kaivalnp commented on code in PR #14178: URL: https://github.com/apache/lucene/pull/14178#discussion_r1955603323
########## lucene/sandbox/src/java22/org/apache/lucene/sandbox/codecs/faiss/FaissKnnVectorsReader.java: ########## @@ -0,0 +1,182 @@ +/* + * 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.sandbox.codecs.faiss; + +import static org.apache.lucene.sandbox.codecs.faiss.FaissKnnVectorsFormat.DATA_CODEC_NAME; +import static org.apache.lucene.sandbox.codecs.faiss.FaissKnnVectorsFormat.DATA_EXTENSION; +import static org.apache.lucene.sandbox.codecs.faiss.FaissKnnVectorsFormat.META_CODEC_NAME; +import static org.apache.lucene.sandbox.codecs.faiss.FaissKnnVectorsFormat.META_EXTENSION; +import static org.apache.lucene.sandbox.codecs.faiss.FaissKnnVectorsFormat.VERSION_CURRENT; +import static org.apache.lucene.sandbox.codecs.faiss.FaissKnnVectorsFormat.VERSION_START; +import static org.apache.lucene.sandbox.codecs.faiss.LibFaissC.indexRead; +import static org.apache.lucene.sandbox.codecs.faiss.LibFaissC.indexSearch; + +import java.io.IOException; +import java.lang.foreign.Arena; +import java.lang.foreign.MemorySegment; +import java.util.HashMap; +import java.util.Map; +import org.apache.lucene.codecs.CodecUtil; +import org.apache.lucene.codecs.KnnVectorsReader; +import org.apache.lucene.codecs.hnsw.FlatVectorsReader; +import org.apache.lucene.index.ByteVectorValues; +import org.apache.lucene.index.FieldInfo; +import org.apache.lucene.index.FloatVectorValues; +import org.apache.lucene.index.IndexFileNames; +import org.apache.lucene.index.SegmentReadState; +import org.apache.lucene.search.KnnCollector; +import org.apache.lucene.store.IOContext; +import org.apache.lucene.store.IndexInput; +import org.apache.lucene.store.ReadAdvice; +import org.apache.lucene.util.Bits; +import org.apache.lucene.util.IOUtils; + +public final class FaissKnnVectorsReader extends KnnVectorsReader { + private final FlatVectorsReader rawVectorsReader; + private final IndexInput meta, data; + private final Map<String, MemorySegment> indexMap; + private final Arena arena; + + public FaissKnnVectorsReader(SegmentReadState state, FlatVectorsReader rawVectorsReader) + throws IOException { + this.rawVectorsReader = rawVectorsReader; + this.indexMap = new HashMap<>(); + this.arena = Arena.ofConfined(); + + boolean failure = true; + try { + meta = + openInput( + state, + META_EXTENSION, + META_CODEC_NAME, + VERSION_START, + VERSION_CURRENT, + state.context); + data = + openInput( + state, + DATA_EXTENSION, + DATA_CODEC_NAME, + VERSION_START, + VERSION_CURRENT, + state.context.withReadAdvice(ReadAdvice.RANDOM)); + + Map.Entry<String, MemorySegment> entry; + while ((entry = parseNextField(state)) != null) { + this.indexMap.put(entry.getKey(), entry.getValue()); + } + + failure = false; + } finally { + if (failure) { + IOUtils.closeWhileHandlingException(this); + } + } + } + + @SuppressWarnings("SameParameterValue") + private IndexInput openInput( + SegmentReadState state, + String extension, + String codecName, + int versionStart, + int versionEnd, + IOContext context) + throws IOException { + + String fileName = + IndexFileNames.segmentFileName(state.segmentInfo.name, state.segmentSuffix, extension); + IndexInput input = state.directory.openInput(fileName, context); + CodecUtil.checkIndexHeader( + input, codecName, versionStart, versionEnd, state.segmentInfo.getId(), state.segmentSuffix); + return input; + } + + private Map.Entry<String, MemorySegment> parseNextField(SegmentReadState state) + throws IOException { + int fieldNumber = meta.readInt(); + if (fieldNumber == -1) { + return null; + } + + FieldInfo fieldInfo = state.fieldInfos.fieldInfo(fieldNumber); + if (fieldInfo == null) { + throw new IllegalStateException("Invalid field"); + } + + long dataOffset = meta.readLong(); + long dataLength = meta.readLong(); + + // See flags defined in c_api/index_io_c.h + int ioFlags = 3; + + // Read index into memory + MemorySegment indexPointer = + indexRead(data.slice(fieldInfo.name, dataOffset, dataLength), ioFlags) + // Ensure timely cleanup + .reinterpret(arena, LibFaissC::freeIndex); Review Comment: Yes, I think Faiss just reads everything into RAM (no memory-mapping like Lucene) -- but I saw an open issue in Faiss to introduce memory-mapped indexes (https://github.com/facebookresearch/faiss/issues/4101) -- we could start using it once merged -- 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: issues-unsubscr...@lucene.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
