Initial project import

tools/v/vlib/time/stopwatch.v

@@ -0,0 +1,79 @@
+// Copyright (c) 2019-2024 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module time
+
+@[params]
+pub struct StopWatchOptions {
+pub:
+	auto_start bool = true
+}
+
+// StopWatch is used to measure elapsed time.
+pub struct StopWatch {
+mut:
+	elapsed u64
+	started bool
+pub mut:
+	start u64
+	end   u64
+}
+
+// new_stopwatch initializes a new StopWatch with the current time as start.
+pub fn new_stopwatch(opts StopWatchOptions) StopWatch {
+	mut initial := u64(0)
+	if opts.auto_start {
+		initial = sys_mono_now()
+	}
+	return StopWatch{
+		elapsed: 0
+		started: opts.auto_start
+		start:   initial
+		end:     0
+	}
+}
+
+// start starts the stopwatch. If the timer was paused, it continues counting.
+pub fn (mut t StopWatch) start() {
+	t.start = sys_mono_now()
+	t.end = 0
+	t.started = true
+}
+
+// restart restarts the stopwatch. If the timer was paused, it restarts counting.
+pub fn (mut t StopWatch) restart() {
+	t.start = sys_mono_now()
+	t.end = 0
+	t.elapsed = 0
+	t.started = true
+}
+
+// stop stops the timer, by setting the end time to the current time.
+pub fn (mut t StopWatch) stop() {
+	t.end = sys_mono_now()
+}
+
+// pause resets the `start` time and adds the current elapsed time to `elapsed`.
+pub fn (mut t StopWatch) pause() {
+	if t.started {
+		if t.end == 0 {
+			t.elapsed += sys_mono_now() - t.start
+		} else {
+			t.elapsed += t.end - t.start
+		}
+	}
+	t.start = 0
+	t.started = false
+}
+
+// elapsed returns the Duration since the last start call.
+pub fn (t StopWatch) elapsed() Duration {
+	if t.started {
+		if t.end == 0 {
+			return Duration(i64(sys_mono_now() - t.start + t.elapsed))
+		} else {
+			return Duration(i64(t.end - t.start + t.elapsed))
+		}
+	}
+	return Duration(i64(t.elapsed))
+}