(build) Compatibility hack debian server

This will make reads more efficient, and possibly pave way for O_DIRECT reads of this data

code/common/model/java/nu/marginalia/model/crawl/HtmlFeature.java

@@ -105,8 +105,6 @@ public enum HtmlFeature {
     }
 
     public int getFeatureBit() {
-        if (getClass().desiredAssertionStatus() && ordinal() >= 32)
-            throw new IllegalStateException("Attempting to extract feature bit of " + name() + ", with ordinal " + ordinal());
         return (1<< ordinal());
     }
 }

code/common/service/java/nu/marginalia/service/ServiceId.java

@@ -7,7 +7,6 @@ public enum ServiceId {
     Search("search-service"),
     Index("index-service"),
     Query("query-service"),
-    Executor("executor-service"),
 
     Control("control-service"),
 

code/execution/api/java/nu/marginalia/executor/client/ExecutorClient.java

@@ -189,7 +189,7 @@ public class ExecutorClient {
         String uriPath = "/transfer/file/" + fileStorage.id();
         String uriQuery = "path=" + URLEncoder.encode(path, StandardCharsets.UTF_8);
 
-        var endpoints = registry.getEndpoints(ServiceKey.forRest(ServiceId.Executor, fileStorage.node()));
+        var endpoints = registry.getEndpoints(ServiceKey.forRest(ServiceId.Index, fileStorage.node()));
         if (endpoints.isEmpty()) {
             throw new RuntimeException("No endpoints for node " + fileStorage.node());
         }

code/execution/java/nu/marginalia/svc/ExecutorFileTransferService.java

@@ -1,4 +1,4 @@
-package nu.marginalia.executor;
+package nu.marginalia.svc;
 
 import com.google.inject.Inject;
 import nu.marginalia.storage.FileStorageService;

code/execution/readme.md

@@ -1,5 +1,5 @@
 The execution subsystem is responsible for the execution of long running tasks on each
-index node.  It lives in the [executor-service](../services-core/executor-service) module. 
+index node.  It lives in the [index-service](../services-core/index-service) module. 
 
 It accomplishes this using the [message queue and actor library](../libraries/message-queue/),
 which permits program state to survive crashes and reboots.

code/execution/test/nu/marginalia/svc/ExecutorFileTransferServiceTest.java

@@ -1,4 +1,4 @@
-package nu.marginalia.executor;
+package nu.marginalia.svc;
 
 import nu.marginalia.storage.FileStorageService;
 import nu.marginalia.storage.model.FileStorage;

code/functions/live-capture/test/nu/marginalia/rss/svc/FeedFetcherServiceTest.java

@@ -87,7 +87,7 @@ class FeedFetcherServiceTest extends AbstractModule {
         bind(DomainCoordinator.class).to(LocalDomainCoordinator.class);
         bind(HikariDataSource.class).toInstance(dataSource);
         bind(ServiceRegistryIf.class).toInstance(Mockito.mock(ServiceRegistryIf.class));
-        bind(ServiceConfiguration.class).toInstance(new ServiceConfiguration(ServiceId.Executor, 1, "", "", 0, UUID.randomUUID()));
+        bind(ServiceConfiguration.class).toInstance(new ServiceConfiguration(ServiceId.Index, 1, "", "", 0, UUID.randomUUID()));
         bind(Integer.class).annotatedWith(Names.named("wmsa-system-node")).toInstance(1);
     }
 

code/functions/search-query/api/java/nu/marginalia/api/searchquery/QueryProtobufCodec.java

@@ -304,7 +304,6 @@ public class QueryProtobufCodec {
                 IndexProtobufCodec.convertRpcQuery(specs.getQuery()),
                 specs.getDomainsList(),
                 specs.getSearchSetIdentifier(),
-                specs.getHumanQuery(),
                 IndexProtobufCodec.convertSpecLimit(specs.getQuality()),
                 IndexProtobufCodec.convertSpecLimit(specs.getYear()),
                 IndexProtobufCodec.convertSpecLimit(specs.getSize()),

code/functions/search-query/api/java/nu/marginalia/api/searchquery/model/query/SearchSpecification.java

@@ -18,8 +18,6 @@ public class SearchSpecification {
 
     public String searchSetIdentifier;
 
-    public final String humanQuery;
-
     public SpecificationLimit quality;
     public SpecificationLimit year;
     public SpecificationLimit size;
@@ -35,7 +33,6 @@ public class SearchSpecification {
     public SearchSpecification(SearchQuery query,
                                List<Integer> domains,
                                String searchSetIdentifier,
-                               String humanQuery,
                                SpecificationLimit quality,
                                SpecificationLimit year,
                                SpecificationLimit size,
@@ -47,7 +44,6 @@ public class SearchSpecification {
         this.query = query;
         this.domains = domains;
         this.searchSetIdentifier = searchSetIdentifier;
-        this.humanQuery = humanQuery;
         this.quality = quality;
         this.year = year;
         this.size = size;
@@ -73,10 +69,6 @@ public class SearchSpecification {
         return this.searchSetIdentifier;
     }
 
-    public String getHumanQuery() {
-        return this.humanQuery;
-    }
-
     public SpecificationLimit getQuality() {
         return this.quality;
     }
@@ -106,14 +98,13 @@ public class SearchSpecification {
     }
 
     public String toString() {
-        return "SearchSpecification(query=" + this.getQuery() + ", domains=" + this.getDomains() + ", searchSetIdentifier=" + this.getSearchSetIdentifier() + ", humanQuery=" + this.getHumanQuery() + ", quality=" + this.getQuality() + ", year=" + this.getYear() + ", size=" + this.getSize() + ", rank=" + this.getRank() + ", queryLimits=" + this.getQueryLimits() + ", queryStrategy=" + this.getQueryStrategy() + ", rankingParams=" + this.getRankingParams() + ")";
+        return "SearchSpecification(query=" + this.getQuery() + ", domains=" + this.getDomains() + ", searchSetIdentifier=" + this.getSearchSetIdentifier() + ", quality=" + this.getQuality() + ", year=" + this.getYear() + ", size=" + this.getSize() + ", rank=" + this.getRank() + ", queryLimits=" + this.getQueryLimits() + ", queryStrategy=" + this.getQueryStrategy() + ", rankingParams=" + this.getRankingParams() + ")";
     }
 
     public static class SearchSpecificationBuilder {
         private SearchQuery query;
         private List<Integer> domains;
         private String searchSetIdentifier;
-        private String humanQuery;
         private SpecificationLimit quality$value;
         private boolean quality$set;
         private SpecificationLimit year$value;
@@ -144,11 +135,6 @@ public class SearchSpecification {
             return this;
         }
 
-        public SearchSpecificationBuilder humanQuery(String humanQuery) {
-            this.humanQuery = humanQuery;
-            return this;
-        }
-
         public SearchSpecificationBuilder quality(SpecificationLimit quality) {
             this.quality$value = quality;
             this.quality$set = true;
@@ -205,11 +191,7 @@ public class SearchSpecification {
             if (!this.rank$set) {
                 rank$value = SpecificationLimit.none();
             }
-            return new SearchSpecification(this.query, this.domains, this.searchSetIdentifier, this.humanQuery, quality$value, year$value, size$value, rank$value, this.queryLimits, this.queryStrategy, this.rankingParams);
-        }
-
-        public String toString() {
-            return "SearchSpecification.SearchSpecificationBuilder(query=" + this.query + ", domains=" + this.domains + ", searchSetIdentifier=" + this.searchSetIdentifier + ", humanQuery=" + this.humanQuery + ", quality$value=" + this.quality$value + ", year$value=" + this.year$value + ", size$value=" + this.size$value + ", rank$value=" + this.rank$value + ", queryLimits=" + this.queryLimits + ", queryStrategy=" + this.queryStrategy + ", rankingParams=" + this.rankingParams + ")";
+            return new SearchSpecification(this.query, this.domains, this.searchSetIdentifier, quality$value, year$value, size$value, rank$value, this.queryLimits, this.queryStrategy, this.rankingParams);
         }
     }
 }

code/functions/search-query/api/java/nu/marginalia/api/searchquery/model/results/ResultRankingContext.java

@@ -1,56 +0,0 @@
-package nu.marginalia.api.searchquery.model.results;
-
-import nu.marginalia.api.searchquery.RpcResultRankingParameters;
-import nu.marginalia.api.searchquery.model.compiled.CqDataInt;
-
-import java.util.BitSet;
-
-public class ResultRankingContext {
-    private final int docCount;
-    public final RpcResultRankingParameters params;
-
-
-    public final BitSet regularMask;
-    public final BitSet ngramsMask;
-
-    /** CqDataInt associated with frequency information of the terms in the query
-     * in the full index.  The dataset is indexed by the compiled query. */
-    public final CqDataInt fullCounts;
-
-    /** CqDataInt associated with frequency information of the terms in the query
-     * in the full index.  The dataset is indexed by the compiled query. */
-    public final CqDataInt priorityCounts;
-
-    public ResultRankingContext(int docCount,
-                                RpcResultRankingParameters params,
-                                BitSet ngramsMask,
-                                BitSet regularMask,
-                                CqDataInt fullCounts,
-                                CqDataInt prioCounts)
-    {
-        this.docCount = docCount;
-        this.params = params;
-
-        this.ngramsMask = ngramsMask;
-        this.regularMask = regularMask;
-
-        this.fullCounts = fullCounts;
-        this.priorityCounts = prioCounts;
-    }
-
-    public int termFreqDocCount() {
-        return docCount;
-    }
-
-    @Override
-    public String toString() {
-        return "ResultRankingContext{" +
-                "docCount=" + docCount +
-                ", params=" + params +
-                ", regularMask=" + regularMask +
-                ", ngramsMask=" + ngramsMask +
-                ", fullCounts=" + fullCounts +
-                ", priorityCounts=" + priorityCounts +
-                '}';
-    }
-}

code/functions/search-query/java/nu/marginalia/functions/searchquery/QueryFactory.java

@@ -34,8 +34,6 @@ public class QueryFactory {
         this.queryExpansion = queryExpansion;
     }
 
-
-
     public ProcessedQuery createQuery(QueryParams params,
                                       @Nullable RpcResultRankingParameters rankingParams) {
         final var query = params.humanQuery();
@@ -153,7 +151,6 @@ public class QueryFactory {
 
         var specsBuilder = SearchSpecification.builder()
                 .query(queryBuilder.build())
-                .humanQuery(query)
                 .quality(qualityLimit)
                 .year(year)
                 .size(size)

code/functions/search-query/test/nu/marginalia/query/svc/QueryFactoryTest.java

@@ -241,7 +241,6 @@ public class QueryFactoryTest {
 
         Assertions.assertTrue(subquery.query.compiledQuery.contains(" bob "));
         Assertions.assertFalse(subquery.query.compiledQuery.contains(" bob's "));
-        Assertions.assertEquals("\"bob's cars\"", subquery.humanQuery);
     }
 
     @Test

code/index/index-forward/build.gradle

@@ -14,6 +14,7 @@ apply from: "$rootProject.projectDir/srcsets.gradle"
 
 dependencies {
     implementation project(':code:libraries:array')
+    implementation project(':code:libraries:native')
     implementation project(':code:libraries:btree')
     implementation project(':code:libraries:coded-sequence')
     implementation project(':code:libraries:language-processing')

code/index/index-forward/java/nu/marginalia/index/forward/ForwardIndexReader.java

@@ -1,9 +1,11 @@
 package nu.marginalia.index.forward;
 
+import it.unimi.dsi.fastutil.longs.Long2IntOpenHashMap;
 import nu.marginalia.array.LongArray;
 import nu.marginalia.array.LongArrayFactory;
+import nu.marginalia.ffi.LinuxSystemCalls;
 import nu.marginalia.index.forward.spans.DocumentSpans;
-import nu.marginalia.index.forward.spans.ForwardIndexSpansReader;
+import nu.marginalia.index.forward.spans.IndexSpansReader;
 import nu.marginalia.model.id.UrlIdCodec;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -22,16 +24,15 @@ import static nu.marginalia.index.forward.ForwardIndexParameters.*;
  * and a mapping between document identifiers to the index into the
  * data array.
  * <p/>
- * Since the total data is relatively small, this is kept in memory to
- * reduce the amount of disk thrashing.
- * <p/>
  * The metadata is a binary encoding of {@see nu.marginalia.idx.DocumentMetadata}
  */
 public class ForwardIndexReader {
     private final LongArray ids;
     private final LongArray data;
 
-    private final ForwardIndexSpansReader spansReader;
+    private volatile Long2IntOpenHashMap idsMap;
+
+    private final IndexSpansReader spansReader;
 
     private final Logger logger = LoggerFactory.getLogger(getClass());
 
@@ -64,7 +65,22 @@ public class ForwardIndexReader {
 
         ids = loadIds(idsFile);
         data = loadData(dataFile);
-        spansReader = new ForwardIndexSpansReader(spansFile);
+
+        LinuxSystemCalls.madviseRandom(data.getMemorySegment());
+        LinuxSystemCalls.madviseRandom(ids.getMemorySegment());
+
+        spansReader = IndexSpansReader.open(spansFile);
+
+        Thread.ofPlatform().start(this::createIdsMap);
+    }
+
+    private void createIdsMap() {
+        Long2IntOpenHashMap idsMap = new Long2IntOpenHashMap((int) ids.size());
+        for (int i = 0; i < ids.size(); i++) {
+            idsMap.put(ids.get(i), i);
+        }
+        this.idsMap = idsMap;
+        logger.info("Forward index loaded into RAM");
     }
 
     private static LongArray loadIds(Path idsFile) throws IOException {
@@ -106,7 +122,11 @@ public class ForwardIndexReader {
     private int idxForDoc(long docId) {
         assert UrlIdCodec.getRank(docId) == 0 : "Forward Index Reader fed dirty reverse index id";
 
-        long offset = ids.binarySearch(docId, 0, ids.size());
+        if (idsMap != null) {
+            return idsMap.getOrDefault(docId, -1);
+        }
+
+        long offset = ids.binarySearch2(docId, 0, ids.size());
 
         if (offset >= ids.size() || offset < 0 || ids.get(offset) != docId) {
             if (getClass().desiredAssertionStatus()) {
@@ -118,22 +138,27 @@ public class ForwardIndexReader {
         return (int) offset;
     }
 
-    public DocumentSpans getDocumentSpans(Arena arena, long docId) {
-        long offset = idxForDoc(docId);
-        if (offset < 0) return new DocumentSpans();
-
-        long encodedOffset = data.get(ENTRY_SIZE * offset + SPANS_OFFSET);
+    public DocumentSpans[] getDocumentSpans(Arena arena, long[] docIds) {
+        long[] offsets = new long[docIds.length];
+        for (int i = 0; i < docIds.length; i++) {
+            long offset = idxForDoc(docIds[i]);
+            if (offset >= 0) {
+                offsets[i] = data.get(ENTRY_SIZE * offset + SPANS_OFFSET);
+            }
+            else {
+                offsets[i] = -1;
+            }
+        }
 
         try {
-            return spansReader.readSpans(arena, encodedOffset);
+            return spansReader.readSpans(arena, offsets);
         }
         catch (IOException ex) {
-            logger.error("Failed to read spans for doc " + docId, ex);
-            return new DocumentSpans();
+            logger.error("Failed to read spans for docIds", ex);
+            return new DocumentSpans[docIds.length];
         }
     }
 
-
     public int totalDocCount() {
         return (int) ids.size();
     }
@@ -141,6 +166,8 @@ public class ForwardIndexReader {
     public void close() {
         if (data != null)
             data.close();
+        if (ids != null)
+            ids.close();
     }
 
     public boolean isLoaded() {

code/index/index-forward/java/nu/marginalia/index/forward/construction/ForwardIndexConverter.java

@@ -5,7 +5,7 @@ import nu.marginalia.array.LongArray;
 import nu.marginalia.array.LongArrayFactory;
 import nu.marginalia.index.domainrankings.DomainRankings;
 import nu.marginalia.index.forward.ForwardIndexParameters;
-import nu.marginalia.index.forward.spans.ForwardIndexSpansWriter;
+import nu.marginalia.index.forward.spans.IndexSpansWriter;
 import nu.marginalia.index.journal.IndexJournal;
 import nu.marginalia.model.id.UrlIdCodec;
 import nu.marginalia.model.idx.DocumentMetadata;
@@ -65,7 +65,7 @@ public class ForwardIndexConverter {
         logger.info("Domain Rankings size = {}", domainRankings.size());
 
         try (var progress = heartbeat.createProcessTaskHeartbeat(TaskSteps.class, "forwardIndexConverter");
-             var spansWriter = new ForwardIndexSpansWriter(outputFileSpansData)
+             var spansWriter = new IndexSpansWriter(outputFileSpansData)
         ) {
             progress.progress(TaskSteps.GET_DOC_IDS);
 

code/index/index-forward/java/nu/marginalia/index/forward/spans/DocumentSpan.java

@@ -11,6 +11,9 @@ public class DocumentSpan {
     /** A list of the interlaced start and end positions of each span in the document of this type */
     private final IntList startsEnds;
 
+    public DocumentSpan(IntList startsEnds) {
+        this.startsEnds = startsEnds;
+    }
     public DocumentSpan(CodedSequence startsEnds) {
         this.startsEnds = startsEnds.values();
     }

code/index/index-forward/java/nu/marginalia/index/forward/spans/DocumentSpans.java

@@ -1,5 +1,6 @@
 package nu.marginalia.index.forward.spans;
 
+import it.unimi.dsi.fastutil.ints.IntList;
 import nu.marginalia.language.sentence.tag.HtmlTag;
 import nu.marginalia.sequence.CodedSequence;
 
@@ -39,6 +40,23 @@ public class DocumentSpans {
         return EMPTY_SPAN;
     }
 
+    void accept(byte code, IntList positions) {
+        if (code == HtmlTag.HEADING.code)
+            this.heading = new DocumentSpan(positions);
+        else if (code == HtmlTag.TITLE.code)
+            this.title = new DocumentSpan(positions);
+        else if (code == HtmlTag.NAV.code)
+            this.nav = new DocumentSpan(positions);
+        else if (code == HtmlTag.CODE.code)
+            this.code = new DocumentSpan(positions);
+        else if (code == HtmlTag.ANCHOR.code)
+            this.anchor = new DocumentSpan(positions);
+        else if (code == HtmlTag.EXTERNAL_LINKTEXT.code)
+            this.externalLinkText = new DocumentSpan(positions);
+        else if (code == HtmlTag.BODY.code)
+            this.body = new DocumentSpan(positions);
+    }
+
     void accept(byte code, CodedSequence positions) {
         if (code == HtmlTag.HEADING.code)
             this.heading = new DocumentSpan(positions);

code/index/index-forward/java/nu/marginalia/index/forward/spans/IndexSpansReader.java

@@ -0,0 +1,25 @@
+package nu.marginalia.index.forward.spans;
+
+import java.io.IOException;
+import java.lang.foreign.Arena;
+import java.nio.file.Path;
+
+public interface IndexSpansReader extends AutoCloseable {
+    DocumentSpans readSpans(Arena arena, long encodedOffset) throws IOException;
+    DocumentSpans[] readSpans(Arena arena, long[] encodedOffsets) throws IOException;
+
+    static IndexSpansReader open(Path fileName) throws IOException {
+        int version = SpansCodec.parseSpanFilesFooter(fileName);
+        if (version == SpansCodec.SpansCodecVersion.COMPRESSED.ordinal()) {
+            return new IndexSpansReaderCompressed(fileName);
+        }
+        else if (version == SpansCodec.SpansCodecVersion.PLAIN.ordinal()) {
+            return new IndexSpansReaderPlain(fileName);
+        }
+        else {
+            throw new IllegalArgumentException("Unsupported spans file version: " + version);
+        }
+    }
+
+    void close() throws IOException;
+}

code/index/index-forward/java/nu/marginalia/index/forward/spans/IndexSpansReaderCompressed.java

@@ -10,11 +10,11 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 
-@SuppressWarnings("preview")
-public class ForwardIndexSpansReader implements AutoCloseable {
+@Deprecated
+public class IndexSpansReaderCompressed implements AutoCloseable, IndexSpansReader {
     private final FileChannel spansFileChannel;
 
-    public ForwardIndexSpansReader(Path spansFile) throws IOException {
+    public IndexSpansReaderCompressed(Path spansFile) throws IOException {
         this.spansFileChannel = (FileChannel) Files.newByteChannel(spansFile, StandardOpenOption.READ);
     }
 
@@ -51,6 +51,17 @@ public class ForwardIndexSpansReader implements AutoCloseable {
         return ret;
     }
 
+    @Override
+    public DocumentSpans[] readSpans(Arena arena, long[] encodedOffsets) throws IOException {
+        DocumentSpans[] ret = new DocumentSpans[encodedOffsets.length];
+        for (int i = 0; i < encodedOffsets.length; i++) {
+            if (encodedOffsets[i] >= 0) {
+                ret[i] = readSpans(arena, encodedOffsets[i]);
+            }
+        }
+        return ret;
+    }
+
     @Override
     public void close() throws IOException {
         spansFileChannel.close();

code/index/index-forward/java/nu/marginalia/index/forward/spans/IndexSpansReaderPlain.java

@@ -0,0 +1,95 @@
+package nu.marginalia.index.forward.spans;
+
+import it.unimi.dsi.fastutil.ints.IntArrayList;
+import nu.marginalia.uring.UringFileReader;
+
+import java.io.IOException;
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.nio.file.Path;
+import java.util.List;
+
+public class IndexSpansReaderPlain implements IndexSpansReader {
+    private final UringFileReader uringReader;
+
+    public IndexSpansReaderPlain(Path spansFile) throws IOException {
+        uringReader = new UringFileReader(spansFile,  true);
+        uringReader.fadviseWillneed();
+    }
+
+    @Override
+    public DocumentSpans readSpans(Arena arena, long encodedOffset) throws IOException {
+        // for testing, slow
+        return readSpans(arena, new long[] { encodedOffset})[0];
+    }
+
+    public DocumentSpans decode(MemorySegment ms) {
+        int count = ms.get(ValueLayout.JAVA_INT, 0);
+        int pos = 4;
+        DocumentSpans ret = new DocumentSpans();
+
+        // Decode each span
+        for (int spanIdx = 0; spanIdx < count; spanIdx++) {
+            byte code = ms.get(ValueLayout.JAVA_BYTE, pos);
+            short len = ms.get(ValueLayout.JAVA_SHORT, pos+2);
+
+            IntArrayList values = new IntArrayList(len);
+
+            pos += 4;
+            for (int i = 0; i < len; i++) {
+                values.add(ms.get(ValueLayout.JAVA_INT, pos + 4*i));
+            }
+            ret.accept(code, values);
+            pos += 4*len;
+        }
+
+        return ret;
+    }
+
+    @Override
+    public DocumentSpans[] readSpans(Arena arena, long[] encodedOffsets) {
+
+        int readCnt = 0;
+        for (long offset : encodedOffsets) {
+            if (offset < 0)
+                continue;
+            readCnt ++;
+        }
+
+        if (readCnt == 0) {
+            return new DocumentSpans[encodedOffsets.length];
+        }
+
+        long[] offsets = new long[readCnt];
+        int[] sizes = new int[readCnt];
+
+        for (int idx = 0, j = 0; idx < encodedOffsets.length; idx++) {
+            if (encodedOffsets[idx] < 0)
+                continue;
+            long offset = encodedOffsets[idx];
+
+            offsets[j] = SpansCodec.decodeStartOffset(offset);
+            sizes[j] = SpansCodec.decodeSize(offset);
+            j++;
+        }
+
+        List<MemorySegment> buffers = uringReader.readUnalignedInDirectMode(arena, offsets, sizes, 4096);
+
+        DocumentSpans[] ret = new DocumentSpans[encodedOffsets.length];
+
+        for (int idx = 0, j = 0; idx < encodedOffsets.length; idx++) {
+            if (encodedOffsets[idx] < 0)
+                continue;
+            ret[idx] = decode(buffers.get(j++));
+        }
+
+        return ret;
+    }
+
+    @Override
+    public void close() throws IOException {
+        uringReader.close();
+    }
+
+}

code/index/index-forward/java/nu/marginalia/index/forward/spans/IndexSpansWriter.java

@@ -1,20 +1,23 @@
 package nu.marginalia.index.forward.spans;
 
+import nu.marginalia.sequence.VarintCodedSequence;
+
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.nio.channels.FileChannel;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 
-public class ForwardIndexSpansWriter implements AutoCloseable {
+public class IndexSpansWriter implements AutoCloseable {
     private final FileChannel outputChannel;
-    private final ByteBuffer work = ByteBuffer.allocate(32);
+    private final ByteBuffer work = ByteBuffer.allocate(4*1024*1024).order(ByteOrder.nativeOrder());
 
     private long stateStartOffset = -1;
     private int stateLength = -1;
 
-    public ForwardIndexSpansWriter(Path outputFileSpansData) throws IOException {
+    public IndexSpansWriter(Path outputFileSpansData) throws IOException {
         this.outputChannel = (FileChannel) Files.newByteChannel(outputFileSpansData, StandardOpenOption.READ, StandardOpenOption.WRITE, StandardOpenOption.CREATE);
     }
 
@@ -23,7 +26,7 @@ public class ForwardIndexSpansWriter implements AutoCloseable {
         stateLength = 0;
 
         work.clear();
-        work.put((byte) count);
+        work.putInt(count);
         work.flip();
 
         while (work.hasRemaining())
@@ -33,12 +36,17 @@ public class ForwardIndexSpansWriter implements AutoCloseable {
     public void writeSpan(byte spanCode, ByteBuffer sequenceData) throws IOException {
         work.clear();
         work.put(spanCode);
-        work.putShort((short) sequenceData.remaining());
+        work.put((byte) 0); // Ensure we're byte aligned
+        var sequence = new VarintCodedSequence(sequenceData);
+        work.putShort((short) sequence.valueCount());
+
+        var iter = sequence.iterator();
+        while (iter.hasNext()) {
+            work.putInt(iter.nextInt());
+        }
         work.flip();
 
-        while (work.hasRemaining() || sequenceData.hasRemaining()) {
-            stateLength += (int) outputChannel.write(new ByteBuffer[]{work, sequenceData});
-        }
+        stateLength += outputChannel.write(work);
     }
 
     public long endRecord() {
@@ -47,6 +55,11 @@ public class ForwardIndexSpansWriter implements AutoCloseable {
 
     @Override
     public void close() throws IOException {
+        ByteBuffer footer = SpansCodec.createSpanFilesFooter(SpansCodec.SpansCodecVersion.PLAIN, (int) (4096 - (outputChannel.position() & 4095)));
+        outputChannel.position(outputChannel.size());
+        while (footer.hasRemaining()) {
+            outputChannel.write(footer, outputChannel.size());
+        }
         outputChannel.close();
     }
 }

code/index/index-forward/java/nu/marginalia/index/forward/spans/SpansCodec.java

@@ -1,6 +1,21 @@
 package nu.marginalia.index.forward.spans;
 
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+
 public class SpansCodec {
+    public static int MAGIC_INT = 0xF000F000;
+    public static int FOOTER_SIZE = 8;
+
+    public enum SpansCodecVersion {
+        @Deprecated
+        COMPRESSED,
+        PLAIN
+    }
+
     public static long encode(long startOffset, long size) {
         assert size < 0x1000_0000L : "Size must be less than 2^28";
 
@@ -11,7 +26,39 @@ public class SpansCodec {
         return encoded >>> 28;
     }
 
