LUCENE-3606: move norms reading to codec

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene3606@1210268 13f79535-47bb-0310-9956-ffa450edef68

lucene/src/java/org/apache/lucene/index/NormsConsumer.java

@@ -61,6 +61,8 @@ final class NormsConsumer extends InvertedDocEndConsumer {
       for (FieldInfo fi : state.fieldInfos) {
         final NormsConsumerPerField toWrite = (NormsConsumerPerField) fieldsToFlush.get(fi);
         int upto = 0;
+        // we must check the final value of omitNorms for the fieldinfo, it could have 
+        // changed for this field since the first time we added it.
         if (!fi.omitNorms && toWrite != null && toWrite.upto > 0) {
           normsOut.startField(fi);
           int docID = 0;

lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.apache.lucene.index.codecs.Codec;
+import org.apache.lucene.index.codecs.NormsReader;
 import org.apache.lucene.index.codecs.PostingsFormat;
 import org.apache.lucene.index.codecs.FieldsProducer;
 import org.apache.lucene.index.codecs.StoredFieldsReader;
@@ -48,6 +49,7 @@ final class SegmentCoreReaders {
   
   final FieldsProducer fields;
   final PerDocValues perDocProducer;
+  final NormsReader norms;
 
   final Directory dir;
   final Directory cfsDir;
@@ -92,6 +94,8 @@ final class SegmentCoreReaders {
       // Ask codec for its Fields
       fields = format.fieldsProducer(segmentReadState);
       assert fields != null;
+      // ask codec for its Norms
+      norms = codec.normsFormat().normsReader(cfsDir, si, fieldInfos, context, dir);
       perDocProducer = codec.docValuesFormat().docsProducer(segmentReadState);
       success = true;
     } finally {
@@ -126,7 +130,7 @@ final class SegmentCoreReaders {
   synchronized void decRef() throws IOException {
     if (ref.decrementAndGet() == 0) {
       IOUtils.close(fields, perDocProducer, termVectorsReaderOrig,
-          fieldsReaderOrig, cfsReader, storeCFSReader);
+          fieldsReaderOrig, cfsReader, storeCFSReader, norms);
       // Now, notify any ReaderFinished listeners:
       if (owner != null) {
         owner.notifyReaderFinishedListeners();

