From 25ec8d532a1c39b9562d2a87f0b3b338e852400c Mon Sep 17 00:00:00 2001
From: Ankita Victor <anvicto@microsoft.com>
Date: Tue, 26 Mar 2024 11:10:26 +0530
Subject: [PATCH] Add Spark function current_timestamp

---
 velox/docs/functions/spark/datetime.rst           |  8 ++++++++
 velox/functions/sparksql/Register.cpp             |  3 ++-
 .../sparksql/tests/DateTimeFunctionsTest.cpp      | 15 ++++++++-------
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/velox/docs/functions/spark/datetime.rst b/velox/docs/functions/spark/datetime.rst
index d7ed56e5fc51..b18900f39b1d 100644
--- a/velox/docs/functions/spark/datetime.rst
+++ b/velox/docs/functions/spark/datetime.rst
@@ -23,6 +23,10 @@ These functions support TIMESTAMP and DATE input types.
         SELECT add_months('2015-01-30', -2); -- '2014-11-30'
         SELECT add_months('2015-03-31', -1); -- '2015-02-28'
 
+.. spark:function:: current_timestamp() -> timestamp
+
+    Returns the current timestamp at the start of query evaluation as a timestamp. If session timezone is set then returns timestamp in that timezone.
+
 .. spark:function:: date_add(start_date, num_days) -> date
 
     Returns the date that is ``num_days`` after ``start_date``. According to the inputs,
@@ -215,6 +219,10 @@ These functions support TIMESTAMP and DATE input types.
         SELECT next_day('2015-07-23', "tu"); -- '2015-07-28'
         SELECT next_day('2015-07-23', "we"); -- '2015-07-29'
 
+.. spark:function:: now() -> timestamp
+
+    Alias for ``current_timestamp() -> timestamp``.
+
 .. spark:function:: second(timestamp) -> integer
 
     Returns the seconds of ``timestamp``.::
diff --git a/velox/functions/sparksql/Register.cpp b/velox/functions/sparksql/Register.cpp
index 35e673e5ca8b..6c2898cf7681 100644
--- a/velox/functions/sparksql/Register.cpp
+++ b/velox/functions/sparksql/Register.cpp
@@ -284,7 +284,8 @@ void registerFunctions(const std::string& prefix) {
   registerFunction<FromUtcTimestampFunction, Timestamp, Timestamp, Varchar>(
       {prefix + "from_utc_timestamp"});
 
-  registerFunction<CurrentTimestampFunction, Timestamp>({prefix + "current_timestamp"});
+  registerFunction<CurrentTimestampFunction, Timestamp>(
+      {prefix + "current_timestamp", prefix + "now"});
 
   registerFunction<UnixDateFunction, int32_t, Date>({prefix + "unix_date"});
 
diff --git a/velox/functions/sparksql/tests/DateTimeFunctionsTest.cpp b/velox/functions/sparksql/tests/DateTimeFunctionsTest.cpp
index 73391566b32d..ad2e10891976 100644
--- a/velox/functions/sparksql/tests/DateTimeFunctionsTest.cpp
+++ b/velox/functions/sparksql/tests/DateTimeFunctionsTest.cpp
@@ -42,16 +42,17 @@ class DateTimeFunctionsTest : public SparkFunctionBaseTest {
   static constexpr int8_t kMinTinyint = std::numeric_limits<int8_t>::min();
   static constexpr int8_t kMaxTinyint = std::numeric_limits<int8_t>::max();
 
-int64_t getCurrentTimestamp(const std::optional<std::string>& timeZone) {
+  int64_t getCurrentTimestamp(const std::optional<std::string>& timeZone) {
     auto now = std::chrono::system_clock::now();
-    auto tp = timeZone.has_value()
-            ? date::make_zoned(
-                  timeZone.value(), now).get_local_time().time_since_epoch()
-            : now.time_since_epoch();
-    auto since_epoch = std::chrono::duration_cast<std::chrono::microseconds>(tp);
+    auto tp = timeZone.has_value() ? date::make_zoned(timeZone.value(), now)
+                                         .get_local_time()
+                                         .time_since_epoch()
+                                   : now.time_since_epoch();
+    auto since_epoch =
+        std::chrono::duration_cast<std::chrono::microseconds>(tp);
     LOG(INFO) << since_epoch.count();
     return since_epoch.count();
-}
+  }
 
  protected:
   void setQueryTimeZone(const std::string& timeZone) {