-    public static long decodeSize(long encoded) {
-        return encoded & 0x0FFF_FFFFL;
+    public static int decodeSize(long encoded) {
+        return (int) (encoded & 0x0FFF_FFFFL);
+    }
+
+    public static ByteBuffer createSpanFilesFooter(SpansCodecVersion version, int padSize) {
+        if (padSize < FOOTER_SIZE) {
+            padSize += 4096;
+        }
+
+        ByteBuffer footer = ByteBuffer.allocate(padSize);
+        footer.position(padSize - FOOTER_SIZE);
+        footer.putInt(SpansCodec.MAGIC_INT);
+        footer.put((byte) version.ordinal());
+        footer.put((byte) 0);
+        footer.put((byte) 0);
+        footer.put((byte) 0);
+        footer.flip();
+        return footer;
+    }
+
+    public static int parseSpanFilesFooter(Path spansFile) throws IOException {
+        ByteBuffer buffer = ByteBuffer.allocate(FOOTER_SIZE);
+
+        try (var fc = FileChannel.open(spansFile, StandardOpenOption.READ)) {
+            if (fc.size() < FOOTER_SIZE) return 0;
+            fc.read(buffer, fc.size() - buffer.capacity());
+            buffer.flip();
+            int magic = buffer.getInt();
+            if (magic != MAGIC_INT) {
+                return 0;
+            }
+            return buffer.get();
+        }
+
     }
 }

code/index/index-forward/test/nu/marginalia/index/forward/IndexSpansReaderTest.java

@@ -1,8 +1,9 @@
 package nu.marginalia.index.forward;
 
 import it.unimi.dsi.fastutil.ints.IntList;
-import nu.marginalia.index.forward.spans.ForwardIndexSpansReader;
-import nu.marginalia.index.forward.spans.ForwardIndexSpansWriter;
+import nu.marginalia.index.forward.spans.IndexSpansReader;
+import nu.marginalia.index.forward.spans.IndexSpansReaderPlain;
+import nu.marginalia.index.forward.spans.IndexSpansWriter;
 import nu.marginalia.language.sentence.tag.HtmlTag;
 import nu.marginalia.sequence.VarintCodedSequence;
 import org.junit.jupiter.api.AfterEach;
@@ -17,10 +18,10 @@ import java.nio.file.Path;
 
 import static org.junit.jupiter.api.Assertions.*;
 
-class ForwardIndexSpansReaderTest {
+class IndexSpansReaderTest {
     Path testFile = Files.createTempFile("test", ".idx");
 
-    ForwardIndexSpansReaderTest() throws IOException {
+    IndexSpansReaderTest() throws IOException {
     }
 
     @AfterEach
@@ -34,7 +35,7 @@ class ForwardIndexSpansReaderTest {
 
         long offset1;
         long offset2;
-        try (var writer = new ForwardIndexSpansWriter(testFile)) {
+        try (var writer = new IndexSpansWriter(testFile)) {
             writer.beginRecord(1);
             writer.writeSpan(HtmlTag.HEADING.code, VarintCodedSequence.generate(1, 3, 5, 8).buffer());
             offset1 = writer.endRecord();
@@ -46,7 +47,7 @@ class ForwardIndexSpansReaderTest {
             offset2 = writer.endRecord();
         }
 
-        try (var reader = new ForwardIndexSpansReader(testFile);
+        try (var reader = IndexSpansReader.open(testFile);
              var arena = Arena.ofConfined()
         ) {
             var spans1 = reader.readSpans(arena, offset1);
@@ -77,13 +78,13 @@ class ForwardIndexSpansReaderTest {
     @Test
     void testContainsRange() throws IOException {
         long offset1;
-        try (var writer = new ForwardIndexSpansWriter(testFile)) {
+        try (var writer = new IndexSpansWriter(testFile)) {
             writer.beginRecord(1);
             writer.writeSpan(HtmlTag.HEADING.code, VarintCodedSequence.generate( 1, 2, 10, 15, 20, 25).buffer());
             offset1 = writer.endRecord();
         }
 
-        try (var reader = new ForwardIndexSpansReader(testFile);
+        try (var reader = new IndexSpansReaderPlain(testFile);
              var arena = Arena.ofConfined()
         ) {
             var spans1 = reader.readSpans(arena, offset1);
@@ -104,13 +105,13 @@ class ForwardIndexSpansReaderTest {
     @Test
     void testContainsRangeExact() throws IOException {
         long offset1;
-        try (var writer = new ForwardIndexSpansWriter(testFile)) {
+        try (var writer = new IndexSpansWriter(testFile)) {
             writer.beginRecord(1);
             writer.writeSpan(HtmlTag.HEADING.code, VarintCodedSequence.generate( 1, 2, 10, 15, 20, 25).buffer());
             offset1 = writer.endRecord();
         }
 
-        try (var reader = new ForwardIndexSpansReader(testFile);
+        try (var reader = new IndexSpansReaderPlain(testFile);
              var arena = Arena.ofConfined()
         ) {
             var spans1 = reader.readSpans(arena, offset1);
@@ -131,13 +132,13 @@ class ForwardIndexSpansReaderTest {
     @Test
     void testCountRangeMatches() throws IOException {
         long offset1;
-        try (var writer = new ForwardIndexSpansWriter(testFile)) {
+        try (var writer = new IndexSpansWriter(testFile)) {
             writer.beginRecord(1);
             writer.writeSpan(HtmlTag.HEADING.code, VarintCodedSequence.generate( 1, 2, 10, 15, 20, 25).buffer());
             offset1 = writer.endRecord();
         }
 
-        try (var reader = new ForwardIndexSpansReader(testFile);
+        try (var reader = new IndexSpansReaderPlain(testFile);
              var arena = Arena.ofConfined()
         ) {
             var spans1 = reader.readSpans(arena, offset1);

code/index/index-perftest/build.gradle

@@ -0,0 +1,54 @@
+plugins {
+    id 'java'
+    id 'application'
+    id 'jvm-test-suite'
+}
+
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(rootProject.ext.jvmVersion))
+    }
+}
+
+application {
+    mainClass = 'nu.marginalia.index.perftest.PerfTestMain'
+}
+
+apply from: "$rootProject.projectDir/srcsets.gradle"
+
+dependencies {
+    implementation project(':code:common:config')
+    implementation project(':code:common:db')
+
+    implementation project(':code:libraries:array')
+    implementation project(':code:libraries:native')
+    implementation project(':code:libraries:btree')
+    implementation project(':code:libraries:term-frequency-dict')
+    implementation project(':code:common:linkdb')
+    implementation project(':code:index')
+    implementation project(':code:index:query')
+    implementation project(':code:index:index-forward')
+    implementation project(':code:index:index-reverse')
+    implementation project(':third-party:commons-codec')
+    implementation project(':code:functions:search-query')
+    implementation project(':code:functions:search-query:api')
+
+    implementation libs.slop
+    implementation libs.roaringbitmap
+    implementation libs.bundles.slf4j
+    implementation libs.guava
+
+    libs.bundles.grpc.get().each {
+        implementation dependencies.create(it) {
+            exclude group: 'com.google.guava'
+        }
+    }
+
+
+    implementation libs.notnull
+    implementation libs.trove
+    implementation libs.fastutil
+    implementation libs.bundles.gson
+    implementation libs.bundles.mariadb
+
+}

code/index/index-perftest/java/nu/marginalia/index/perftest/IoPatternsMain.java

@@ -0,0 +1,262 @@
+package nu.marginalia.index.perftest;
+
+import nu.marginalia.ffi.LinuxSystemCalls;
+import nu.marginalia.uring.UringFileReader;
+
+import java.io.IOException;
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+import java.util.stream.LongStream;
+
+public class IoPatternsMain {
+
+    static void testBuffered(int sz, int small, int large, int iters) {
+        try {
+            Path largeFile = Path.of("/home/vlofgren/largefile.dat");
+            long fileSize = Files.size(largeFile);
+
+            Random r = new Random();
+            List<MemorySegment> segments = new ArrayList<>();
+            for (int i = 0; i < sz; i++) {
+                if (small == large) {
+                    segments.add(Arena.ofAuto().allocate(small));
+                }
+                else {
+                    segments.add(Arena.ofAuto().allocate(r.nextInt(small, large)));
+                }
+            }
+            List<Long> offsets = new ArrayList<>();
+
+            long[] samples = new long[1000];
+            int si = 0;
+
+            try (UringFileReader reader = new UringFileReader(largeFile, false)) {
+                for (int iter = 0; iter < iters; ) {
+                    if (si == samples.length) {
+                        Arrays.sort(samples);
+                        double p1 = samples[10] / 1_000.;
+                        double p10 = samples[100] / 1_000.;
+                        double p90 = samples[900] / 1_000.;
+                        double p99 = samples[990] / 1_000.;
+                        double avg = LongStream.of(samples).average().getAsDouble() / 1000.;
+                        System.out.println("B"+"\t"+avg+"\t"+p1 + " " + p10 + " " + p90 + " " + p99);
+                        si = 0;
+                        iter++;
+                    }
+
+                    offsets.clear();
+                    for (int i = 0; i < sz; i++) {
+                        offsets.add(r.nextLong(0, fileSize - 256));
+                    }
+
+                    long st = System.nanoTime();
+                    reader.read(segments, offsets);
+                    long et = System.nanoTime();
+
+                    samples[si++] = et - st;
+
+                }
+
+            }
+        }
+        catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    static void testBufferedPread(int sz, int iters) {
+        try {
+            Path largeFile = Path.of("/home/vlofgren/largefile.dat");
+            long fileSize = Files.size(largeFile);
+
+            Random r = new Random();
+            List<MemorySegment> segments = new ArrayList<>();
+            for (int i = 0; i < sz; i++) {
+                segments.add(Arena.ofAuto().allocate(r.nextInt(24, 256)));
+            }
+            List<Long> offsets = new ArrayList<>();
+
+            long[] samples = new long[1000];
+            int si = 0;
+
+            int fd = -1;
+            try {
+                fd = LinuxSystemCalls.openBuffered(largeFile);
+                LinuxSystemCalls.fadviseRandom(fd);
+
+                for (int iter = 0; iter < iters; ) {
+                    if (si == samples.length) {
+                        Arrays.sort(samples);
+                        double p1 = samples[10] / 1_000.;
+                        double p10 = samples[100] / 1_000.;
+                        double p90 = samples[900] / 1_000.;
+                        double p99 = samples[990] / 1_000.;
+                        double avg = LongStream.of(samples).average().getAsDouble() / 1000.;
+                        System.out.println("BP"+"\t"+avg+"\t"+p1 + " " + p10 + " " + p90 + " " + p99);
+                        si = 0;
+                        iter++;
+                    }
+
+                    offsets.clear();
+                    for (int i = 0; i < sz; i++) {
+                        offsets.add(r.nextLong(0, fileSize - 256));
+                    }
+
+                    long st = System.nanoTime();
+                    for (int i = 0; i < sz; i++) {
+                        LinuxSystemCalls.readAt(fd, segments.get(i), offsets.get(i));
+                    }
+                    long et = System.nanoTime();
+
+                    samples[si++] = et - st;
+                }
+            }
+            finally {
+                LinuxSystemCalls.closeFd(fd);
+            }
+        }
+        catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+
+    static void testDirect(int blockSize, int sz, int iters) {
+        try {
+            Path largeFile = Path.of("/home/vlofgren/largefile.dat");
+            int fileSizeBlocks = (int) ((Files.size(largeFile) & -blockSize) / blockSize);
+
+            Random r = new Random();
+            List<MemorySegment> segments = new ArrayList<>();
+            for (int i = 0; i < sz; i++) {
+                segments.add(Arena.ofAuto().allocate(blockSize, blockSize));
+            }
+            List<Long> offsets = new ArrayList<>();
+
+            long[] samples = new long[1000];
+            int si = 0;
+
+            try (UringFileReader reader = new UringFileReader(largeFile, true)) {
+                for (int iter = 0; iter < iters; ) {
+                    if (si == samples.length) {
+                        Arrays.sort(samples);
+                        double p1 = samples[10] / 1_000.;
+                        double p10 = samples[100] / 1_000.;
+                        double p90 = samples[900] / 1_000.;
+                        double p99 = samples[990] / 1_000.;
+                        double avg = LongStream.of(samples).average().getAsDouble() / 1000.;
+                        System.out.println("DN"+blockSize+"\t"+avg+"\t"+p1 + " " + p10 + " " + p90 + " " + p99);
+                        si = 0;
+                        iters++;
+                    }
+
+                    offsets.clear();
+                    for (int i = 0; i < sz; i++) {
+                        offsets.add(blockSize * r.nextLong(0, fileSizeBlocks));
+                    }
+
+                    long st = System.nanoTime();
+                    reader.read(segments, offsets);
+                    long et = System.nanoTime();
+
+                    samples[si++] = et - st;
+
+                }
+
+            }
+        }
+        catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+
+    static void testDirect1(int blockSize, int iters) {
+        try {
+            Path largeFile = Path.of("/home/vlofgren/largefile.dat");
+            int fileSizeBlocks = (int) ((Files.size(largeFile) & -blockSize) / blockSize);
+
+            Random r = new Random();
+            MemorySegment segment = Arena.global().allocate(blockSize, blockSize);
+
+            long[] samples = new long[1000];
+            int si = 0;
+
+            int fd = LinuxSystemCalls.openDirect(largeFile);
+            if (fd < 0) {
+                throw new IOException("open failed");
+            }
+            try {
+                for (int iter = 0; iter < iters; ) {
+                    if (si == samples.length) {
+                        Arrays.sort(samples);
+                        double p1 = samples[10] / 1_000.;
+                        double p10 = samples[100] / 1_000.;
+                        double p90 = samples[900] / 1_000.;
+                        double p99 = samples[990] / 1_000.;
+                        double avg = LongStream.of(samples).average().getAsDouble() / 1000.;
+                        System.out.println("D1"+blockSize+"\t"+avg+"\t"+p1 + " " + p10 + " " + p90 + " " + p99);
+                        si = 0;
+                        iters++;
+                    }
+
+
+                    long st = System.nanoTime();
+                    int ret;
+                    long readOffset = blockSize * r.nextLong(0, fileSizeBlocks);
+                    if (blockSize != (ret = LinuxSystemCalls.readAt(fd, segment, readOffset))) {
+                        throw new IOException("pread failed: " + ret);
+                    }
+                    long et = System.nanoTime();
+
+                    samples[si++] = et - st;
+
+                }
+
+            }
+            finally {
+                LinuxSystemCalls.closeFd(fd);
+            }
+        }
+        catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+//        Thread.ofPlatform().start(() -> testBuffered(128,  32, 65536,1000));
+        Thread.ofPlatform().start(() -> testDirect(8192*4, 128,1000));
+//        Thread.ofPlatform().start(() -> testBuffered(128, 1000));
+//        Thread.ofPlatform().start(() -> testBuffered(128, 1000));
+//        Thread.ofPlatform().start(() -> testBuffered(128, 1000));
+//        Thread.ofPlatform().start(() -> testBufferedPread(128, 1000));
+
+//        Thread.ofPlatform().start(() -> testDirect1(1024, 1000));
+//        Thread.ofPlatform().start(() -> testDirect1(1024, 1000));
+//        Thread.ofPlatform().start(() -> testDirect1(1024, 1000));
+//        Thread.ofPlatform().start(() -> testDirect1(1024*1024, 1000));
+//        Thread.ofPlatform().start(() -> testDirect1(1024*1024, 1000));
+//        Thread.ofPlatform().start(() -> testDirect(512, 512,1000));
+//        Thread.ofPlatform().start(() -> testDirect(512, 512,1000));
+//        Thread.ofPlatform().start(() -> testDirect(512, 512,1000));
+//        Thread.ofPlatform().start(() -> testDirect(512, 100));
+//        Thread.ofPlatform().start(() -> testDirect(512, 100));
+//        Thread.ofPlatform().start(() -> testDirect(512, 100));
+//        Thread.ofPlatform().start(() -> testDirect(512, 100));
+//        Thread.ofPlatform().start(() -> testBuffered(512, 1000));
+//        Thread.ofPlatform().start(() -> testBuffered(512, 1000));
+//        Thread.ofPlatform().start(() -> testBuffered(512, 1000));
+//        Thread.ofPlatform().start(() -> testBuffered(512, 1000));
+//        Thread.ofPlatform().start(() -> testBuffered(100));
+//        Thread.ofPlatform().start(() -> testBuffered(100));
+
+        for (;;);
+//        testBuffered(100);
+    }
+}

code/index/index-perftest/java/nu/marginalia/index/perftest/PerfTestMain.java

@@ -0,0 +1,313 @@
+package nu.marginalia.index.perftest;
+
+import gnu.trove.list.array.TLongArrayList;
+import nu.marginalia.api.searchquery.RpcQueryLimits;
+import nu.marginalia.api.searchquery.model.query.NsfwFilterTier;
+import nu.marginalia.api.searchquery.model.query.QueryParams;
+import nu.marginalia.api.searchquery.model.query.SearchSpecification;
+import nu.marginalia.api.searchquery.model.results.PrototypeRankingParameters;
+import nu.marginalia.array.page.LongQueryBuffer;
+import nu.marginalia.functions.searchquery.QueryFactory;
+import nu.marginalia.functions.searchquery.query_parser.QueryExpansion;
+import nu.marginalia.index.FullReverseIndexReader;
+import nu.marginalia.index.IndexQueryExecution;
+import nu.marginalia.index.PrioReverseIndexReader;
+import nu.marginalia.index.forward.ForwardIndexReader;
+import nu.marginalia.index.index.CombinedIndexReader;
+import nu.marginalia.index.index.StatefulIndex;
+import nu.marginalia.index.model.ResultRankingContext;
+import nu.marginalia.index.model.SearchParameters;
+import nu.marginalia.index.model.SearchTerms;
+import nu.marginalia.index.positions.PositionsFileReader;
+import nu.marginalia.index.query.IndexQuery;
+import nu.marginalia.index.query.IndexSearchBudget;
+import nu.marginalia.index.results.DomainRankingOverrides;
+import nu.marginalia.index.results.IndexResultRankingService;
+import nu.marginalia.index.results.model.ids.CombinedDocIdList;
+import nu.marginalia.index.searchset.SearchSetAny;
+import nu.marginalia.linkdb.docs.DocumentDbReader;
+import nu.marginalia.segmentation.NgramLexicon;
+import nu.marginalia.term_frequency_dict.TermFrequencyDict;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.sql.SQLException;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.TimeoutException;
+
+public class PerfTestMain {
+    static Duration warmupTime = Duration.ofMinutes(1);
+    static Duration runTime = Duration.ofMinutes(10);
+
+    public static void main(String[] args) {
+        if (args.length != 4) {
+            System.err.println("Arguments: home-dir index-dir query");
+            System.exit(255);
+        }
+
+        try {
+            Path indexDir = Paths.get(args[0]);
+            if (!Files.isDirectory(indexDir)) {
+                System.err.println("Index directory is not a directory");
+                System.exit(255);
+            }
+            Path homeDir = Paths.get(args[1]);
+            String scenario = args[2];
+            String query = args[3];
+
+            switch (scenario) {
+                case "valuation" -> runValuation(indexDir, homeDir, query);
+                case "lookup" -> runLookup(indexDir, homeDir, query);
+                case "execution" -> runExecution(indexDir, homeDir, query);
+            }
+
+            System.exit(0);
+        }
+        catch (NumberFormatException e) {
+            System.err.println("Arguments: data-dir index-dir query");
+            System.exit(255);
+        }
+        catch (Exception ex) {
+            System.err.println("Error during testing");
+            ex.printStackTrace();
+            System.exit(255);
+        }
+        System.out.println(Arrays.toString(args));
+    }
+
+    private static CombinedIndexReader createCombinedIndexReader(Path indexDir) throws IOException {
+
+        return new CombinedIndexReader(
+                new ForwardIndexReader(
+                        indexDir.resolve("ir/fwd-doc-id.dat"),
+                        indexDir.resolve("ir/fwd-doc-data.dat"),
+                        indexDir.resolve("ir/fwd-spans.dat")
+                ),
+                new FullReverseIndexReader(
+                        "full",
+                        indexDir.resolve("ir/rev-words.dat"),
+                        indexDir.resolve("ir/rev-docs.dat"),
+                        new PositionsFileReader(indexDir.resolve("ir/rev-positions.dat"))
+                ),
+                new PrioReverseIndexReader(
+                        "prio",
+                        indexDir.resolve("ir/rev-prio-words.dat"),
+                        indexDir.resolve("ir/rev-prio-docs.dat")
+                )
+        );
+    }
+
+    private static IndexResultRankingService createIndexResultRankingService(Path indexDir, CombinedIndexReader combinedIndexReader) throws IOException, SQLException {
+        return new IndexResultRankingService(
+                new DocumentDbReader(indexDir.resolve("ldbr/documents.db")),
+                new StatefulIndex(combinedIndexReader),
+                new DomainRankingOverrides(null, Path.of("xxxx"))
+        );
+    }
+
+    static QueryFactory createQueryFactory(Path homeDir) throws IOException {
+        return new QueryFactory(
+                new QueryExpansion(
+                        new TermFrequencyDict(homeDir.resolve("model/tfreq-new-algo3.bin")),
+                        new NgramLexicon()
+                )
+        );
+    }
+
+    public static void runValuation(Path homeDir,
+                                    Path indexDir,
+                                    String rawQuery) throws IOException, SQLException, TimeoutException {
+
+        CombinedIndexReader indexReader = createCombinedIndexReader(indexDir);
+        QueryFactory queryFactory = createQueryFactory(homeDir);
+        IndexResultRankingService rankingService = createIndexResultRankingService(indexDir, indexReader);
+
+        var queryLimits = RpcQueryLimits.newBuilder()
+                .setTimeoutMs(10_000)
+                .setResultsTotal(1000)
+                .setResultsByDomain(10)
+                .setFetchSize(4096)
+                .build();
+        SearchSpecification parsedQuery = queryFactory.createQuery(new QueryParams(rawQuery, queryLimits, "NONE", NsfwFilterTier.OFF), PrototypeRankingParameters.sensibleDefaults()).specs;
+
+        System.out.println("Query compiled to: " + parsedQuery.query.compiledQuery);
+
+        SearchParameters searchParameters = new SearchParameters(parsedQuery, new SearchSetAny());
+
+        List<IndexQuery> queries = indexReader.createQueries(new SearchTerms(searchParameters.query, searchParameters.compiledQueryIds), searchParameters.queryParams, new IndexSearchBudget(10_000));
+
+        TLongArrayList allResults = new TLongArrayList();
+        LongQueryBuffer buffer = new LongQueryBuffer(512);
+
+        for (var query : queries) {
+            while (query.hasMore() && allResults.size() < 512 ) {
+                query.getMoreResults(buffer);
+                allResults.addAll(buffer.copyData());
+            }
+            if (allResults.size() >= 512)
+                break;
+        }
+        allResults.sort();
+        if (allResults.size() > 512) {
+            allResults.subList(512,  allResults.size()).clear();
+        }
+
+        var rankingContext = ResultRankingContext.create(indexReader, searchParameters);
+        var rankingData = rankingService.prepareRankingData(rankingContext, new CombinedDocIdList(allResults.toArray()), null);
+
+        int sum = 0;
+
+        Instant runEndTime = Instant.now().plus(runTime);
+        Instant runStartTime =  Instant.now();
+        int sum2 = 0;
+        List<Double> times = new ArrayList<>();
+
+        int iter;
+        for (iter = 0;; iter++) {
+            IndexSearchBudget budget = new IndexSearchBudget(10000);
+            long start = System.nanoTime();
+            sum2 += rankingService.rankResults(budget, rankingContext, rankingData, false).size();
+            long end = System.nanoTime();
+            times.add((end - start)/1_000_000.);
+
+            if ((iter % 100) == 0) {
+                if (Instant.now().isAfter(runEndTime)) {
+                    break;
+                }
+                if (times.size() > 100) {
+                    double[] timesSample = times.stream().mapToDouble(Double::doubleValue).skip(times.size() - 100).sorted().toArray();
+                    System.out.format("P1: %f P10: %f, P90: %f, P99: %f\n", timesSample[1], timesSample[10], timesSample[90], timesSample[99]);
+                }
+                System.out.println(Duration.between(runStartTime, Instant.now()).toMillis() / 1000. + " best times: " + (allResults.size() / 512.) *  times.stream().mapToDouble(Double::doubleValue).sorted().limit(3).average().orElse(-1));
+            }
+        }
+        System.out.println("Benchmark complete after " + iter + " iters!");
+
+        System.out.println("Best times: " + (allResults.size() / 512.) *  times.stream().mapToDouble(Double::doubleValue).sorted().limit(3).average().orElse(-1));
+        System.out.println("Warmup sum: " + sum);
+        System.out.println("Main sum: " + sum2);
+        System.out.println(rankingData.size());
+    }
+
+    public static void runExecution(Path homeDir,
+                                    Path indexDir,
+                                    String rawQuery) throws IOException, SQLException, InterruptedException {
+
+        CombinedIndexReader indexReader = createCombinedIndexReader(indexDir);
+        QueryFactory queryFactory = createQueryFactory(homeDir);
+        IndexResultRankingService rankingService = createIndexResultRankingService(indexDir, indexReader);
+
+        var queryLimits = RpcQueryLimits.newBuilder()
+                .setTimeoutMs(50)
+                .setResultsTotal(1000)
+                .setResultsByDomain(10)
+                .setFetchSize(4096)
+                .build();
+        SearchSpecification parsedQuery = queryFactory.createQuery(new QueryParams(rawQuery, queryLimits, "NONE", NsfwFilterTier.OFF), PrototypeRankingParameters.sensibleDefaults()).specs;
+        System.out.println("Query compiled to: " + parsedQuery.query.compiledQuery);
+
+        System.out.println("Running warmup loop!");
+        int sum = 0;
+
+        Instant runEndTime = Instant.now().plus(runTime);
+        Instant runStartTime =  Instant.now();
+        int sum2 = 0;
+        List<Double> rates = new ArrayList<>();
+        List<Double> times = new ArrayList<>();
+        int iter;
+        for (iter = 0;; iter++) {
+            SearchParameters searchParameters = new SearchParameters(parsedQuery, new SearchSetAny());
+            var execution = new IndexQueryExecution(searchParameters, rankingService, indexReader);
+            long start = System.nanoTime();
+            execution.run();
+            long end = System.nanoTime();
+            sum2 += execution.itemsProcessed();
+            rates.add(execution.itemsProcessed() / ((end - start)/1_000_000_000.));
+            times.add((end - start)/1_000_000.);
+            indexReader.reset();
+            if ((iter % 100) == 0) {
+                if (Instant.now().isAfter(runEndTime)) {
+                    break;
+                }
+                if (times.size() > 100) {
+                    double[] timesSample = times.stream().mapToDouble(Double::doubleValue).skip(times.size() - 100).sorted().toArray();
+                    System.out.format("P1: %f P10: %f, P90: %f, P99: %f\n", timesSample[1], timesSample[10], timesSample[90], timesSample[99]);
+                }
+                System.out.println(Duration.between(runStartTime, Instant.now()).toMillis() / 1000. + " best rates: " +  rates.stream().mapToDouble(Double::doubleValue).map(i -> -i).sorted().map(i -> -i).limit(3).average().orElse(-1));
+            }
+        }
+
+        System.out.println("Benchmark complete after " + iter + " iters!");
+        System.out.println("Best counts: " + rates.stream().mapToDouble(Double::doubleValue).map(i -> -i).sorted().map(i -> -i).limit(3).average().orElse(-1));
+        System.out.println("Warmup sum: " + sum);
+        System.out.println("Main sum: " + sum2);
+    }
+
+    public static void runLookup(Path homeDir,
+                                    Path indexDir,
+                                    String rawQuery) throws IOException, SQLException
+    {
+
+        CombinedIndexReader indexReader = createCombinedIndexReader(indexDir);
+        QueryFactory queryFactory = createQueryFactory(homeDir);
+
+        var queryLimits = RpcQueryLimits.newBuilder()
+                .setTimeoutMs(10_000)
+                .setResultsTotal(1000)
+                .setResultsByDomain(10)
+                .setFetchSize(4096)
+                .build();
+        SearchSpecification parsedQuery = queryFactory.createQuery(new QueryParams(rawQuery, queryLimits, "NONE", NsfwFilterTier.OFF), PrototypeRankingParameters.sensibleDefaults()).specs;
+
+        System.out.println("Query compiled to: " + parsedQuery.query.compiledQuery);
+
+        SearchParameters searchParameters = new SearchParameters(parsedQuery, new SearchSetAny());
+
+
+        Instant runEndTime = Instant.now().plus(runTime);
+
+        LongQueryBuffer buffer = new LongQueryBuffer(512);
+        int sum1 = 0;
+        int iter;
+
+        Instant runStartTime =  Instant.now();
+        int sum2 = 0;
+        List<Double> times = new ArrayList<>();
+        for (iter = 0;; iter++) {
+            indexReader.reset();
+            List<IndexQuery> queries = indexReader.createQueries(new SearchTerms(searchParameters.query, searchParameters.compiledQueryIds), searchParameters.queryParams, new IndexSearchBudget(150));
+
+            long start = System.nanoTime();
+            for (var query : queries) {
+                while (query.hasMore()) {
+                    query.getMoreResults(buffer);
+                    sum1 += buffer.end;
+                    buffer.reset();
+                }
+            }
+            long end = System.nanoTime();
+            times.add((end - start)/1_000_000_000.);
+
+            if ((iter % 10) == 0) {
+                if (Instant.now().isAfter(runEndTime)) {
+                    break;
+                }
+                if (times.size() > 100) {
+                    double[] timesSample = times.stream().mapToDouble(Double::doubleValue).skip(times.size() - 100).sorted().toArray();
+                    System.out.format("P1: %f P10: %f, P90: %f, P99: %f\n", timesSample[1], timesSample[10], timesSample[90], timesSample[99]);
+                }
+                System.out.println(Duration.between(runStartTime, Instant.now()).toMillis() / 1000. + " best times: " + times.stream().mapToDouble(Double::doubleValue).sorted().limit(3).average().orElse(-1));
+            }
+        }
+        System.out.println("Benchmark complete after " + iter + " iters!");
+        System.out.println("Best times: " + times.stream().mapToDouble(Double::doubleValue).sorted().limit(3).average().orElse(-1));
+        System.out.println("Warmup sum: " + sum1);
+        System.out.println("Main sum: " + sum2);
+    }
+}

code/index/index-reverse/build.gradle

@@ -15,6 +15,7 @@ apply from: "$rootProject.projectDir/srcsets.gradle"
 
 dependencies {
     implementation project(':code:libraries:array')
+    implementation project(':code:libraries:native')
     implementation project(':code:libraries:btree')
     implementation project(':code:libraries:coded-sequence')
     implementation project(':code:libraries:random-write-funnel')

code/index/index-reverse/java/nu/marginalia/index/FullIndexEntrySource.java

@@ -1,32 +1,26 @@
 package nu.marginalia.index;
 
 import nu.marginalia.array.page.LongQueryBuffer;
-import nu.marginalia.btree.BTreeReader;
 import nu.marginalia.index.query.EntrySource;
-
-import static java.lang.Math.min;
+import nu.marginalia.skiplist.SkipListReader;
 
 public class FullIndexEntrySource implements EntrySource {
     private final String name;
-    private final BTreeReader reader;
 
     int pos;
     int endOffset;
 
