kaivalnp commented on code in PR #15979: URL: https://github.com/apache/lucene/pull/15979#discussion_r3647782409
########## lucene/core/src/java/org/apache/lucene/codecs/lucene106/dedup/DedupUtil.java: ########## @@ -0,0 +1,562 @@ +/* + * 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.lucene106.dedup; + +import static org.apache.lucene.index.VectorEncoding.BYTE; +import static org.apache.lucene.index.VectorEncoding.FLOAT32; +import static org.apache.lucene.util.StringHelper.GOOD_FAST_HASH_SEED; +import static org.apache.lucene.util.StringHelper.murmurhash3_x64_128; + +import java.io.IOException; +import org.apache.lucene.codecs.hnsw.FlatVectorsScorer; +import org.apache.lucene.codecs.lucene95.OffHeapByteVectorValues; +import org.apache.lucene.codecs.lucene95.OffHeapFloatVectorValues; +import org.apache.lucene.codecs.lucene95.OrdToDocDISIReaderConfiguration; +import org.apache.lucene.index.ByteVectorValues; +import org.apache.lucene.index.DocsWithFieldSet; +import org.apache.lucene.index.FieldInfo; +import org.apache.lucene.index.FloatVectorValues; +import org.apache.lucene.index.KnnVectorValues; +import org.apache.lucene.index.VectorEncoding; +import org.apache.lucene.index.VectorSimilarityFunction; +import org.apache.lucene.internal.hppc.IntArrayList; +import org.apache.lucene.search.DocIdSetIterator; +import org.apache.lucene.search.VectorScorer; +import org.apache.lucene.store.IndexInput; +import org.apache.lucene.store.IndexOutput; +import org.apache.lucene.store.RandomAccessInput; +import org.apache.lucene.util.ArrayUtil; +import org.apache.lucene.util.LongValues; +import org.apache.lucene.util.hnsw.RandomVectorScorer; +import org.apache.lucene.util.packed.DirectReader; +import org.apache.lucene.util.packed.DirectWriter; + +/** + * Shared helpers for the de-duplicating flat format: reading / writing field and group metadata, + * vector hashing and alignment, and the {@link DedupVectorValues} views used on the read path. + * + * @lucene.experimental + */ +final class DedupUtil { + + private static final int DIRECT_MONOTONIC_BLOCK_SHIFT = 16; + + private static final int END_MARKER = -1; + + private static final int ORD_TO_VEC_ALIGN_BYTES = 4; + + // TODO: Evaluate using fewer bits. + private static final int ORD_TO_VEC_BITS_PER_VALUE = 32; + + static final int ORD_UNKNOWN = -1; + + static final int SCRATCH_SIZE = 16; + + /** Key used to group vectors (dimension + encoding). */ + record GroupKey(int dimension, VectorEncoding encoding) { + GroupKey(FieldInfo fieldInfo) { + this(fieldInfo.getVectorDimension(), fieldInfo.getVectorEncoding()); + } + } + + /** + * Vector values that share a single copy of each distinct vector across the documents and fields + * that reference it. + * + * <p>Every instance is backed by two views: the {@code delegate} maps ordinals to docs and drives + * iteration (one entry per document), while the {@code groupView} holds the de-duplicated vectors + * (one entry per distinct vector). {@code ordToVecOrd} translates a document ordinal into its + * group ordinal. + */ + sealed interface DedupVectorValues { + /** The dense view over distinct vectors, indexed by group ordinal. */ + KnnVectorValues getGroupView(); + + /** Maps a per-document ordinal to its group ordinal in {@link #getGroupView()}. */ + OrdToVecOrd getOrdToVecOrd(); + } + + /** + * Maps a field's per-document ordinal to the ordinal of its (shared) vector within the group. + * Backed on-heap while writing and off-heap while reading. + */ + sealed interface OrdToVecOrd { Review Comment: I don't think we can have `final` interfaces (only concrete classes can have it) -- `sealed` ensures that all implementations of this interface are `final`-ized themselves. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
