Dont flush settings on exit after import (#1179)

Fixes bug when importing settings zip that would have the new settings be over written, and would not actually update

photon-core/src/main/java/org/photonvision/common/configuration/ConfigManager.java

@@ -50,6 +50,10 @@ public class ConfigManager {
     private final Thread settingsSaveThread;
     private long saveRequestTimestamp = -1;
 
+    // special case flag to disable flushing settings to disk at shutdown. Avoids the jvm shutdown
+    // hook overwriting the settings we just uploaded
+    private boolean flushOnShutdown = true;
+
     enum ConfigSaveStrategy {
         SQL,
         LEGACY,
@@ -303,4 +307,19 @@ public class ConfigManager {
         if (!ret.exists()) ret.mkdirs();
         return ret;
     }
+
+    /**
+     * Disable flushing settings to disk as part of our JVM exit hook. Used to prevent uploading all
+     * settings from getting its new configs overwritten at program exit and before theyre all loaded.
+     */
+    public void disableFlushOnShutdown() {
+        this.flushOnShutdown = false;
+    }
+
+    public void onJvmExit() {
+        if (flushOnShutdown) {
+            logger.info("Force-flushing settings...");
+            saveToDisk();
+        }
+    }
 }

photon-core/src/main/java/org/photonvision/common/hardware/HardwareManager.java

@@ -145,8 +145,7 @@ public class HardwareManager {
         logger.info("Shutting down LEDs...");
         if (visionLED != null) visionLED.setState(false);
 
-        logger.info("Force-flushing settings...");
-        ConfigManager.getInstance().saveToDisk();
+        ConfigManager.getInstance().onJvmExit();
     }
 
     public boolean restartDevice() {

photon-server/src/main/java/org/photonvision/server/RequestHandler.java

@@ -94,6 +94,7 @@ public class RequestHandler {
             ctx.status(200);
             ctx.result("Successfully saved the uploaded settings zip, rebooting...");
             logger.info("Successfully saved the uploaded settings zip, rebooting...");
+            ConfigManager.getInstance().disableFlushOnShutdown();
             restartProgram();
         } else {
             ctx.status(500);