iprithv commented on code in PR #16214:
URL: https://github.com/apache/lucene/pull/16214#discussion_r3374974915
##########
lucene/core/src/java/org/apache/lucene/index/ReadersAndUpdates.java:
##########
@@ -460,6 +510,187 @@ public long cost() {
}
}
+ /**
+ * Writes a new generation of KNN vector files for each field that has
pending vector updates. For
+ * each such field we bump a new {@code vectorGen}, write {@code
.vec/.vemf/.vex/.vem} files at
+ * that gen suffix where the vectors are the existing field vectors overlaid
with the updates, and
+ * the HNSW graph is rebuilt eagerly (via the standard {@link
KnnVectorsWriter} flush path). The
+ * base reader (gen == -1) plus other untouched fields are left in place.
Vector analogue of
+ * {@link #handleDVUpdates}.
+ */
+ @SuppressWarnings("unchecked")
+ private synchronized void handleVectorUpdates(
+ FieldInfos infos,
+ Directory dir,
+ KnnVectorsFormat vectorsFormat,
+ final SegmentReader reader,
+ Map<Integer, Set<String>> fieldFiles,
+ long maxDelGen,
+ InfoStream infoStream,
+ boolean deferVectorGraphRebuild)
+ throws IOException {
+ for (Entry<String, List<KnnVectorFieldUpdates>> ent :
pendingVectorUpdates.entrySet()) {
+ final String field = ent.getKey();
+ final List<KnnVectorFieldUpdates> updates = ent.getValue();
+ final List<KnnVectorFieldUpdates> updatesToApply = new ArrayList<>();
+ for (KnnVectorFieldUpdates update : updates) {
+ if (update.delGen <= maxDelGen) {
+ updatesToApply.add(update);
+ }
+ }
+ if (updatesToApply.isEmpty()) {
+ continue;
+ }
+
+ // Reject quantized formats: only the unquantized Lucene99 HNSW format
is supported for
+ // in-place vector updates.
+ KnnVectorsFormat perFieldFormat = vectorsFormat;
+ if (vectorsFormat instanceof PerFieldKnnVectorsFormat perField) {
+ perFieldFormat = perField.getKnnVectorsFormatForField(field);
+ }
+ if (perFieldFormat instanceof Lucene99HnswVectorsFormat == false) {
+ throw new UnsupportedOperationException(
+ "in-place vector update is only supported for "
+ + Lucene99HnswVectorsFormat.class.getSimpleName()
+ + " but field ["
+ + field
+ + "] uses "
+ + perFieldFormat.getClass().getSimpleName());
+ }
+
+ final long nextVectorGen = info.getNextVectorGen();
+ final String segmentSuffix = Long.toString(nextVectorGen,
Character.MAX_RADIX);
+ final IOContext updatesContext = IOContext.flush(new
FlushInfo(info.info.maxDoc(), 0));
+
+ // Stamp the new vectorGen onto the (shared, cloned) FieldInfo so it is
persisted by
+ // writeFieldInfosGen and picked up at read time. A single-field
FieldInfos is handed to the
+ // vectors writer for this gen.
+ final FieldInfo fieldInfo = infos.fieldInfo(field);
+ assert fieldInfo != null && fieldInfo.hasVectorValues();
+ fieldInfo.setVectorGen(nextVectorGen);
+ final FieldInfos fieldInfos = new FieldInfos(new FieldInfo[]
{fieldInfo});
+
+ // Choose the writer format for this generation. When deferring the
graph rebuild we write
+ // only
+ // the flat vectors and skip building the HNSW graph: the gen's
".vex/.vem" carry an empty
+ // graph
+ // (vectorIndexLength == 0), so the reader falls back to an exact scan
on this segment until
+ // the
+ // next merge rebuilds the graph using the codec's normal format. The
graph build is
+ // suppressed
+ // by raising the "tiny segment" threshold above the segment size (so
shouldCreateGraph() is
+ // always false for this write). We wrap it in a
PerFieldKnnVectorsFormat so file naming and
+ // the
+ // per-field suffix attributes match what the (always per-field) reader
reconstructs.
