Automatically refresh placefiles that failed to load

scwx-qt/source/scwx/qt/manager/placefile_manager.cpp

@@ -105,6 +105,8 @@ public:
 
    void CancelRefresh();
    void ScheduleRefresh();
+   void ScheduleRefresh(
+      const std::chrono::system_clock::duration timeUntilNextUpdate);
    void Update();
    void UpdateAsync();
 
@@ -150,6 +152,8 @@ public:
 
    std::string                           lastRadarSite_ {};
    std::chrono::system_clock::time_point lastUpdateTime_ {};
+
+   std::size_t failureCount_ {};
 };
 
 PlacefileManager::PlacefileManager() : p(std::make_unique<Impl>(this))
@@ -542,6 +546,11 @@ void PlacefileManager::Impl::PlacefileRecord::Update()
    if (url.isLocalFile())
    {
       updatedPlacefile = gr::Placefile::Load(name);
+
+      if (updatedPlacefile == nullptr)
+      {
+         logger_->error("Local placefile not found: {}", name);
+      }
    }
    else
    {
@@ -625,6 +634,7 @@ void PlacefileManager::Impl::PlacefileRecord::Update()
          placefile_      = updatedPlacefile;
          title_          = placefile_->title();
          lastUpdateTime_ = std::chrono::system_clock::now();
+         failureCount_   = 0;
 
          // Update font resources
          {
@@ -645,11 +655,31 @@ void PlacefileManager::Impl::PlacefileRecord::Update()
          // Notify slots of the placefile update
          Q_EMIT p->self_->PlacefileUpdated(name);
       }
-   }
 
       // Update refresh timer
       ScheduleRefresh();
    }
+   else if (enabled_)
+   {
+      using namespace std::chrono_literals;
+
+      ++failureCount_;
+
+      // Update refresh timer if the file failed to load, in case it is able to
+      // be resolved later
+      if (url.isLocalFile())
+      {
+         ScheduleRefresh(10s);
+      }
+      else
+      {
+         // Start attempting to refresh at 15 seconds, and start backing off
+         // until retrying every 60 seconds
+         ScheduleRefresh(
+            std::min<std::chrono::seconds>(15s * failureCount_, 60s));
+      }
+   }
+}
 
 void PlacefileManager::Impl::PlacefileRecord::ScheduleRefresh()
 {
@@ -666,6 +696,12 @@ void PlacefileManager::Impl::PlacefileRecord::ScheduleRefresh()
    auto nextUpdateTime      = lastUpdateTime_ + refresh_time();
    auto timeUntilNextUpdate = nextUpdateTime - std::chrono::system_clock::now();
 
+   ScheduleRefresh(timeUntilNextUpdate);
+}
+
+void PlacefileManager::Impl::PlacefileRecord::ScheduleRefresh(
+   const std::chrono::system_clock::duration timeUntilNextUpdate)
+{
    logger_->debug(
       "Scheduled refresh in {:%M:%S} ({})",
       std::chrono::duration_cast<std::chrono::seconds>(timeUntilNextUpdate),

wxdata/source/scwx/gr/placefile.cpp

@@ -154,9 +154,17 @@ std::shared_ptr<Placefile::Font> Placefile::font(std::size_t i)
 
 std::shared_ptr<Placefile> Placefile::Load(const std::string& filename)
 {
+   std::shared_ptr<Placefile> placefile = nullptr;
+
    logger_->debug("Loading placefile: {}", filename);
    std::ifstream f(filename, std::ios_base::in);
-   return Load(filename, f);
+
+   if (f.is_open())
+   {
+      placefile = Load(filename, f);
+   }
+
+   return placefile;
 }
 
 std::shared_ptr<Placefile> Placefile::Load(const std::string& name,