUCENE-6501: The subreader structure in ParallelCompositeReader

lucene/core/src/java/org/apache/lucene/index/SlowCompositeReaderWrapper.java

@@ -46,7 +46,6 @@ public final class SlowCompositeReaderWrapper extends LeafReader {
 
   private final CompositeReader in;
   private final Fields fields;
-  private final Bits liveDocs;
   private final boolean merging;
   
   /** This method is sugar for getting an {@link LeafReader} from
@@ -66,7 +65,6 @@ public final class SlowCompositeReaderWrapper extends LeafReader {
     super();
     in = reader;
     fields = MultiFields.getFields(in);
-    liveDocs = MultiFields.getLiveDocs(in);
     in.registerParentReader(this);
     this.merging = merging;
   }
@@ -230,7 +228,7 @@ public final class SlowCompositeReaderWrapper extends LeafReader {
   @Override
   public Bits getLiveDocs() {
     ensureOpen();
-    return liveDocs;
+    return MultiFields.getLiveDocs(in);
   }
 
   @Override

lucene/test-framework/src/test/org/apache/lucene/index/TestAssertingLeafReader.java

@@ -0,0 +1,74 @@
+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 org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
+import org.apache.lucene.search.QueryUtils.FCInvisibleMultiReader;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.util.Bits;
+import org.apache.lucene.util.IOUtils;
+import org.apache.lucene.util.LuceneTestCase;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+public class TestAssertingLeafReader extends LuceneTestCase {
+  public void testAssertBits() throws Exception {
+    Directory dir = newDirectory();
+    IndexWriter w = new IndexWriter(dir, newIndexWriterConfig());
+    // Not deleted:
+    w.addDocument(new Document());
+
+    // Does get deleted:
+    Document doc = new Document();
+    doc.add(newStringField("id", "0", Field.Store.NO));
+    w.addDocument(doc);
+    w.commit();
+
+    w.deleteDocuments(new Term("id", "0"));
+    w.close();
+
+    // Now we have index with 1 segment with 2 docs one of which is marked deleted
+
+    IndexReader r = DirectoryReader.open(dir);
+    assertEquals(1, r.leaves().size());
+    assertEquals(2, r.maxDoc());
+    assertEquals(1, r.numDocs());
+
+    r = new AssertingDirectoryReader((DirectoryReader) r);
+
+    final IndexReader r2 = SlowCompositeReaderWrapper.wrap(r);
+   
+    Thread thread = new Thread() {
+      @Override
+      public void run() {
+        for(LeafReaderContext context : r2.leaves()) {
+          context.reader().getLiveDocs().get(0);
+        }
+      }
+    };
+    thread.start();
+    thread.join();
+
+    IOUtils.close(r2, dir);
+  }
+}