-    final int entrySize;
+    private final SkipListReader reader;
     private final long wordId;
 
     public FullIndexEntrySource(String name,
-                                BTreeReader reader,
-                                int entrySize,
+                                SkipListReader reader,
                                 long wordId) {
         this.name = name;
         this.reader = reader;
-        this.entrySize = entrySize;
         this.wordId = wordId;
 
         pos = 0;
-        endOffset = pos + entrySize * reader.numEntries();
     }
 
     @Override
@@ -36,32 +30,14 @@ public class FullIndexEntrySource implements EntrySource {
 
     @Override
     public void read(LongQueryBuffer buffer) {
-        buffer.reset();
-        buffer.end = min(buffer.end, endOffset - pos);
-        reader.readData(buffer.data, buffer.end, pos);
-        pos += buffer.end;
-
-        destagger(buffer);
-        buffer.uniq();
-    }
-
-    private void destagger(LongQueryBuffer buffer) {
-        if (entrySize == 1)
-            return;
-
-        for (int ri = entrySize, wi=1; ri < buffer.end ; ri+=entrySize, wi++) {
-            buffer.data.set(wi, buffer.data.get(ri));
-        }
-
-        buffer.end /= entrySize;
+        reader.getData(buffer);
     }
 
     @Override
     public boolean hasMore() {
-        return pos < endOffset;
+        return !reader.atEnd();
     }
 
-
     @Override
     public String indexName() {
         return name + ":" + Long.toHexString(wordId);

code/index/index-reverse/java/nu/marginalia/index/FullReverseIndexReader.java

@@ -2,16 +2,17 @@ package nu.marginalia.index;
 
 import nu.marginalia.array.LongArray;
 import nu.marginalia.array.LongArrayFactory;
+import nu.marginalia.array.pool.BufferPool;
 import nu.marginalia.btree.BTreeReader;
-import nu.marginalia.index.positions.TermData;
+import nu.marginalia.ffi.LinuxSystemCalls;
 import nu.marginalia.index.positions.PositionsFileReader;
-import nu.marginalia.index.query.EmptyEntrySource;
-import nu.marginalia.index.query.EntrySource;
-import nu.marginalia.index.query.ReverseIndexRejectFilter;
-import nu.marginalia.index.query.ReverseIndexRetainFilter;
+import nu.marginalia.index.positions.TermData;
+import nu.marginalia.index.query.*;
 import nu.marginalia.index.query.filter.QueryFilterLetThrough;
 import nu.marginalia.index.query.filter.QueryFilterNoPass;
 import nu.marginalia.index.query.filter.QueryFilterStepIf;
+import nu.marginalia.skiplist.SkipListConstants;
+import nu.marginalia.skiplist.SkipListReader;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -20,10 +21,12 @@ import java.lang.foreign.Arena;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.concurrent.Executors;
+import java.util.function.Consumer;
 
 public class FullReverseIndexReader {
     private final LongArray words;
     private final LongArray documents;
+
     private final long wordsDataOffset;
     private final Logger logger = LoggerFactory.getLogger(getClass());
     private final BTreeReader wordsBTreeReader;
@@ -31,6 +34,8 @@ public class FullReverseIndexReader {
 
     private final PositionsFileReader positionsFileReader;
 
+    private final BufferPool dataPool;
+
     public FullReverseIndexReader(String name,
                                   Path words,
                                   Path documents,
@@ -44,6 +49,7 @@ public class FullReverseIndexReader {
             this.documents = null;
             this.wordsBTreeReader = null;
             this.wordsDataOffset = -1;
+            this.dataPool = null;
             return;
         }
 
@@ -52,6 +58,11 @@ public class FullReverseIndexReader {
         this.words = LongArrayFactory.mmapForReadingShared(words);
         this.documents = LongArrayFactory.mmapForReadingShared(documents);
 
+        LinuxSystemCalls.madviseRandom(this.words.getMemorySegment());
+        LinuxSystemCalls.madviseRandom(this.documents.getMemorySegment());
+
+        dataPool = new BufferPool(documents, SkipListConstants.BLOCK_SIZE, (int) (Long.getLong("index.bufferPoolSize", 512*1024*1024L) / SkipListConstants.BLOCK_SIZE));
+
         wordsBTreeReader = new BTreeReader(this.words, ReverseIndexParameters.wordsBTreeContext, 0);
         wordsDataOffset = wordsBTreeReader.getHeader().dataOffsetLongs();
 
@@ -62,6 +73,11 @@ public class FullReverseIndexReader {
         }
     }
 
+    public void reset() {
+        dataPool.reset();
+    }
+
+
     private void selfTest() {
         logger.info("Running self test program");
 
@@ -76,6 +92,15 @@ public class FullReverseIndexReader {
         ReverseIndexSelfTest.runSelfTest6(wordsDataRange, documents);
     }
 
+    public void eachDocRange(Consumer<LongArray> eachDocRange) {
+        long wordsDataSize = wordsBTreeReader.getHeader().numEntries() * 2L;
+        var wordsDataRange = words.range(wordsDataOffset, wordsDataOffset + wordsDataSize);
+
+        for (long i = 1; i < wordsDataRange.size(); i+=2) {
+            var docsBTreeReader = new BTreeReader(documents, ReverseIndexParameters.fullDocsBTreeContext, wordsDataRange.get(i));
+            eachDocRange.accept(docsBTreeReader.data());
+        }
+    }
 
     /** Calculate the offset of the word in the documents.
      * If the return-value is negative, the term does not exist
@@ -101,27 +126,27 @@ public class FullReverseIndexReader {
         if (offset < 0) // No documents
             return new EmptyEntrySource();
 
-        return new FullIndexEntrySource(name, createReaderNew(offset), 2, termId);
+        return new FullIndexEntrySource(name, getReader(offset), termId);
     }
 
     /** Create a filter step requiring the specified termId to exist in the documents */
-    public QueryFilterStepIf also(long termId) {
+    public QueryFilterStepIf also(long termId, IndexSearchBudget budget) {
         long offset = wordOffset(termId);
 
         if (offset < 0) // No documents
             return new QueryFilterNoPass();
 
-        return new ReverseIndexRetainFilter(createReaderNew(offset), name, termId);
+        return new ReverseIndexRetainFilter(getReader(offset), name, termId, budget);
     }
 
     /** Create a filter step requiring the specified termId to be absent from the documents */
-    public QueryFilterStepIf not(long termId) {
+    public QueryFilterStepIf not(long termId, IndexSearchBudget budget) {
         long offset = wordOffset(termId);
 
         if (offset < 0) // No documents
             return new QueryFilterLetThrough();
 
-        return new ReverseIndexRejectFilter(createReaderNew(offset));
+        return new ReverseIndexRejectFilter(getReader(offset), budget);
     }
 
     /** Return the number of documents with the termId in the index */
@@ -131,15 +156,39 @@ public class FullReverseIndexReader {
         if (offset < 0)
             return 0;
 
-        return createReaderNew(offset).numEntries();
+        return getReader(offset).estimateSize();
     }
 
     /** Create a BTreeReader for the document offset associated with a termId */
-    private BTreeReader createReaderNew(long offset) {
-        return new BTreeReader(
-                documents,
-                ReverseIndexParameters.fullDocsBTreeContext,
-                offset);
+    private SkipListReader getReader(long offset) {
+        return new SkipListReader(dataPool, offset);
+    }
+
+    public TermData[] getTermData(Arena arena,
+                                  long[] termIds,
+                                  long[] docIds)
+    {
+
+        long[] offsetsAll = new long[termIds.length * docIds.length];
+
+        for (int i = 0; i < termIds.length; i++) {
+            long termId = termIds[i];
+            long offset = wordOffset(termId);
+
+            if (offset < 0) {
+                // This is likely a bug in the code, but we can't throw an exception here
+                logger.debug("Missing offset for word {}", termId);
+                continue;
+            }
+
+            var reader = getReader(offset);
+
+            // Read the size and offset of the position data
+            var offsetsForTerm = reader.getValueOffsets(docIds);
+            System.arraycopy(offsetsForTerm, 0, offsetsAll, i * docIds.length, docIds.length);
+        }
+
+        return positionsFileReader.getTermData(arena, offsetsAll);
     }
 
     public TermData[] getTermData(Arena arena,
@@ -156,20 +205,22 @@ public class FullReverseIndexReader {
             return ret;
         }
 
-        var reader = createReaderNew(offset);
+        var reader = getReader(offset);
 
         // Read the size and offset of the position data
-        var offsets = reader.queryData(docIds, 1);
+        var offsets = reader.getValueOffsets(docIds);
 
-        for (int i = 0; i < docIds.length; i++) {
-            if (offsets[i] == 0)
-                continue;
-            ret[i] = positionsFileReader.getTermData(arena, offsets[i]);
-        }
-        return ret;
+        return positionsFileReader.getTermData(arena, offsets);
     }
 
     public void close() {
+        try {
+            dataPool.close();
+        }
+        catch (Exception e) {
+            logger.warn("Error while closing bufferPool", e);
+        }
+
         if (documents != null)
             documents.close();
 

code/index/index-reverse/java/nu/marginalia/index/PrioIndexEntrySource.java

@@ -13,7 +13,7 @@ import java.nio.channels.FileChannel;
 public class PrioIndexEntrySource implements EntrySource {
     private final String name;
 
-    private final ByteBuffer readData = ByteBuffer.allocate(1024);
+    private final ByteBuffer readData = ByteBuffer.allocate(8*1024);
     private final BitReader bitReader = new BitReader(readData, this::fillReadBuffer);
 
     private final FileChannel docsFileChannel;

code/index/index-reverse/java/nu/marginalia/index/PrioReverseIndexReader.java

@@ -3,6 +3,7 @@ package nu.marginalia.index;
 import nu.marginalia.array.LongArray;
 import nu.marginalia.array.LongArrayFactory;
 import nu.marginalia.btree.BTreeReader;
+import nu.marginalia.ffi.LinuxSystemCalls;
 import nu.marginalia.index.query.EmptyEntrySource;
 import nu.marginalia.index.query.EntrySource;
 import org.slf4j.Logger;
@@ -40,6 +41,8 @@ public class PrioReverseIndexReader {
 
         this.words = LongArrayFactory.mmapForReadingShared(words);
 
+        LinuxSystemCalls.madviseRandom(this.words.getMemorySegment());
+
         wordsBTreeReader = new BTreeReader(this.words, ReverseIndexParameters.wordsBTreeContext, 0);
         wordsDataOffset = wordsBTreeReader.getHeader().dataOffsetLongs();
 

code/index/index-reverse/java/nu/marginalia/index/ReverseIndexParameters.java

@@ -5,7 +5,7 @@ import nu.marginalia.btree.model.BTreeContext;
 
 public class ReverseIndexParameters
 {
-    public static final BTreeContext prioDocsBTreeContext = new BTreeContext(5, 1, BTreeBlockSize.BS_2048);
-    public static final BTreeContext fullDocsBTreeContext = new BTreeContext(5, 2, BTreeBlockSize.BS_2048);
-    public static final BTreeContext wordsBTreeContext = new BTreeContext(5, 2, BTreeBlockSize.BS_2048);
+    public static final BTreeContext prioDocsBTreeContext = new BTreeContext(5, 1, BTreeBlockSize.BS_512);
+    public static final BTreeContext fullDocsBTreeContext = new BTreeContext(5, 2, BTreeBlockSize.BS_512);
+    public static final BTreeContext wordsBTreeContext = new BTreeContext(5, 2, BTreeBlockSize.BS_512);
 }

code/index/index-reverse/java/nu/marginalia/index/construction/PositionsFileConstructor.java

@@ -14,62 +14,103 @@ import java.nio.file.StandardOpenOption;
  *
  * The positions data is concatenated in the file, with each term's metadata
  * followed by its positions.  The metadata is a single byte, and the positions
- * are encoded using the Elias Gamma code, with zero padded bits at the end to
- * get octet alignment.
- *
+ * are encoded varints.
  * <p></p>
  *
  * It is the responsibility of the caller to keep track of the byte offset of
  * each posting in the file.
  */
 public class PositionsFileConstructor implements AutoCloseable {
-    private final ByteBuffer workBuffer = ByteBuffer.allocate(65536);
-    
     private final Path file;
     private final FileChannel channel;
 
-    private long offset;
-
     public PositionsFileConstructor(Path file) throws IOException {
         this.file = file;
 
         channel = FileChannel.open(file, StandardOpenOption.CREATE, StandardOpenOption.WRITE);
     }
 
+    /** Represents a block of positions lists.  Each writer thread should hold on to
+     * a block object to ensure the locality of its positions lists.
+     * When finished, commit() must be run.
+     * */
+    public class PositionsFileBlock {
+        private final ByteBuffer workBuffer = ByteBuffer.allocate(1024*1024*16);
+        private long position;
+
+        public PositionsFileBlock(long position) {
+            this.position = position;
+        }
+
+        public boolean fitsData(int size) {
+            return workBuffer.remaining() >= size;
+        }
+
+        public void commit() throws IOException {
+            workBuffer.position(0);
+            workBuffer.limit(workBuffer.capacity());
+            int pos = 0;
+            while (workBuffer.hasRemaining()) {
+                pos += channel.write(workBuffer, this.position + pos + workBuffer.position());
+            }
+        }
+
+        private void relocate() throws IOException {
+            workBuffer.clear();
+            position = channel.position();
+            while (workBuffer.hasRemaining()) {
+                channel.write(workBuffer);
+            }
+            workBuffer.clear();
+        }
+
+        public long position() {
+            return this.position + workBuffer.position();
+        }
+        public void put(byte b) {
+            workBuffer.put(b);
+        }
+        public void put(ByteBuffer buffer) {
+            workBuffer.put(buffer);
+        }
+    }
+
+    public PositionsFileBlock getBlock() throws IOException {
+        synchronized (this) {
+            var block = new PositionsFileBlock(channel.position());
+            block.relocate();
+            return block;
+        }
+    }
+
     /** Add a term to the positions file
+     *
+     * @param block a block token to ensure data locality
      * @param termMeta the term metadata
      * @param positionsBuffer the positions of the term
+     *
      * @return the offset of the term in the file, with the size of the data in the highest byte
      */
-    public long add(byte termMeta, ByteBuffer positionsBuffer) throws IOException {
-        synchronized (file) {
-            int size = 1 + positionsBuffer.remaining();
+    public long add(PositionsFileBlock block, byte termMeta, ByteBuffer positionsBuffer) throws IOException {
+        int size = 1 + positionsBuffer.remaining();
 
-            if (workBuffer.remaining() < size) {
-                workBuffer.flip();
-                channel.write(workBuffer);
-                workBuffer.clear();
+        if (!block.fitsData(size)) {
+            synchronized (this) {
+                block.commit();
+                block.relocate();
             }
+        }
+        synchronized (file) {
+            long offset = block.position();
 
-            workBuffer.put(termMeta);
-            workBuffer.put(positionsBuffer);
+            block.put(termMeta);
+            block.put(positionsBuffer);
 
-            long ret = PositionCodec.encode(size, offset);
-
-            offset += size;
-
-            return ret;
+            return PositionCodec.encode(size, offset);
         }
     }
 
     public void close() throws IOException {
-        if (workBuffer.hasRemaining()) {
-            workBuffer.flip();
-
-            while (workBuffer.hasRemaining())
-                channel.write(workBuffer);
-        }
-
         channel.force(false);
         channel.close();
     }

code/index/index-reverse/java/nu/marginalia/index/construction/full/FullIndexBTreeTransformer.java

@@ -1,46 +0,0 @@
-package nu.marginalia.index.construction.full;
-
-import nu.marginalia.array.LongArray;
-import nu.marginalia.array.algo.LongArrayTransformations;
-import nu.marginalia.btree.BTreeWriter;
-import nu.marginalia.btree.model.BTreeContext;
-
-import java.io.IOException;
-
-/** Constructs the BTrees in a reverse index */
-public class FullIndexBTreeTransformer implements LongArrayTransformations.LongIOTransformer {
-    private final BTreeWriter writer;
-    private final int entrySize;
-    private final LongArray documentsArray;
-
-    long start = 0;
-    long writeOffset = 0;
-
-    public FullIndexBTreeTransformer(LongArray urlsFileMap,
-                                     int entrySize,
-                                     BTreeContext bTreeContext,
-                                     LongArray documentsArray) {
-        this.documentsArray = documentsArray;
-        this.writer = new BTreeWriter(urlsFileMap, bTreeContext);
-        this.entrySize = entrySize;
-    }
-
-    @Override
-    public long transform(long pos, long end) throws IOException {
-
-        final int size = (int) ((end - start) / entrySize);
-
-        if (size == 0) {
-            return -1;
-        }
-
-        final long offsetForBlock = writeOffset;
-
-        writeOffset += writer.write(writeOffset, size,
-                mapRegion -> mapRegion.transferFrom(documentsArray, start, 0, end - start)
-        );
-
-        start = end;
-        return offsetForBlock;
-    }
-}

code/index/index-reverse/java/nu/marginalia/index/construction/full/FullIndexSkipListTransformer.java

@@ -0,0 +1,40 @@
+package nu.marginalia.index.construction.full;
+
+import nu.marginalia.array.LongArray;
+import nu.marginalia.array.algo.LongArrayTransformations;
+import nu.marginalia.skiplist.SkipListWriter;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+/** Constructs the BTrees in a reverse index */
+public class FullIndexSkipListTransformer implements LongArrayTransformations.LongIOTransformer, AutoCloseable {
+    private final SkipListWriter writer;
+    private final LongArray documentsArray;
+
+    long start = 0;
+
+    public FullIndexSkipListTransformer(Path docsOutputFile,
+                                        LongArray documentsArray) throws IOException {
+        this.documentsArray = documentsArray;
+        this.writer = new SkipListWriter(docsOutputFile);
+    }
+
+    @Override
+    public long transform(long pos, long end) throws IOException {
+
+        final int size = (int) ((end - start) / 2);
+
+        if (size == 0) {
+            return -1;
+        }
+
+        long offset = writer.writeList(documentsArray, start, size);
+        start = end;
+        return offset;
+    }
+
+    public void close() throws IOException {
+        writer.close();
+    }
+}

code/index/index-reverse/java/nu/marginalia/index/construction/full/FullPreindex.java

@@ -6,7 +6,6 @@ import nu.marginalia.btree.BTreeWriter;
 import nu.marginalia.index.ReverseIndexParameters;
 import nu.marginalia.index.construction.CountToOffsetTransformer;
 import nu.marginalia.index.construction.DocIdRewriter;
-import nu.marginalia.index.construction.IndexSizeEstimator;
 import nu.marginalia.index.construction.PositionsFileConstructor;
 import nu.marginalia.index.journal.IndexJournalPage;
 import org.slf4j.Logger;
@@ -81,15 +80,11 @@ public class FullPreindex {
 
         // Estimate the size of the docs index data
         offsets.transformEach(0, offsets.size(), new CountToOffsetTransformer(2));
-        IndexSizeEstimator sizeEstimator = new IndexSizeEstimator(ReverseIndexParameters.fullDocsBTreeContext, 2);
-        offsets.fold(0, 0, offsets.size(), sizeEstimator);
 
         // Write the docs file
-        LongArray finalDocs = LongArrayFactory.mmapForWritingConfined(outputFileDocs, sizeEstimator.size);
-        offsets.transformEachIO(0, offsets.size(),
-                new FullIndexBTreeTransformer(finalDocs, 2,
-                        ReverseIndexParameters.fullDocsBTreeContext,
-                        documents.documents));
+        try (var transformer = new FullIndexSkipListTransformer(outputFileDocs, documents.documents)) {
+            offsets.transformEachIO(0, offsets.size(), transformer);
+        }
 
         LongArray wordIds = segments.wordIds;
 
@@ -102,7 +97,7 @@ public class FullPreindex {
         // Estimate the size of the words index data
         long wordsSize = ReverseIndexParameters.wordsBTreeContext.calculateSize((int) offsets.size());
 
-        // Construct the tree
+        // Construct the keywords tree
         LongArray wordsArray = LongArrayFactory.mmapForWritingConfined(outputFileWords, wordsSize);
 
         new BTreeWriter(wordsArray, ReverseIndexParameters.wordsBTreeContext)
@@ -113,8 +108,6 @@ public class FullPreindex {
             }
         });
 
-        finalDocs.force();
-        finalDocs.close();
         wordsArray.force();
         wordsArray.close();
 

code/index/index-reverse/java/nu/marginalia/index/construction/full/FullPreindexDocuments.java

@@ -12,10 +12,8 @@ import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
-import java.nio.channels.FileChannel;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.StandardOpenOption;
 import java.util.List;
 
 /** A LongArray with document data, segmented according to
@@ -52,11 +50,6 @@ public class FullPreindexDocuments {
         return new FullPreindexDocuments(docsFileMap, docsFile);
     }
 
-    public FileChannel createDocumentsFileChannel() throws IOException {
-        return (FileChannel) Files.newByteChannel(file, StandardOpenOption.READ);
-    }
-
-
     public LongArray slice(long start, long end) {
         return documents.range(start, end);
     }
@@ -86,6 +79,8 @@ public class FullPreindexDocuments {
             var offsetMap = segments.asMap(RECORD_SIZE_LONGS);
             offsetMap.defaultReturnValue(0);
 
+            var positionsBlock = positionsFileConstructor.getBlock();
+
             while (docIds.hasRemaining()) {
                 long docId = docIds.get();
                 long rankEncodedId = docIdRewriter.rewriteDocId(docId);
@@ -101,12 +96,13 @@ public class FullPreindexDocuments {
                     ByteBuffer pos = tPos.get(i);
 
                     long offset = offsetMap.addTo(termId, RECORD_SIZE_LONGS);
-                    long encodedPosOffset = positionsFileConstructor.add(meta, pos);
+                    long encodedPosOffset = positionsFileConstructor.add(positionsBlock, meta, pos);
 
                     assembly.put(offset + 0, rankEncodedId);
                     assembly.put(offset + 1, encodedPosOffset);
                 }
             }
+            positionsBlock.commit();
 
             assembly.write(docsFile);
         }

code/index/index-reverse/java/nu/marginalia/index/positions/PositionsFileReader.java

@@ -1,43 +1,72 @@
 package nu.marginalia.index.positions;
 
+import nu.marginalia.uring.UringFileReader;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.lang.foreign.Arena;
-import java.nio.channels.FileChannel;
+import java.lang.foreign.MemorySegment;
+import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.StandardOpenOption;
+import java.util.List;
 
+/** Reads positions data from the positions file */
 public class PositionsFileReader implements AutoCloseable {
-    private final FileChannel positions;
+
+    private final UringFileReader uringFileReader;
     private static final Logger logger = LoggerFactory.getLogger(PositionsFileReader.class);
 
     public PositionsFileReader(Path positionsFile) throws IOException {
-        this.positions = FileChannel.open(positionsFile, StandardOpenOption.READ);
-    }
-
-    /** Get the positions for a term in the index, as pointed out by the encoded offset;
-     * intermediate buffers are allocated from the provided arena allocator. */
-    public TermData getTermData(Arena arena, long sizeEncodedOffset) {
-        int length = PositionCodec.decodeSize(sizeEncodedOffset);
-        long offset = PositionCodec.decodeOffset(sizeEncodedOffset);
-
-        var segment = arena.allocate(length);
-        var buffer = segment.asByteBuffer();
-
-        try {
-            positions.read(buffer, offset);
-        } catch (IOException e) {
-            throw new RuntimeException(e);
+        if ((Files.size(positionsFile) & 4095) != 0) {
+            throw new IllegalArgumentException("Positions file is not block aligned in size: " + Files.size(positionsFile));
         }
-
-        return new TermData(buffer);
+        uringFileReader = new UringFileReader(positionsFile, true);
     }
 
