off heap indexing fix

Signed-off-by: Bharathwaj G <bharath78910@gmail.com>

server/src/main/java/org/opensearch/index/codec/freshstartree/builder/OffHeapBufferedSingleTreeBuilder.java

@@ -211,7 +211,13 @@ private byte[] serializeStarTreeRecord(Record starTreeRecord) {
     private Record deserializeStarTreeRecord(RandomAccessInput buffer, long offset) throws IOException {
         long[] dimensions = new long[_numDimensions];
         for (int i = 0; i < _numDimensions; i++) {
-            dimensions[i] = buffer.readLong(offset);
+            try {
+                dimensions[i] = buffer.readLong(offset);
+            } catch(Exception e) {
+                logger.info("Error reading dimension value at offset " + offset + " for dimension"
+                    + " " + i + " : _numReadableStarTreeRecords = " + _numReadableStarTreeRecords);
+                throw e;
+            }
             offset += Long.BYTES;
         }
         Object[] metrics = new Object[_numMetrics];
@@ -367,6 +373,8 @@ public Record getSegmentRecord(int docID, long recordBytes) throws IOException {
 
     @Override
     Iterator<Record> generateRecordsForStarNode(int startDocId, int endDocId, int dimensionId) throws IOException {
+        // End doc id is not inclusive but start doc is inclusive
+        // Hence we need to check if buffer is readable till endDocId - 1
         ensureBufferReadable(endDocId, true);
 
         // Sort all records using an int array
@@ -453,10 +461,20 @@ private void ensureBufferReadable(int docId, boolean endDocCheck) throws IOExcep
             return;
         }
         IndexInput in = null;
+        /**
+         * If docId is less then the _numDocs , then we need to find a previous file associated with doc id
+         * The fileToByteSizeMap is in the following format
+         * file1 -> 521
+         * file2 -> 780
+         *
+         * which represents that file1 contains all docs till "520".
+         * "prevStartDocId" essentially tracks the "start doc id" of the range in the present file
+         * "_numReadableStarTreeRecords" tracks the "end doc id + 1" of the range in the present file
+         */
         if (docId < _numDocs) {
             int prevStartDocId = 0;
             for (Map.Entry<String, Integer> entry : fileToByteSizeMap.entrySet()) {
-                if (docId < entry.getValue() - 1) {
+                if (docId < entry.getValue()) {
                     in = state.directory.openInput(entry.getKey(), state.context);
                     starTreeRecordRandomInput = in.randomAccessSlice(in.getFilePointer(), in.length() - in.getFilePointer());
                     _numReadableStarTreeRecords = entry.getValue();

server/src/main/java/org/opensearch/index/codec/freshstartree/query/StarTreeFilter.java

@@ -16,6 +16,8 @@
  */
 package org.opensearch.index.codec.freshstartree.query;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.NumericDocValues;
 import org.apache.lucene.index.SortedNumericDocValues;
@@ -41,6 +43,8 @@
 
 /** Filter operator for star tree data structure. */
 public class StarTreeFilter {
+    private static final Logger logger = LogManager.getLogger(StarTreeFilter.class);
+
 
     /** Helper class to wrap the result from traversing the star tree. */
     static class StarTreeResult {
@@ -125,6 +129,7 @@ private StarTreeResult traverseStarTree() throws IOException {
 
         StarTree starTree = _starTree;
         List<String> dimensionNames = starTree.getDimensionNames();
+        logger.info("Dimension names {}", dimensionNames);
         StarTreeNode starTreeRootNode = starTree.getRoot();
 
         // Track whether we have found a leaf node added to the queue. If we have found a leaf node, and

server/src/main/java/org/opensearch/index/codec/freshstartree/query/StarTreeQueryBuilder.java

@@ -8,6 +8,8 @@
 
 package org.opensearch.index.codec.freshstartree.query;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.lucene.search.Query;
 import org.opensearch.core.ParseField;
 import org.opensearch.core.common.ParsingException;
@@ -16,6 +18,7 @@
 import org.opensearch.core.xcontent.ObjectParser;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;
+import org.opensearch.index.codec.freshstartree.builder.BaseSingleTreeBuilder;
 import org.opensearch.index.query.AbstractQueryBuilder;
 import org.opensearch.index.query.BoolQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;
@@ -38,6 +41,7 @@ public class StarTreeQueryBuilder extends AbstractQueryBuilder<StarTreeQueryBuil
 
     private final Set<String> groupBy = new HashSet<>();
     Map<String, List<Predicate<Long>>> predicateMap = new HashMap<>();
+    private static final Logger logger = LogManager.getLogger(StarTreeQueryBuilder.class);
 
     public StarTreeQueryBuilder() {}
 
@@ -140,8 +144,10 @@ public static StarTreeQueryBuilder fromXContent(XContentParser parser) {
     protected Query doToQuery(QueryShardContext context) {
         // TODO : star tree supports either group by or filter
         if (predicateMap.size() > 0) {
+            logger.info("Predicates: {} ", this.groupBy.toString() );
             return new StarTreeQuery(predicateMap, new HashSet<>());
         }
+        logger.info("Group by : {} ", this.groupBy.toString() );
         return new StarTreeQuery(new HashMap<>(), this.groupBy);
     }