replay: pause/resume using spacebar (#22278)

* pause/resume using spacebar

* Update selfdrive/ui/replay/replay.cc

Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>

selfdrive/ui/replay/main.cc

@@ -55,6 +55,8 @@ void keyboardThread(Replay *replay) {
       replay->relativeSeek(-10);
     } else if (c == 'G') {
       replay->relativeSeek(0);
+    } else if (c == ' ') {
+      replay->pause(!replay->isPaused());
     }
   }
 }

selfdrive/ui/replay/replay.cc

@@ -66,6 +66,15 @@ void Replay::relativeSeek(int seconds) {
   seekTo(current_ts + seconds);
 }
 
+void Replay::pause(bool pause) {
+  updating_events = true;
+  std::unique_lock lk(lock);
+  qDebug() << (pause ? "paused..." : "resuming");
+  paused_ = pause;
+  updating_events = false;
+  stream_cv_.notify_one();
+}
+
 void Replay::setCurrentSegment(int n) {
   if (current_segment.exchange(n) != n) {
     emit segmentChanged(n);
@@ -160,6 +169,7 @@ void Replay::stream() {
 
   while (true) {
     std::unique_lock lk(lock);
+    stream_cv_.wait(lk, [=]() { return paused_ == false; });
 
     uint64_t evt_start_ts = seek_ts != -1 ? route_start_ts + (seek_ts * 1e9) : cur_mono_time;
     Event cur_event(cur_which, evt_start_ts);

selfdrive/ui/replay/replay.h

@@ -20,6 +20,8 @@ public:
   void start(int seconds = 0);
   void relativeSeek(int seconds);
   void seekTo(int seconds);
+  void pause(bool pause);
+  bool isPaused() const { return paused_; }
 
 signals:
  void segmentChanged(int);
@@ -42,6 +44,8 @@ protected:
 
   // logs
   std::mutex lock;
+  bool paused_ = false;
+  std::condition_variable stream_cv_;
   std::atomic<bool> updating_events = false;
   std::vector<Event *> *events = nullptr;
   std::unordered_map<uint32_t, EncodeIdx> *eidx = nullptr;