     @Override
     public void close() throws IOException {
-        positions.close();
+        uringFileReader.close();
+    }
+
+    /** Get the positions for a keywords in the index, as pointed out by the encoded offsets;
+     * intermediate buffers are allocated from the provided arena allocator. */
+    public TermData[] getTermData(Arena arena, long[] offsets) {
+
+        int cnt = 0;
+
+        for (int i = 0; i < offsets.length; i++) {
+            long encodedOffset = offsets[i];
+            if (encodedOffset == 0) continue;
+            cnt++;
+        }
+
+        if (cnt == 0) {
+            return new TermData[offsets.length];
+        }
+
+        long[] readOffsets = new long[cnt];
+        int[] readSizes = new int[cnt];
+
+        for (int i = 0, j = 0; i < offsets.length; i++) {
+            long encodedOffset = offsets[i];
+            if (encodedOffset == 0) continue;
+
+            readSizes[j] = PositionCodec.decodeSize(encodedOffset);
+            readOffsets[j] = PositionCodec.decodeOffset(encodedOffset);
+            j++;
+        }
+
+        List<MemorySegment> buffers = uringFileReader.readUnalignedInDirectMode(arena, readOffsets, readSizes, 4096);
+
+        TermData[] ret = new TermData[offsets.length];
+        for (int i = 0, j=0; i < offsets.length; i++) {
+            long encodedOffset = offsets[i];
+            if (encodedOffset == 0) continue;
+            ret[i] = new TermData(buffers.get(j++).asByteBuffer());
+        }
+
+        return ret;
     }
 
 }

code/index/index-reverse/java/nu/marginalia/index/query/ReverseIndexRejectFilter.java

@@ -1,24 +1,22 @@
 package nu.marginalia.index.query;
 
 import nu.marginalia.array.page.LongQueryBuffer;
-import nu.marginalia.btree.BTreeReader;
 import nu.marginalia.index.query.filter.QueryFilterStepIf;
+import nu.marginalia.skiplist.SkipListReader;
 
-public record ReverseIndexRejectFilter(BTreeReader range) implements QueryFilterStepIf {
+public record ReverseIndexRejectFilter(SkipListReader range, IndexSearchBudget budget) implements QueryFilterStepIf {
 
     @Override
     public void apply(LongQueryBuffer buffer) {
-        range.rejectEntries(buffer);
+        while (budget.hasTimeLeft() && range.tryRejectData(buffer));
+
         buffer.finalizeFiltering();
     }
 
-    public boolean test(long id) {
-        return range.findEntry(id) < 0;
-    }
 
     @Override
     public double cost() {
-        return range.numEntries();
+        return 1;
     }
 
     @Override

code/index/index-reverse/java/nu/marginalia/index/query/ReverseIndexRetainFilter.java

@@ -1,24 +1,21 @@
 package nu.marginalia.index.query;
 
 import nu.marginalia.array.page.LongQueryBuffer;
-import nu.marginalia.btree.BTreeReader;
 import nu.marginalia.index.query.filter.QueryFilterStepIf;
+import nu.marginalia.skiplist.SkipListReader;
 
-public record ReverseIndexRetainFilter(BTreeReader range, String name, long wordId) implements QueryFilterStepIf {
+public record ReverseIndexRetainFilter(SkipListReader range, String name, long wordId, IndexSearchBudget budget) implements QueryFilterStepIf {
 
     @Override
     public void apply(LongQueryBuffer buffer) {
-        range.retainEntries(buffer);
-        buffer.finalizeFiltering();
-    }
+        while (budget.hasTimeLeft() && range.tryRetainData(buffer));
 
-    public boolean test(long id) {
-        return range.findEntry(id) >= 0;
+        buffer.finalizeFiltering();
     }
 
     @Override
     public double cost() {
-        return range.numEntries();
+        return 1;
     }
 
     @Override

code/index/index-reverse/test/nu/marginalia/index/PositionsFileReaderTest.java

@@ -11,7 +11,6 @@ import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
 import java.lang.foreign.Arena;
-import java.nio.ByteBuffer;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
@@ -32,32 +31,32 @@ class PositionsFileReaderTest {
 
     @Test
     void getTermData() throws IOException {
-        ByteBuffer workArea = ByteBuffer.allocate(8192);
         long key1, key2, key3;
         try (PositionsFileConstructor constructor = new PositionsFileConstructor(file)) {
-            key1 = constructor.add((byte) 43, VarintCodedSequence.generate(1, 2, 3).buffer());
-            key2 = constructor.add((byte) 51, VarintCodedSequence.generate(2, 3, 5, 1000, 5000, 20241).buffer());
-            key3 = constructor.add((byte) 61, VarintCodedSequence.generate(3, 5, 7).buffer());
+            var block = constructor.getBlock();
+            key1 = constructor.add(block, (byte) 43, VarintCodedSequence.generate(1, 2, 3).buffer());
+            key2 = constructor.add(block, (byte) 51, VarintCodedSequence.generate(2, 3, 5, 1000, 5000, 20241).buffer());
+            key3 = constructor.add(block, (byte) 61, VarintCodedSequence.generate(3, 5, 7).buffer());
+            block.commit();
         }
 
         System.out.println("key1: " + Long.toHexString(key1));
         System.out.println("key2: " + Long.toHexString(key2));
         System.out.println("key3: " + Long.toHexString(key3));
 
-        try (Arena arena = Arena.ofConfined();
+        try (Arena arena = Arena.ofShared();
             PositionsFileReader reader = new PositionsFileReader(file))
         {
-            TermData data1 = reader.getTermData(arena, key1);
-            assertEquals(43, data1.flags());
-            assertEquals(IntList.of( 1, 2, 3), data1.positions().values());
+            TermData[] data = reader.getTermData(arena, new long[] { key1, key2, key3 });
 
-            TermData data2 = reader.getTermData(arena, key2);
-            assertEquals(51, data2.flags());
-            assertEquals(IntList.of(2, 3, 5, 1000, 5000, 20241), data2.positions().values());
+            assertEquals(43, data[0].flags());
+            assertEquals(IntList.of( 1, 2, 3), data[0].positions().values());
 
-            TermData data3 = reader.getTermData(arena, key3);
-            assertEquals(61, data3.flags());
-            assertEquals(IntList.of(3, 5, 7), data3.positions().values());
+            assertEquals(51, data[1].flags());
+            assertEquals(IntList.of(2, 3, 5, 1000, 5000, 20241), data[1].positions().values());
+
+            assertEquals(61, data[2].flags());
+            assertEquals(IntList.of(3, 5, 7), data[2].positions().values());
         }
     }
 }

code/index/index-reverse/test/nu/marginalia/index/construction/full/FullPreindexFinalizeTest.java

@@ -1,149 +0,0 @@
-
-package nu.marginalia.index.construction.full;
-
-import nu.marginalia.array.LongArrayFactory;
-import nu.marginalia.btree.model.BTreeHeader;
-import nu.marginalia.hash.MurmurHash3_128;
-import nu.marginalia.index.construction.DocIdRewriter;
-import nu.marginalia.index.construction.PositionsFileConstructor;
-import org.junit.jupiter.api.AfterEach;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
-import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.ArrayList;
-import java.util.List;
-
-import static nu.marginalia.index.construction.full.TestJournalFactory.EntryDataWithWordMeta;
-import static nu.marginalia.index.construction.full.TestJournalFactory.wm;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
-class FullPreindexFinalizeTest {
-    TestJournalFactory journalFactory;
-    Path positionsFile;
-    Path countsFile;
-    Path wordsIdFile;
-    Path docsFile;
-    Path tempDir;
-
-    @BeforeEach
-    public void setUp() throws IOException  {
-        journalFactory = new TestJournalFactory();
-
-        positionsFile = Files.createTempFile("positions", ".dat");
-        countsFile = Files.createTempFile("counts", ".dat");
-        wordsIdFile = Files.createTempFile("words", ".dat");
-        docsFile = Files.createTempFile("docs", ".dat");
-        tempDir = Files.createTempDirectory("sort");
-    }
-
-    @AfterEach
-    public void tearDown() throws IOException {
-        journalFactory.clear();
-
-        Files.deleteIfExists(countsFile);
-        Files.deleteIfExists(wordsIdFile);
-        List<Path> contents = new ArrayList<>();
-        Files.list(tempDir).forEach(contents::add);
-        for (var tempFile : contents) {
-            Files.delete(tempFile);
-        }
-        Files.delete(tempDir);
-    }
-
-    MurmurHash3_128 hash = new MurmurHash3_128();
-    long termId(String keyword) {
-        return hash.hashKeyword(keyword);
-    }
-
-    @Test
-    public void testFinalizeSimple() throws IOException {
-        var reader = journalFactory.createReader(new EntryDataWithWordMeta(100, 101, wm(50, 51)));
-        var preindex = FullPreindex.constructPreindex(reader,
-                new PositionsFileConstructor(positionsFile),
-                DocIdRewriter.identity(), tempDir);
-
-
-        preindex.finalizeIndex(tempDir.resolve( "docs.dat"), tempDir.resolve("words.dat"));
-        preindex.delete();
-
-        Path wordsFile = tempDir.resolve("words.dat");
-        Path docsFile =  tempDir.resolve("docs.dat");
-
-        assertTrue(Files.exists(wordsFile));
-        assertTrue(Files.exists(docsFile));
-
-        System.out.println(Files.size(wordsFile));
-        System.out.println(Files.size(docsFile));
-
-        var docsArray = LongArrayFactory.mmapForReadingConfined(docsFile);
-        var wordsArray = LongArrayFactory.mmapForReadingConfined(wordsFile);
-
-        var docsHeader = new BTreeHeader(docsArray, 0);
-        var wordsHeader = new BTreeHeader(wordsArray, 0);
-
-        assertEquals(1, docsHeader.numEntries());
-        assertEquals(1, wordsHeader.numEntries());
-
-        assertEquals(100, docsArray.get(docsHeader.dataOffsetLongs() + 0));
-        assertEquals(termId("50"), wordsArray.get(wordsHeader.dataOffsetLongs()));
-    }
-
-
-    @Test
-    public void testFinalizeSimple2x2() throws IOException {
-        var reader = journalFactory.createReader(
-                new EntryDataWithWordMeta(100, 101, wm(50, 51)),
-                new EntryDataWithWordMeta(101, 101, wm(51, 52))
-                );
-
-        var preindex = FullPreindex.constructPreindex(reader,
-                new PositionsFileConstructor(positionsFile),
-                DocIdRewriter.identity(), tempDir);
-
-        preindex.finalizeIndex(tempDir.resolve( "docs.dat"), tempDir.resolve("words.dat"));
-        preindex.delete();
-
-        Path wordsFile = tempDir.resolve("words.dat");
-        Path docsFile =  tempDir.resolve("docs.dat");
-
-        assertTrue(Files.exists(wordsFile));
-        assertTrue(Files.exists(docsFile));
-
-        System.out.println(Files.size(wordsFile));
-        System.out.println(Files.size(docsFile));
-
-        var docsArray = LongArrayFactory.mmapForReadingConfined(docsFile);
-        var wordsArray = LongArrayFactory.mmapForReadingConfined(wordsFile);
-
-
-        var wordsHeader = new BTreeHeader(wordsArray, 0);
-
-        System.out.println(wordsHeader);
-
-        assertEquals(2, wordsHeader.numEntries());
-
-        long offset1 = wordsArray.get(wordsHeader.dataOffsetLongs() + 1);
-        long offset2 = wordsArray.get(wordsHeader.dataOffsetLongs() + 3);
-
-        assertEquals(termId("50"), wordsArray.get(wordsHeader.dataOffsetLongs()));
-        assertEquals(termId("50"), wordsArray.get(wordsHeader.dataOffsetLongs()));
-
-        BTreeHeader docsHeader;
-
-        docsHeader = new BTreeHeader(docsArray, offset1);
-        System.out.println(docsHeader);
-        assertEquals(1, docsHeader.numEntries());
-
-        assertEquals(100, docsArray.get(docsHeader.dataOffsetLongs() + 0));
-
-        docsHeader = new BTreeHeader(docsArray, offset2);
-        System.out.println(docsHeader);
-        assertEquals(1, docsHeader.numEntries());
-
-        assertEquals(101, docsArray.get(docsHeader.dataOffsetLongs() + 0));
-    }
-}

code/index/java/nu/marginalia/index/IndexGrpcService.java

@@ -7,24 +7,13 @@ import io.grpc.stub.StreamObserver;
 import io.prometheus.client.Counter;
 import io.prometheus.client.Gauge;
 import io.prometheus.client.Histogram;
-import it.unimi.dsi.fastutil.longs.LongArrayList;
 import nu.marginalia.api.searchquery.IndexApiGrpc;
 import nu.marginalia.api.searchquery.RpcDecoratedResultItem;
 import nu.marginalia.api.searchquery.RpcIndexQuery;
-import nu.marginalia.api.searchquery.RpcResultRankingParameters;
-import nu.marginalia.api.searchquery.model.compiled.CompiledQuery;
-import nu.marginalia.api.searchquery.model.compiled.CompiledQueryLong;
-import nu.marginalia.api.searchquery.model.compiled.CqDataInt;
 import nu.marginalia.api.searchquery.model.query.SearchSpecification;
-import nu.marginalia.api.searchquery.model.results.ResultRankingContext;
-import nu.marginalia.array.page.LongQueryBuffer;
 import nu.marginalia.index.index.StatefulIndex;
 import nu.marginalia.index.model.SearchParameters;
-import nu.marginalia.index.model.SearchTerms;
-import nu.marginalia.index.query.IndexQuery;
-import nu.marginalia.index.query.IndexSearchBudget;
 import nu.marginalia.index.results.IndexResultRankingService;
-import nu.marginalia.index.results.model.ids.CombinedDocIdList;
 import nu.marginalia.index.searchset.SearchSet;
 import nu.marginalia.index.searchset.SearchSetsService;
 import nu.marginalia.index.searchset.SmallSearchSet;
@@ -35,14 +24,7 @@ import org.slf4j.LoggerFactory;
 import org.slf4j.Marker;
 import org.slf4j.MarkerFactory;
 
-import java.util.BitSet;
 import java.util.List;
-import java.util.concurrent.ArrayBlockingQueue;
-import java.util.concurrent.Executor;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.atomic.AtomicLong;
 
 @Singleton
 public class IndexGrpcService
@@ -88,23 +70,22 @@ public class IndexGrpcService
     private final StatefulIndex statefulIndex;
     private final SearchSetsService searchSetsService;
 
-    private final IndexResultRankingService resultValuator;
+    private final IndexResultRankingService rankingService;
 
     private final String nodeName;
 
-    private static final int indexValuationThreads = Integer.getInteger("index.valuationThreads", 16);
 
     @Inject
     public IndexGrpcService(ServiceConfiguration serviceConfiguration,
                             StatefulIndex statefulIndex,
                             SearchSetsService searchSetsService,
-                            IndexResultRankingService resultValuator)
+                            IndexResultRankingService rankingService)
     {
         var nodeId = serviceConfiguration.node();
         this.nodeName = Integer.toString(nodeId);
         this.statefulIndex = statefulIndex;
         this.searchSetsService = searchSetsService;
-        this.resultValuator = resultValuator;
+        this.rankingService = rankingService;
     }
 
     // GRPC endpoint
@@ -121,7 +102,13 @@ public class IndexGrpcService
                     .time(() -> {
                         // Perform the search
                         try {
-                            return executeSearch(params);
+
+                            if (!statefulIndex.isLoaded()) {
+                                // Short-circuit if the index is not loaded, as we trivially know that there can be no results
+                                return List.of();
+                            }
+
+                            return new IndexQueryExecution(params, rankingService, statefulIndex.get()).run();
                         }
                         catch (Exception ex) {
                             logger.error("Error in handling request", ex);
@@ -157,7 +144,12 @@ public class IndexGrpcService
     // exists for test access
     public List<RpcDecoratedResultItem> justQuery(SearchSpecification specsSet) {
         try {
-            return executeSearch(new SearchParameters(specsSet, getSearchSet(specsSet)));
+            if (!statefulIndex.isLoaded()) {
+                // Short-circuit if the index is not loaded, as we trivially know that there can be no results
+                return List.of();
+            }
+
+            return new IndexQueryExecution(new SearchParameters(specsSet, getSearchSet(specsSet)), rankingService, statefulIndex.get()).run();
         }
         catch (Exception ex) {
             logger.error("Error in handling request", ex);
@@ -183,262 +175,6 @@ public class IndexGrpcService
         return searchSetsService.getSearchSetByName(request.getSearchSetIdentifier());
     }
 
-    // accessible for tests
-    public List<RpcDecoratedResultItem> executeSearch(SearchParameters params) throws Exception {
-
-        if (!statefulIndex.isLoaded()) {
-            // Short-circuit if the index is not loaded, as we trivially know that there can be no results
-            return List.of();
-        }
-
-        ResultRankingContext rankingContext = createRankingContext(params.rankingParams,
-                params.compiledQuery,
-                params.compiledQueryIds);
-
-        var queryExecution = new QueryExecution(rankingContext, params.fetchSize);
-
-        List<RpcDecoratedResultItem> ret = queryExecution.run(params);
-
-        wmsa_index_query_exec_block_time
-                .labels(nodeName)
-                .set(queryExecution.getBlockTime() / 1000.);
-        wmsa_index_query_exec_stall_time
-                .labels(nodeName)
-                .set(queryExecution.getStallTime() / 1000.);
-
-        return ret;
-    }
-
-    /** This class is responsible for ranking the results and adding the best results to the
-     * resultHeap, which depending on the state of the indexLookup threads may or may not block
-     */
-    private ResultRankingContext createRankingContext(RpcResultRankingParameters rankingParams,
-                                                      CompiledQuery<String> compiledQuery,
-                                                      CompiledQueryLong compiledQueryIds)
-    {
-
-        int[] full = new int[compiledQueryIds.size()];
-        int[] prio = new int[compiledQueryIds.size()];
-
-        BitSet ngramsMask = new BitSet(compiledQuery.size());
-        BitSet regularMask = new BitSet(compiledQuery.size());
-
-        var currentIndex = statefulIndex.get();
-
-        for (int idx = 0; idx < compiledQueryIds.size(); idx++) {
-            long id = compiledQueryIds.at(idx);
-            full[idx] = currentIndex.numHits(id);
-            prio[idx] = currentIndex.numHitsPrio(id);
-
-            if (compiledQuery.at(idx).contains("_")) {
-                ngramsMask.set(idx);
-            }
-            else {
-                regularMask.set(idx);
-            }
-        }
-
-        return new ResultRankingContext(currentIndex.totalDocCount(),
-                rankingParams,
-                ngramsMask,
-                regularMask,
-                new CqDataInt(full),
-                new CqDataInt(prio));
-    }
-
-    /** This class is responsible for executing a search query. It uses a thread pool to
-     * execute the subqueries and their valuation in parallel. The results are then combined
-     * into a bounded priority queue, and finally the best results are returned.
-     */
-    private class QueryExecution {
-
-        private static final Executor workerPool = Executors.newCachedThreadPool();
-
-        /** The queue where the results from the index lookup threads are placed,
-         * pending ranking by the result ranker threads */
-        private final ArrayBlockingQueue<CombinedDocIdList> resultCandidateQueue
-                = new ArrayBlockingQueue<>(64);
-        private final ResultPriorityQueue resultHeap;
-
-        private final ResultRankingContext resultRankingContext;
-        private final AtomicInteger remainingIndexTasks = new AtomicInteger(0);
-
-        private final AtomicInteger remainingValuationTasks = new AtomicInteger(0);
-        private final AtomicLong blockTime = new AtomicLong(0);
-
-        private final AtomicLong stallTime = new AtomicLong(0);
-
-        public long getStallTime() {
-            return stallTime.get();
-        }
-
-        public long getBlockTime() {
-            return blockTime.get();
-        }
-
-        private QueryExecution(ResultRankingContext resultRankingContext, int maxResults) {
-            this.resultRankingContext = resultRankingContext;
-            this.resultHeap = new ResultPriorityQueue(maxResults);
-        }
-
-        /** Execute a search query */
-        public List<RpcDecoratedResultItem> run(SearchParameters parameters) throws Exception {
-
-            var terms = new SearchTerms(parameters.query, parameters.compiledQueryIds);
-
-            var currentIndex = statefulIndex.get();
-            for (var indexQuery : currentIndex.createQueries(terms, parameters.queryParams)) {
-                workerPool.execute(new IndexLookup(indexQuery, parameters.budget));
-            }
-
-            for (int i = 0; i < indexValuationThreads; i++) {
-                workerPool.execute(new ResultRanker(parameters, resultRankingContext));
-            }
-
-            // Wait for all tasks to complete
-            awaitCompletion();
-
-            // Return the best results
-            return resultValuator.selectBestResults(parameters, resultRankingContext, resultHeap);
-        }
-
-        /** Wait for all tasks to complete */
-        private void awaitCompletion() throws InterruptedException {
-            synchronized (remainingValuationTasks) {
-                while (remainingValuationTasks.get() > 0) {
-                    remainingValuationTasks.wait(20);
-                }
-            }
-        }
-        /** This class is responsible for executing a subquery and adding the results to the
-         * resultCandidateQueue, which depending on the state of the valuator threads may
-         * or may not block */
-        class IndexLookup implements Runnable {
-            private final IndexQuery query;
-
-            private final IndexSearchBudget budget;
-
-            IndexLookup(IndexQuery query,
-                        IndexSearchBudget budget) {
-                this.query = query;
-                this.budget = budget;
-
-                remainingIndexTasks.incrementAndGet();
-            }
-
-            public void run() {
-                try {
-                    executeSearch();
-                }
-                catch (Exception ex) {
-                    logger.error("Error in index lookup", ex);
-                }
-                finally {
-                    synchronized (remainingIndexTasks) {
-                        if (remainingIndexTasks.decrementAndGet() == 0) {
-                            remainingIndexTasks.notifyAll();
-                        }
-                    }
-                }
-            }
-
-            private void executeSearch() {
-                final LongArrayList results = new LongArrayList(16);
-
-                // These queries are different indices for one subquery
-                final LongQueryBuffer buffer = new LongQueryBuffer(4096);
-
-                while (query.hasMore() && budget.hasTimeLeft())
-                {
-                    buffer.reset();
-                    query.getMoreResults(buffer);
-
-                    for (int i = 0; i < buffer.end; i+=16) {
-                        for (int j = 0; j < Math.min(buffer.end - i, 16); j++) {
-                            results.add(buffer.data.get(i+j));
-                        }
-                        enqueueResults(new CombinedDocIdList(results));
-                        results.clear();
-                    }
-                }
-
-                buffer.dispose();
-            }
-
-            private void enqueueResults(CombinedDocIdList resultIds) {
-                long remainingTime = budget.timeLeft();
-
-                try {
-                    if (!resultCandidateQueue.offer(resultIds)) {
-                        long start = System.currentTimeMillis();
-                        resultCandidateQueue.offer(resultIds, remainingTime, TimeUnit.MILLISECONDS);
-                        blockTime.addAndGet(System.currentTimeMillis() - start);
-                    }
-                }
-                catch (InterruptedException e) {
-                    logger.warn("Interrupted while waiting to offer resultIds to queue", e);
-                }
-            }
-
-        }
-        class ResultRanker implements Runnable {
-            private final SearchParameters parameters;
-
-            private final ResultRankingContext rankingContext;
-
-            ResultRanker(SearchParameters parameters, ResultRankingContext rankingContext) {
-                this.parameters = parameters;
-                this.rankingContext = rankingContext;
-
-                remainingValuationTasks.incrementAndGet();
-            }
-
-            public void run() {
-                try {
-                    while (parameters.budget.timeLeft() > 0 && execute());
-                }
-                catch (InterruptedException e) {
-                    logger.warn("Interrupted while waiting to poll resultIds from queue", e);
-                }
-                catch (Exception e) {
-                    logger.error("Exception while ranking results", e);
-                }
-                finally {
-                    synchronized (remainingValuationTasks) {
-                        if (remainingValuationTasks.decrementAndGet() == 0)
-                            remainingValuationTasks.notifyAll();
-                    }
-                }
-            }
-
-            private boolean execute() throws Exception {
-                long start = System.currentTimeMillis();
-
-                // Do a relatively short poll to ensure we terminate in a timely manner
-                // in the event all work is done
-                final long pollTime = Math.clamp(parameters.budget.timeLeft(), 1, 5);
-                CombinedDocIdList resultIds = resultCandidateQueue.poll(pollTime, TimeUnit.MILLISECONDS);
-
-                if (resultIds == null) {
-                    // check if we are done and can terminate
-                    if (remainingIndexTasks.get() == 0 && resultCandidateQueue.isEmpty()) {
-                        return false;
-                    }
-                }
-                else {
-                    stallTime.addAndGet(System.currentTimeMillis() - start);
-
-                    resultHeap.addAll(
-                            resultValuator.rankResults(parameters, false, rankingContext, resultIds)
-                    );
-                }
-
-                return true; // keep going
-            }
-
-        }
-
-    }
 
