From 13645e24569811a61a49d1e85d76e24f653eac42 Mon Sep 17 00:00:00 2001
From: kbkpbot <kbkpbot@sina.com>
Date: Sun, 20 Apr 2025 08:25:13 +0800
Subject: [PATCH] log: add local time / utc time selection support (#24268)

---
 vlib/log/log.v      | 15 +++++++++++++--
 vlib/log/log_test.v |  7 +++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/vlib/log/log.v b/vlib/log/log.v
index 410fe372fe..42f43fb0b3 100644
--- a/vlib/log/log.v
+++ b/vlib/log/log.v
@@ -38,6 +38,7 @@ mut:
 	time_format        TimeFormat = .tf_rfc3339_micro
 	custom_time_format string     = 'MMMM Do YY N kk:mm:ss A' // timestamp with custom format
 	short_tag          bool
+	local_time         bool // use local time or utc time in log
 	always_flush       bool // flush after every single .fatal(), .error(), .warn(), .info(), .debug() call
 	output_stream      io.Writer = stderr
 pub mut:
@@ -119,7 +120,7 @@ pub fn (mut l Log) reopen() ! {
 
 // log_file writes log line `s` with `level` to the log file.
 fn (mut l Log) log_file(s string, level Level) {
-	timestamp := l.time_format(time.utc())
+	timestamp := l.time_format(if l.local_time { time.now() } else { time.utc() })
 	e := tag_to_file(level, l.short_tag)
 
 	unsafe {
@@ -142,7 +143,7 @@ fn (mut l Log) log_file(s string, level Level) {
 
 // log_stream writes log line `s` with `level` to stderr or stderr depending on set output stream.
 fn (mut l Log) log_stream(s string, level Level) {
-	timestamp := l.time_format(time.utc())
+	timestamp := l.time_format(if l.local_time { time.now() } else { time.utc() })
 	tag := tag_to_console(level, l.short_tag)
 	msg := '${timestamp} [${tag}] ${s}\n'
 	arr := msg.bytes()
@@ -313,6 +314,16 @@ pub fn (l Log) get_short_tag() bool {
 	return l.short_tag
 }
 
+// set_local_time will set the log using local time
+pub fn (mut l Log) set_local_time(enabled bool) {
+	l.local_time = enabled
+}
+
+// get_local_time will get the log using local time state
+pub fn (l Log) get_local_time() bool {
+	return l.local_time
+}
+
 // use_stdout will restore the old behaviour of logging to stdout, instead of stderr.
 // It will also silence the deprecation note in the transition period.
 pub fn use_stdout() {
diff --git a/vlib/log/log_test.v b/vlib/log/log_test.v
index 7195191009..90d5f94957 100644
--- a/vlib/log/log_test.v
+++ b/vlib/log/log_test.v
@@ -134,6 +134,13 @@ fn test_log_time_format() {
 	assert TimeFormat.tf_custom_format == l.get_time_format()
 	l.info('${@FN} custom like January 1st 22 AD 13:45:33 PM')
 	assert true
+	l.set_time_format(.tf_default)
+	l.set_local_time(true)
+	l.info('${@FN} time log in local time')
+	assert l.get_local_time()
+	l.set_local_time(false)
+	l.info('${@FN} time log in utc time')
+	assert !l.get_local_time()
 	println(@FN + ' end')
 }