lucene/src/java/org/apache/lucene/index/SegmentNorms.java

@@ -1,187 +0,0 @@
-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.io.IOException;
-import java.util.concurrent.atomic.AtomicInteger;
-
-import org.apache.lucene.store.FlushInfo;
-import org.apache.lucene.store.IOContext;
-import org.apache.lucene.store.IndexInput;
-import org.apache.lucene.store.IndexOutput;
-/**
- * Byte[] referencing is used because a new norm object needs 
- * to be created for each clone, and the byte array is all 
- * that is needed for sharing between cloned readers.  The 
- * current norm referencing is for sharing between readers 
- * whereas the byte[] referencing is for copy on write which 
- * is independent of reader references (i.e. incRef, decRef).
- */
-
-final class SegmentNorms implements Cloneable {
-
-  int refCount = 1;
-
-  // If this instance is a clone, the originalNorm
-  // references the Norm that has a real open IndexInput:
-  private SegmentNorms origNorm;
-
-  private IndexInput in;
-  private long normSeek;
-
-  // null until bytes is set
-  private AtomicInteger bytesRef;
-  private byte[] bytes;
-  private int number;
-  
-  private final SegmentReader owner;
-  
-  public SegmentNorms(IndexInput in, int number, long normSeek, SegmentReader owner) {
-    this.in = in;
-    this.number = number;
-    this.normSeek = normSeek;
-    this.owner = owner;
-  }
-
-  public synchronized void incRef() {
-    assert refCount > 0 && (origNorm == null || origNorm.refCount > 0);
-    refCount++;
-  }
-
-  private void closeInput() throws IOException {
-    if (in != null) {
-      if (in != owner.singleNormStream) {
-        // It's private to us -- just close it
-        in.close();
-      } else {
-        // We are sharing this with others -- decRef and
-        // maybe close the shared norm stream
-        if (owner.singleNormRef.decrementAndGet() == 0) {
-          owner.singleNormStream.close();
-          owner.singleNormStream = null;
-        }
-      }
-
-      in = null;
-    }
-  }
-
-  public synchronized void decRef() throws IOException {
-    assert refCount > 0 && (origNorm == null || origNorm.refCount > 0);
-
-    if (--refCount == 0) {
-      if (origNorm != null) {
-        origNorm.decRef();
-        origNorm = null;
-      } else {
-        closeInput();
-      }
-
-      if (bytes != null) {
-        assert bytesRef != null;
-        bytesRef.decrementAndGet();
-        bytes = null;
-        bytesRef = null;
-      } else {
-        assert bytesRef == null;
-      }
-    }
-  }
-
-  // Load & cache full bytes array.  Returns bytes.
-  public synchronized byte[] bytes() throws IOException {
-    assert refCount > 0 && (origNorm == null || origNorm.refCount > 0);
-    if (bytes == null) {                     // value not yet read
-      assert bytesRef == null;
-      if (origNorm != null) {
-        // Ask origNorm to load so that for a series of
-        // reopened readers we share a single read-only
-        // byte[]
-        bytes = origNorm.bytes();
-        bytesRef = origNorm.bytesRef;
-        bytesRef.incrementAndGet();
-
-        // Once we've loaded the bytes we no longer need
-        // origNorm:
-        origNorm.decRef();
-        origNorm = null;
-
-      } else {
-        // We are the origNorm, so load the bytes for real
-        // ourself:
-        final int count = owner.maxDoc();
-        bytes = new byte[count];
-
-        // Since we are orig, in must not be null
-        assert in != null;
-
-        // Read from disk.
-        synchronized(in) {
-          in.seek(normSeek);
-          in.readBytes(bytes, 0, count, false);
-        }
-
-        bytesRef = new AtomicInteger(1);
-        closeInput();
-      }
-    }
-
-    return bytes;
-  }
-
-  // Only for testing
-  AtomicInteger bytesRef() {
-    return bytesRef;
-  }
-  
-  // Returns a copy of this Norm instance that shares
-  // IndexInput & bytes with the original one
-  @Override
-  public synchronized Object clone() {
-    assert refCount > 0 && (origNorm == null || origNorm.refCount > 0);
-      
-    SegmentNorms clone;
-    try {
-      clone = (SegmentNorms) super.clone();
-    } catch (CloneNotSupportedException cnse) {
-      // Cannot happen
-      throw new RuntimeException("unexpected CloneNotSupportedException", cnse);
-    }
-    clone.refCount = 1;
-
-    if (bytes != null) {
-      assert bytesRef != null;
-      assert origNorm == null;
-
-      // Clone holds a reference to my bytes:
-      clone.bytesRef.incrementAndGet();
-    } else {
-      assert bytesRef == null;
-      if (origNorm == null) {
-        // I become the origNorm for the clone:
-        clone.origNorm = this;
-      }
-      clone.origNorm.incRef();
-    }
-
-    // Only the origNorm will actually readBytes from in:
-    clone.in = null;
-
-    return clone;
-  }
-}

lucene/src/java/org/apache/lucene/index/SegmentReader.java

@@ -20,25 +20,20 @@ package org.apache.lucene.index;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.apache.lucene.store.Directory;
-import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.index.FieldInfo.IndexOptions;
 import org.apache.lucene.index.codecs.StoredFieldsReader;
 import org.apache.lucene.index.codecs.PerDocValues;
 import org.apache.lucene.index.codecs.TermVectorsReader;
-import org.apache.lucene.index.codecs.lucene40.Lucene40NormsWriter;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.BitVector;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.CloseableThreadLocal;
-import org.apache.lucene.util.StringHelper;
 
 /**
  * @lucene.experimental
@@ -65,10 +60,6 @@ public class SegmentReader extends IndexReader implements Cloneable {
   private SegmentInfo rollbackSegmentInfo;
   private int rollbackPendingDeleteCount;
 
-  // optionally used for the .nrm file shared by multiple norms
-  IndexInput singleNormStream;
-  AtomicInteger singleNormRef;
-
   SegmentCoreReaders core;
 
   /**
@@ -80,8 +71,6 @@ public class SegmentReader extends IndexReader implements Cloneable {
       return core.getFieldsReaderOrig().clone();
     }
   }
-
-  Map<String,SegmentNorms> norms = new HashMap<String,SegmentNorms>();
   
   /**
    * @throws CorruptIndexException if the index is corrupt
@@ -114,7 +103,6 @@ public class SegmentReader extends IndexReader implements Cloneable {
         instance.core.openDocStores(si);
       }
       instance.loadLiveDocs(context);
-      instance.openNorms(instance.core.cfsDir, context);
       success = true;
     } finally {
 