 }
 

code/index/java/nu/marginalia/index/IndexQueryExecution.java

@@ -0,0 +1,228 @@
+package nu.marginalia.index;
+
+import nu.marginalia.api.searchquery.RpcDecoratedResultItem;
+import nu.marginalia.array.page.LongQueryBuffer;
+import nu.marginalia.index.index.CombinedIndexReader;
+import nu.marginalia.index.model.ResultRankingContext;
+import nu.marginalia.index.model.SearchParameters;
+import nu.marginalia.index.model.SearchTerms;
+import nu.marginalia.index.query.IndexQuery;
+import nu.marginalia.index.query.IndexSearchBudget;
+import nu.marginalia.index.results.IndexResultRankingService;
+import nu.marginalia.index.results.model.ids.CombinedDocIdList;
+import nu.marginalia.skiplist.SkipListConstants;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicLong;
+
+/** Performs an index query */
+public class IndexQueryExecution {
+
+    private static final int indexValuationThreads = Integer.getInteger("index.valuationThreads", 16);
+    private static final int indexPreparationThreads = Integer.getInteger("index.preparationThreads", 4);
+
+    // Since most NVMe drives have a maximum read size of 128 KB, and most small reads are 512B
+    // this should probably be 128*1024 / 512 = 256 to reduce queue depth and optimize tail latency
+    private static final int evaluationBatchSize = 256;
+
+    // This should probably be SkipListConstants.BLOCK_SIZE / 16 in order to reduce the number of unnecessary read
+    // operations per lookup and again optimize tail latency
+    private static final int lookupBatchSize = SkipListConstants.BLOCK_SIZE / 16;
+
+    private static final AtomicLong lookupTime = new AtomicLong();
+    private static final AtomicLong prepTime = new AtomicLong();
+    private static final AtomicLong valuationTime = new AtomicLong();
+
+    private static final ExecutorService threadPool = new ThreadPoolExecutor(indexValuationThreads, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<>());
+    private static final Logger log = LoggerFactory.getLogger(IndexQueryExecution.class);
+
+    private final IndexResultRankingService rankingService;
+
+    private final ResultRankingContext rankingContext;
+    private final List<IndexQuery> queries;
+    private final IndexSearchBudget budget;
+    private final ResultPriorityQueue resultHeap;
+    private final CountDownLatch lookupCountdown;
+    private final CountDownLatch preparationCountdown;
+    private final CountDownLatch rankingCountdown;
+
+    private final ArrayBlockingQueue<CombinedDocIdList> fullPreparationQueue = new ArrayBlockingQueue<>(8, true);
+    private final ArrayBlockingQueue<CombinedDocIdList> priorityPreparationQueue = new ArrayBlockingQueue<>(8, true);
+    private final ArrayBlockingQueue<IndexResultRankingService.RankingData> fullEvaluationQueue = new ArrayBlockingQueue<>(8, true);
+    private final ArrayBlockingQueue<IndexResultRankingService.RankingData> priorityEvaluationQueue = new ArrayBlockingQueue<>(8, true);
+
+    private final int limitTotal;
+    private final int limitByDomain;
+
+    static {
+        Thread.ofPlatform().daemon().start(() -> {
+            for (;;) {
+                try {
+                    TimeUnit.SECONDS.sleep(10);
+                }
+                catch (InterruptedException e) {
+                    e.printStackTrace();
+                    break;
+                }
+                log.info("Lookup: {}, Valuation: {}, Prep Time: {}", lookupTime.get() / 1_000_000_000.,  valuationTime.get() / 1_000_000_000., prepTime.get() / 1_000_000_000.);
+            }
+        });
+    }
+
+    public IndexQueryExecution(SearchParameters params,
+                               IndexResultRankingService rankingService,
+                               CombinedIndexReader currentIndex) {
+        this.rankingService = rankingService;
+
+        resultHeap = new ResultPriorityQueue(params.fetchSize);
+
+        budget = params.budget;
+        limitByDomain = params.limitByDomain;
+        limitTotal = params.limitTotal;
+
+        rankingContext = ResultRankingContext.create(currentIndex, params);
+        queries = currentIndex.createQueries(new SearchTerms(params.query, params.compiledQueryIds), params.queryParams, budget);
+
+        lookupCountdown = new CountDownLatch(queries.size());
+        preparationCountdown = new CountDownLatch(indexPreparationThreads * 2);
+        rankingCountdown = new CountDownLatch(indexValuationThreads * 2);
+    }
+
+    public List<RpcDecoratedResultItem> run() throws InterruptedException, SQLException {
+        for (IndexQuery query : queries) {
+            threadPool.submit(() -> lookup(query));
+        }
+
+        for (int i = 0; i < indexPreparationThreads; i++) {
+            threadPool.submit(() -> prepare(priorityPreparationQueue, priorityEvaluationQueue));
+            threadPool.submit(() -> prepare(fullPreparationQueue, fullEvaluationQueue));
+        }
+
+        // Spawn lookup tasks for each query
+        for (int i = 0; i < indexValuationThreads; i++) {
+            threadPool.submit(() -> evaluate(priorityEvaluationQueue));
+            threadPool.submit(() -> evaluate(fullEvaluationQueue));
+        }
+
+        // Await lookup task termination
+        lookupCountdown.await();
+        preparationCountdown.await();
+        rankingCountdown.await();
+
+        // Deallocate any leftover ranking data buffers
+        for (var data : priorityEvaluationQueue) {
+            data.close();
+        }
+        for (var data : fullEvaluationQueue) {
+            data.close();
+        }
+
+        // Final result selection
+        return rankingService.selectBestResults(limitByDomain, limitTotal, rankingContext, resultHeap.toList());
+    }
+
+    private List<Future<?>> lookup(IndexQuery query) {
+        final LongQueryBuffer buffer = new LongQueryBuffer(lookupBatchSize);
+        List<Future<?>> evaluationJobs = new ArrayList<>();
+        try {
+            while (query.hasMore() && budget.hasTimeLeft()) {
+
+                buffer.zero();
+
+                long st = System.nanoTime();
+                query.getMoreResults(buffer);
+                long et = System.nanoTime();
+                lookupTime.addAndGet(et - st);
+
+                if (buffer.isEmpty())
+                    continue;
+
+                var queue = query.isPrioritized() ? priorityPreparationQueue : fullPreparationQueue;
+
+                if (buffer.end <= evaluationBatchSize) {
+                    var docIds = new CombinedDocIdList(buffer);
+
+                    if (!queue.offer(docIds, Math.max(1, budget.timeLeft()), TimeUnit.MILLISECONDS))
+                        break;
+                }
+                else {
+                    long[] bufferData = buffer.copyData();
+                    for (int start = 0; start < bufferData.length; start+= evaluationBatchSize) {
+
+                        long[] slice =  Arrays.copyOfRange(bufferData, start,
+                                Math.min(start + evaluationBatchSize, bufferData.length));
+
+                        var docIds = new CombinedDocIdList(slice);
+
+                        if (!queue.offer(docIds, Math.max(1, budget.timeLeft()), TimeUnit.MILLISECONDS))
+                            break;
+
+                    }
+                }
+            }
+        } catch (RuntimeException | InterruptedException ex) {
+            log.error("Exception in lookup thread", ex);
+        } finally {
+            buffer.dispose();
+            lookupCountdown.countDown();
+        }
+
+        return evaluationJobs;
+    }
+
+    private void prepare(ArrayBlockingQueue<CombinedDocIdList> inputQueue, ArrayBlockingQueue<IndexResultRankingService.RankingData> outputQueue) {
+        try {
+            while (budget.hasTimeLeft() && (lookupCountdown.getCount() > 0 || !inputQueue.isEmpty())) {
+                var docIds = inputQueue.poll(Math.clamp(budget.timeLeft(), 1, 5), TimeUnit.MILLISECONDS);
+                if (docIds == null) continue;
+                long st = System.nanoTime();
+                var preparedData = rankingService.prepareRankingData(rankingContext, docIds, budget);
+                long et = System.nanoTime();
+                prepTime.addAndGet(et - st);
+                if (!outputQueue.offer(preparedData, Math.max(1, budget.timeLeft()), TimeUnit.MILLISECONDS))
+                    preparedData.close();
+            }
+        } catch (TimeoutException ex) {
+            // This is normal
+        } catch (Exception ex) {
+            if (!(ex.getCause() instanceof InterruptedException)) {
+                log.error("Exception in lookup thread", ex);
+            }  // suppress logging for interrupted ex
+        } finally {
+            preparationCountdown.countDown();
+        }
+    }
+
+    private void evaluate(ArrayBlockingQueue<IndexResultRankingService.RankingData> queue) {
+        try {
+            while (budget.hasTimeLeft() && (preparationCountdown.getCount() > 0 || !queue.isEmpty())) {
+                var rankingData = queue.poll(Math.clamp(budget.timeLeft(), 1, 5), TimeUnit.MILLISECONDS);
+                if (rankingData == null) continue;
+
+                try (rankingData) {
+                    long st =  System.nanoTime();
+                    resultHeap.addAll(rankingService.rankResults(budget, rankingContext, rankingData, false));
+                    long et = System.nanoTime();
+                    valuationTime.addAndGet(et - st);
+                }
+            }
+        } catch (Exception ex) {
+            if (!(ex.getCause() instanceof InterruptedException)) {
+                log.error("Exception in lookup thread", ex);
+            }  // suppress logging for interrupted ex
+        } finally {
+            rankingCountdown.countDown();
+        }
+    }
+
+    public int itemsProcessed() {
+        return resultHeap.getItemsProcessed();
+    }
+
+}

code/index/java/nu/marginalia/index/ResultPriorityQueue.java

@@ -1,5 +1,6 @@
 package nu.marginalia.index;
 
+import com.google.common.collect.MinMaxPriorityQueue;
 import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
 import nu.marginalia.api.searchquery.model.results.SearchResultItem;
 import org.jetbrains.annotations.NotNull;
@@ -9,108 +10,52 @@ import java.util.*;
 /** A priority queue for search results. This class is not thread-safe,
  * in general, except for concurrent use of the addAll method.
  * <p></p>
- * The class implements a subset of the Collection interface, and
- * is intended to be used as a priority queue for search results,
- * with a maximum size.
- * <p></p>
  * Since the expected use case is to add a large number of items
  * and then iterate over the items, the class is optimized for
  * this scenario, and does not implement other mutating methods
  * than addAll().
  */
-public class ResultPriorityQueue implements Iterable<SearchResultItem>,
-        Collection<SearchResultItem> {
-    private final int limit;
-    private final ArrayList<SearchResultItem> backingList = new ArrayList<>();
+public class ResultPriorityQueue implements Iterable<SearchResultItem> {
     private final LongOpenHashSet idsInSet = new LongOpenHashSet();
+    private final MinMaxPriorityQueue<SearchResultItem> queue;
+
+    private int itemsProcessed = 0;
 
     public ResultPriorityQueue(int limit) {
-        this.limit = limit;
+        this.queue = MinMaxPriorityQueue.<SearchResultItem>orderedBy(Comparator.naturalOrder()).maximumSize(limit).create();
     }
 
     public Iterator<SearchResultItem> iterator() {
-        return backingList.iterator();
-    }
-
-    @NotNull
-    @Override
-    public Object[] toArray() {
-        return backingList.toArray();
-    }
-
-    @NotNull
-    @Override
-    public <T> T[] toArray(@NotNull T[] a) {
-        return backingList.toArray(a);
-    }
-
-    @Override
-    public boolean add(SearchResultItem searchResultItem) {
-        throw new UnsupportedOperationException("Use addAll instead");
-    }
-
-    @Override
-    public boolean remove(Object o) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public boolean containsAll(@NotNull Collection<?> c) {
-        return idsInSet.containsAll(c);
+        return queue.iterator();
     }
 
     /** Adds all items to the queue, and returns true if any items were added.
      * This is a thread-safe operation.
      */
-    @Override
     public synchronized boolean addAll(@NotNull Collection<? extends SearchResultItem> items) {
-        boolean itemsAdded = false;
-        for (var item: items) {
-            if (idsInSet.add(item.getDocumentId())) {
-                backingList.add(item);
-                itemsAdded = true;
-            }
-        }
-        if (!itemsAdded) {
-            return false;
-        }
+        itemsProcessed+=items.size();
 
-        backingList.sort(Comparator.naturalOrder());
-        if (backingList.size() > limit) {
-            backingList.subList(limit, backingList.size()).clear();
+        for (var item : items) {
+            if (idsInSet.add(item.getDocumentId())) {
+                queue.add(item);
+            }
         }
 
         return true;
     }
 
-    @Override
-    public boolean removeAll(@NotNull Collection<?> c) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public boolean retainAll(@NotNull Collection<?> c) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public void clear() {
-        backingList.clear();
-        idsInSet.clear();
+    public synchronized List<SearchResultItem> toList() {
+        return new ArrayList<>(queue);
     }
 
     public int size() {
-        return backingList.size();
+        return queue.size();
+    }
+    public int getItemsProcessed() {
+        return itemsProcessed;
     }
-
-    @Override
     public boolean isEmpty() {
-        return backingList.isEmpty();
-    }
-
-    @Override
-    public boolean contains(Object o) {
-        return backingList.contains(o);
+        return queue.isEmpty();
     }
 
 }

code/index/java/nu/marginalia/index/index/CombinedIndexReader.java

@@ -5,14 +5,17 @@ import it.unimi.dsi.fastutil.longs.LongList;
 import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
 import it.unimi.dsi.fastutil.longs.LongSet;
 import nu.marginalia.api.searchquery.model.compiled.aggregate.CompiledQueryAggregates;
+import nu.marginalia.array.page.LongQueryBuffer;
 import nu.marginalia.index.FullReverseIndexReader;
 import nu.marginalia.index.PrioReverseIndexReader;
 import nu.marginalia.index.forward.ForwardIndexReader;
 import nu.marginalia.index.forward.spans.DocumentSpans;
 import nu.marginalia.index.model.QueryParams;
 import nu.marginalia.index.model.SearchTerms;
+import nu.marginalia.index.positions.TermData;
 import nu.marginalia.index.query.IndexQuery;
 import nu.marginalia.index.query.IndexQueryBuilder;
+import nu.marginalia.index.query.IndexSearchBudget;
 import nu.marginalia.index.query.filter.QueryFilterStepIf;
 import nu.marginalia.index.query.limit.SpecificationLimitType;
 import nu.marginalia.index.results.model.ids.CombinedDocIdList;
@@ -25,6 +28,7 @@ import org.slf4j.LoggerFactory;
 import java.lang.foreign.Arena;
 import java.time.Duration;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -55,20 +59,19 @@ public class CombinedIndexReader {
         return new IndexQueryBuilderImpl(reverseIndexFullReader, query);
     }
 
-    public QueryFilterStepIf hasWordFull(long termId) {
-        return reverseIndexFullReader.also(termId);
+    public QueryFilterStepIf hasWordFull(long termId, IndexSearchBudget budget) {
+        return reverseIndexFullReader.also(termId, budget);
     }
 
     /** Creates a query builder for terms in the priority index */
     public IndexQueryBuilder findPriorityWord(long wordId) {
-        return newQueryBuilder(new IndexQuery(reverseIndexPriorityReader.documents(wordId)))
+        return newQueryBuilder(new IndexQuery(reverseIndexPriorityReader.documents(wordId), true))
                 .withSourceTerms(wordId);
     }
 
     /** Creates a query builder for terms in the full index */
     public IndexQueryBuilder findFullWord(long wordId) {
-        return newQueryBuilder(
-                new IndexQuery(reverseIndexFullReader.documents(wordId)))
+        return newQueryBuilder(new IndexQuery(reverseIndexFullReader.documents(wordId), false))
                 .withSourceTerms(wordId);
     }
 
@@ -82,7 +85,12 @@ public class CombinedIndexReader {
         return reverseIndexFullReader.numDocuments(word);
     }
 
-    public List<IndexQuery> createQueries(SearchTerms terms, QueryParams params) {
+    /** Reset caches and buffers */
+    public void reset() {
+        reverseIndexFullReader.reset();
+    }
+
+    public List<IndexQuery> createQueries(SearchTerms terms, QueryParams params, IndexSearchBudget budget) {
 
         if (!isLoaded()) {
             logger.warn("Index reader not ready");
@@ -123,7 +131,7 @@ public class CombinedIndexReader {
                         continue;
                     }
 
-                    head.addInclusionFilter(hasWordFull(termId));
+                    head.addInclusionFilter(hasWordFull(termId, budget));
                 }
                 queryHeads.add(head);
             }
@@ -132,7 +140,7 @@ public class CombinedIndexReader {
             if (paths.size() < 4) {
                 var prioHead = findPriorityWord(elements.getLong(0));
                 for (int i = 1; i < elements.size(); i++) {
-                    prioHead.addInclusionFilter(hasWordFull(elements.getLong(i)));
+                    prioHead.addInclusionFilter(hasWordFull(elements.getLong(i), budget));
                 }
                 queryHeads.add(prioHead);
             }
@@ -143,11 +151,11 @@ public class CombinedIndexReader {
 
             // Advice terms are a special case, mandatory but not ranked, and exempt from re-writing
             for (long term : terms.advice()) {
-                query = query.also(term);
+                query = query.also(term, budget);
             }
 
             for (long term : terms.excludes()) {
-                query = query.not(term);
+                query = query.not(term, budget);
             }
 
             // Run these filter steps last, as they'll worst-case cause as many page faults as there are
@@ -178,6 +186,18 @@ public class CombinedIndexReader {
     }
 
     /** Retrieves the term metadata for the specified word for the provided documents */
+    public TermMetadataList[] getTermMetadata(Arena arena,
+                                            long[] wordIds,
+                                            CombinedDocIdList docIds)
+    {
+        TermData[] combinedTermData = reverseIndexFullReader.getTermData(arena, wordIds, docIds.array());
+        TermMetadataList[] ret = new TermMetadataList[wordIds.length];
+        for (int i = 0; i < wordIds.length; i++) {
+            ret[i] = new TermMetadataList(Arrays.copyOfRange(combinedTermData, i*docIds.size(), (i+1)*docIds.size()));
+        }
+        return ret;
+    }
+
     public TermMetadataList getTermMetadata(Arena arena,
                                             long wordId,
                                             CombinedDocIdList docIds)
@@ -205,14 +225,19 @@ public class CombinedIndexReader {
         return forwardIndexReader.getDocumentSize(docId);
     }
 
-    /** Retrieves the document spans for the specified document */
-    public DocumentSpans getDocumentSpans(Arena arena, long docId) {
-        return forwardIndexReader.getDocumentSpans(arena, docId);
+    /** Retrieves the document spans for the specified documents */
+    public DocumentSpans[] getDocumentSpans(Arena arena, CombinedDocIdList docIds) {
+        long[] decodedIDs = docIds.array();
+        for (int i = 0; i < decodedIDs.length; i++) {
+            decodedIDs[i] = UrlIdCodec.removeRank(decodedIDs[i]);
+        }
+
+        return forwardIndexReader.getDocumentSpans(arena, decodedIDs);
     }
 
     /** Close the indexes (this is not done immediately)
      * */
-    public void close() throws InterruptedException {
+    public void close() {
        /* Delay the invocation of close method to allow for a clean shutdown of the service.
         *
         * This is especially important when using Unsafe-based LongArrays, since we have
@@ -227,7 +252,7 @@ public class CombinedIndexReader {
     }
 
 
-    private void delayedCall(Runnable call, Duration delay) throws InterruptedException {
+    private void delayedCall(Runnable call, Duration delay) {
         Thread.ofPlatform().start(() -> {
             try {
                 TimeUnit.SECONDS.sleep(delay.toSeconds());
@@ -248,25 +273,47 @@ public class CombinedIndexReader {
 class ParamMatchingQueryFilter implements QueryFilterStepIf {
     private final QueryParams params;
     private final ForwardIndexReader forwardIndexReader;
-
+    private final boolean imposesMetaConstraint;
     public ParamMatchingQueryFilter(QueryParams params,
                                     ForwardIndexReader forwardIndexReader)
     {
         this.params = params;
         this.forwardIndexReader = forwardIndexReader;
+        this.imposesMetaConstraint = params.imposesDomainMetadataConstraint();
     }
 
     @Override
+    public void apply(LongQueryBuffer buffer) {
+        if (!imposesMetaConstraint && !params.searchSet().imposesConstraint()) {
+            return;
+        }
+
+        while (buffer.hasMore()) {
+            if (test(buffer.currentValue())) {
+                buffer.retainAndAdvance();
+            }
+            else {
+                buffer.rejectAndAdvance();
+            }
+        }
+
+        buffer.finalizeFiltering();
+    }
+
     public boolean test(long combinedId) {
         long docId = UrlIdCodec.removeRank(combinedId);
         int domainId = UrlIdCodec.getDomainId(docId);
 
-        long meta = forwardIndexReader.getDocMeta(docId);
-
-        if (!validateDomain(domainId, meta)) {
+        if (!validateDomain(domainId)) {
             return false;
         }
 
+        if (!imposesMetaConstraint) {
+            return true;
+        }
+
+        long meta = forwardIndexReader.getDocMeta(docId);
+
         if (!validateQuality(meta)) {
             return false;
         }
@@ -286,8 +333,8 @@ class ParamMatchingQueryFilter implements QueryFilterStepIf {
         return true;
     }
 
-    private boolean validateDomain(int domainId, long meta) {
-        return params.searchSet().contains(domainId, meta);
+    private boolean validateDomain(int domainId) {
+        return params.searchSet().contains(domainId);
     }
 
     private boolean validateQuality(long meta) {
@@ -338,4 +385,5 @@ class ParamMatchingQueryFilter implements QueryFilterStepIf {
     public String describe() {
         return getClass().getSimpleName();
     }
+
 }

code/index/java/nu/marginalia/index/index/IndexQueryBuilderImpl.java

@@ -1,11 +1,10 @@
 package nu.marginalia.index.index;
 
-import java.util.List;
 import gnu.trove.set.hash.TLongHashSet;
 import nu.marginalia.index.FullReverseIndexReader;
 import nu.marginalia.index.query.IndexQuery;
 import nu.marginalia.index.query.IndexQueryBuilder;
-import nu.marginalia.index.query.filter.QueryFilterAnyOf;
+import nu.marginalia.index.query.IndexSearchBudget;
 import nu.marginalia.index.query.filter.QueryFilterStepIf;
 
 public class IndexQueryBuilderImpl implements IndexQueryBuilder  {
@@ -32,18 +31,18 @@ public class IndexQueryBuilderImpl implements IndexQueryBuilder  {
         return this;
     }
 
-    public IndexQueryBuilder also(long termId) {
+    public IndexQueryBuilder also(long termId, IndexSearchBudget budget) {
 
         if (alreadyConsideredTerms.add(termId)) {
-            query.addInclusionFilter(reverseIndexFullReader.also(termId));
+            query.addInclusionFilter(reverseIndexFullReader.also(termId, budget));
         }
 
         return this;
     }
 
-    public IndexQueryBuilder not(long termId) {
+    public IndexQueryBuilder not(long termId, IndexSearchBudget budget) {
 
-        query.addInclusionFilter(reverseIndexFullReader.not(termId));
+        query.addInclusionFilter(reverseIndexFullReader.not(termId, budget));
 
         return this;
     }
@@ -55,20 +54,6 @@ public class IndexQueryBuilderImpl implements IndexQueryBuilder  {
         return this;
     }
 
-    public IndexQueryBuilder addInclusionFilterAny(List<QueryFilterStepIf> filterSteps) {
-        if (filterSteps.isEmpty())
-            return this;
-
-        if (filterSteps.size() == 1) {
-            query.addInclusionFilter(filterSteps.getFirst());
-        }
-        else {
-            query.addInclusionFilter(new QueryFilterAnyOf(filterSteps));
-        }
-
-        return this;
-    }
-
     public IndexQuery build() {
         return query;
     }

code/index/java/nu/marginalia/index/index/StatefulIndex.java

@@ -35,6 +35,13 @@ public class StatefulIndex {
         this.eventLog = eventLog;
     }
 
+    /** For use in testing only */
+    public StatefulIndex(CombinedIndexReader combinedIndexReader) {
+        this.combinedIndexReader = combinedIndexReader;
+        this.servicesFactory = null;
+        this.eventLog = null;
+    }
+
     public void init() {
         Lock lock = indexReplacementLock.writeLock();
 

code/index/java/nu/marginalia/index/model/QueryParams.java

@@ -1,8 +1,9 @@
 package nu.marginalia.index.model;
 
-import nu.marginalia.index.searchset.SearchSet;
 import nu.marginalia.index.query.limit.QueryStrategy;
 import nu.marginalia.index.query.limit.SpecificationLimit;
+import nu.marginalia.index.query.limit.SpecificationLimitType;
+import nu.marginalia.index.searchset.SearchSet;
 
 import java.util.Objects;
 
@@ -41,6 +42,13 @@ public final class QueryParams {
         this.queryStrategy = queryStrategy;
     }
 
+    public boolean imposesDomainMetadataConstraint() {
+        return qualityLimit.type() != SpecificationLimitType.NONE
+                ||  year.type() != SpecificationLimitType.NONE
+                ||  size.type() != SpecificationLimitType.NONE
+                ||  rank.type() != SpecificationLimitType.NONE;
+    }
+
     public SpecificationLimit qualityLimit() {
         return qualityLimit;
     }

code/index/java/nu/marginalia/index/model/ResultRankingContext.java

@@ -0,0 +1,106 @@
+package nu.marginalia.index.model;
+
+import nu.marginalia.api.searchquery.RpcResultRankingParameters;
+import nu.marginalia.api.searchquery.model.compiled.CompiledQuery;
+import nu.marginalia.api.searchquery.model.compiled.CompiledQueryLong;
+import nu.marginalia.api.searchquery.model.compiled.CqDataInt;
+import nu.marginalia.api.searchquery.model.query.SearchQuery;
+import nu.marginalia.index.index.CombinedIndexReader;
+
+import java.util.BitSet;
+
+public class ResultRankingContext {
+    private final int docCount;
+    public final RpcResultRankingParameters params;
+    public final SearchQuery searchQuery;
+    public final QueryParams queryParams;
+
+    public final CompiledQuery<String> compiledQuery;
+    public final CompiledQueryLong compiledQueryIds;
+
+    public final BitSet regularMask;
+    public final BitSet ngramsMask;
+
+    /** CqDataInt associated with frequency information of the terms in the query
+     * in the full index.  The dataset is indexed by the compiled query. */
+    public final CqDataInt fullCounts;
+
+    /** CqDataInt associated with frequency information of the terms in the query
+     * in the full index.  The dataset is indexed by the compiled query. */
+    public final CqDataInt priorityCounts;
+
+    public static ResultRankingContext create(CombinedIndexReader currentIndex, SearchParameters searchParameters) {
+
+        var compiledQueryIds = searchParameters.compiledQueryIds;
+        var compiledQuery = searchParameters.compiledQuery;
+
+        int[] full = new int[compiledQueryIds.size()];
+        int[] prio = new int[compiledQueryIds.size()];
+
+        BitSet ngramsMask = new BitSet(compiledQuery.size());
+        BitSet regularMask = new BitSet(compiledQuery.size());
+
+        for (int idx = 0; idx < compiledQueryIds.size(); idx++) {
+            long id = compiledQueryIds.at(idx);
+            full[idx] = currentIndex.numHits(id);
+            prio[idx] = currentIndex.numHitsPrio(id);
+
+            if (compiledQuery.at(idx).contains("_")) {
+                ngramsMask.set(idx);
+            }
+            else {
+                regularMask.set(idx);
+            }
+        }
+
+        return new ResultRankingContext(currentIndex.totalDocCount(),
+                searchParameters,
+                compiledQuery,
+                compiledQueryIds,
+                ngramsMask,
+                regularMask,
+                new CqDataInt(full),
+                new CqDataInt(prio));
+    }
+
+    public ResultRankingContext(int docCount,
+                                SearchParameters searchParameters,
+                                CompiledQuery<String> compiledQuery,
+                                CompiledQueryLong compiledQueryIds,
+                                BitSet ngramsMask,
+                                BitSet regularMask,
+                                CqDataInt fullCounts,
+                                CqDataInt prioCounts)
+    {
+        this.docCount = docCount;
+
+        this.searchQuery = searchParameters.query;
+        this.params = searchParameters.rankingParams;
+        this.queryParams = searchParameters.queryParams;
+
+        this.compiledQuery = compiledQuery;
+        this.compiledQueryIds = compiledQueryIds;
+
+        this.ngramsMask = ngramsMask;
+        this.regularMask = regularMask;
+
+        this.fullCounts = fullCounts;
+        this.priorityCounts = prioCounts;
+    }
+
+    public int termFreqDocCount() {
+        return docCount;
+    }
+
+    @Override
+    public String toString() {
+        return "ResultRankingContext{" +
+                "docCount=" + docCount +
+                ", params=" + params +
+                ", regularMask=" + regularMask +
+                ", ngramsMask=" + ngramsMask +
+                ", fullCounts=" + fullCounts +
+                ", priorityCounts=" + priorityCounts +
+                '}';
+    }
+}

code/index/java/nu/marginalia/index/model/SearchParameters.java

@@ -43,7 +43,7 @@ public class SearchParameters {
         var limits = specsSet.queryLimits;
 
         this.fetchSize = limits.getFetchSize();
-        this.budget = new IndexSearchBudget(limits.getTimeoutMs());
+        this.budget = new IndexSearchBudget(Math.max(limits.getTimeoutMs()/2, limits.getTimeoutMs()-50));
         this.query = specsSet.query;
         this.limitByDomain = limits.getResultsByDomain();
         this.limitTotal = limits.getResultsTotal();
@@ -67,9 +67,7 @@ public class SearchParameters {
 
         this.fetchSize = limits.getFetchSize();
 
-        // The time budget is halved because this is the point when we start to
-        // wrap up the search and return the results.
-        this.budget = new IndexSearchBudget(limits.getTimeoutMs() / 2);
+        this.budget = new IndexSearchBudget(Math.max(limits.getTimeoutMs()/2, limits.getTimeoutMs()-50));
         this.query = IndexProtobufCodec.convertRpcQuery(request.getQuery());
 
         this.limitByDomain = limits.getResultsByDomain();

code/index/java/nu/marginalia/index/results/Bm25GraphVisitor.java

@@ -2,7 +2,7 @@ package nu.marginalia.index.results;
 
 import nu.marginalia.api.searchquery.model.compiled.CqDataInt;
 import nu.marginalia.api.searchquery.model.compiled.CqExpression;
-import nu.marginalia.api.searchquery.model.results.ResultRankingContext;
+import nu.marginalia.index.model.ResultRankingContext;
 
 import java.util.BitSet;
 import java.util.List;

code/index/java/nu/marginalia/index/results/IndexResultRankingService.java

@@ -12,13 +12,14 @@ import nu.marginalia.api.searchquery.model.compiled.CompiledQuery;
 import nu.marginalia.api.searchquery.model.compiled.CqDataLong;
 import nu.marginalia.api.searchquery.model.query.SearchPhraseConstraint;
 import nu.marginalia.api.searchquery.model.query.SearchQuery;
-import nu.marginalia.api.searchquery.model.results.ResultRankingContext;
 import nu.marginalia.api.searchquery.model.results.SearchResultItem;
 import nu.marginalia.api.searchquery.model.results.debug.DebugRankingFactors;
+import nu.marginalia.index.forward.spans.DocumentSpans;
 import nu.marginalia.index.index.CombinedIndexReader;
 import nu.marginalia.index.index.StatefulIndex;
-import nu.marginalia.index.model.SearchParameters;
+import nu.marginalia.index.model.ResultRankingContext;
 import nu.marginalia.index.model.SearchTermsUtil;
+import nu.marginalia.index.query.IndexSearchBudget;
 import nu.marginalia.index.results.model.PhraseConstraintGroupList;
 import nu.marginalia.index.results.model.QuerySearchTerms;
 import nu.marginalia.index.results.model.ids.CombinedDocIdList;
@@ -30,9 +31,15 @@ import nu.marginalia.sequence.CodedSequence;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nullable;
 import java.lang.foreign.Arena;
 import java.sql.SQLException;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 @Singleton
 public class IndexResultRankingService {
@@ -52,96 +59,142 @@ public class IndexResultRankingService {
         this.domainRankingOverrides = domainRankingOverrides;
     }
 
