De-dup raw vectors?

lucene/core/src/java/org/apache/lucene/codecs/lucene104/Lucene104FlatVectorsFormat.java

@@ -0,0 +1,70 @@
+/*
+ * 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.codecs.lucene104;
+
+import java.io.IOException;
+import org.apache.lucene.codecs.hnsw.FlatVectorsFormat;
+import org.apache.lucene.codecs.hnsw.FlatVectorsReader;
+import org.apache.lucene.codecs.hnsw.FlatVectorsScorer;
+import org.apache.lucene.codecs.hnsw.FlatVectorsWriter;
+import org.apache.lucene.codecs.lucene90.IndexedDISI;
+import org.apache.lucene.index.SegmentReadState;
+import org.apache.lucene.index.SegmentWriteState;
+import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.store.IndexOutput;
+
+/**
+ * Lucene 10.4 flat vector format, details TBD.
+ *
+ * @lucene.experimental
+ */
+public final class Lucene104FlatVectorsFormat extends FlatVectorsFormat {
+
+  static final String NAME = "Lucene104FlatVectorsFormat";
+  static final String META_CODEC_NAME = "Lucene104FlatVectorsFormatMeta";
+  static final String VECTOR_DATA_CODEC_NAME = "Lucene104FlatVectorsFormatData";
+  static final String META_EXTENSION = "vemf";
+  static final String VECTOR_DATA_EXTENSION = "vec";
+
+  public static final int VERSION_START = 0;
+  public static final int VERSION_CURRENT = VERSION_START;
+
+  static final int DIRECT_MONOTONIC_BLOCK_SHIFT = 16;
+  private final FlatVectorsScorer vectorsScorer;
+
+  /** Constructs a format */
+  public Lucene104FlatVectorsFormat(FlatVectorsScorer vectorsScorer) {
+    super(NAME);
+    this.vectorsScorer = vectorsScorer;
+  }
+
+  @Override
+  public FlatVectorsWriter fieldsWriter(SegmentWriteState state) throws IOException {
+    return new Lucene104FlatVectorsWriter(state, vectorsScorer);
+  }
+
+  @Override
+  public FlatVectorsReader fieldsReader(SegmentReadState state) throws IOException {
+    return new Lucene104FlatVectorsReader(state, vectorsScorer);
+  }
+
+  @Override
+  public String toString() {
+    return "Lucene104FlatVectorsFormat(" + "vectorsScorer=" + vectorsScorer + ')';
+  }
+}