@@ -278,24 +266,6 @@ public class SegmentReader extends IndexReader implements Cloneable {
           clone.liveDocsRef = liveDocsRef;
         }
       }
-
-      clone.norms = new HashMap<String,SegmentNorms>();
-
-      // Clone norms
-      for (FieldInfo fi : core.fieldInfos) {
-        // Clone unchanged norms to the cloned reader
-        if (doClone || !fieldNormsChanged.contains(fi.number)) {
-          final String curField = fi.name;
-          SegmentNorms norm = this.norms.get(curField);
-          if (norm != null)
-            clone.norms.put(curField, (SegmentNorms) norm.clone());
-        }
-      }
-
-      // If we are not cloning, then this will open anew
-      // any norms that have changed:
-      clone.openNorms(si.getUseCompoundFile() ? core.getCFSReader() : directory(), IOContext.DEFAULT);
-
       success = true;
     } finally {
       if (!success) {
@@ -395,9 +365,6 @@ public class SegmentReader extends IndexReader implements Cloneable {
       liveDocs = null;
     }
 
-    for (final SegmentNorms norm : norms.values()) {
-      norm.decRef();
-    }
     if (core != null) {
       core.decRef();
     }
@@ -545,95 +512,14 @@ public class SegmentReader extends IndexReader implements Cloneable {
   @Override
   public boolean hasNorms(String field) {
     ensureOpen();
-    return norms.containsKey(field);
+    FieldInfo fi = core.fieldInfos.fieldInfo(field);
+    return fi != null && fi.isIndexed && !fi.omitNorms;
   }
 
   @Override
   public byte[] norms(String field) throws IOException {
     ensureOpen();
-    final SegmentNorms norm = norms.get(field);
+    return core.norms.norms(field);
-    if (norm == null) {
-      // not indexed, or norms not stored
-      return null;  
-    }
-    return norm.bytes();
-  }
-
-  private void openNorms(Directory cfsDir, IOContext context) throws IOException {
-    boolean normsInitiallyEmpty = norms.isEmpty(); // only used for assert
-    long nextNormSeek = Lucene40NormsWriter.NORMS_HEADER.length; //skip header (header unused for now)
-    int maxDoc = maxDoc();
-    for (FieldInfo fi : core.fieldInfos) {
-      if (norms.containsKey(fi.name)) {
-        // in case this SegmentReader is being re-opened, we might be able to
-        // reuse some norm instances and skip loading them here
-        continue;
-      }
-      if (fi.isIndexed && !fi.omitNorms) {
-        Directory d = directory();
-        String fileName = si.getNormFileName(fi.number);
-        if (!si.hasSeparateNorms(fi.number)) {
-          d = cfsDir;
-        }
-        
-        // singleNormFile means multiple norms share this file
-        boolean singleNormFile = IndexFileNames.matchesExtension(fileName, IndexFileNames.NORMS_EXTENSION);
-        IndexInput normInput = null;
-        long normSeek;
-
-        if (singleNormFile) {
-          normSeek = nextNormSeek;
-          if (singleNormStream == null) {
-            singleNormStream = d.openInput(fileName, context);
-            singleNormRef = new AtomicInteger(1);
-          } else {
-            singleNormRef.incrementAndGet();
-          }
-          // All norms in the .nrm file can share a single IndexInput since
-          // they are only used in a synchronized context.
-          // If this were to change in the future, a clone could be done here.
-          normInput = singleNormStream;
-        } else {
-          normInput = d.openInput(fileName, context);
-          // if the segment was created in 3.2 or after, we wrote the header for sure,
-          // and don't need to do the sketchy file size check. otherwise, we check 
-          // if the size is exactly equal to maxDoc to detect a headerless file.
-          // NOTE: remove this check in Lucene 5.0!
-          String version = si.getVersion();
-          final boolean isUnversioned = 
-            (version == null || StringHelper.getVersionComparator().compare(version, "3.2") < 0)
-            && normInput.length() == maxDoc();
-          if (isUnversioned) {
-            normSeek = 0;
-          } else {
-            normSeek = Lucene40NormsWriter.NORMS_HEADER.length;
-          }
-        }
-
-        norms.put(fi.name, new SegmentNorms(normInput, fi.number, normSeek, this));
-        nextNormSeek += maxDoc; // increment also if some norms are separate
-      }
-    }
-    // nocommit: change to a real check? see LUCENE-3619
-    assert singleNormStream == null || !normsInitiallyEmpty || nextNormSeek == singleNormStream.length();
-  }
-
-  // for testing only
-  boolean normsClosed() {
-    if (singleNormStream != null) {
-      return false;
-    }
-    for (final SegmentNorms norm : norms.values()) {
-      if (norm.refCount > 0) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  // for testing only
-  boolean normsClosed(String field) {
-    return norms.get(field).refCount == 0;
   }
 
