cache large leaf element text strings

platform/core-impl/src/com/intellij/psi/impl/source/tree/LeafElement.java

@@ -19,9 +19,11 @@ package com.intellij.psi.impl.source.tree;
 import com.intellij.lang.ASTFactory;
 import com.intellij.lang.ASTNode;
 import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.util.Key;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.tree.TokenSet;
+import com.intellij.reference.SoftReference;
 import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.text.CharArrayUtil;
 import org.jetbrains.annotations.NotNull;
@@ -29,6 +31,7 @@ import org.jetbrains.annotations.Nullable;
 
 public abstract class LeafElement extends TreeElement {
   private static final Logger LOG = Logger.getInstance("com.intellij.psi.impl.source.tree.LeafElement");
+  private static final Key<SoftReference<String>> CACHED_TEXT = Key.create("CACHED_TEXT");
 
   private static final int TEXT_MATCHES_THRESHOLD = 5;
 
@@ -58,6 +61,15 @@ public abstract class LeafElement extends TreeElement {
 
   @Override
   public String getText() {
+    if (myText.length() > 1000 && !(myText instanceof String)) { // e.g. a large text file
+      String text = SoftReference.dereference(getUserData(CACHED_TEXT));
+      if (text == null) {
+        text = myText.toString();
+        putUserData(CACHED_TEXT, new SoftReference<String>(text));
+      }
+      return text;
+    }
+
     return myText.toString();
   }
 

spellchecker/testSrc/com/intellij/spellchecker/inspection/SpellcheckerPerformanceTest.groovy

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2000-2014 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.spellchecker.inspection
+import com.intellij.testFramework.PlatformTestUtil
+/**
+ * @author peter
+ */
+public class SpellcheckerPerformanceTest extends SpellcheckerInspectionTestCase {
+
+  public void "test large text file with many typos"() {
+    int typoCount = 150000
+    String text = "aaaaaaaaa " * typoCount // about 1.5M
+    myFixture.configureFromExistingVirtualFile(myFixture.addFileToProject("foo.txt", text).virtualFile)
+
+    myFixture.enableInspections(inspectionTools)
+    PlatformTestUtil.assertTiming("highlighting too long", 5000) { assertSize(typoCount, myFixture.doHighlighting()) }
+  }
+  
+}