-    public List<SearchResultItem> rankResults(SearchParameters params,
-                                              boolean exportDebugData,
-                                              ResultRankingContext rankingContext,
-                                              CombinedDocIdList resultIds)
-    {
-        if (resultIds.isEmpty())
-            return List.of();
+    public RankingData prepareRankingData(ResultRankingContext rankingContext, CombinedDocIdList resultIds, @Nullable IndexSearchBudget budget) throws TimeoutException {
+        return new RankingData(rankingContext, resultIds, budget);
+    }
 
-        IndexResultScoreCalculator resultRanker = new IndexResultScoreCalculator(statefulIndex, domainRankingOverrides, rankingContext, params);
+    public final class RankingData implements AutoCloseable {
+        final Arena arena;
 
-        List<SearchResultItem> results = new ArrayList<>(resultIds.size());
+        private final TermMetadataList[] termsForDocs;
+        private final DocumentSpans[] documentSpans;
+        private final long[] flags;
+        private final CodedSequence[] positions;
+        private final CombinedDocIdList resultIds;
+        private final QuerySearchTerms searchTerms;
+        private AtomicBoolean closed = new AtomicBoolean(false);
+        int pos = -1;
 
-        // Get the current index reader, which is the one we'll use for this calculation,
-        // this may change during the calculation, but we don't want to switch over mid-calculation
-        final CombinedIndexReader currentIndex = statefulIndex.get();
+        public RankingData(ResultRankingContext rankingContext, CombinedDocIdList resultIds, @Nullable IndexSearchBudget budget) throws TimeoutException {
+            this.resultIds = resultIds;
+            this.arena = Arena.ofShared();
 
-        final QuerySearchTerms searchTerms = getSearchTerms(params.compiledQuery, params.query);
-        final int termCount = searchTerms.termIdsAll.size();
+            this.searchTerms = getSearchTerms(rankingContext.compiledQuery, rankingContext.searchQuery);
+            final int termCount = searchTerms.termIdsAll.size();
 
-        // We use an arena for the position data to avoid gc pressure
-        // from the gamma coded sequences, which can be large and have a lifetime
-        // that matches the try block here
-        try (var arena = Arena.ofConfined()) {
+            this.flags = new long[termCount];
+            this.positions = new CodedSequence[termCount];
 
-            TermMetadataList[] termsForDocs = new TermMetadataList[termCount];
-            for (int ti = 0; ti < termCount; ti++) {
-                termsForDocs[ti] = currentIndex.getTermMetadata(arena, searchTerms.termIdsAll.at(ti), resultIds);
-            }
+            // Get the current index reader, which is the one we'll use for this calculation,
+            // this may change during the calculation, but we don't want to switch over mid-calculation
 
-            // Data for the document.  We arrange this in arrays outside the calculation function to avoid
-            // hash lookups in the inner loop, as it's hot code, and we don't want unnecessary cpu cache
-            // thrashing in there; out here we can rely on implicit array ordering to match up the data.
+            final CombinedIndexReader currentIndex = statefulIndex.get();
 
-            long[] flags = new long[termCount];
-            CodedSequence[] positions = new CodedSequence[termCount];
+            // Perform expensive I/O operations
 
-            // Iterate over documents by their index in the combinedDocIds, as we need the index for the
-            // term data arrays as well
+            this.termsForDocs = currentIndex.getTermMetadata(arena, searchTerms.termIdsAll.array, resultIds);
+            if (!budget.hasTimeLeft())
+                throw new TimeoutException();
+            this.documentSpans = currentIndex.getDocumentSpans(arena, resultIds);
+        }
 
-            for (int i = 0; i < resultIds.size(); i++) {
+        public CodedSequence[] positions() {
+            return positions;
+        }
+        public long[] flags() {
+            return flags;
+        }
+        public long resultId() {
+            return resultIds.at(pos);
+        }
+        public DocumentSpans documentSpans() {
+            return documentSpans[pos];
+        }
 
-                // Prepare term-level data for the document
+        public boolean next() {
+            if (++pos < resultIds.size()) {
                 for (int ti = 0; ti < flags.length; ti++) {
                     var tfd = termsForDocs[ti];
 
                     assert tfd != null : "No term data for term " + ti;
 
-                    flags[ti] = tfd.flag(i);
-                    positions[ti] = tfd.position(i);
+                    flags[ti] = tfd.flag(pos);
+                    positions[ti] = tfd.position(pos);
                 }
+                return true;
+            }
+            return false;
+        }
 
-                // Ignore documents that don't match the mandatory constraints
-                if (!searchTerms.phraseConstraints.testMandatory(positions)) {
-                    continue;
-                }
+        public int size() {
+            return resultIds.size();
+        }
 
-                if (!exportDebugData) {
-                    var score = resultRanker.calculateScore(arena, null, resultIds.at(i), searchTerms, flags, positions);
-                    if (score != null) {
-                        results.add(score);
-                    }
-                }
-                else {
-                    var rankingFactors = new DebugRankingFactors();
-                    var score = resultRanker.calculateScore(arena, rankingFactors, resultIds.at(i), searchTerms, flags, positions);
-                    if (score != null) {
-                        score.debugRankingFactors = rankingFactors;
-                        results.add(score);
-                    }
-                }
+        public void close() {
+            if (closed.compareAndSet(false, true)) {
+                arena.close();
+            }
+        }
+
+    }
+
+    public List<SearchResultItem> rankResults(
+            IndexSearchBudget budget,
+            ResultRankingContext rankingContext,
+            RankingData rankingData,
+            boolean exportDebugData)
+    {
+        IndexResultScoreCalculator resultRanker = new IndexResultScoreCalculator(statefulIndex, domainRankingOverrides, rankingContext);
+
+        List<SearchResultItem> results = new ArrayList<>(rankingData.size());
+
+        // Iterate over documents by their index in the combinedDocIds, as we need the index for the
+        // term data arrays as well
+
+        var searchTerms = rankingData.searchTerms;
+
+        while (rankingData.next() && budget.hasTimeLeft()) {
+
+            // Ignore documents that don't match the mandatory constraints
+            if (!searchTerms.phraseConstraints.testMandatory(rankingData.positions())) {
+                continue;
             }
 
-            return results;
+            if (!exportDebugData) {
+                var score = resultRanker.calculateScore(null, rankingData.resultId(), searchTerms, rankingData.flags(), rankingData.positions(), rankingData.documentSpans());
+                if (score != null) {
+                    results.add(score);
+                }
+            }
+            else {
+                var rankingFactors = new DebugRankingFactors();
+                var score = resultRanker.calculateScore( rankingFactors, rankingData.resultId(), searchTerms, rankingData.flags(), rankingData.positions(), rankingData.documentSpans());
+
+                if (score != null) {
+                    score.debugRankingFactors = rankingFactors;
+                    results.add(score);
+                }
+            }
         }
+
+        return results;
     }
 
 
-    public List<RpcDecoratedResultItem> selectBestResults(SearchParameters params,
+    public List<RpcDecoratedResultItem> selectBestResults(int limitByDomain,
+                                                          int limitTotal,
                                                           ResultRankingContext resultRankingContext,
-                                                          Collection<SearchResultItem> results) throws SQLException {
+                                                          List<SearchResultItem> results) throws SQLException {
 
-        var domainCountFilter = new IndexResultDomainDeduplicator(params.limitByDomain);
+        var domainCountFilter = new IndexResultDomainDeduplicator(limitByDomain);
 
         List<SearchResultItem> resultsList = new ArrayList<>(results.size());
-        TLongList idsList = new TLongArrayList(params.limitTotal);
+        TLongList idsList = new TLongArrayList(limitTotal);
 
         for (var item : results) {
             if (domainCountFilter.test(item)) {
 
-                if (resultsList.size() < params.limitTotal) {
+                if (resultsList.size() < limitTotal) {
                     resultsList.add(item);
                     idsList.add(item.getDocumentId());
                 }
@@ -159,19 +212,26 @@ public class IndexResultRankingService {
         // for the selected results, as this would be comically expensive to do for all the results we
         // discard along the way
 
-        if (params.rankingParams.getExportDebugData()) {
+        if (resultRankingContext.params.getExportDebugData()) {
             var combinedIdsList = new LongArrayList(resultsList.size());
             for (var item : resultsList) {
                 combinedIdsList.add(item.combinedId);
             }
 
             resultsList.clear();
-            resultsList.addAll(this.rankResults(
-                    params,
-                    true,
-                    resultRankingContext,
-                    new CombinedDocIdList(combinedIdsList))
-            );
+            IndexSearchBudget budget = new IndexSearchBudget(10000);
+            try (var data = prepareRankingData(resultRankingContext,  new CombinedDocIdList(combinedIdsList), null)) {
+                resultsList.addAll(this.rankResults(
+                        budget,
+                        resultRankingContext,
+                        data,
+                        true)
+                );
+            }
+            catch (TimeoutException ex) {
+                // this won't happen since we passed null for budget
+            }
+
         }
 
         // Fetch the document details for the selected results in one go, from the local document database
@@ -247,7 +307,7 @@ public class IndexResultRankingService {
 
                 var termOutputs = RpcResultTermRankingOutputs.newBuilder();
 
-                CqDataLong termIds = params.compiledQueryIds.data;;
+                CqDataLong termIds = resultRankingContext.compiledQueryIds.data;
 
                 for (var entry : debugFactors.getTermFactors()) {
                     String term = "[ERROR IN LOOKUP]";
@@ -255,7 +315,7 @@ public class IndexResultRankingService {
                     // CURSED: This is a linear search, but the number of terms is small, and it's in a debug path
                     for (int i = 0; i < termIds.size(); i++) {
                         if (termIds.get(i) == entry.termId()) {
-                            term = params.compiledQuery.at(i);
+                            term = resultRankingContext.compiledQuery.at(i);
                             break;
                         }
                     }

code/index/java/nu/marginalia/index/results/IndexResultScoreCalculator.java

@@ -6,14 +6,13 @@ import nu.marginalia.api.searchquery.RpcResultRankingParameters;
 import nu.marginalia.api.searchquery.RpcTemporalBias;
 import nu.marginalia.api.searchquery.model.compiled.CompiledQuery;
 import nu.marginalia.api.searchquery.model.compiled.CompiledQueryLong;
-import nu.marginalia.api.searchquery.model.results.ResultRankingContext;
 import nu.marginalia.api.searchquery.model.results.SearchResultItem;
 import nu.marginalia.api.searchquery.model.results.debug.DebugRankingFactors;
 import nu.marginalia.index.forward.spans.DocumentSpans;
 import nu.marginalia.index.index.CombinedIndexReader;
 import nu.marginalia.index.index.StatefulIndex;
 import nu.marginalia.index.model.QueryParams;
-import nu.marginalia.index.model.SearchParameters;
+import nu.marginalia.index.model.ResultRankingContext;
 import nu.marginalia.index.query.limit.QueryStrategy;
 import nu.marginalia.index.results.model.PhraseConstraintGroupList;
 import nu.marginalia.index.results.model.QuerySearchTerms;
@@ -28,7 +27,6 @@ import nu.marginalia.sequence.CodedSequence;
 import nu.marginalia.sequence.SequenceOperations;
 
 import javax.annotation.Nullable;
-import java.lang.foreign.Arena;
 import java.util.BitSet;
 
 import static nu.marginalia.api.searchquery.model.compiled.aggregate.CompiledQueryAggregates.booleanAggregate;
@@ -47,24 +45,23 @@ public class IndexResultScoreCalculator {
 
     public IndexResultScoreCalculator(StatefulIndex statefulIndex,
                                       DomainRankingOverrides domainRankingOverrides,
-                                      ResultRankingContext rankingContext,
-                                      SearchParameters params)
+                                      ResultRankingContext rankingContext)
     {
         this.index = statefulIndex.get();
         this.domainRankingOverrides = domainRankingOverrides;
         this.rankingContext = rankingContext;
 
-        this.queryParams = params.queryParams;
-        this.compiledQuery = params.compiledQuery;
+        this.queryParams = rankingContext.queryParams;
+        this.compiledQuery = rankingContext.compiledQuery;
     }
 
     @Nullable
-    public SearchResultItem calculateScore(Arena arena,
-                                           @Nullable DebugRankingFactors debugRankingFactors,
+    public SearchResultItem calculateScore(@Nullable DebugRankingFactors debugRankingFactors,
                                            long combinedId,
                                            QuerySearchTerms searchTerms,
                                            long[] wordFlags,
-                                           CodedSequence[] positions)
+                                           CodedSequence[] positions,
+                                           DocumentSpans spans)
     {
 
         CompiledQuery<CodedSequence> positionsQuery = compiledQuery.root.newQuery(positions);
@@ -92,8 +89,6 @@ public class IndexResultScoreCalculator {
         int docSize = index.getDocumentSize(docId);
         if (docSize <= 0) docSize = 5000;
 
-        DocumentSpans spans = index.getDocumentSpans(arena, docId);
-
         if (debugRankingFactors != null) {
             debugRankingFactors.addDocumentFactor("doc.docId", Long.toString(combinedId));
             debugRankingFactors.addDocumentFactor("doc.combinedId", Long.toString(docId));
@@ -235,7 +230,7 @@ public class IndexResultScoreCalculator {
         long result = 0;
         int bit = 0;
 
-        IntIterator intersection = phraseConstraints.getFullGroup().findIntersections(positions).intIterator();
+        IntIterator intersection = phraseConstraints.getFullGroup().findIntersections(positions, 64).intIterator();
 
         while (intersection.hasNext() && bit < 64) {
             bit = (int) (Math.sqrt(intersection.nextInt()));

code/index/java/nu/marginalia/index/results/TermFlagsGraphVisitor.java

@@ -3,7 +3,7 @@ package nu.marginalia.index.results;
 import nu.marginalia.api.searchquery.model.compiled.CqDataInt;
 import nu.marginalia.api.searchquery.model.compiled.CqDataLong;
 import nu.marginalia.api.searchquery.model.compiled.CqExpression;
-import nu.marginalia.api.searchquery.model.results.ResultRankingContext;
+import nu.marginalia.index.model.ResultRankingContext;
 import nu.marginalia.model.idx.WordFlags;
 
 import java.util.List;

code/index/java/nu/marginalia/index/results/model/PhraseConstraintGroupList.java

@@ -58,6 +58,7 @@ public class PhraseConstraintGroupList {
         private final int[] offsets;
         private final BitSet present;
         private final BitSet termIdsMask;
+        private final int presentCardinality;
 
         public final int size;
         public PhraseConstraintGroup(List<String> terms, TermIdList termIdsAll) {
@@ -85,6 +86,8 @@ public class PhraseConstraintGroupList {
                     termIdsMask.set(idx);
                 }
             }
+
+            presentCardinality = present.cardinality();
         }
 
         /** Returns true if the term with index termIdx in the query is in the group */
@@ -93,7 +96,7 @@ public class PhraseConstraintGroupList {
         }
 
         public boolean test(CodedSequence[] positions) {
-            IntIterator[] sequences = new IntIterator[present.cardinality()];
+            IntIterator[] sequences = new IntIterator[presentCardinality];
 
             for (int oi = 0, si = 0; oi < offsets.length; oi++) {
                 if (!present.get(oi)) {
@@ -120,7 +123,7 @@ public class PhraseConstraintGroupList {
 
 
         public IntList findIntersections(IntList[] positions) {
-            IntList[] sequences = new IntList[present.cardinality()];
+            IntList[] sequences = new IntList[presentCardinality];
             int[] iterOffsets = new int[sequences.length];
 
             for (int oi = 0, si = 0; oi < offsets.length; oi++) {
@@ -144,12 +147,41 @@ public class PhraseConstraintGroupList {
                 iterOffsets[si - 1] = -oi;
             }
 
-            return SequenceOperations.findIntersections(sequences, iterOffsets);
+            return SequenceOperations.findIntersections(sequences, iterOffsets, Integer.MAX_VALUE);
+        }
+
+
+        public IntList findIntersections(IntList[] positions, int n) {
+            IntList[] sequences = new IntList[presentCardinality];
+            int[] iterOffsets = new int[sequences.length];
+
+            for (int oi = 0, si = 0; oi < offsets.length; oi++) {
+                if (!present.get(oi)) {
+                    continue;
+                }
+                int offset = offsets[oi];
+                if (offset < 0)
+                    return IntList.of();
+
+                // Create iterators that are offset by their relative position in the
+                // sequence.  This is done by subtracting the index from the offset,
+                // so that when we intersect them, an overlap means that the terms are
+                // in the correct order.  Note the offset is negative!
+
+                var posForTerm = positions[offset];
+                if (posForTerm == null) {
+                    return IntList.of();
+                }
+                sequences[si++] = posForTerm;
+                iterOffsets[si - 1] = -oi;
+            }
+
+            return SequenceOperations.findIntersections(sequences, iterOffsets, n);
         }
 
         public int minDistance(IntList[] positions) {
-            List<IntList> sequences = new ArrayList<>(present.cardinality());
-            IntList iterOffsets = new IntArrayList(present.cardinality());
+            List<IntList> sequences = new ArrayList<>(presentCardinality);
+            IntList iterOffsets = new IntArrayList(presentCardinality);
 
             for (int oi = 0; oi < offsets.length; oi++) {
                 if (!present.get(oi)) {

code/index/java/nu/marginalia/index/results/model/ids/CombinedDocIdList.java

@@ -1,7 +1,7 @@
 package nu.marginalia.index.results.model.ids;
 
 import it.unimi.dsi.fastutil.longs.LongArrayList;
-import org.roaringbitmap.longlong.Roaring64Bitmap;
+import nu.marginalia.array.page.LongQueryBuffer;
 
 import java.util.Arrays;
 import java.util.stream.LongStream;
@@ -17,17 +17,23 @@ public final class CombinedDocIdList {
     public CombinedDocIdList(long... data) {
         this.data = Arrays.copyOf(data, data.length);
     }
-
+    public CombinedDocIdList(LongQueryBuffer buffer) {
+        this.data = buffer.copyData();
+    }
     public CombinedDocIdList(LongArrayList data) {
         this.data = data.toLongArray();
     }
-    public CombinedDocIdList(Roaring64Bitmap data) {
-        this.data = data.toArray();
-    }
     public CombinedDocIdList() {
         this.data = new long[0];
     }
 
+    public static CombinedDocIdList combineLists(CombinedDocIdList one, CombinedDocIdList other) {
+        long[] data = new long[one.size() + other.size()];
+        System.arraycopy(one.data, 0, data, 0, one.data.length);
+        System.arraycopy(other.data, 0, data, one.data.length, other.data.length);
+        return new CombinedDocIdList(data);
+    }
+
     public int size() {
         return data.length;
     }

code/index/java/nu/marginalia/index/results/model/ids/TermIdList.java

@@ -6,7 +6,7 @@ import java.util.Arrays;
 import java.util.stream.LongStream;
 
 public final class TermIdList {
-    private final long[] array;
+    public final long[] array;
 
     public TermIdList(long[] array) {
         this.array = array;

code/index/java/nu/marginalia/index/searchset/RankingSearchSet.java

@@ -59,7 +59,7 @@ public class RankingSearchSet implements SearchSet {
     }
 
     @Override
-    public boolean contains(int domainId, long documentMetadata) {
+    public boolean contains(int domainId) {
 
         // This is the main check
         if (set.contains(domainId) || set.isEmpty()) {

code/index/java/nu/marginalia/index/searchset/SearchSet.java

@@ -7,6 +7,10 @@ public interface SearchSet {
      *  or if the documentMetadata vibes with the set
      *
      */
-    boolean contains(int domainId, long documentMetadata);
+    boolean contains(int domainId);
+
+    default boolean imposesConstraint() {
+        return true;
+    }
 
 }

code/index/java/nu/marginalia/index/searchset/SearchSetAny.java

@@ -2,7 +2,7 @@ package nu.marginalia.index.searchset;
 
 public class SearchSetAny implements SearchSet {
     @Override
-    public boolean contains(int domainId, long meta) {
+    public boolean contains(int domainId) {
         return true;
     }
 
@@ -10,4 +10,9 @@ public class SearchSetAny implements SearchSet {
     public String toString() {
         return getClass().getSimpleName();
     }
+
+    @Override
+    public boolean imposesConstraint() {
+        return false;
+    }
 }

code/index/java/nu/marginalia/index/searchset/SmallSearchSet.java

@@ -14,7 +14,7 @@ public class SmallSearchSet implements SearchSet {
     }
 
     @Override
-    public boolean contains(int domainId, long meta) {
+    public boolean contains(int domainId) {
         return entries.contains(domainId);
     }
 

code/index/query/java/nu/marginalia/index/query/IndexQuery.java

@@ -1,7 +1,7 @@
 package nu.marginalia.index.query;
 
-import nu.marginalia.index.query.filter.QueryFilterStepIf;
 import nu.marginalia.array.page.LongQueryBuffer;
+import nu.marginalia.index.query.filter.QueryFilterStepIf;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -18,15 +18,16 @@ import java.util.stream.Collectors;
 public class IndexQuery {
     private final List<EntrySource> sources;
     private final List<QueryFilterStepIf> inclusionFilter = new ArrayList<>(10);
+    private boolean prioritize = false;
 
-    public IndexQuery(List<EntrySource> sources)
+    public IndexQuery(EntrySource source, boolean prioritize)
     {
-        this.sources = sources;
+        this.sources = List.of(source);
+        this.prioritize = prioritize;
     }
 
-    public IndexQuery(EntrySource... sources)
-    {
-        this.sources = List.of(sources);
+    public boolean isPrioritized() {
+        return prioritize;
     }
     /** Adds a filter to the query.  The filter will be applied to the results
      * after they are read from the sources.
@@ -60,6 +61,7 @@ public class IndexQuery {
         if (!fillBuffer(dest))
             return;
 
+
         for (var filter : inclusionFilter) {
             filter.apply(dest);
 
@@ -73,6 +75,8 @@ public class IndexQuery {
 
     private boolean fillBuffer(LongQueryBuffer dest) {
         for (;;) {
+            dest.zero();
+
             EntrySource source = sources.get(si);
             source.read(dest);
 
@@ -102,6 +106,7 @@ public class IndexQuery {
 
         return sb.toString();
     }
+
 }
 
 

code/index/query/java/nu/marginalia/index/query/IndexQueryBuilder.java

@@ -2,8 +2,6 @@ package nu.marginalia.index.query;
 
 import nu.marginalia.index.query.filter.QueryFilterStepIf;
 
-import java.util.List;
-
 /** Builds a query.
  * <p />
  * Note: The query builder may omit predicates that are deemed redundant.
@@ -11,14 +9,13 @@ import java.util.List;
 public interface IndexQueryBuilder {
     /** Filters documents that also contain termId, within the full index.
      */
-    IndexQueryBuilder also(long termId);
+    IndexQueryBuilder also(long termId, IndexSearchBudget budget);
 
     /** Excludes documents that contain termId, within the full index
      */
-    IndexQueryBuilder not(long termId);
+    IndexQueryBuilder not(long termId, IndexSearchBudget budget);
 
     IndexQueryBuilder addInclusionFilter(QueryFilterStepIf filterStep);
-    IndexQueryBuilder addInclusionFilterAny(List<QueryFilterStepIf> filterStep);
 
     IndexQuery build();
 }

code/index/query/java/nu/marginalia/index/query/IndexSearchBudget.java

@@ -10,5 +10,5 @@ public class IndexSearchBudget {
     }
 
     public boolean hasTimeLeft() { return System.currentTimeMillis() < timeout; }
-    public long timeLeft() { return timeout - System.currentTimeMillis(); }
+    public long timeLeft() { return Math.max(0, timeout - System.currentTimeMillis()); }
 }

code/index/query/java/nu/marginalia/index/query/filter/QueryFilterAllOf.java

@@ -1,71 +0,0 @@
-package nu.marginalia.index.query.filter;
-
-import nu.marginalia.array.page.LongQueryBuffer;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.StringJoiner;
-
-public class QueryFilterAllOf implements QueryFilterStepIf {
-    private final List<QueryFilterStepIf> steps;
-
-    public QueryFilterAllOf(List<? extends QueryFilterStepIf> steps) {
-        this.steps = new ArrayList<>(steps.size());
-
-        for (var step : steps) {
-            if (step instanceof QueryFilterAllOf allOf) {
-                this.steps.addAll(allOf.steps);
-            }
-            else {
-                this.steps.add(step);
-            }
-        }
-    }
-
-    public QueryFilterAllOf(QueryFilterStepIf... steps) {
-        this(List.of(steps));
-    }
-
-    public double cost() {
-        double prod = 1.;
-
-        for (var step : steps) {
-            double cost = step.cost();
-            if (cost > 1.0) {
-                prod *= Math.log(cost);
-            }
-            else {
-                prod += cost;
-            }
-        }
-
-        return prod;
-    }
-
-    @Override
-    public boolean test(long value) {
-        for (var step : steps) {
-            if (!step.test(value))
-                return false;
-        }
-        return true;
-    }
-
-
-    public void apply(LongQueryBuffer buffer) {
-        if (steps.isEmpty())
-            return;
-
-        for (var step : steps) {
-            step.apply(buffer);
-        }
-    }
-
-    public String describe() {
-        StringJoiner sj = new StringJoiner(",", "[All Of: ", "]");
-        for (var step : steps) {
-            sj.add(step.describe());
-        }
-        return sj.toString();
-    }
-}

code/index/query/java/nu/marginalia/index/query/filter/QueryFilterAnyOf.java

@@ -1,86 +0,0 @@
-package nu.marginalia.index.query.filter;
-
-import nu.marginalia.array.page.LongQueryBuffer;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.StringJoiner;
-
-public class QueryFilterAnyOf implements QueryFilterStepIf {
-    private final List<QueryFilterStepIf> steps;
-
-    public QueryFilterAnyOf(List<? extends QueryFilterStepIf> steps) {
-        this.steps = new ArrayList<>(steps.size());
-
-        for (var step : steps) {
-            if (step instanceof QueryFilterAnyOf anyOf) {
-                this.steps.addAll(anyOf.steps);
-            } else {
-                this.steps.add(step);
-            }
-        }
-    }
-
-    public QueryFilterAnyOf(QueryFilterStepIf... steps) {
-        this(List.of(steps));
-    }
-
-    public double cost() {
-        return steps.stream().mapToDouble(QueryFilterStepIf::cost).sum();
-    }
-
-    @Override
-    public boolean test(long value) {
-        for (var step : steps) {
-            if (step.test(value))
-                return true;
-        }
-        return false;
-    }
-
-
-    public void apply(LongQueryBuffer buffer) {
-        if (steps.isEmpty())
-            return;
-
-        if (steps.size() == 1) {
-            steps.getFirst().apply(buffer);
-            return;
-        }
-
-        int start = 0;
-        final int endOfValidData = buffer.end; // End of valid data range
-
-        // The filters act as a partitioning function, where anything before buffer.end
-        // is "in", and is guaranteed to be sorted; and anything after buffer.end is "out"
-        // but no sorting guaranteed is provided.
-
-        // To provide a conditional filter, we re-sort the "out" range, slice it and apply filtering to the slice
-
-        for (var step : steps)
-        {
-            var slice = buffer.slice(start, endOfValidData);
-            slice.data.sort(0, slice.size());
-
-            step.apply(slice);
-            start += slice.end;
-        }
-
-        // After we're done, read and write pointers should be 0 and "end" should be the length of valid data,
-        // normally done through buffer.finalizeFiltering(); but that won't work here
-        buffer.reset();
-        buffer.end = start;
-
-        // After all filters have been applied, we must re-sort all the retained data
-        // to uphold the sortedness contract
-        buffer.data.sort(0, buffer.end);
-    }
-
-    public String describe() {
-        StringJoiner sj = new StringJoiner(",", "[Any Of: ", "]");
-        for (var step : steps) {
-            sj.add(step.describe());
-        }
-        return sj.toString();
-    }
-}

code/index/query/java/nu/marginalia/index/query/filter/QueryFilterLetThrough.java

