From 74ff443db61767c2b4a17668801a8c5a9cbdb5c6 Mon Sep 17 00:00:00 2001
From: "Egor.Ushakov" <egor.ushakov@jetbrains.com>
Date: Mon, 30 May 2016 12:44:32 +0300
Subject: [PATCH] IDEA-156071 Simple static method renderers are much slower
 than toString - cache TypeEvaluator result

---
 .../evaluation/expression/TypeEvaluator.java     | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/java/debugger/impl/src/com/intellij/debugger/engine/evaluation/expression/TypeEvaluator.java b/java/debugger/impl/src/com/intellij/debugger/engine/evaluation/expression/TypeEvaluator.java
index 667948e5242c..aa23b7b0d659 100644
--- a/java/debugger/impl/src/com/intellij/debugger/engine/evaluation/expression/TypeEvaluator.java
+++ b/java/debugger/impl/src/com/intellij/debugger/engine/evaluation/expression/TypeEvaluator.java
@@ -26,12 +26,19 @@ import com.intellij.debugger.engine.JVMName;
 import com.intellij.debugger.engine.evaluation.EvaluateException;
 import com.intellij.debugger.engine.evaluation.EvaluateExceptionUtil;
 import com.intellij.debugger.engine.evaluation.EvaluationContextImpl;
+import com.intellij.reference.SoftReference;
+import com.sun.jdi.ClassLoaderReference;
 import com.sun.jdi.ReferenceType;
 import org.jetbrains.annotations.NotNull;
 
+import java.lang.ref.WeakReference;
+
 public class TypeEvaluator implements Evaluator {
   private final JVMName myTypeName;
 
+  private WeakReference<ReferenceType> myLastResult;
+  private WeakReference<ClassLoaderReference> myLastClassLoader;
+
   public TypeEvaluator(@NotNull JVMName typeName) {
     myTypeName = typeName;
   }
@@ -44,12 +51,19 @@ public class TypeEvaluator implements Evaluator {
    * @return ReferenceType in the target VM, with the given fully qualified name
    */
   public Object evaluate(EvaluationContextImpl context) throws EvaluateException {
+    ClassLoaderReference classLoader = context.getClassLoader();
+    Object lastRes = SoftReference.dereference(myLastResult);
+    if (lastRes != null && classLoader == SoftReference.dereference(myLastClassLoader)) {
+      return lastRes;
+    }
     DebugProcessImpl debugProcess = context.getDebugProcess();
     String typeName = myTypeName.getName(debugProcess);
-    final ReferenceType type = debugProcess.findClass(context, typeName, context.getClassLoader());
+    ReferenceType type = debugProcess.findClass(context, typeName, classLoader);
     if (type == null) {
       throw EvaluateExceptionUtil.createEvaluateException(DebuggerBundle.message("error.class.not.loaded", typeName));
     }
+    myLastClassLoader = new WeakReference<>(classLoader);
+    myLastResult = new WeakReference<>(type);
     return type;
   }