fix: avoid repeated scan until workspace folder changes

Author: FluoriteCafe-work

src/syncHandler.ts

@@ -47,7 +47,7 @@ class SyncHandler implements Disposable {
 
         this.disposables.push(workspace.onDidChangeWorkspaceFolders(() => {
             this.refresh();
-            setImmediate(() => upgradeManager.scan());  // Deferred
+            setImmediate(() => upgradeManager.scan(true));  // Deferred
         }));
 
         try {

src/upgrade/upgradeManager.ts

@@ -24,6 +24,7 @@ function shouldRunCheckup() {
 
 class UpgradeManager {
     private static watcherSetup = false;
+    private static scanned = false;
 
     public static initialize(context: ExtensionContext) {
         notificationManager.initialize(context);
@@ -45,15 +46,19 @@ class UpgradeManager {
         }));
 
         // Defer the expensive scan operation to not block extension activation
-        setImmediate(() => UpgradeManager.scan());
+        setImmediate(() => UpgradeManager.scan(false));
     }
 
-    public static scan() {
+    public static scan(forceRescan: boolean) {
         return instrumentOperation("java.dependency.scan", async (_operationId: string) => {
             if (!shouldRunCheckup()) {
                 return;
             }
 
+            if (forceRescan) {
+                UpgradeManager.scanned = false;
+            }
+
             if (!(await languageServerApiManager.ready())) {
                 sendInfo(_operationId, { skipReason: "languageServerNotReady" });
                 return;
@@ -67,6 +72,11 @@ class UpgradeManager {
                 return;
             }
 
+            if (UpgradeManager.scanned) {
+                return;
+            }
+            UpgradeManager.scanned = true;
+
             workspace.workspaceFolders?.forEach((folder) =>
                 UpgradeManager.runDependencyCheckup(folder)
             );
@@ -109,7 +119,7 @@ class UpgradeManager {
             const onDidServerModeChange: Event<string> = extensionApi.onDidServerModeChange;
             contextManager.context.subscriptions.push(onDidServerModeChange((mode: LanguageServerMode) => {
                 if (mode !== LanguageServerMode.LightWeight) {
-                    UpgradeManager.scan();
+                    UpgradeManager.scan(false);
                 }
             }));
             UpgradeManager.watcherSetup = true;