From 7a531d89735f67fe413067b58e2512bba99be4e6 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Tue, 26 May 2015 19:37:13 +0200
Subject: [PATCH] cache XmlExtension per file

---
 .../src/com/intellij/xml/XmlExtension.java        | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/xml/xml-psi-impl/src/com/intellij/xml/XmlExtension.java b/xml/xml-psi-impl/src/com/intellij/xml/XmlExtension.java
index f76f9b113982..5a70693e97a9 100644
--- a/xml/xml-psi-impl/src/com/intellij/xml/XmlExtension.java
+++ b/xml/xml-psi-impl/src/com/intellij/xml/XmlExtension.java
@@ -25,6 +25,9 @@ import com.intellij.psi.impl.source.xml.SchemaPrefix;
 import com.intellij.psi.impl.source.xml.TagNameReference;
 import com.intellij.psi.search.LocalSearchScope;
 import com.intellij.psi.search.SearchScope;
+import com.intellij.psi.util.CachedValueProvider;
+import com.intellij.psi.util.CachedValuesManager;
+import com.intellij.psi.util.PsiModificationTracker;
 import com.intellij.psi.xml.XmlAttribute;
 import com.intellij.psi.xml.XmlDocument;
 import com.intellij.psi.xml.XmlFile;
@@ -43,7 +46,17 @@ public abstract class XmlExtension {
 
   public static final XmlExtension DEFAULT_EXTENSION = new DefaultXmlExtension();
 
-  public static XmlExtension getExtension(PsiFile file) {
+  public static XmlExtension getExtension(@NotNull final PsiFile file) {
+    return CachedValuesManager.getCachedValue(file, new CachedValueProvider<XmlExtension>() {
+      @Nullable
+      @Override
+      public Result<XmlExtension> compute() {
+        return Result.create(calcExtension(file), PsiModificationTracker.MODIFICATION_COUNT);
+      }
+    });
+  }
+
+  private static XmlExtension calcExtension(PsiFile file) {
     for (XmlExtension extension : Extensions.getExtensions(EP_NAME)) {
       if (extension.isAvailable(file)) {
         return extension;