From 98ef9efb4d18389d97d468add4225e1de56b850b Mon Sep 17 00:00:00 2001
From: Shreyansh Ray <rayshrey@amazon.com>
Date: Fri, 3 Jan 2025 14:53:07 +0530
Subject: [PATCH] Add support for date fields

---
 .../opensearch/index/get/ShardGetService.java    | 16 ++++++++++++++++
 .../org/opensearch/search/fetch/FetchPhase.java  | 16 ++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/server/src/main/java/org/opensearch/index/get/ShardGetService.java b/server/src/main/java/org/opensearch/index/get/ShardGetService.java
index 9fef3c8362fed..026f9d18fc346 100644
--- a/server/src/main/java/org/opensearch/index/get/ShardGetService.java
+++ b/server/src/main/java/org/opensearch/index/get/ShardGetService.java
@@ -54,6 +54,7 @@
 import org.opensearch.common.lucene.uid.VersionsAndSeqNoResolver.DocIdAndVersion;
 import org.opensearch.common.metrics.CounterMetric;
 import org.opensearch.common.metrics.MeanMetric;
+import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
@@ -70,6 +71,7 @@
 import org.opensearch.index.fielddata.SortedNumericDoubleValues;
 import org.opensearch.index.fieldvisitor.CustomFieldsVisitor;
 import org.opensearch.index.fieldvisitor.FieldsVisitor;
+import org.opensearch.index.mapper.DateFieldMapper;
 import org.opensearch.index.mapper.DocumentMapper;
 import org.opensearch.index.mapper.FieldMapper;
 import org.opensearch.index.mapper.IdFieldMapper;
@@ -566,6 +568,20 @@ private static Map<String, Object> buildUsingDocValues(int docId, LeafReader rea
                                                 }
                                             }
                                     }
+                                } else if (fieldMapper instanceof DateFieldMapper) {
+                                    DateFormatter dateFormatter = ((DateFieldMapper) fieldMapper).fieldType().dateTimeFormatter();
+                                    if (sndv.advanceExact(docId)) {
+                                        int size = sndv.docValueCount();
+                                        String[] vals = new String[size];
+                                        for (int i = 0; i < size; i++) {
+                                            vals[i] = dateFormatter.formatMillis(sndv.nextValue());
+                                        }
+                                        if (size > 1) {
+                                            docValues.put(fieldName, vals);
+                                        } else {
+                                            docValues.put(fieldName, vals[0]);
+                                        }
+                                    }
                                 }
                                 break;
                         }
diff --git a/server/src/main/java/org/opensearch/search/fetch/FetchPhase.java b/server/src/main/java/org/opensearch/search/fetch/FetchPhase.java
index 86a34e420cda8..fa9c3463f59d6 100644
--- a/server/src/main/java/org/opensearch/search/fetch/FetchPhase.java
+++ b/server/src/main/java/org/opensearch/search/fetch/FetchPhase.java
@@ -54,6 +54,7 @@
 import org.opensearch.common.document.DocumentField;
 import org.opensearch.common.lucene.index.SequentialStoredFieldsLeafReader;
 import org.opensearch.common.lucene.search.Queries;
+import org.opensearch.common.time.DateFormatter;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
@@ -68,6 +69,7 @@
 import org.opensearch.index.fielddata.SortedNumericDoubleValues;
 import org.opensearch.index.fieldvisitor.CustomFieldsVisitor;
 import org.opensearch.index.fieldvisitor.FieldsVisitor;
+import org.opensearch.index.mapper.DateFieldMapper;
 import org.opensearch.index.mapper.DocumentMapper;
 import org.opensearch.index.mapper.FieldMapper;
 import org.opensearch.index.mapper.MappedFieldType;
@@ -488,6 +490,20 @@ private static Map<String, Object> buildUsingDocValues(int docId, LeafReader rea
                                                 }
                                             }
                                     }
+                                } else if (fieldMapper instanceof DateFieldMapper) {
+                                    DateFormatter dateFormatter = ((DateFieldMapper) fieldMapper).fieldType().dateTimeFormatter();
+                                    if (sndv.advanceExact(docId)) {
+                                        int size = sndv.docValueCount();
+                                        String[] vals = new String[size];
+                                        for (int i = 0; i < size; i++) {
+                                            vals[i] = dateFormatter.formatMillis(sndv.nextValue());
+                                        }
+                                        if (size > 1) {
+                                            docValues.put(fieldName, vals);
+                                        } else {
+                                            docValues.put(fieldName, vals[0]);
+                                        }
+                                    }
                                 }
                                 break;
                         }