From 62ebe4b99d9324c40bb045fe4dc5b658722c7a5b Mon Sep 17 00:00:00 2001
From: Alexey Kudravtsev <cdr@intellij.com>
Date: Fri, 10 Nov 2017 12:37:03 +0300
Subject: [PATCH] optimisation: do not compute and cache all inheritors when in
 EDT

---
 .../psi/impl/search/JavaClassInheritorsSearcher.java        | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/java/java-indexing-impl/src/com/intellij/psi/impl/search/JavaClassInheritorsSearcher.java b/java/java-indexing-impl/src/com/intellij/psi/impl/search/JavaClassInheritorsSearcher.java
index 4033e4aa25c0..34709ed13d02 100644
--- a/java/java-indexing-impl/src/com/intellij/psi/impl/search/JavaClassInheritorsSearcher.java
+++ b/java/java-indexing-impl/src/com/intellij/psi/impl/search/JavaClassInheritorsSearcher.java
@@ -85,6 +85,12 @@ public class JavaClassInheritorsSearcher extends QueryExecutorBase<PsiClass, Cla
       return;
     }
 
+    if (!parameters.isCheckDeep() && ApplicationManager.getApplication().isDispatchThread()) {
+      // optimisation: if under EDT we've been asked for one inheritor, to improve latency do not bother to compute and cache them all
+      DirectClassInheritorsSearch.search(baseClass, searchScope).forEach(consumer);
+      return;
+    }
+
     Iterable<PsiClass> cached = getOrComputeSubClasses(project, baseClass, searchScope);
 
     for (final PsiClass subClass : cached) {