+ final KnnVectorsFormat writeFormat;
+ if (deferVectorGraphRebuild) {
+ final KnnVectorsFormat noGraphFormat =
+ new Lucene99HnswVectorsFormat(
+ Lucene99HnswVectorsFormat.DEFAULT_MAX_CONN,
+ Lucene99HnswVectorsFormat.DEFAULT_BEAM_WIDTH,
+ info.info.maxDoc() + 1);
+ writeFormat =
+ new PerFieldKnnVectorsFormat() {
+ @Override
+ public KnnVectorsFormat getKnnVectorsFormatForField(String f) {
+ return noGraphFormat;
+ }
+ };
+ } else {
+ writeFormat = vectorsFormat;
+ }
+
+ final TrackingDirectoryWrapper trackingDir = new
TrackingDirectoryWrapper(dir);
+ final SegmentWriteState state =
+ new SegmentWriteState(
+ null, trackingDir, info.info, fieldInfos, null, updatesContext,
segmentSuffix);
+
+ try (KnnVectorsWriter writer = writeFormat.fieldsWriter(state)) {
+ final KnnVectorFieldUpdates.Iterator mergedIterator =
+
KnnVectorFieldUpdates.mergedIterator(toIteratorArray(updatesToApply));
+ if (fieldInfo.getVectorEncoding() == VectorEncoding.FLOAT32) {
+ KnnFieldVectorsWriter<float[]> fieldWriter =
+ (KnnFieldVectorsWriter<float[]>) writer.addField(fieldInfo);
+ writeOverlayFloatVectors(reader, field, mergedIterator, fieldWriter);
+ } else {
+ KnnFieldVectorsWriter<byte[]> fieldWriter =
+ (KnnFieldVectorsWriter<byte[]>) writer.addField(fieldInfo);
+ writeOverlayByteVectors(reader, field, mergedIterator, fieldWriter);
+ }
+ writer.flush(info.info.maxDoc(), null);
+ writer.finish();
+ }
+
+ info.advanceVectorGen();
+ assert !fieldFiles.containsKey(fieldInfo.number);
+ fieldFiles.put(fieldInfo.number, trackingDir.getCreatedFiles());
+ }
+ }
+
+ private static KnnVectorFieldUpdates.Iterator[] toIteratorArray(
+ List<KnnVectorFieldUpdates> updatesToApply) {
+ KnnVectorFieldUpdates.Iterator[] subs =
+ new KnnVectorFieldUpdates.Iterator[updatesToApply.size()];
+ for (int i = 0; i < subs.length; i++) {
+ subs[i] = updatesToApply.get(i).iterator();
+ }
+ return subs;
+ }
+
+ /**
+ * Feeds the field writer, in docID order, every doc that currently has a
float vector for {@code
+ * field}, substituting the updated vector when the merged update iterator
has one for that doc.
+ */
+ private static void writeOverlayFloatVectors(
Review Comment:
If a user calls updateFloatVectorValue targeting a doc that doesn't actually
have a vector for that field, wouldn't the update just silently disappears? The
overlay loop only iterates docs that already have vectors, so any update
targeting a doc without one gets skipped with no error.
##########
lucene/core/src/java/org/apache/lucene/index/KnnVectorFieldUpdates.java:
##########
@@ -0,0 +1,335 @@
+/*
+ * 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.index;
+
+import static org.apache.lucene.search.DocIdSetIterator.NO_MORE_DOCS;
+
+import java.util.Comparator;
+import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.util.ArrayUtil;
+import org.apache.lucene.util.PriorityQueue;
+
+/**
+ * Holds in-place KNN vector updates of a single field, for a set of documents
within one segment.
+ * This is the vector analogue of {@link DocValuesFieldUpdates}: it
accumulates (docID -> new
+ * vector) entries during resolution, sorts them by docID at {@link #finish()}
(stable, so that the
+ * last update to a docID within a packet wins), and exposes an {@link
Iterator} that the write path
+ * overlays onto the existing vectors.
+ *
+ * @lucene.experimental
+ */
+abstract class KnnVectorFieldUpdates {
+
+ final String field;
+ final VectorEncoding encoding;
+ final long delGen;
+ final int maxDoc;
+ final int dimension;
+ protected int[] docs = new int[8];
+ protected int size;
+ private boolean finished;
+
+ protected KnnVectorFieldUpdates(
+ int maxDoc, long delGen, String field, VectorEncoding encoding, int
dimension) {
+ this.maxDoc = maxDoc;
+ this.delGen = delGen;
+ this.field = field;
+ this.encoding = encoding;
+ this.dimension = dimension;
+ }
+
+ /** Reserves a slot for the next doc and returns its ordinal. Subclasses
store the value. */
+ protected final int reserve(int doc) {
+ if (finished) {
+ throw new IllegalStateException("already finished");
+ }
+ assert doc < maxDoc;
+ if (size == docs.length) {
+ docs = ArrayUtil.grow(docs, size + 1);
+ }
+ docs[size] = doc;
+ return size++;
+ }
+
+ boolean getFinished() {
+ return finished;
+ }
+
+ boolean any() {
+ return size > 0;
+ }
+
+ /** Freezes structures and stably sorts updates by docID (last write to a
docID wins). */
+ final void finish() {
Review Comment:
This allocates a boxed Integer[] array and sorts it with a comparator, then
copies everything into new arrays. DocValuesFieldUpdates.finish() does the same
job in-place with IntroSorter and zero boxing, that's the established pattern
here. No reason to diverge from it, especially since vectors are large so the
extra copies are worse, not better.
