From 153b7f00df38ffc44198a83f71279061ad5ebe26 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Thu, 28 Nov 2024 12:47:05 +0200
Subject: [PATCH] time: add module helpers unix_milli/1, unix_micro/1,
 unix_nano/1 and tests for them (#22997)

---
 vlib/time/unix.v      | 41 +++++++++++++++++++++++------------------
 vlib/time/unix_test.v | 12 ++++++++++++
 2 files changed, 35 insertions(+), 18 deletions(-)
 create mode 100644 vlib/time/unix_test.v

diff --git a/vlib/time/unix.v b/vlib/time/unix.v
index 0fa4b24ee..f91fcf982 100644
--- a/vlib/time/unix.v
+++ b/vlib/time/unix.v
@@ -3,25 +3,30 @@
 // that can be found in the LICENSE file.
 module time
 
-// unix returns a Time struct calculated from a Unix timestamp (number of seconds since 1970-01-01)
+// unix returns a Time calculated from the given Unix timestamp in seconds since 1970-01-01
 pub fn unix(epoch i64) Time {
-	// Split into day and time
-	mut day_offset := epoch / seconds_per_day
-	if epoch % seconds_per_day < 0 {
-		// Compensate for round towards zero on integers as we want floored instead
-		day_offset--
-	}
-	year, month, day := calculate_date_from_day_offset(day_offset)
-	hr, min, sec := calculate_time_from_second_offset(epoch % seconds_per_day)
-	return Time{
-		year:   year
-		month:  month
-		day:    day
-		hour:   hr
-		minute: min
-		second: sec
-		unix:   epoch
-	}
+	return unix_nanosecond(epoch, 0)
+}
+
+// unix_milli returns a Time calculated from the given Unix timestamp in milliseconds since 1970-01-01
+pub fn unix_milli(ms i64) Time {
+	return ts_to_time_impl(ms, 1_000, 1_000_000)
+}
+
+// unix_micro returns a Time calculated from the given Unix timestamp in microseconds since 1970-01-01
+pub fn unix_micro(us i64) Time {
+	return ts_to_time_impl(us, 1_000_000, 1_000)
+}
+
+// unix_nano returns a Time calculated from the given Unix timestamp in nanoseconds since 1970-01-01
+pub fn unix_nano(ns i64) Time {
+	return ts_to_time_impl(ns, 1_000_000_000, 1)
+}
+
+fn ts_to_time_impl(value i64, down i64, up i64) Time {
+	epoch := value / down
+	remainder := (value % down) * up
+	return unix_nanosecond(epoch, int(remainder))
 }
 
 // unix_microsecond returns a Time struct, given an Unix timestamp in seconds, and a microsecond value
diff --git a/vlib/time/unix_test.v b/vlib/time/unix_test.v
new file mode 100644
index 000000000..8a99af90a
--- /dev/null
+++ b/vlib/time/unix_test.v
@@ -0,0 +1,12 @@
+import time
+
+fn test_unix_timestamp_conversion_to_time() {
+	t := time.now()
+	ss := dump(time.unix(t.unix()))
+	sms := dump(time.unix_milli(t.unix_milli()))
+	sus := dump(time.unix_micro(t.unix_micro()))
+	sns := dump(time.unix_nano(t.unix_nano()))
+	assert sns.format_ss() == ss.format_ss()
+	assert sns.format_ss_milli() == sms.format_ss_milli()
+	assert sns.format_ss_micro() == sus.format_ss_micro()
+}
-- 
2.39.5