   /**

lucene/src/java/org/apache/lucene/index/codecs/NormsFormat.java

@@ -20,14 +20,18 @@ package org.apache.lucene.index.codecs;
 import java.io.IOException;
 import java.util.Set;
 
+import org.apache.lucene.index.FieldInfos;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentWriteState;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 
 /**
  * format for normalization factors
  */
 public abstract class NormsFormat {
+  /** Note: separateNormsDir should not be used! */
+  public abstract NormsReader normsReader(Directory dir, SegmentInfo info, FieldInfos fields, IOContext context, Directory separateNormsDir) throws IOException;
   public abstract NormsWriter normsWriter(SegmentWriteState state) throws IOException;
   public abstract void files(Directory dir, SegmentInfo info, Set<String> files) throws IOException;
 }

lucene/src/java/org/apache/lucene/index/codecs/NormsReader.java

@@ -0,0 +1,26 @@
+package org.apache.lucene.index.codecs;
+
+/**
+ * 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.Closeable;
+import java.io.IOException;
+
+//simple api just for now before switching to docvalues apis
+public abstract class NormsReader implements Closeable {
+  public abstract byte[] norms(String name) throws IOException;
+}

lucene/src/java/org/apache/lucene/index/codecs/lucene40/Lucene40NormsFormat.java

@@ -20,14 +20,22 @@ package org.apache.lucene.index.codecs.lucene40;
 import java.io.IOException;
 import java.util.Set;
 
+import org.apache.lucene.index.FieldInfos;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentWriteState;
 import org.apache.lucene.index.codecs.NormsFormat;
+import org.apache.lucene.index.codecs.NormsReader;
 import org.apache.lucene.index.codecs.NormsWriter;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 
 public class Lucene40NormsFormat extends NormsFormat {
 
+  @Override
+  public NormsReader normsReader(Directory dir, SegmentInfo info, FieldInfos fields, IOContext context, Directory separateNormsDir) throws IOException {
+    return new Lucene40NormsReader(dir, info, fields, context, separateNormsDir);
+  }
+
   @Override
   public NormsWriter normsWriter(SegmentWriteState state) throws IOException {
     return new Lucene40NormsWriter(state.directory, state.segmentName, state.context);