##########
lucene/core/src/java/org/apache/lucene/codecs/lucene94/Lucene94FieldInfosFormat.java:
##########
@@ -454,6 +458,8 @@ public void write(
output.writeVInt(fi.getVectorDimension());
output.writeByte((byte) fi.getVectorEncoding().ordinal());
output.writeByte(distFuncToOrd(fi.getVectorSimilarityFunction()));
+ // per-field KNN vector update generation (FORMAT_VECTOR_GEN+)
+ output.writeLong(fi.getVectorGen());
Review Comment:
The new vectorGen long is written unconditionally for every field, even
plain text fields that will never have vectors. That's 8 extra bytes per field
in every index. Could either only write it for fields with hasVectorValues(),
or use a flag bit to signal presence, rather than bumping the format version
and paying the cost everywhere.
##########
lucene/core/src/java/org/apache/lucene/index/BufferedUpdates.java:
##########
@@ -155,6 +159,15 @@ void addBinaryUpdate(BinaryDocValuesUpdate update, int
docIDUpto) {
numFieldUpdates.incrementAndGet();
}
+ void addVectorUpdate(KnnVectorUpdate update, int docIDUpto) {
+ FieldUpdatesBuffer buffer =
+ vectorUpdates.computeIfAbsent(
Review Comment:
The first update for a field gets added twice. computeIfAbsent creates the
buffer with the initial value already stored, then the next line
unconditionally calls buffer.addUpdate() again with the same value. Compare
with addNumericUpdate/addBinaryUpdate which have an if/else to avoid this.
Harmless due to last-write-wins but wastes memory and looks like a bug.
##########
lucene/core/src/java/org/apache/lucene/index/SegmentVectorsProducer.java:
##########
@@ -0,0 +1,148 @@
+/*
+ * 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.index;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.IdentityHashMap;
+import java.util.Set;
+import org.apache.lucene.codecs.KnnVectorsReader;
+import org.apache.lucene.internal.hppc.IntObjectHashMap;
+import org.apache.lucene.internal.hppc.LongArrayList;
+import org.apache.lucene.search.AcceptDocs;
+import org.apache.lucene.search.KnnCollector;
+import org.apache.lucene.store.Directory;
+
+/**
+ * Encapsulates multiple per-generation {@link KnnVectorsReader}s as one
reader when there are KNN
+ * vector updates. This is the vector analogue of {@link
SegmentDocValuesProducer}.
+ *
+ * <p>Fields with no vector updates (vectorGen == -1) are served from the
shared, immutable base
+ * reader held by {@link SegmentCoreReaders}; that base reader is never closed
by this producer (its
+ * lifecycle is owned by the core). Fields with updates are served from
per-gen readers tracked by
+ * {@link SegmentKnnVectors} via reference counting.
+ */
+class SegmentVectorsProducer extends KnnVectorsReader {
+
+ private final FieldInfos fieldInfos;
+ final IntObjectHashMap<KnnVectorsReader> readersByField = new
IntObjectHashMap<>();
+ // distinct gen readers (excluding the base core reader) for checkIntegrity
+ final Set<KnnVectorsReader> genReaders =
+ Collections.newSetFromMap(new IdentityHashMap<KnnVectorsReader,
Boolean>());
+ final LongArrayList vectorGens = new LongArrayList();
+
+ /**
+ * Creates a new producer that handles updated KNN vector fields.
+ *
+ * @param si commit point
+ * @param dir directory
+ * @param baseCoreReader the shared base (gen == -1) reader from {@link
SegmentCoreReaders}; may
+ * be {@code null} if the core has no vector fields
+ * @param allInfos all fieldinfos including updated ones
+ * @param segKnnVectors per-gen reader cache
+ */
+ SegmentVectorsProducer(
+ SegmentCommitInfo si,
+ Directory dir,
+ KnnVectorsReader baseCoreReader,
+ FieldInfos allInfos,
+ SegmentKnnVectors segKnnVectors)
+ throws IOException {
+ this.fieldInfos = allInfos;
+ try {
+ for (FieldInfo fi : allInfos) {
+ if (fi.hasVectorValues() == false) {
+ continue;
+ }
+ long vectorGen = fi.getVectorGen();
+ if (vectorGen == -1) {
+ // served from the shared base core reader; not tracked here
+ readersByField.put(fi.number, baseCoreReader);
+ } else {
+ assert !vectorGens.contains(vectorGen);
Review Comment:
vectorGens is a LongArrayList (a list, not a set). If two fields ever share
a generation in the future, you'd decRef the same gen-reader twice, which would
close it prematurely. SegmentDocValuesProducer handles dvGens with
deduplication awareness. Should at least deduplicate here or use a set to be
safe.
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