@@ -4,11 +4,6 @@ import nu.marginalia.array.page.LongQueryBuffer;
 
 public class QueryFilterLetThrough implements QueryFilterStepIf {
 
-    @Override
-    public boolean test(long value) {
-        return true;
-    }
-
     @Override
     public void apply(LongQueryBuffer buffer) {
         buffer.retainAll();

code/index/query/java/nu/marginalia/index/query/filter/QueryFilterNoPass.java

@@ -5,11 +5,6 @@ import nu.marginalia.array.page.LongQueryBuffer;
 public class QueryFilterNoPass implements QueryFilterStepIf {
     static final QueryFilterStepIf instance = new QueryFilterNoPass();
 
-    @Override
-    public boolean test(long value) {
-        return false;
-    }
-
     public void apply(LongQueryBuffer buffer) {
         buffer.finalizeFiltering();
     }

code/index/query/java/nu/marginalia/index/query/filter/QueryFilterStepExcludeFromPredicate.java

@@ -1,27 +0,0 @@
-package nu.marginalia.index.query.filter;
-
-import java.util.function.LongPredicate;
-
-public class QueryFilterStepExcludeFromPredicate implements QueryFilterStepIf {
-    private final LongPredicate pred;
-
-    public QueryFilterStepExcludeFromPredicate(LongPredicate pred) {
-        this.pred = pred;
-    }
-
-    @Override
-    public boolean test(long value) {
-        return !pred.test(value);
-    }
-
-    @Override
-    public double cost() {
-        return 1;
-    }
-
-    @Override
-    public String describe() {
-        return "[!Predicate]";
-    }
-
-}

code/index/query/java/nu/marginalia/index/query/filter/QueryFilterStepFromPredicate.java

@@ -1,27 +0,0 @@
-package nu.marginalia.index.query.filter;
-
-import java.util.function.LongPredicate;
-
-public class QueryFilterStepFromPredicate implements QueryFilterStepIf {
-    private final LongPredicate pred;
-
-    public QueryFilterStepFromPredicate(LongPredicate pred) {
-        this.pred = pred;
-    }
-
-    @Override
-    public boolean test(long value) {
-        return pred.test(value);
-    }
-
-    @Override
-    public double cost() {
-        return 1;
-    }
-
-    @Override
-    public String describe() {
-        return "[Predicate]";
-    }
-
-}

code/index/query/java/nu/marginalia/index/query/filter/QueryFilterStepIf.java

@@ -3,8 +3,6 @@ package nu.marginalia.index.query.filter;
 import nu.marginalia.array.page.LongQueryBuffer;
 
 public interface QueryFilterStepIf extends Comparable<QueryFilterStepIf> {
-    boolean test(long value);
-
     double cost();
 
     default int compareTo(QueryFilterStepIf other) {
@@ -22,17 +20,7 @@ public interface QueryFilterStepIf extends Comparable<QueryFilterStepIf> {
      *
      * <p>ASSUMPTION: buffer is sorted up until end.</p>
      */
-    default void apply(LongQueryBuffer buffer) {
-        while (buffer.hasMore()) {
-            if (test(buffer.currentValue())) {
-                buffer.retainAndAdvance();
-            }
-            else {
-                buffer.rejectAndAdvance();
-            }
-        }
-        buffer.finalizeFiltering();
-    }
+    void apply(LongQueryBuffer buffer);
 
 }
 

code/index/query/test/nu/marginalia/index/query/filter/QueryFilterStepIfTest.java

@@ -1,93 +0,0 @@
-package nu.marginalia.index.query.filter;
-
-import nu.marginalia.array.page.LongQueryBuffer;
-import org.junit.jupiter.api.Test;
-
-import java.util.List;
-
-import static org.junit.jupiter.api.Assertions.*;
-
-class QueryFilterStepIfTest {
-
-    private LongQueryBuffer createBuffer(long... data) {
-        return new LongQueryBuffer(data, data.length);
-    }
-
-    @Test
-    public void testPassThrough() {
-        var buffer = createBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-        var filter = new QueryFilterLetThrough();
-        filter.apply(buffer);
-        assertArrayEquals(new long[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, buffer.copyData());
-    }
-
-    @Test
-    public void testNoPass() {
-        var buffer = createBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-        var filter = new QueryFilterNoPass();
-        filter.apply(buffer);
-        assertArrayEquals(new long[]{}, buffer.copyData());
-    }
-
-    @Test
-    public void testIncludePredicate() {
-        var buffer = createBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-        var filter = new QueryFilterStepFromPredicate(value -> value % 2 == 0);
-        filter.apply(buffer);
-        assertArrayEquals(new long[]{2, 4, 6, 8, 10}, buffer.copyData());
-    }
-
-    @Test
-    public void testExcludePredicate() {
-        var buffer = createBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-        var filter = new QueryFilterStepExcludeFromPredicate(value -> value % 2 == 1);
-        filter.apply(buffer);
-        assertArrayEquals(new long[]{2, 4, 6, 8, 10}, buffer.copyData());
-    }
-
-    @Test
-    public void testSuccessiveApplication() {
-        var buffer = createBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-        var filter1 = new QueryFilterStepFromPredicate(value -> value % 2 == 0);
-        var filter2 = new QueryFilterStepExcludeFromPredicate(value -> value <= 6);
-        filter1.apply(buffer);
-        filter2.apply(buffer);
-        assertArrayEquals(new long[]{8, 10}, buffer.copyData());
-    }
-
-    @Test
-    public void testSuccessiveApplicationWithAllOf() {
-        var buffer = createBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-        var filter1 = new QueryFilterStepFromPredicate(value -> value % 2 == 0);
-        var filter2 = new QueryFilterStepExcludeFromPredicate(value -> value <= 6);
-        new QueryFilterAllOf(List.of(filter1, filter2)).apply(buffer);
-        assertArrayEquals(new long[]{8, 10}, buffer.copyData());
-    }
-    @Test
-    public void testCombinedOrAnd() {
-        var buffer = createBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-
-        var filter1 = new QueryFilterStepFromPredicate(value -> value % 2 == 0);
-        var filter2 = new QueryFilterStepFromPredicate(value -> value <= 5);
-        var filter1_2 = new QueryFilterAllOf(List.of(filter1, filter2));
-
-        var filter3 = new QueryFilterStepFromPredicate(value -> value % 2 == 1);
-        var filter4 = new QueryFilterStepFromPredicate(value -> value > 5);
-        var filter3_4 = new QueryFilterAllOf(List.of(filter3, filter4));
-
-        var filter12_34 = new QueryFilterAnyOf(List.of(filter1_2, filter3_4));
-
-        filter12_34.apply(buffer);
-
-        assertArrayEquals(new long[]{2, 4, 7, 9}, buffer.copyData());
-    }
-    @Test
-    public void testCombinedApplication() {
-        var buffer = createBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-        var filter1 = new QueryFilterStepFromPredicate(value -> value % 3 == 0);
-        var filter2 = new QueryFilterStepFromPredicate(value -> value % 5 == 0);
-        var filter = new QueryFilterAnyOf(List.of(filter1, filter2));
-        filter.apply(buffer);
-        assertArrayEquals(new long[]{3, 5, 6, 9, 10}, buffer.copyData());
-    }
-}

code/index/test/nu/marginalia/index/CombinedIndexReaderTest.java

@@ -16,6 +16,7 @@ import nu.marginalia.index.index.StatefulIndex;
 import nu.marginalia.index.journal.IndexJournal;
 import nu.marginalia.index.journal.IndexJournalSlopWriter;
 import nu.marginalia.index.positions.TermData;
+import nu.marginalia.index.query.IndexSearchBudget;
 import nu.marginalia.index.results.model.ids.CombinedDocIdList;
 import nu.marginalia.linkdb.docs.DocumentDbReader;
 import nu.marginalia.linkdb.docs.DocumentDbWriter;
@@ -156,7 +157,7 @@ public class CombinedIndexReaderTest {
         var reader = indexFactory.getCombinedIndexReader();
         var query = reader
                 .findFullWord(kw("hello"))
-                .also(kw("world"))
+                .also(kw("world"), new IndexSearchBudget(10_000))
                 .build();
 
         var buffer = new LongQueryBuffer(32);
@@ -198,8 +199,8 @@ public class CombinedIndexReaderTest {
 
         var reader = indexFactory.getCombinedIndexReader();
         var query = reader.findFullWord(kw("hello"))
-                .also(kw("world"))
-                .not(kw("goodbye"))
+                .also(kw("world"), new IndexSearchBudget(10_000))
+                .not(kw("goodbye"), new IndexSearchBudget(10_000))
                 .build();
 
         var buffer = new LongQueryBuffer(32);
@@ -255,18 +256,19 @@ public class CombinedIndexReaderTest {
         Path outputFileDocs = ReverseIndexFullFileNames.resolve(IndexLocations.getCurrentIndex(fileStorageService), ReverseIndexFullFileNames.FileIdentifier.DOCS, ReverseIndexFullFileNames.FileVersion.NEXT);
         Path outputFileWords = ReverseIndexFullFileNames.resolve(IndexLocations.getCurrentIndex(fileStorageService), ReverseIndexFullFileNames.FileIdentifier.WORDS, ReverseIndexFullFileNames.FileVersion.NEXT);
         Path outputFilePositions = ReverseIndexFullFileNames.resolve(IndexLocations.getCurrentIndex(fileStorageService), ReverseIndexFullFileNames.FileIdentifier.POSITIONS, ReverseIndexFullFileNames.FileVersion.NEXT);
+
         Path workDir = IndexLocations.getIndexConstructionArea(fileStorageService);
         Path tmpDir = workDir.resolve("tmp");
 
         if (!Files.isDirectory(tmpDir)) Files.createDirectories(tmpDir);
 
-        var constructor = new FullIndexConstructor(
-                outputFileDocs,
-                outputFileWords,
-                outputFilePositions,
-                DocIdRewriter.identity(),
-                tmpDir);
-
+        var constructor =
+                new FullIndexConstructor(
+                        outputFileDocs,
+                        outputFileWords,
+                        outputFilePositions,
+                        DocIdRewriter.identity(),
+                        tmpDir);
         constructor.createReverseIndex(new FakeProcessHeartbeat(), "name", workDir);
     }
 

code/index/test/nu/marginalia/index/IndexQueryServiceIntegrationSmokeTest.java

@@ -411,8 +411,6 @@ public class IndexQueryServiceIntegrationSmokeTest {
                 .filter(v -> (id % v) == 0)
                 .toArray();
 
-        System.out.println("id:" + id + " factors: " + Arrays.toString(factors));
-
         long fullId = fullId(id);
 
         ldbw.add(new DocdbUrlDetail(

code/index/test/nu/marginalia/index/searchset/RankingSearchSetTest.java

@@ -25,10 +25,10 @@ class RankingSearchSetTest {
         set.write();
 
         RankingSearchSet set2 = new RankingSearchSet("ACADEMIA", p);
-        assertTrue(set2.contains(1, 0));
-        assertTrue(set2.contains(5, 0));
-        assertTrue(set2.contains(7, 0));
-        assertTrue(set2.contains(9, 0));
+        assertTrue(set2.contains(1));
+        assertTrue(set2.contains(5));
+        assertTrue(set2.contains(7));
+        assertTrue(set2.contains(9));
 
         Files.delete(p);
 

code/libraries/array/build.gradle

@@ -21,7 +21,7 @@ dependencies {
     implementation libs.lz4
     implementation libs.guava
 
-    implementation project(':code:libraries:array:cpp')
+    implementation project(':code:libraries:native')
 
     testImplementation libs.bundles.slf4j.test
     testImplementation libs.bundles.junit

code/libraries/array/cpp/build.gradle

@@ -1,26 +0,0 @@
-plugins {
-    id 'java'
-}
-
-java {
-    toolchain {
-        languageVersion.set(JavaLanguageVersion.of(rootProject.ext.jvmVersion))
-    }
-}
-
-dependencies {
-    implementation libs.bundles.slf4j
-}
-
-apply from: "$rootProject.projectDir/srcsets.gradle"
-
-// We use a custom task to compile the C++ code into a shared library
-// with a shellscript as gradle's c++ tasks are kind of insufferable
-
-tasks.register('compileCpp', Exec) {
-    inputs.files('compile.sh', 'src/main/cpp/cpphelpers.cpp', 'src/main/public/cpphelpers.h')
-    outputs.file 'resources/libcpp.so'
-    commandLine 'sh', 'compile.sh'
-}
-
-processResources.dependsOn('compileCpp')

code/libraries/array/cpp/compile.sh

@@ -1,10 +0,0 @@
-#!/usr/bin/env sh
-
-CXX=${CXX:-g++}
-
-if ! which ${CXX} > /dev/null; then
-    echo "g++ not found, skipping compilation"
-    exit 0
-fi
-
-${CXX} -O3 -march=native -std=c++14 -shared -Isrc/main/public src/main/cpp/*.cpp -o resources/libcpp.so

code/libraries/array/cpp/src/main/public/cpphelpers.hpp

@@ -1,8 +0,0 @@
-#include <stdint.h>
-
-#pragma once
-
-extern "C" {
-  void ms_sort_64(int64_t* area, uint64_t start, uint64_t end);
-  void ms_sort_128(int64_t* area, uint64_t start, uint64_t end);
-}

code/libraries/array/java/nu/marginalia/array/DirectFileReader.java

@@ -0,0 +1,55 @@
+package nu.marginalia.array;
+
+import nu.marginalia.ffi.LinuxSystemCalls;
+
+import java.io.IOException;
+import java.lang.foreign.MemorySegment;
+import java.nio.file.Path;
+
+public class DirectFileReader implements AutoCloseable {
+    int fd;
+
+    public DirectFileReader(Path filename) throws IOException {
+        fd = LinuxSystemCalls.openDirect(filename);
+        if (fd < 0) {
+            throw new IOException("Error opening direct file: " + filename);
+        }
+    }
+
+    public void readAligned(LongArray dest, long offset) throws IOException {
+        readAligned(dest.getMemorySegment(), offset);
+    }
+
+    public void readAligned(MemorySegment segment, long offset) throws IOException {
+        if (LinuxSystemCalls.readAt(fd, segment, offset) != segment.byteSize()) {
+            throw new IOException("Failed to read data at " + offset);
+        }
+    }
+
+    public void readUnaligned(MemorySegment dest, MemorySegment alignedBuffer, long fileOffset) throws IOException {
+        int destOffset = 0;
+
+        for (long totalBytesToCopy = dest.byteSize(); totalBytesToCopy > 0; ) {
+            long alignedPageAddress = fileOffset & -4096L;
+            long srcPageOffset = fileOffset & 4095L;
+            long srcPageEnd = Math.min(srcPageOffset + totalBytesToCopy, 4096);
+
+            // wrapper for O_DIRECT pread
+            if (LinuxSystemCalls.readAt(fd, alignedBuffer, alignedPageAddress) != alignedBuffer.byteSize()) {
+                throw new IOException("Failed to read data at " + alignedPageAddress + " of size " + dest.byteSize());
+            }
+
+            int bytesToCopy = (int) (srcPageEnd - srcPageOffset);
+
+            MemorySegment.copy(alignedBuffer, srcPageOffset, dest, destOffset, bytesToCopy);
+
+            destOffset += bytesToCopy;
+            fileOffset += bytesToCopy;
+            totalBytesToCopy -= bytesToCopy;
+        }
+    }
+
+    public void close() {
+        LinuxSystemCalls.closeFd(fd);
+    }
+}

code/libraries/array/java/nu/marginalia/array/LongArrayFactory.java

@@ -5,6 +5,7 @@ import nu.marginalia.array.page.UnsafeLongArray;
 
 import java.io.IOException;
 import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
@@ -25,6 +26,13 @@ public class LongArrayFactory {
             return SegmentLongArray.onHeap(Arena.ofShared(), size);
     }
 
+    public static LongArray onHeapManaged(Arena arena, long size) {
+        if (useUnsafe)
+            return UnsafeLongArray.wrap(arena.allocate(8 * size));
+        else
+            return SegmentLongArray.wrap(arena.allocate(8 * size));
+    }
+
     public static LongArray mmapForReadingConfined(Path filename) throws IOException  {
         if (useUnsafe)
             return UnsafeLongArray.fromMmapReadOnly(Arena.ofConfined(), filename, 0, Files.size(filename) / 8);
@@ -66,4 +74,13 @@ public class LongArrayFactory {
         else
             return SegmentLongArray.fromMmapReadWrite(Arena.ofShared(), filename, 0, size);
     }
+
+    public static LongArray wrap(MemorySegment ms) {
+        if (useUnsafe) {
+            return UnsafeLongArray.wrap(ms);
+        }
+        else {
+            return SegmentLongArray.wrap(ms);
+        }
+    }
 }

code/libraries/array/java/nu/marginalia/array/algo/LongArraySearch.java

@@ -20,6 +20,27 @@ public interface LongArraySearch extends LongArrayBase {
         return fromIndex + low;
     }
 
+    default long binarySearch2(long key, long fromIndex, long toIndex) {
+        long low = 0;
+        long len = toIndex - fromIndex;
+
+        while (len > 0) {
+            var half = len / 2;
+            long val = get(fromIndex + low + half);
+            if (val < key) {
+                low += len - half;
+            }
+            else if (val == key) {
+                low += half;
+                break;
+            }
+            len = half;
+        }
+
+        return fromIndex + low;
+    }
+
+
     default long binarySearchN(int sz, long key, long fromIndex, long toIndex) {
         long low = 0;
         long high = (toIndex - fromIndex)/sz - 1;
@@ -33,6 +54,7 @@ public interface LongArraySearch extends LongArrayBase {
             len = half;
         }
 
+
         return fromIndex + sz * low;
     }
 

code/libraries/array/java/nu/marginalia/array/algo/LongArraySort.java

@@ -1,7 +1,7 @@
 package nu.marginalia.array.algo;
 
-import nu.marginalia.NativeAlgos;
 import nu.marginalia.array.LongArray;
+import nu.marginalia.ffi.NativeAlgos;
 
 import java.io.IOException;
 import java.nio.channels.FileChannel;

code/libraries/array/java/nu/marginalia/array/page/LongQueryBuffer.java

@@ -3,6 +3,8 @@ package nu.marginalia.array.page;
 import nu.marginalia.array.LongArray;
 import nu.marginalia.array.LongArrayFactory;
 
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 
@@ -36,13 +38,12 @@ public class LongQueryBuffer {
 
     public LongQueryBuffer(int size) {
         this.data = LongArrayFactory.onHeapConfined(size);
-        this.end = size;
+        this.end = 0;
     }
 
     public LongQueryBuffer(long[] data, int size) {
         this.data = LongArrayFactory.onHeapConfined(size);
         this.data.set(0, data);
-
         this.end = size;
     }
 
@@ -52,6 +53,26 @@ public class LongQueryBuffer {
         return copy;
     }
 
+    public long[] copyFilterData() {
+        long[] copy = new long[write];
+        data.forEach(0, write, (pos, val) -> copy[(int)pos]=val );
+        return copy;
+    }
+
+    public boolean fitsMore() {
+        return end < data.size();
+    }
+
+    public int addData(MemorySegment source, long sourceOffset, int nMax) {
+        int n = Math.min(nMax, (int) data.size() - end);
+
+        MemorySegment.copy(source, ValueLayout.JAVA_LONG, sourceOffset, data.getMemorySegment(), ValueLayout.JAVA_LONG, 8L * end, n);
+
+        end += n;
+
+        return n;
+    }
+
     /** Dispose of the buffer and release resources */
     public void dispose() {
         data.close();

code/libraries/array/java/nu/marginalia/array/page/SegmentLongArray.java

@@ -29,6 +29,10 @@ public class SegmentLongArray implements LongArray {
         this.arena = arena;
     }
 
+    public static SegmentLongArray wrap(MemorySegment segment) {
+        return new SegmentLongArray(segment, null);
+    }
+
     public static SegmentLongArray onHeap(Arena arena, long size) {
         return new SegmentLongArray(arena.allocate(WORD_SIZE*size, 16), arena);
     }

code/libraries/array/java/nu/marginalia/array/page/UnsafeLongArray.java

@@ -50,6 +50,10 @@ public class UnsafeLongArray implements LongArray {
         this.channel = channel;
     }
 
+    public static UnsafeLongArray wrap(MemorySegment ms) {
+        return new UnsafeLongArray(ms, null);
+    }
+
     public static UnsafeLongArray onHeap(Arena arena, long size) {
         return new UnsafeLongArray(arena.allocate(WORD_SIZE*size, 16), arena);
     }
@@ -77,6 +81,10 @@ public class UnsafeLongArray implements LongArray {
 
     @Override
     public LongArray range(long start, long end) {
+
+        assert end >= start : end + "<" + start;
+        assert end <= size() : end + "<" + size();
+
         return new UnsafeLongArray(
             segment.asSlice(
                 start * JAVA_LONG.byteSize(),
@@ -93,6 +101,7 @@ public class UnsafeLongArray implements LongArray {
 
     @Override
     public long get(long at) {
+
         try {
             return unsafe.getLong(segment.address() + at * JAVA_LONG.byteSize());
         }
@@ -120,6 +129,7 @@ public class UnsafeLongArray implements LongArray {
 
     @Override
     public void set(long start, long end, LongBuffer buffer, int bufferStart) {
+        System.out.println("setA@"+ start + "#" + hashCode() + "-" + Thread.currentThread().threadId());
         for (int i = 0; i < end - start; i++) {
             unsafe.putLong(segment.address() + (start + i) * JAVA_LONG.byteSize(), buffer.get(bufferStart + i));
         }

code/libraries/array/java/nu/marginalia/array/pool/BufferEvictionPolicy.java

@@ -0,0 +1,6 @@
+package nu.marginalia.array.pool;
+
+public enum BufferEvictionPolicy {
+    READ_ONCE,
+    CACHE
+}

code/libraries/array/java/nu/marginalia/array/pool/BufferPool.java

@@ -0,0 +1,220 @@
+package nu.marginalia.array.pool;
+
+import nu.marginalia.ffi.LinuxSystemCalls;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.Nullable;
+import java.io.IOException;
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class BufferPool implements AutoCloseable {
+    private static final Logger logger = LoggerFactory.getLogger(BufferPool.class);
+
+    private final MemoryPage[] pages;
+
+    private final long fileSize;
+    private final Arena arena;
+    private final int fd;
+    private final int pageSizeBytes;
+    private PoolLru poolLru;
+
+    private final AtomicInteger diskReadCount = new AtomicInteger();
+    private final AtomicInteger cacheReadCount = new AtomicInteger();
+
+    private volatile boolean running = true;
+
+    /** Unassociate all buffers with their addresses, ensuring they will not be cacheable */
+    public synchronized void reset() {
+        for (var page : pages) {
+            page.pageAddress(-1);
+        }
+        try {
+            poolLru.stop();
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+        poolLru = new PoolLru(pages);
+    }
+
+    public BufferPool(Path filename, int pageSizeBytes, int poolSize) {
+        this.fd = LinuxSystemCalls.openDirect(filename);
+        this.pageSizeBytes = pageSizeBytes;
+        try {
+            this.fileSize = Files.size(filename);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        this.arena = Arena.ofShared();
+        this.pages = new UnsafeMemoryPage[poolSize];
+
+        MemorySegment memoryArea = arena.allocate((long) pageSizeBytes*poolSize, 4096);
+        for (int i = 0; i < pages.length; i++) {
+            if (Boolean.getBoolean("system.noSunMiscUnsafe")) {
+                pages[i] = (MemoryPage) new SegmentMemoryPage(memoryArea.asSlice((long) i*pageSizeBytes, pageSizeBytes), i);
+            }
+            else {
+                pages[i] = (MemoryPage) new UnsafeMemoryPage(memoryArea.asSlice((long) i*pageSizeBytes, pageSizeBytes), i);
+            }
+        }
+
+        this.poolLru = new PoolLru(pages);
+
+        Thread.ofPlatform().start(() -> {
+            int diskReadOld = 0;
+            int cacheReadOld = 0;
+
+            while (running) {
+                try {
+                    TimeUnit.SECONDS.sleep(30);
+                } catch (InterruptedException e) {
+                    logger.info("Sleep interrupted", e);
+                    break;
+                }
+
+                int diskRead = diskReadCount.get();
+                int cacheRead = cacheReadCount.get();
+                int heldCount = 0;
+                for (var page : pages) {
+                    if (page.isHeld()) {
+                        heldCount++;
+                    }
+                }
+
+                if (diskRead != diskReadOld || cacheRead != cacheReadOld) {
+                    logger.info("[#{}:{}] Disk/Cached: {}/{}, heldCount={}/{}, fqs={}, rcc={}", hashCode(), pageSizeBytes, diskRead, cacheRead, heldCount, pages.length, poolLru.getFreeQueueSize(), poolLru.getReclaimCycles());
+                }
+            }
+        });
+    }
+
+    public void close() {
+        running = false;
+
+        try {
+            poolLru.stop();
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+        LinuxSystemCalls.closeFd(fd);
+        arena.close();
+
+        System.out.println("Disk read count: " + diskReadCount.get());
+        System.out.println("Cached read count: " + cacheReadCount.get());
+    }
+
+    @Nullable
+    public MemoryPage getExistingBufferForReading(long address) {
+        MemoryPage cachedBuffer = poolLru.get(address);
+        if (cachedBuffer != null && cachedBuffer.pageAddress() == address) {
+
+            // Try to acquire the page normally
+            if (cachedBuffer.acquireAsReader(address)) {
+                cacheReadCount.incrementAndGet();
+
+                return cachedBuffer;
+            }
+
+            if (cachedBuffer.pageAddress() != address)
+                return null;
+
+            // The page we are looking for is currently being written
+            waitForPageWrite(cachedBuffer);
+
+            if (cachedBuffer.acquireAsReader(address)) {
+                this.cacheReadCount.incrementAndGet();
+                return cachedBuffer;
+            }
+        }
+
+        return null;
+    }
+
+    public MemoryPage get(long address) {
+        // Look through available pages for the one we're looking for
+        MemoryPage buffer = getExistingBufferForReading(address);
+
+        if (buffer == null) {
+            buffer = read(address, true);
+        }
+
+        return buffer;
+    }
+
+    private MemoryPage read(long address, boolean acquire) {
+        // If the page is not available, read it from the caller's thread
+        if (address + pageSizeBytes > fileSize) {
+            throw new RuntimeException("Address " + address + " too large for page size " + pageSizeBytes + " and file size" + fileSize);
+        }
+        if ((address & 511) != 0) {
+            throw new  RuntimeException("Address " + address + " not aligned");
+        }
+        MemoryPage buffer = acquireFreePage(address);
+        poolLru.register(buffer);
+        populateBuffer(buffer);
+
+        if (acquire) {
+            if (!buffer.pinCount().compareAndSet(-1, 1)) {
+                throw new IllegalStateException("Panic! Write lock was not held during write!");
+            }
+        }
+        else {
+            if (!buffer.pinCount().compareAndSet(-1, 0)) {
+                throw new IllegalStateException("Panic! Write lock was not held during write!");
+            }
+        }
+
+        diskReadCount.incrementAndGet();
+
+        return buffer;
+    }
+
+    private MemoryPage acquireFreePage(long address) {
+        for (;;) {
+            var free = poolLru.getFree();
+            if (free != null && free.acquireForWriting(address)) {
+                return free;
+            }
+        }
+    }
+
+    private void populateBuffer(MemoryPage buffer) {
+        if (getClass().desiredAssertionStatus()) {
+            buffer.getMemorySegment().set(ValueLayout.JAVA_INT, 0, 9999);
+        }
+        LinuxSystemCalls.readAt(fd, buffer.getMemorySegment(), buffer.pageAddress());
+        assert buffer.getMemorySegment().get(ValueLayout.JAVA_INT, 0) != 9999;
+        buffer.dirty(false);
+
+        if (buffer.pinCount().get() > 1) {
+            synchronized (buffer) {
+                buffer.notifyAll();
+            }
+        }
+    }
+
+    private void waitForPageWrite(MemoryPage page) {
+        if (!page.dirty()) {
+            return;
+        }
+
+        synchronized (page) {
+            while (page.dirty()) {
+                try {
+                    page.wait(0, 1000);
+                }
+                catch (InterruptedException ex) {
+                    throw new RuntimeException(ex);
+                }
+            }
+        }
+    }
+
+
+}

