FindDfaProblemCauseFix: move computation to background thread (IDEA-209947)

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/TrackingRunner.java

@@ -14,6 +14,7 @@ import com.intellij.codeInspection.dataFlow.value.DfaVariableValue;
 import com.intellij.codeInspection.dataFlow.value.VariableDescriptor;
 import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.util.Pair;
+import com.intellij.openapi.util.Segment;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
 import com.intellij.util.ArrayUtil;
@@ -91,7 +92,7 @@ public class TrackingRunner extends StandardDataFlowRunner {
   public static class CauseItem {
     final @NotNull List<CauseItem> myChildren;
     final @NotNull DfaProblemType myProblem;
-    final @Nullable PsiElement myTarget;
+    final @Nullable SmartPsiElementPointer<PsiElement> myTarget;
 
     CauseItem(@NotNull String problem, @Nullable PsiElement target) {
       this(new CustomDfaProblemType(problem), target);
@@ -100,7 +101,7 @@ public class TrackingRunner extends StandardDataFlowRunner {
     CauseItem(@NotNull DfaProblemType problem, @Nullable PsiElement target) {
       myChildren = new ArrayList<>();
       myProblem = problem;
-      myTarget = target;
+      myTarget = target == null ? null : SmartPointerManager.createPointer(target);
     }
 
     CauseItem(@NotNull String problem, @NotNull MemoryStateChange change) {
@@ -135,7 +136,8 @@ public class TrackingRunner extends StandardDataFlowRunner {
     }
 
     private String dump(Document doc, int indent) {
-      return StringUtil.repeat("  ", indent) + render(doc) + (myTarget == null ? "" : " (" + myTarget.getText() + ")") + "\n" +
+      PsiElement target = getTarget();
+      return StringUtil.repeat("  ", indent) + render(doc) + (target == null ? "" : " (" + target.getText() + ")") + "\n" +
              StreamEx.of(myChildren).map(child -> child.dump(doc, indent + 1)).joining();
     }
 
@@ -145,14 +147,19 @@ public class TrackingRunner extends StandardDataFlowRunner {
 
     @Nullable
     public PsiElement getTarget() {
-      return myTarget;
+      return myTarget != null ? myTarget.getElement() : null;
+    }
+    
+    public Segment getTargetSegment() {
+      return myTarget == null ? null : myTarget.getRange();
     }
 
     public String render(Document doc) {
-      if (myTarget != null) {
+      Segment range = getTargetSegment();
+      if (range != null) {
         String cause = myProblem.toString();
         if (cause.endsWith("#ref")) {
-          int offset = myTarget.getTextRange().getStartOffset();
+          int offset = range.getStartOffset();
           int number = doc.getLineNumber(offset);
           return cause.replaceFirst("#ref$", "line #" + (number + 1));
         }

java/java-impl/src/com/intellij/codeInspection/dataFlow/fix/FindDfaProblemCauseFix.java

@@ -10,6 +10,8 @@ import com.intellij.codeInspection.ProblemDescriptor;
 import com.intellij.codeInspection.dataFlow.TrackingRunner;
 import com.intellij.ide.util.PsiNavigationSupport;
 import com.intellij.lang.injection.InjectedLanguageManager;
+import com.intellij.openapi.application.ApplicationManager;
+import com.intellij.openapi.application.ReadAction;
 import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.fileEditor.FileEditorManager;
@@ -19,6 +21,7 @@ import com.intellij.openapi.ui.popup.JBPopupAdapter;
 import com.intellij.openapi.ui.popup.JBPopupFactory;
 import com.intellij.openapi.ui.popup.LightweightWindowEvent;
 import com.intellij.openapi.util.Pair;
+import com.intellij.openapi.util.Segment;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
@@ -62,22 +65,28 @@ public class FindDfaProblemCauseFix implements LocalQuickFix, LowPriorityAction
 
   @Override
   public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
+    ApplicationManager.getApplication().executeOnPooledThread(() -> ReadAction.run(this::findCause));
+  }
+
+  private void findCause() {
     PsiExpression element = myAnchor.getElement();
     if (element == null) return;
+    PsiFile file = element.getContainingFile();
+    List<TrackingRunner.CauseItem> items =
+      TrackingRunner.findProblemCause(myUnknownMembersAsNullable, myIgnoreAssertStatements, element, myProblemType);
+    
+    ApplicationManager.getApplication().invokeLater(() -> ReadAction.run(() -> displayProblemCause(file, items)));
+  }
+
+  private static void displayProblemCause(PsiFile file, List<TrackingRunner.CauseItem> items) {
+    if (!file.isValid()) return;
+    Project project = file.getProject();
     Editor editor = FileEditorManager.getInstance(project).getSelectedTextEditor();
     if (editor == null) return;
     Document document = editor.getDocument();
-    PsiFile file = element.getContainingFile();
     PsiFile topLevelFile = InjectedLanguageManager.getInstance(project).getTopLevelFile(file);
     if (topLevelFile == null || document != topLevelFile.getViewProvider().getDocument()) return;
-    List<TrackingRunner.CauseItem> items =
-      TrackingRunner.findProblemCause(myUnknownMembersAsNullable, myIgnoreAssertStatements, element, myProblemType);
     TrackingRunner.CauseItem root = ContainerUtil.getOnlyItem(items);
-    if (root == null) {
-      HintManagerImpl hintManager = (HintManagerImpl)HintManager.getInstance();
-      hintManager.showErrorHint(editor, "Unable to find the cause");
-      return;
-    }
     class CauseWithDepth {
       final int myDepth;
       final TrackingRunner.CauseItem myCauseItem;
@@ -92,8 +101,12 @@ public class FindDfaProblemCauseFix implements LocalQuickFix, LowPriorityAction
         return StringUtil.repeat("  ", myDepth - 1) + myCauseItem.render(document);
       }
     }
-    List<CauseWithDepth> causes =
-      EntryStream.ofTree(root, (depth, c) -> c.children()).skip(1).mapKeyValue((d, i) -> new CauseWithDepth(d, i)).toList();
+    List<CauseWithDepth> causes;
+    if (root == null) {
+      causes = Collections.emptyList();
+    } else {
+      causes = EntryStream.ofTree(root, (depth, c) -> c.children()).skip(1).mapKeyValue((d, i) -> new CauseWithDepth(d, i)).toList();
+    }
     if (causes.isEmpty()) {
       HintManagerImpl hintManager = (HintManagerImpl)HintManager.getInstance();
       hintManager.showErrorHint(editor, "Unable to find the cause");
@@ -117,9 +130,9 @@ public class FindDfaProblemCauseFix implements LocalQuickFix, LowPriorityAction
         if (h == null) return;
         h.dropHighlight();
         if (cause == null) return;
-        PsiElement target = cause.myCauseItem.getTarget();
-        if (target == null || !target.isValid()) return;
-        TextRange range = target.getTextRange();
+        Segment target = cause.myCauseItem.getTargetSegment();
+        if (target == null) return;
+        TextRange range = TextRange.create(target);
         h.highlight(Pair.create(range, Collections.singletonList(range)));
       })
       .addListener(new JBPopupAdapter() {