Removed offset calculation in ObjectFieldDef and moved it to the AddDocumentHandler

Author: dhruva-r

src/main/java/com/yelp/nrtsearch/server/field/ObjectFieldDef.java

@@ -76,10 +76,8 @@ public void parseFieldWithChildren(
       int totalDocs = fieldValueMaps.size();
       List<Document> childDocuments = new ArrayList<>(totalDocs);
 
-      for (int i = 0; i < totalDocs; i++) {
-        // Calculate offset as n-i (total docs minus current index)
-        int offset = totalDocs - i;
-        childDocuments.add(createChildDocument(fieldValueMaps.get(i), facetHierarchyPaths, offset));
+      for (Map<String, Object> fieldValueMap : fieldValueMaps) {
+        childDocuments.add(createChildDocument(fieldValueMap, facetHierarchyPaths));
       }
 
       documentsContext.addChildDocuments(this.getName(), childDocuments);
@@ -91,18 +89,15 @@ public void parseFieldWithChildren(
    *
    * @param fieldValue the field value to include in the document
    * @param facetHierarchyPaths facet hierarchy paths
-   * @param offset the offset value to set for this document (n-i)
    * @return lucene document
    */
   private Document createChildDocument(
-      Map<String, Object> fieldValue, List<List<String>> facetHierarchyPaths, int offset) {
+      Map<String, Object> fieldValue, List<List<String>> facetHierarchyPaths) {
     Document document = new Document();
     parseFieldWithChildrenObject(document, List.of(fieldValue), facetHierarchyPaths);
     ((IndexableFieldDef<?>) (IndexState.getMetaField(IndexState.NESTED_PATH)))
         .parseDocumentField(document, List.of(this.getName()), List.of());
 
-    ((IndexableFieldDef<?>) (IndexState.getMetaField(IndexState.NESTED_DOCUMENT_OFFSET)))
-        .parseDocumentField(document, List.of(String.valueOf(offset)), List.of());
     return document;
   }
 

src/main/java/com/yelp/nrtsearch/server/handler/AddDocumentHandler.java

@@ -576,8 +576,7 @@ private void updateNestedDocuments(
             e.getValue().stream().map(v -> handleFacets(indexState, shardState, v)).toList());
       }
 
-      // Add global offset calculation for all nested documents
-      // addGlobalNestedDocumentOffsets(documents);
+      addGlobalNestedDocumentOffsets(documents);
 
       Document rootDoc = handleFacets(indexState, shardState, documentsContext.getRootDocument());
 
@@ -612,8 +611,7 @@ private void addNestedDocuments(
             e.getValue().stream().map(v -> handleFacets(indexState, shardState, v)).toList());
       }
 
-      // Add global offset calculation for all nested documents
-      // addGlobalNestedDocumentOffsets(documents);
+      addGlobalNestedDocumentOffsets(documents);
 
       Document rootDoc = handleFacets(indexState, shardState, documentsContext.getRootDocument());
       documents.add(rootDoc);
@@ -700,8 +698,13 @@ private Document handleFacets(IndexState indexState, ShardState shardState, Docu
     }
 
     /**
-     * Add global offset calculation for all nested documents This ensures unique offset values
-     * across all nested fields in a document
+     * Adds global offset values to nested documents for proper ordering and retrieval.
+     *
+     * <p>This method calculates and assigns a global offset to each nested document within a parent
+     * document. The offset calculation uses reverse ordering (totalNestedDocs - currentIndex)
+     *
+     * @param nestedDocuments the list of nested documents to process; must not be null or empty
+     * @throws IllegalArgumentException if nestedDocuments is null
      */
     private void addGlobalNestedDocumentOffsets(List<Document> nestedDocuments) {
       int totalNestedDocs = nestedDocuments.size();