code/libraries/array/java/nu/marginalia/array/pool/MemoryPage.java

@@ -0,0 +1,32 @@
+package nu.marginalia.array.pool;
+
+import java.lang.foreign.MemorySegment;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public interface MemoryPage extends AutoCloseable {
+    boolean isHeld();
+
+    MemorySegment getMemorySegment();
+
+    byte getByte(int offset);
+    int getInt(int offset);
+    long getLong(int offset);
+
+    int binarySearchLong(long key, int baseOffset, int fromIndex, int toIndex);
+    boolean acquireForWriting(long intendedAddress);
+    boolean acquireAsReader(long expectedAddress);
+
+    AtomicInteger pinCount();
+
+    void increaseClock(int val);
+    void touchClock(int val);
+    boolean decreaseClock();
+
+    long pageAddress();
+    void pageAddress(long address);
+
+    boolean dirty();
+    void dirty(boolean val);
+
+    void close();
+}

code/libraries/array/java/nu/marginalia/array/pool/PoolLru.java

@@ -0,0 +1,186 @@
+package nu.marginalia.array.pool;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.LinkedHashMap;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.locks.LockSupport;
+import java.util.concurrent.locks.StampedLock;
+
+/** LRU for pool buffers
+ * */
+public class PoolLru {
+    private static final Logger logger = LoggerFactory.getLogger(PoolLru.class);
+
+    private final int maxSize;
+    private final LinkedHashMap<Long, MemoryPage> backingMap;
+    private final MemoryPage[] pages;
+
+    private final int[] freeQueue;
+    private volatile long reclaimCycles;
+    private final AtomicLong clockWriteIdx;
+    private final AtomicLong clockReadIdx;
+
+    private final StampedLock lock = new StampedLock();
+    private final Thread reclaimThread;
+
+    private volatile boolean running = true;
+
+    public PoolLru(MemoryPage[] pages) {
+        backingMap = new LinkedHashMap<>(pages.length, 0.75f);
+        this.pages = pages;
+        // Pre-assign all entries with nonsense memory locations
+        for (int i = 0; i < pages.length; i++) {
+            backingMap.put(-i-1L, pages[i]);
+        }
+        maxSize = backingMap.size();
+
+        freeQueue = new int[pages.length];
+
+        for (int i = 0; i < freeQueue.length; i++) {
+            freeQueue[i] = i;
+        }
+
+        clockReadIdx = new AtomicLong();
+        clockWriteIdx = new AtomicLong(freeQueue.length);
+
+        reclaimThread = Thread.ofPlatform().start(this::reclaimThread);
+    }
+
+    public void stop() throws InterruptedException {
+        running = false;
+        reclaimThread.interrupt();
+        reclaimThread.join();
+    }
+    /** Attempt to get a buffer already associated with the address */
+    public MemoryPage get(long address) {
+        var res = getAssociatedItem(address);
+        if (res != null) {
+            res.increaseClock(1);
+        }
+        return res;
+    }
+
+    private MemoryPage getAssociatedItem(long address) {
+        long stamp = lock.tryOptimisticRead();
+        MemoryPage res = backingMap.get(address);
+        if (lock.validate(stamp)) {
+            return res;
+        }
+        stamp = lock.readLock();
+        try {
+            return backingMap.get(address);
+        }
+        finally {
+            lock.unlockRead(stamp);
+        }
+    }
+
+    /** Associate the buffer with an address */
+    public void register(MemoryPage buffer) {
+        long stamp = lock.writeLock();
+        try {
+            backingMap.put(buffer.pageAddress(), buffer);
+            buffer.touchClock(1);
+            // Evict the last entry if we've exceeded the
+            while (backingMap.size() >= maxSize) {
+                backingMap.pollFirstEntry();
+            }
+        }
+        finally {
+            lock.unlockWrite(stamp);
+        }
+    }
+
+    public void deregister(MemoryPage buffer) {
+        long stamp = lock.writeLock();
+        try {
+            backingMap.remove(buffer.pageAddress(), buffer);
+        }
+        finally {
+            lock.unlockWrite(stamp);
+        }
+    }
+
+    /** Attempt to get a free buffer from the pool
+     *
+     * @return An unheld buffer, or null if the attempt failed
+     * */
+    public MemoryPage getFree() {
+        for (;;) {
+            var readIdx = clockReadIdx.get();
+            var writeIdx = clockWriteIdx.get();
+
+            if (writeIdx - readIdx == freeQueue.length / 4) {
+                LockSupport.unpark(reclaimThread);
+            } else if (readIdx == writeIdx) {
+                LockSupport.unpark(reclaimThread);
+                synchronized (this) {
+                    try {
+                        wait(0, 1000);
+                    } catch (InterruptedException e) {
+                        throw new RuntimeException(e);
+                    }
+                }
+                continue;
+            }
+
+            if (clockReadIdx.compareAndSet(readIdx, readIdx + 1)) {
+                return pages[freeQueue[(int) (readIdx % freeQueue.length)]];
+            }
+        }
+    }
+
+    private void reclaimThread() {
+        int pageIdx = 0;
+
+        while (running && !Thread.interrupted()) {
+            long readIdx = clockReadIdx.get();
+            long writeIdx = clockWriteIdx.get();
+            int queueSize = (int) (writeIdx - readIdx);
+            int targetQueueSize = freeQueue.length / 2;
+
+            if (queueSize >= targetQueueSize) {
+                LockSupport.parkNanos(100_000);
+                continue;
+            }
+
+            int toClaim = targetQueueSize - queueSize;
+            if (toClaim == 0)
+                continue;
+
+            ++reclaimCycles;
+            do {
+                if (++pageIdx >= pages.length) {
+                    pageIdx = 0;
+                }
+                var currentPage = pages[pageIdx];
+
+                if (currentPage.decreaseClock()) {
+                    if (!currentPage.isHeld()) {
+                        freeQueue[(int) (clockWriteIdx.getAndIncrement() % freeQueue.length)] = pageIdx;
+                        deregister(pages[pageIdx]);
+                        toClaim--;
+                    }
+                    else {
+                        currentPage.touchClock(1);
+                    }
+                }
+
+            } while (running && toClaim >= 0);
+
+            synchronized (this) {
+                notifyAll();
+            }
+        }
+    }
+
+    public int getFreeQueueSize() {
+        return (int) (clockWriteIdx.get() - clockReadIdx.get());
+    }
+
+    public long getReclaimCycles() {
+        return reclaimCycles;
+    }
+}

code/libraries/array/java/nu/marginalia/array/pool/SegmentMemoryPage.java

@@ -0,0 +1,163 @@
+package nu.marginalia.array.pool;
+
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/** Variant of SegmentLongArray that uses Unsafe to access the memory.
+ * */
+
+@SuppressWarnings("preview")
+public class SegmentMemoryPage implements MemoryPage, AutoCloseable {
+
+    private final MemorySegment segment;
+    public final int ord;
+
+    private volatile long pageAddress = -1;
+    private volatile boolean dirty = false;
+
+    /** Pin count is used as a read-write condition.
+     * <p></p>
+     * When the pin count is 0, the page is free.
+     * When it is -1, it is held for writing.
+     * When it is greater than 0, it is held for reading.
+     */
+    private final AtomicInteger pinCount = new AtomicInteger(0);
+    private final AtomicInteger clock = new AtomicInteger();
+
+    public SegmentMemoryPage(MemorySegment segment, int ord) {
+        this.segment = segment;
+        this.ord = ord;
+    }
+
+    public int hashCode() {
+        return (int) segment.address();
+    }
+    public boolean equals(Object obj) {
+        return obj == this;
+    }
+
+    @Override
+    public void increaseClock(int val) {
+        clock.addAndGet(val);
+    }
+    @Override
+    public void touchClock(int val) {
+        clock.set(val);
+    }
+    @Override
+    public boolean decreaseClock() {
+        for (;;) {
+            int cv = clock.get();
+            if (cv == 0)
+                return true;
+            if (clock.compareAndSet(cv, cv-1)) {
+                return cv == 1;
+            }
+        }
+    }
+
+    @Override
+    public long pageAddress() {
+        return pageAddress;
+    }
+
+    @Override
+    public void pageAddress(long address) {
+        this.pageAddress = address;
+    }
+
+    @Override
+    public AtomicInteger pinCount() {
+        return pinCount;
+    }
+
+    @Override
+    public boolean dirty() {
+        return dirty;
+    }
+
+    @Override
+    public void dirty(boolean val) {
+        this.dirty = val;
+    }
+
+    @Override
+    public boolean isHeld() {
+        return 0 != this.pinCount.get();
+    }
+
+    @Override
+    public byte getByte(int offset) {
+        return segment.get(ValueLayout.JAVA_BYTE, offset);
+    }
+    @Override
+    public int getInt(int offset) {
+        return segment.get(ValueLayout.JAVA_INT, offset);
+    }
+    @Override
+    public long getLong(int offset) {
+        return segment.get(ValueLayout.JAVA_LONG, offset);
+    }
+
+    @Override
+    public int binarySearchLong(long key, int baseOffset, int fromIndex, int toIndex) {
+        int low = 0;
+        int len = toIndex - fromIndex;
+
+        while (len > 0) {
+            var half = len / 2;
+            long val = getLong(baseOffset + 8 * (fromIndex + low + half));
+            if (val < key) {
+                low += len - half;
+            } else if (val == key) {
+                low += half;
+                break;
+            }
+            len = half;
+        }
+
+        return fromIndex + low;
+    }
+
+    @Override
+    public boolean acquireForWriting(long intendedAddress) {
+        if (pinCount.compareAndSet(0, -1)) {
+            pageAddress = intendedAddress;
+            dirty = true;
+            return true;
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean acquireAsReader(long expectedAddress) {
+        int pinCountVal;
+
+        while ((pinCountVal = pinCount.get()) >= 0) {
+            if (pinCount.compareAndSet(pinCountVal, pinCountVal+1)) {
+                if (pageAddress != expectedAddress) {
+                    pinCount.decrementAndGet();
+                    return false;
+                }
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+
+    /** Close yields the buffer back to the pool (unless held by multiple readers), but does not deallocate it */
+    @Override
+    public void close() {
+        pinCount.decrementAndGet();
+    }
+
+    @Override
+    public MemorySegment getMemorySegment() {
+        return segment;
+    }
+
+}

code/libraries/array/java/nu/marginalia/array/pool/UnsafeMemoryPage.java

@@ -0,0 +1,167 @@
+package nu.marginalia.array.pool;
+
+import nu.marginalia.array.page.UnsafeProvider;
+import sun.misc.Unsafe;
+
+import java.lang.foreign.MemorySegment;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/** Variant of SegmentLongArray that uses Unsafe to access the memory.
+ * */
+
+@SuppressWarnings("preview")
+public class UnsafeMemoryPage implements MemoryPage, AutoCloseable {
+
+    private static final Unsafe unsafe = UnsafeProvider.getUnsafe();
+
+    private final MemorySegment segment;
+    public final int ord;
+
+    private volatile long pageAddress = -1;
+    private volatile boolean dirty = false;
+
+    /** Pin count is used as a read-write condition.
+     * <p></p>
+     * When the pin count is 0, the page is free.
+     * When it is -1, it is held for writing.
+     * When it is greater than 0, it is held for reading.
+     */
+    private final AtomicInteger pinCount = new AtomicInteger(0);
+    private final AtomicInteger clock = new AtomicInteger();
+
+    public UnsafeMemoryPage(MemorySegment segment, int ord) {
+        this.segment = segment;
+        this.ord = ord;
+    }
+
+    public int hashCode() {
+        return (int) segment.address();
+    }
+    public boolean equals(Object obj) {
+        return obj == this;
+    }
+
+    public void increaseClock(int val) {
+        clock.addAndGet(val);
+    }
+    public void touchClock(int val) {
+        clock.set(val);
+    }
+    public boolean decreaseClock() {
+        for (;;) {
+            int cv = clock.get();
+            if (cv == 0)
+                return true;
+            if (clock.compareAndSet(cv, cv-1)) {
+                return cv == 1;
+            }
+        }
+    }
+
+    @Override
+    public long pageAddress() {
+        return pageAddress;
+    }
+
+    @Override
+    public void pageAddress(long address) {
+        this.pageAddress = address;
+    }
+
+    @Override
+    public AtomicInteger pinCount() {
+        return pinCount;
+    }
+
+    @Override
+    public boolean dirty() {
+        return dirty;
+    }
+
+    @Override
+    public void dirty(boolean val) {
+        this.dirty = val;
+    }
+
+    @Override
+    public boolean isHeld() {
+        return 0 != this.pinCount.get();
+    }
+
+    public byte getByte(int offset) {
+        assert offset >= 0;
+        assert offset + 1 <= segment.byteSize();
+        return unsafe.getByte(segment.address() + offset);
+    }
+    public int getInt(int offset) {
+        assert offset >= 0;
+        assert offset + 4 <= segment.byteSize();
+        return unsafe.getInt(segment.address() + offset);
+    }
+    public long getLong(int offset) {
+        assert offset >= 0;
+        assert offset + 8 <= segment.byteSize();
+        return unsafe.getLong(segment.address() + offset);
+    }
+
+    public int binarySearchLong(long key, int baseOffset, int fromIndex, int toIndex) {
+        int low = 0;
+        int len = toIndex - fromIndex;
+
+        while (len > 0) {
+            var half = len / 2;
+            long val = getLong(baseOffset + 8 * (fromIndex + low + half));
+            if (val < key) {
+                low += len - half;
+            }
+            else if (val == key) {
+                low += half;
+                break;
+            }
+            len = half;
+        }
+
+        return fromIndex + low;
+    }
+
+    @Override
+    public boolean acquireForWriting(long intendedAddress) {
+        if (pinCount.compareAndSet(0, -1)) {
+            pageAddress = intendedAddress;
+            dirty = true;
+            return true;
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean acquireAsReader(long expectedAddress) {
+        int pinCountVal;
+
+        while ((pinCountVal = pinCount.get()) >= 0) {
+            if (pinCount.compareAndSet(pinCountVal, pinCountVal+1)) {
+                if (pageAddress != expectedAddress) {
+                    pinCount.decrementAndGet();
+                    return false;
+                }
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+
+    /** Close yields the buffer back to the pool (unless held by multiple readers), but does not deallocate it */
+    @Override
+    public void close() {
+        pinCount.decrementAndGet();
+    }
+
+    @Override
+    public MemorySegment getMemorySegment() {
+        return segment;
+    }
+
+}

code/libraries/array/src/jmh/java/nu/marginalia/array/page/SortBenchmark.java

@@ -1,8 +1,8 @@
 package nu.marginalia.array.page;
 
-import nu.marginalia.NativeAlgos;
 import nu.marginalia.array.LongArray;
 import nu.marginalia.array.algo.LongArraySort;
+import nu.marginalia.ffi.NativeAlgos;
 import org.openjdk.jmh.annotations.*;
 
 import java.lang.foreign.Arena;

code/libraries/array/test/nu/marginalia/NativeAlgosTest.java

@@ -0,0 +1,72 @@
+package nu.marginalia;
+
+import nu.marginalia.array.DirectFileReader;
+import nu.marginalia.array.LongArray;
+import nu.marginalia.array.LongArrayFactory;
+import nu.marginalia.ffi.LinuxSystemCalls;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.nio.file.Path;
+
+public class NativeAlgosTest {
+    @Test
+    public void test() throws IOException {
+        LongArray array = LongArrayFactory.mmapForWritingShared(Path.of("/tmp/test"), 1024);
+        for (int i = 0; i < 1024; i++) {
+            array.set(i, i);
+        }
+        array.close();
+
+        var ms = Arena.global().allocate(512, 8);
+
+        int fd = LinuxSystemCalls.openDirect(Path.of("/tmp/test"));
+        int ret = LinuxSystemCalls.readAt(fd, ms, 512);
+        System.out.println(ret);
+        System.out.println(ms.byteSize());
+        LinuxSystemCalls.closeFd(fd);
+
+        var array2 = LongArrayFactory.wrap(ms);
+        for (int i = 0; i < array2.size(); i++) {
+            System.out.println(i + ": " + array2.get(i));
+        }
+
+    }
+
+    @Test
+    void testDirectFileReader() throws IOException {
+        LongArray array = LongArrayFactory.mmapForWritingShared(Path.of("/tmp/test"), 1024);
+        for (int i = 0; i < 1024; i++) {
+            array.set(i, i);
+        }
+        array.close();
+
+
+        try (var dfr = new DirectFileReader(Path.of("/tmp/test"))) {
+            LongArray array2 = LongArrayFactory.onHeapConfined(64);
+            dfr.readAligned(array2, 0);
+            for (int i = 0; i < array2.size(); i++) {
+                System.out.println(i + ": " + array2.get(i));
+            }
+        }
+
+        var alignedBuffer = Arena.ofAuto().allocate(4096, 4096);
+        try (var dfr = new DirectFileReader(Path.of("/tmp/test"))) {
+            MemorySegment dest = Arena.ofAuto().allocate(504, 1);
+            dfr.readUnaligned(dest, alignedBuffer, 8);
+
+            for (int i = 0; i < dest.byteSize(); i+=8) {
+                System.out.println(i + ": " + dest.get(ValueLayout.JAVA_LONG, i));
+            }
+
+            dfr.readUnaligned(dest, alignedBuffer, 4000);
+            for (int i = 0; i < dest.byteSize(); i+=8) {
+                System.out.println(i + ": " + dest.get(ValueLayout.JAVA_LONG, i));
+            }
+        }
+    }
+
+}

code/libraries/array/test/nu/marginalia/array/NativeAlgosTest.java

@@ -0,0 +1,95 @@
+package nu.marginalia.array;
+
+import nu.marginalia.ffi.LinuxSystemCalls;
+import nu.marginalia.uring.UringFileReader;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.nio.file.Path;
+import java.util.List;
+
+public class NativeAlgosTest {
+    @Test
+    public void test() throws IOException {
+        LongArray array = LongArrayFactory.mmapForWritingShared(Path.of("/tmp/test"), 1024);
+        for (int i = 0; i < 1024; i++) {
+            array.set(i, i);
+        }
+        array.close();
+
+        var ms = Arena.global().allocate(512, 8);
+
+        int fd = LinuxSystemCalls.openDirect(Path.of("/tmp/test"));
+        int ret = LinuxSystemCalls.readAt(fd, ms, 512);
+        System.out.println(ret);
+        System.out.println(ms.byteSize());
+        LinuxSystemCalls.closeFd(fd);
+
+        var array2 = LongArrayFactory.wrap(ms);
+        for (int i = 0; i < array2.size(); i++) {
+            System.out.println(i + ": " + array2.get(i));
+        }
+
+    }
+
+    @Test
+    void testDirectFileReader() throws IOException {
+        LongArray array = LongArrayFactory.mmapForWritingShared(Path.of("/tmp/test"), 1024);
+        for (int i = 0; i < 1024; i++) {
+            array.set(i, i);
+        }
+        array.close();
+
+
+        try (var dfr = new DirectFileReader(Path.of("/tmp/test"))) {
+            LongArray array2 = LongArrayFactory.onHeapConfined(64);
+            dfr.readAligned(array2, 0);
+            for (int i = 0; i < array2.size(); i++) {
+                System.out.println(i + ": " + array2.get(i));
+            }
+        }
+
+        var alignedBuffer = Arena.ofAuto().allocate(4096, 4096);
+        try (var dfr = new DirectFileReader(Path.of("/tmp/test"))) {
+            MemorySegment dest = Arena.ofAuto().allocate(504, 1);
+            dfr.readUnaligned(dest, alignedBuffer, 8);
+
+            for (int i = 0; i < dest.byteSize(); i+=8) {
+                System.out.println(i + ": " + dest.get(ValueLayout.JAVA_LONG, i));
+            }
+
+            dfr.readUnaligned(dest, alignedBuffer, 4000);
+            for (int i = 0; i < dest.byteSize(); i+=8) {
+                System.out.println(i + ": " + dest.get(ValueLayout.JAVA_LONG, i));
+            }
+        }
+    }
+
+    @Test
+    void testAioFileReader() throws IOException {
+        LongArray array = LongArrayFactory.mmapForWritingShared(Path.of("/tmp/test"), 1024);
+        for (int i = 0; i < 1024; i++) {
+            array.set(i, i);
+        }
+        array.close();
+
+        try (var dfr = new UringFileReader(Path.of("/tmp/test"),  false)) {
+            MemorySegment buf1 = Arena.ofAuto().allocate(32, 8);
+            MemorySegment buf2 = Arena.ofAuto().allocate(16, 8);
+
+            dfr.read(List.of(buf1, buf2), List.of(0L, 8L));
+
+            for (int i = 0; i < buf1.byteSize(); i+=8) {
+                System.out.println(buf1.get(ValueLayout.JAVA_LONG, i));
+            }
+
+            for (int i = 0; i < buf2.byteSize(); i+=8) {
+                System.out.println(buf2.get(ValueLayout.JAVA_LONG, i));
+            }
+        }
+
+    }
+}

code/libraries/array/test/nu/marginalia/array/algo/LongArraySearchTest.java

@@ -32,9 +32,21 @@ class LongArraySearchTest {
     @Test
     public void testEmptyRange() {
         assertTrue(segmentArray.binarySearchN(2, 0, 0, 0) <= 0);
+
         assertTrue(segmentArray.binarySearch(0, 0, 0) <= 0);
     }
 
+    @Test
+    public void testBinarySearchNCase() {
+        try (var array = LongArrayFactory.onHeapConfined(1024)) {
+            for (int i = 0; i < 64; i++) {
+                array.set(2*i, 3*i);
+                array.set(2*i+1, i);
+                System.out.println(i + ":" + array.get(i));
+            }
+            System.out.println(array.binarySearchN(2, 3, 0, 64));
+        }
+    }
 
     void binarySearchTester(LongArray array) {
         for (int i = 0; i < array.size() * 3; i++) {

code/libraries/array/test/nu/marginalia/array/pool/UnsafeMemoryPageTest.java

@@ -0,0 +1,36 @@
+package nu.marginalia.array.pool;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemorySegment;
+
+import static java.lang.foreign.ValueLayout.JAVA_LONG;
+
+class UnsafeMemoryPageTest {
+
+    @Test
+    void binarySearchLong() {
+        MemorySegment ms = Arena.ofAuto().allocate(8 * 9);
+        ms.setAtIndex(JAVA_LONG, 0, 2260);
+        ms.setAtIndex(JAVA_LONG, 1, 2513);
+        ms.setAtIndex(JAVA_LONG, 2, 3531);
+        ms.setAtIndex(JAVA_LONG, 3, 4637);
+        ms.setAtIndex(JAVA_LONG, 4, 4975);
+        ms.setAtIndex(JAVA_LONG, 5, 6647);
+        ms.setAtIndex(JAVA_LONG, 6, 7179);
+        ms.setAtIndex(JAVA_LONG, 7, 7509);
+        ms.setAtIndex(JAVA_LONG, 8, 8000);
+        UnsafeMemoryPage page = new UnsafeMemoryPage(ms, 1);
+        Assertions.assertEquals(0, page.binarySearchLong(2260, 0, 0, 9));
+        Assertions.assertEquals(1, page.binarySearchLong(2513, 0, 0, 9));
+        Assertions.assertEquals(2, page.binarySearchLong(3531, 0, 0, 9));
+        Assertions.assertEquals(3, page.binarySearchLong(4637, 0, 0, 9));
+        Assertions.assertEquals(4, page.binarySearchLong(4975, 0, 0, 9));
+        Assertions.assertEquals(5, page.binarySearchLong(6647, 0, 0, 9));
+        Assertions.assertEquals(6, page.binarySearchLong(7179, 0, 0, 9));
+        Assertions.assertEquals(7, page.binarySearchLong(7509, 0, 0, 9));
+        Assertions.assertEquals(8, page.binarySearchLong(8000, 0, 0, 9));
+    }
+}

code/libraries/btree/build.gradle

@@ -14,6 +14,8 @@ dependencies {
     implementation project(':code:libraries:array')
 
     implementation libs.bundles.slf4j
+    implementation libs.fastutil
+    implementation libs.notnull
 
     testImplementation libs.bundles.slf4j.test
     testImplementation libs.bundles.junit

code/libraries/btree/java/nu/marginalia/btree/BTreeReader.java

@@ -187,11 +187,8 @@ public class BTreeReader {
 
         /** Move the pointer to the next layer in the direction of the provided key */
         public void walkTowardChild(long key) {
-
             final long searchStart = layerOffsets[layer] + pointerOffset;
-
             final long nextLayerOffset = index.binarySearch(key, searchStart, searchStart + ctx.pageSize()) - searchStart;
-
             layer --;
             maxValueInBlock = index.get(searchStart + nextLayerOffset);
             pointerOffset = ctx.pageSize() * (pointerOffset + nextLayerOffset);
@@ -250,21 +247,20 @@ public class BTreeReader {
             long dataIndex = findData(buffer.currentValue());
             if (dataIndex >= 0) {
                 buffer.retainAndAdvance();
-
-                if (buffer.hasMore() && buffer.currentValue() <= maxValueInBlock) {
-                    long relOffsetInBlock = dataIndex - pointerOffset * ctx.entrySize;
-
-                    long remainingTotal = dataBlockEnd - dataIndex;
-                    long remainingBlock = ctx.pageSize() - relOffsetInBlock; // >= 0
-
-                    long searchEnd = dataIndex + min(remainingTotal, remainingBlock);
-
-                    data.retainN(buffer, ctx.entrySize, maxValueInBlock, dataIndex, searchEnd);
-                }
             }
             else {
                 buffer.rejectAndAdvance();
             }
+            if (buffer.hasMore() && buffer.currentValue() <= maxValueInBlock) {
+                long relOffsetInBlock = dataIndex - pointerOffset * ctx.entrySize;
+
+                long remainingTotal = dataBlockEnd - dataIndex;
+                long remainingBlock = ctx.pageSize() - relOffsetInBlock; // >= 0
+
+                long searchEnd = dataIndex + min(remainingTotal, remainingBlock);
+
+                data.retainN(buffer, ctx.entrySize, maxValueInBlock, dataIndex, searchEnd);
+            }
 
         }