optimization: return LocalSearchScope.EMPTY instead of GlobalSearchScope.EMPTY_SCOPE explicitly to avoid unnecessary FileBasedIndex accesses during search

GitOrigin-RevId: b7cf8f4b4dec2f79f2231b97b091cc0ed7978473

java/java-impl/src/com/intellij/ide/util/scopeChooser/ClassHierarchyScopeDescriptor.java

@@ -15,7 +15,6 @@ import com.intellij.psi.PsiClass;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.presentation.java.ClassPresentationUtil;
-import com.intellij.psi.search.GlobalSearchScope;
 import com.intellij.psi.search.LocalSearchScope;
 import com.intellij.psi.search.SearchScope;
 import com.intellij.psi.search.searches.ClassInheritorsSearch;
@@ -66,8 +65,9 @@ public class ClassHierarchyScopeDescriptor extends ScopeDescriptor {
 
       PsiClass aClass = chooser.getSelected();
       if (aClass == null) {
-        myCachedScope = GlobalSearchScope.EMPTY_SCOPE;
+        myCachedScope = LocalSearchScope.EMPTY;
-      } else {
+      }
+      else {
         final List<PsiElement> classesToSearch = new LinkedList<>();
         classesToSearch.add(aClass);
 

java/java-indexing-api/src/com/intellij/psi/search/searches/MethodReferencesSearch.java

@@ -86,7 +86,7 @@ public final class MethodReferencesSearch extends ExtensibleQueryFactory<PsiRefe
     public SearchScope getEffectiveSearchScope () {
       SearchScope scope = myEffectiveScope;
       if (scope == null) {
-        if (!myMethod.isValid()) return GlobalSearchScope.EMPTY_SCOPE;
+        if (!myMethod.isValid()) return LocalSearchScope.EMPTY;
 
         myEffectiveScope = scope = myScope.intersectWith(PsiSearchHelper.getInstance(myMethod.getProject()).getUseScope(myMethod));
       }

java/java-indexing-impl/src/com/intellij/psi/impl/search/AllClassesSearchExecutor.java

@@ -24,7 +24,7 @@ public class AllClassesSearchExecutor implements QueryExecutor<PsiClass, AllClas
   public boolean execute(@NotNull final AllClassesSearch.SearchParameters queryParameters, @NotNull final Processor<? super PsiClass> consumer) {
     SearchScope scope = queryParameters.getScope();
 
-    if (scope == GlobalSearchScope.EMPTY_SCOPE) {
+    if (SearchScope.isEmptyScope(scope)) {
       return true;
     }
 

java/java-indexing-impl/src/com/intellij/psi/impl/search/JavaFunctionalExpressionSearcher.java

@@ -49,6 +49,7 @@ import com.intellij.util.containers.MultiMap;
 import com.intellij.util.indexing.FileBasedIndex;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.TestOnly;
 
 import java.util.*;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -59,7 +60,7 @@ public final class JavaFunctionalExpressionSearcher extends QueryExecutorBase<Ps
 
   @Override
   public void processQuery(@NotNull SearchParameters p, @NotNull Processor<? super PsiFunctionalExpression> consumer) {
-    if (ReadAction.compute(() -> p.getEffectiveSearchScope()) == GlobalSearchScope.EMPTY_SCOPE) {
+    if (SearchScope.isEmptyScope(ReadAction.compute(() -> p.getEffectiveSearchScope()))) {
       return;
     }
     Session session = ReadAction.compute(() -> new Session(p, consumer));
@@ -474,7 +475,9 @@ public final class JavaFunctionalExpressionSearcher extends QueryExecutorBase<Ps
       scope = parameters.getEffectiveSearchScope();
     }
 
-    public Set<VirtualFile> getFilesLookedInside() {
+    @NotNull
+    @TestOnly
+    Set<VirtualFile> getFilesLookedInside() {
       return filesLookedInside;
     }
 

java/java-indexing-impl/src/com/intellij/psi/impl/search/MethodUsagesSearcher.java

@@ -44,7 +44,7 @@ public class MethodUsagesSearcher extends QueryExecutorBase<PsiReference, Method
     SearchRequestCollector collector = p.getOptimizer();
 
