feat(video2x): improved the timer

Signed-off-by: k4yt3x <i@k4yt3x.com>

src/timer.cpp

@@ -0,0 +1,76 @@
+#include "timer.h"
+
+#include <sys/types.h>
+
+Timer::Timer() : running(false), paused(false), elapsed_time(0) {}
+
+Timer::~Timer() {
+    stop();
+}
+
+void Timer::start() {
+    if (running) {
+        return;
+    }
+
+    running = true;
+    paused = false;
+    elapsed_time = 0;
+    start_time = std::chrono::steady_clock::now();
+
+    timer_thread = std::thread([this]() {
+        while (running) {
+            if (!paused) {
+                update_elapsed_time();
+            }
+            std::this_thread::sleep_for(std::chrono::milliseconds(10));
+        }
+    });
+}
+
+void Timer::pause() {
+    if (running && !paused) {
+        paused = true;
+        pause_start_time = std::chrono::steady_clock::now();
+    }
+}
+
+void Timer::resume() {
+    if (running && paused) {
+        paused = false;
+        auto pause_end_time = std::chrono::steady_clock::now();
+        auto pause_duration =
+            std::chrono::duration_cast<std::chrono::milliseconds>(pause_end_time - pause_start_time)
+                .count();
+        start_time += std::chrono::milliseconds(pause_duration);
+    }
+}
+
+void Timer::stop() {
+    running = false;
+    if (timer_thread.joinable()) {
+        timer_thread.join();
+    }
+    update_elapsed_time();
+}
+
+bool Timer::is_running() const {
+    return running;
+}
+
+bool Timer::is_paused() const {
+    return paused;
+}
+
+int64_t Timer::get_elapsed_time() const {
+    return elapsed_time;
+}
+
+void Timer::update_elapsed_time() {
+    if (running && !paused) {
+        auto current_time = std::chrono::steady_clock::now();
+        elapsed_time =
+            std::chrono::duration_cast<std::chrono::milliseconds>(current_time - start_time)
+                .count();
+    }
+}