@@ -32,9 +32,12 @@ public interface PointWriter extends Closeable {
   /** Add a new point from byte array*/
   void append(byte[] packedValue, int docID) throws IOException;
 
-  /** Add a new point from byteRef */
+  /** Add a new point from byteRef and docId */
   void append(BytesRef packedValue, int docID) throws IOException;
 
+  /** Add a new point from byteRef. The last 4 bytes contain the docID*/
+  void append(BytesRef packedValueWithDocId) throws IOException;
+
   /** Returns a {@link PointReader} iterator to step through all previously added points */
   PointReader getReader(long startPoint, long length) throws 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.
 */
package org.apache.lucene.util.bkd;


import java.io.Closeable;
import java.io.IOException;

import org.apache.lucene.util.BytesRef;

/** Appends many points, and then at the end provides a {@link PointReader} to iterate
 *  those points.  This abstracts away whether we write to disk, or use simple arrays
 *  in heap.
 *
 *  @lucene.internal
 *  */
public interface PointWriter extends Closeable {
  /** Add a new point from byte array*/
  void append(byte[] packedValue, int docID) throws IOException;

  /** Add a new point from byteRef */
  void append(BytesRef packedValue, int docID) throws IOException;

  /** Returns a {@link PointReader} iterator to step through all previously added points */
  PointReader getReader(long startPoint, long length) throws IOException;

  /** Return the number of points in this writer */
  long count();

  /** Removes any temp files behind this writer */
  void destroy() throws IOException;

}


I don't like that this interface has 3 different append methods. I think it should have at most 2. From what I can tell we can easily get rid of `void append(byte[] packedValue, int docID)` and use a _scratch_ value where necessary. the `void append(BytesRef packedValueWithDocId) throws IOException;` method is difficult since it expects the format to be correct. I would feel much better if we had a way to verify that the format is correct like passing the reader instead of a bytesRef or a dedicated interface.