lucene/src/java/org/apache/lucene/index/codecs/lucene40/Lucene40NormsReader.java

@@ -0,0 +1,153 @@
+package org.apache.lucene.index.codecs.lucene40;
+
+/**
+ * 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 java.util.HashMap;
+import java.util.IdentityHashMap;
+import java.util.Map;
+
+import org.apache.lucene.index.FieldInfo;
+import org.apache.lucene.index.FieldInfos;
+import org.apache.lucene.index.IndexFileNames;
+import org.apache.lucene.index.SegmentInfo;
+import org.apache.lucene.index.codecs.NormsReader;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.util.IOUtils;
+import org.apache.lucene.util.StringHelper;
+
+public class Lucene40NormsReader extends NormsReader {
+  // this would be replaced by Source/SourceCache in a dv impl.
+  // for now we have our own mini-version
+  Map<String,Norm> norms = new HashMap<String,Norm>();
+  // any .nrm or .sNN files we have open at any time.
+  // TODO: just a list, and double-close() separate norms files?
+  Map<IndexInput,Boolean> openFiles = new IdentityHashMap<IndexInput,Boolean>();
+  // points to a singleNormFile
+  IndexInput singleNormStream;
+  final int maxdoc;
+  
+  // note: just like segmentreader in 3.x, we open up all the files here (including separate norms) up front.
+  // but we just don't do any seeks or reading yet.
+  public Lucene40NormsReader(Directory dir, SegmentInfo info, FieldInfos fields, IOContext context, Directory separateNormsDir) throws IOException {
+    maxdoc = info.docCount;
+    boolean success = false;
+    try {
+      long nextNormSeek = Lucene40NormsWriter.NORMS_HEADER.length; //skip header (header unused for now)
+      for (FieldInfo fi : fields) {
+        if (fi.isIndexed && !fi.omitNorms) {
+          String fileName = info.getNormFileName(fi.number);
+          Directory d = info.hasSeparateNorms(fi.number) ? separateNormsDir : dir;
+        
+          // singleNormFile means multiple norms share this file
+          boolean singleNormFile = IndexFileNames.matchesExtension(fileName, IndexFileNames.NORMS_EXTENSION);
+          IndexInput normInput = null;
+          long normSeek;
+
+          if (singleNormFile) {
+            normSeek = nextNormSeek;
+            if (singleNormStream == null) {
+              singleNormStream = d.openInput(fileName, context);
+              openFiles.put(singleNormStream, Boolean.TRUE);
+            }
+            // All norms in the .nrm file can share a single IndexInput since
+            // they are only used in a synchronized context.
+            // If this were to change in the future, a clone could be done here.
+            normInput = singleNormStream;
+          } else {
+            normInput = d.openInput(fileName, context);
+            openFiles.put(normInput, Boolean.TRUE);
+            // if the segment was created in 3.2 or after, we wrote the header for sure,
+            // and don't need to do the sketchy file size check. otherwise, we check 
+            // if the size is exactly equal to maxDoc to detect a headerless file.
+            // NOTE: remove this check in Lucene 5.0!
+            String version = info.getVersion();
+            final boolean isUnversioned = 
+                (version == null || StringHelper.getVersionComparator().compare(version, "3.2") < 0)
+                && normInput.length() == maxdoc;
+            if (isUnversioned) {
+              normSeek = 0;
+            } else {
+              normSeek = Lucene40NormsWriter.NORMS_HEADER.length;
+            }
+          }
+
+          Norm norm = new Norm();
+          norm.file = normInput;
+          norm.offset = normSeek;
+          norms.put(fi.name, norm);
+          nextNormSeek += maxdoc; // increment also if some norms are separate
+        }
+      }
+      // nocommit: change to a real check? see LUCENE-3619
+      assert singleNormStream == null || nextNormSeek == singleNormStream.length();
+      success = true;
+    } finally {
+      if (!success) {
+        if (openFiles != null) {
+          IOUtils.closeWhileHandlingException(openFiles.keySet());
+        }
+      }
+    }
+  }
+  
+  @Override
+  public byte[] norms(String name) throws IOException {
+    Norm norm = norms.get(name);
+    return norm == null ? null : norm.bytes();
+  }
+  
+
+  @Override
+  public void close() throws IOException {
+    try {
+      if (openFiles != null) {
+        IOUtils.close(openFiles.keySet());
+      }
+    } finally {
+      norms = null;
+      openFiles = null;
+    }
+  }
+  
+  class Norm {
+    IndexInput file;
+    long offset;
+    byte bytes[];
+    
+    synchronized byte[] bytes() throws IOException {
+      if (bytes == null) {
+        bytes = new byte[maxdoc];
+        // some norms share fds
+        synchronized(file) {
+          file.seek(offset);
+          file.readBytes(bytes, 0, bytes.length, false);
+        }
+        // we are done with this file
+        if (file != singleNormStream) {
+          openFiles.remove(file);
+          file.close();
+          file = null;
+        }
+      }
+      return bytes;
+    }
+  }
+}

lucene/src/java/org/apache/lucene/index/codecs/lucene40/Lucene40NormsWriter.java

@@ -62,8 +62,8 @@ public class Lucene40NormsWriter extends NormsWriter {
   
   @Override
   public void finish(int numDocs) throws IOException {
-    if (4+normCount*numDocs != out.getFilePointer()) {
+    if (4+normCount*(long)numDocs != out.getFilePointer()) {
-      throw new RuntimeException(".nrm file size mismatch: expected=" + (4+normCount*numDocs) + " actual=" + out.getFilePointer());
+      throw new RuntimeException(".nrm file size mismatch: expected=" + (4+normCount*(long)numDocs) + " actual=" + out.getFilePointer());
     }
   }
 

lucene/src/test/org/apache/lucene/index/TestIndexReaderReopen.java

@@ -761,7 +761,8 @@ public class TestIndexReaderReopen extends LuceneTestCase {
     assertEquals(0, reader.getRefCount());
     
     if (checkNormsClosed && reader instanceof SegmentReader) {
-      assertTrue(((SegmentReader) reader).normsClosed());
+      // TODO: should we really assert something here? we check for open files and this is obselete...
+      // assertTrue(((SegmentReader) reader).normsClosed());
     }
     
     if (checkSubReaders) {