[wpiutil] Add DataLog and DataLogManager Stop() (#5860)

Restarting a stopped log results in creating a new log file with fresh copies of the same start records and schema data records.

Also check to see if the file has been deleted or if the log file exceeds 1.8 GB, and start a new one.

ntcoreffi/src/main/native/cpp/DataLogManager.cpp

@@ -264,12 +264,18 @@ Thread::~Thread() {
 void Thread::Main() {
   // based on free disk space, scan for "old" FRC_*.wpilog files and remove
   {
-    uintmax_t freeSpace = fs::space(m_logDir).free;
+    std::error_code ec;
+    uintmax_t freeSpace;
+    auto freeSpaceInfo = fs::space(m_logDir, ec);
+    if (!ec) {
+      freeSpace = freeSpaceInfo.available;
+    } else {
+      freeSpace = UINTMAX_MAX;
+    }
     if (freeSpace < kFreeSpaceThreshold) {
       // Delete oldest FRC_*.wpilog files (ignore FRC_TBD_*.wpilog as we just
       // created one)
       std::vector<fs::directory_entry> entries;
-      std::error_code ec;
       for (auto&& entry : fs::directory_iterator{m_logDir, ec}) {
         auto stem = entry.path().stem().string();
         if (wpi::starts_with(stem, "FRC_") &&
@@ -462,6 +468,9 @@ static Instance& GetInstance(std::string_view dir = "",
                              std::string_view filename = "",
                              double period = 0.25) {
   static Instance instance(dir, filename, period);
+  if (!instance.owner) {
+    instance.owner.Start(MakeLogDir(dir), filename, period);
+  }
   return instance;
 }
 
@@ -470,6 +479,12 @@ void DataLogManager::Start(std::string_view dir, std::string_view filename,
   GetInstance(dir, filename, period);
 }
 
+void DataLogManager::Stop() {
+  auto& inst = GetInstance();
+  inst.owner.GetThread()->m_log.Stop();
+  inst.owner.Stop();
+}
+
 void DataLogManager::Log(std::string_view message) {
   GetInstance().owner.GetThread()->m_messageLog.Append(message);
   fmt::print("{}\n", message);
@@ -503,6 +518,10 @@ void DLM_Start(const char* dir, const char* filename, double period) {
   DataLogManager::Start(dir, filename, period);
 }
 
+void DLM_Stop(void) {
+  DataLogManager::Stop();
+}
+
 void DLM_Log(const char* message) {
   DataLogManager::Log(message);
 }