performance: ignore whitespace during spell checking, fix test to perform actual inspections instead of skipping them altogether

spellchecker/src/com/intellij/spellchecker/tokenizer/SpellcheckingStrategy.java

@@ -52,6 +52,9 @@ public class SpellcheckingStrategy {
 
   @NotNull
   public Tokenizer getTokenizer(PsiElement element) {
+    if (element instanceof PsiWhiteSpace) {
+      return EMPTY_TOKENIZER;
+    }
     if (element instanceof PsiLanguageInjectionHost && InjectedLanguageUtil.hasInjections((PsiLanguageInjectionHost)element)) {
       return EMPTY_TOKENIZER;
     }

spellchecker/testSrc/com/intellij/spellchecker/inspection/SpellcheckerInspectionTestCase.java

@@ -25,7 +25,7 @@ public abstract class SpellcheckerInspectionTestCase extends LightPlatformCodeIn
     return true;
   }
 
-  public static String getSpellcheckerTestDataPath() {
+  static String getSpellcheckerTestDataPath() {
     return "/spellchecker/testData/";
   }
 
@@ -34,7 +34,7 @@ public abstract class SpellcheckerInspectionTestCase extends LightPlatformCodeIn
     myFixture.testHighlighting(false, false, true, file);
   }
 
-  public static LocalInspectionTool[] getInspectionTools() {
+  static LocalInspectionTool[] getInspectionTools() {
     return new LocalInspectionTool[]{new SpellCheckingInspection()};
   }
 }

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

@@ -15,10 +15,19 @@
  */
 package com.intellij.spellchecker.inspection;
 
+import com.intellij.codeHighlighting.Pass;
+import com.intellij.codeHighlighting.TextEditorHighlightingPass;
+import com.intellij.codeInsight.daemon.DaemonCodeAnalyzer;
+import com.intellij.codeInsight.daemon.impl.HighlightInfo;
+import com.intellij.codeInsight.daemon.impl.TextEditorHighlightingPassRegistrarEx;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.testFramework.PlatformTestUtil;
-import com.intellij.util.ThrowableRunnable;
+import com.intellij.testFramework.fixtures.impl.CodeInsightTestFixtureImpl;
+import com.intellij.util.ArrayUtil;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
 
 /**
  * @author peter
@@ -46,14 +55,47 @@ public class SpellcheckerPerformanceTest extends SpellcheckerInspectionTestCase
     myFixture.enableInspections(getInspectionTools());
 
     start = System.currentTimeMillis();
-    assertSize(typoCount, myFixture.doHighlighting());
+    assertSize(typoCount, runLocalInspections());
     System.out.println("warm-up took " + (System.currentTimeMillis() - start) + " ms");
 
-    PlatformTestUtil.startPerformanceTest("many typos highlighting", 1000, new ThrowableRunnable() {
-      @Override
-      public void run() {
-        assertSize(typoCount, myFixture.doHighlighting());
-      }
-    }).cpuBound().useLegacyScaling().assertTiming();
+    PlatformTestUtil.startPerformanceTest("many typos highlighting", 10000, () -> {
+      DaemonCodeAnalyzer.getInstance(getProject()).restart();
+      assertSize(typoCount, runLocalInspections());
+    }).cpuBound().assertTiming();
+  }
+
+  public void testManyWhitespaces() {
+    final int count = 100000;
+    String text = StringUtil.repeat("//\n     \t      \t    \n   \n", count);
+
+    long start = System.currentTimeMillis();
+    VirtualFile file = myFixture.addFileToProject("foo.java", text).getVirtualFile();
+    System.out.println("creation took " + (System.currentTimeMillis() - start) + " ms");
+
+    start = System.currentTimeMillis();
+    myFixture.configureFromExistingVirtualFile(file);
+    System.out.println("configure took " + (System.currentTimeMillis() - start) + " ms");
+
+    start = System.currentTimeMillis();
+    List<HighlightInfo> infos = runLocalInspections();
+    assertEmpty(infos);
+    System.out.println("warm-up took " + (System.currentTimeMillis() - start) + " ms");
+
+    PlatformTestUtil.startPerformanceTest("many whitespaces highlighting", 4000, () -> {
+      DaemonCodeAnalyzer.getInstance(getProject()).restart();
+      assertEmpty(runLocalInspections());
+    }).cpuBound().assertTiming();
+  }
+
+  @NotNull
+  private List<HighlightInfo> runLocalInspections() {
+    myFixture.enableInspections(getInspectionTools());
+    TextEditorHighlightingPassRegistrarEx passRegistrar = TextEditorHighlightingPassRegistrarEx.getInstanceEx(getProject());
+    List<TextEditorHighlightingPass> passes = passRegistrar.instantiatePasses(myFixture.getFile(), myFixture.getEditor(), new int[0]);
+    int[] toIgnore = passes.stream().mapToInt(TextEditorHighlightingPass::getId).toArray();
+    int i = ArrayUtil.find(toIgnore, Pass.LOCAL_INSPECTIONS);
+    toIgnore[i] = 0; // ignore everything except Pass.LOCAL_INSPECTIONS
+
+    return CodeInsightTestFixtureImpl.instantiateAndRun(myFixture.getFile(), myFixture.getEditor(), toIgnore, false);
   }
 }