     SearchScope searchScope = DumbService.getInstance(p.getProject()).runReadActionInSmartMode(p::getEffectiveSearchScope);
-    if (searchScope == GlobalSearchScope.EMPTY_SCOPE) {
+    if (SearchScope.isEmptyScope(searchScope)) {
       return;
     }
 

java/java-indexing-impl/src/com/intellij/psi/impl/search/SimpleAccessorReferenceSearcher.java

@@ -6,10 +6,7 @@ import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiMethod;
 import com.intellij.psi.PsiReference;
-import com.intellij.psi.search.GlobalSearchScope;
+import com.intellij.psi.search.*;
-import com.intellij.psi.search.SearchRequestCollector;
-import com.intellij.psi.search.SearchScope;
-import com.intellij.psi.search.UsageSearchContext;
 import com.intellij.psi.search.searches.ReferencesSearch;
 import com.intellij.psi.util.PropertyUtilBase;
 import com.intellij.util.Processor;
@@ -34,7 +31,7 @@ public class SimpleAccessorReferenceSearcher extends QueryExecutorBase<PsiRefere
   static void addPropertyAccessUsages(@NotNull PsiMethod method, @NotNull SearchScope scope, @NotNull SearchRequestCollector collector) {
     final String propertyName = PropertyUtilBase.getPropertyName(method);
     if (StringUtil.isNotEmpty(propertyName)) {
-      SearchScope additional = GlobalSearchScope.EMPTY_SCOPE;
+      SearchScope additional = LocalSearchScope.EMPTY;
       for (CustomPropertyScopeProvider provider : CustomPropertyScopeProvider.EP_NAME.getExtensionList()) {
         additional = additional.union(provider.getScope(method.getProject()));
       }

platform/analysis-api/src/com/intellij/analysis/AnalysisScope.java

@@ -683,7 +683,7 @@ public class AnalysisScope {
       case FILE:
         return GlobalSearchScope.fileScope((PsiFile)myElement);
       case INVALID:
-        return GlobalSearchScope.EMPTY_SCOPE;
+        return LocalSearchScope.EMPTY;
       case MODULE:
         GlobalSearchScope moduleScope = GlobalSearchScope.moduleScope(myModule);
         return myIncludeTestSource ? moduleScope : GlobalSearchScope.notScope(GlobalSearchScopesCore.projectTestScope(myModule.getProject())).intersectWith(moduleScope);
@@ -710,7 +710,7 @@ public class AnalysisScope {
         };
       default:
         LOG.error("invalid type " + myType);
-        return GlobalSearchScope.EMPTY_SCOPE;
+        return LocalSearchScope.EMPTY;
     }
   }
 

platform/core-api/src/com/intellij/psi/search/DelegatingGlobalSearchScope.java

@@ -111,10 +111,12 @@ public class DelegatingGlobalSearchScope extends GlobalSearchScope {
     return result;
   }
 
+  @NotNull
   public GlobalSearchScope getDelegate() {
     return myBaseScope;
   }
-  
+
+  @NotNull
   public GlobalSearchScope unwrap() {
     return myBaseScope instanceof DelegatingGlobalSearchScope ? ((DelegatingGlobalSearchScope)myBaseScope).unwrap() : myBaseScope;
   }

platform/core-api/src/com/intellij/psi/search/GlobalSearchScope.java

@@ -112,15 +112,14 @@ public abstract class GlobalSearchScope extends SearchScope implements ProjectAw
   @Contract(pure = true)
   public SearchScope intersectWith(@NotNull SearchScope scope2) {
     if (scope2 instanceof LocalSearchScope) {
-      LocalSearchScope localScope2 = (LocalSearchScope)scope2;
+      return intersectWith((LocalSearchScope)scope2);
-      return intersectWith(localScope2);
     }
     return intersectWith((GlobalSearchScope)scope2);
   }
 
   @NotNull
   @Contract(pure = true)
-  public SearchScope intersectWith(@NotNull LocalSearchScope localScope2) {
+  public LocalSearchScope intersectWith(@NotNull LocalSearchScope localScope2) {
     PsiElement[] elements2 = localScope2.getScope();
     List<PsiElement> result = new ArrayList<>(elements2.length);
     for (final PsiElement element2 : elements2) {
@@ -128,7 +127,7 @@ public abstract class GlobalSearchScope extends SearchScope implements ProjectAw
         result.add(element2);
       }
     }
-    return result.isEmpty() ? EMPTY_SCOPE : new LocalSearchScope(result.toArray(PsiElement.EMPTY_ARRAY), null, localScope2.isIgnoreInjectedPsi());
+    return result.isEmpty() ? LocalSearchScope.EMPTY : new LocalSearchScope(result.toArray(PsiElement.EMPTY_ARRAY), null, localScope2.isIgnoreInjectedPsi());
   }
 
