Use magic static for groups container

rzblue · Oct 21, 2024 · 7e0248c · 7e0248c
1 parent ab2daf0
commit 7e0248c
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Showing 3 changed files with 25 additions and 17 deletions.
diff --git a/wpilibc/src/main/native/cpp/Alert.cpp b/wpilibc/src/main/native/cpp/Alert.cpp
@@ -20,18 +20,22 @@
 
 using namespace frc;
 
-wpi::StringMap<Alert::SendableAlerts> Alert::groups;
+Alert::SendableAlerts& Alert::GetGroupSendable(std::string_view group) {
+  static wpi::StringMap<Alert::SendableAlerts> groups;
+
+  auto [iter, exists] = groups.try_emplace(group);
+  SendableAlerts& sendable = iter->getValue();
+  if (!exists) {
+    frc::SmartDashboard::PutData(group, &iter->getValue());
+  }
+  return sendable;
+}
 
 Alert::Alert(std::string_view text, AlertType type)
     : Alert("Alerts", text, type) {}
 
 Alert::Alert(std::string_view group, std::string_view text, AlertType type)
-    : m_type(type), m_text(text), m_group{group} {
-  if (!groups.contains(group)) {
-    frc::SmartDashboard::PutData(group,
-                                 &groups.try_emplace(group).first->getValue());
-  }
-}
+    : m_type(type), m_text(text), m_group{group} {}
 
 Alert::~Alert() {
   Set(false);
@@ -44,9 +48,11 @@ void Alert::Set(bool active) {
 
   if (active) {
     m_activeStartTime = frc::RobotController::GetFPGATime();
-    groups[m_group].GetSetForType(m_type).emplace(m_activeStartTime, m_text);
+    GetGroupSendable(m_group).GetSetForType(m_type).emplace(m_activeStartTime,
+                                                            m_text);
   } else {
-    groups[m_group].GetSetForType(m_type).erase({m_activeStartTime, m_text});
+    GetGroupSendable(m_group).GetSetForType(m_type).erase(
+        {m_activeStartTime, m_text});
   }
   m_active = active;
 }
@@ -57,7 +63,7 @@ void Alert::SetText(std::string_view text) {
   }
 
   if (m_active) {
-    auto set = groups[m_group].GetSetForType(m_type);
+    auto set = GetGroupSendable(m_group).GetSetForType(m_type);
     auto iter = set.find({m_activeStartTime, m_text});
     auto hint = set.erase(iter);
     set.emplace_hint(hint, m_activeStartTime, m_text);

diff --git a/wpilibc/src/main/native/include/frc/Alert.h b/wpilibc/src/main/native/include/frc/Alert.h
@@ -113,12 +113,6 @@ class Alert {
   void SetText(std::string_view text);
 
  private:
-  AlertType m_type;
-  std::string m_text;
-  std::string m_group;  // todo: could store iterator or reference to the actual
-                        // SendableAlerts, would remove lookup
-  bool m_active = false;
-  uint64_t m_activeStartTime;
   class PublishedAlert {
    public:
     PublishedAlert(uint64_t timestamp, const std::string_view text)
@@ -143,7 +137,14 @@ class Alert {
     std::array<std::set<PublishedAlert>, 3> m_alerts;
   };
 
-  static wpi::StringMap<SendableAlerts> groups;
+  AlertType m_type;
+  std::string m_text;
+  std::string m_group;
+
+  bool m_active = false;
+  uint64_t m_activeStartTime;
+
+  static SendableAlerts& GetGroupSendable(std::string_view group);
 };
 
 std::string format_as(Alert::AlertType type);

diff --git a/wpilibc/src/test/native/cpp/AlertsTest.cpp b/wpilibc/src/test/native/cpp/AlertsTest.cpp
@@ -5,6 +5,7 @@
 #include <frc/Alert.h>
 
 #include <chrono>
+#include <string>
 
 #include <fmt/format.h>
 #include <gtest/gtest.h>