   @Override

platform/core-api/src/com/intellij/psi/search/NonClasspathDirectoriesScope.java

@@ -34,12 +34,12 @@ import java.util.Set;
 public class NonClasspathDirectoriesScope extends GlobalSearchScope {
   private final Set<VirtualFile> myRoots;
 
-  public NonClasspathDirectoriesScope(@NotNull Collection<VirtualFile> roots) {
+  public NonClasspathDirectoriesScope(@NotNull Collection<? extends VirtualFile> roots) {
     myRoots = new HashSet<>(roots);
   }
 
   @NotNull
-  public static GlobalSearchScope compose(@NotNull List<VirtualFile> roots) {
+  public static GlobalSearchScope compose(@NotNull List<? extends VirtualFile> roots) {
     if (roots.isEmpty()) {
       return EMPTY_SCOPE;
     }

platform/core-api/src/com/intellij/psi/search/SearchScope.java

@@ -64,4 +64,11 @@ public abstract class SearchScope {
 
   @Contract(pure = true)
   public abstract boolean contains(@NotNull VirtualFile file);
+
+  /**
+   * @return true if the scope is a special constant denoting an empty GlobalSearchScope or LocalSearchScope
+   */
+  public static boolean isEmptyScope(@NotNull SearchScope scope) {
+    return scope == GlobalSearchScope.EMPTY_SCOPE || scope == LocalSearchScope.EMPTY;
+  }
 }

platform/indexing-api/src/com/intellij/psi/search/SearchRequestCollector.java

@@ -129,7 +129,7 @@ public class SearchRequestCollector {
     if (searchScope instanceof LocalSearchScope && ((LocalSearchScope)searchScope).getScope().length == 0) {
       return false;
     }
-    return searchScope != GlobalSearchScope.EMPTY_SCOPE && !StringUtil.isEmpty(word);
+    return !SearchScope.isEmptyScope(searchScope) && !StringUtil.isEmpty(word);
   }
 
   public void searchQuery(@NotNull QuerySearchRequest request) {

platform/indexing-api/src/com/intellij/psi/search/searches/ReferencesSearch.java

@@ -107,7 +107,7 @@ public final class ReferencesSearch extends ExtensibleQueryFactory<PsiReference,
 
       SearchScope scope = myEffectiveScope;
       if (scope == null) {
-        if (!myElementToSearch.isValid()) return GlobalSearchScope.EMPTY_SCOPE;
+        if (!myElementToSearch.isValid()) return LocalSearchScope.EMPTY;
 
         SearchScope useScope = PsiSearchHelper.getInstance(myElementToSearch.getProject()).getUseScope(myElementToSearch);
         myEffectiveScope = scope = myScope.intersectWith(useScope);

platform/indexing-impl/src/com/intellij/model/search/impl/SearchWordQueryBuilderImpl.kt

@@ -9,7 +9,7 @@ import com.intellij.model.search.SearchWordQueryBuilder
 import com.intellij.model.search.TextOccurrence
 import com.intellij.openapi.fileTypes.FileType
 import com.intellij.openapi.project.Project
-import com.intellij.psi.search.GlobalSearchScope
+import com.intellij.psi.search.LocalSearchScope
 import com.intellij.psi.search.PsiSearchScopeUtil.restrictScopeTo
 import com.intellij.psi.search.PsiSearchScopeUtil.restrictScopeToFileLanguage
 import com.intellij.psi.search.SearchScope
@@ -23,7 +23,7 @@ internal data class SearchWordQueryBuilderImpl(
   private val myContainerName: String? = null,
   private val myCaseSensitive: Boolean = true,
   private val mySearchContexts: Set<SearchContext> = emptySet(),
-  private val mySearchScope: SearchScope = GlobalSearchScope.EMPTY_SCOPE,
+  private val mySearchScope: SearchScope = LocalSearchScope.EMPTY,
   private val myFileTypes: Collection<FileType>? = null,
   private val myFileLanguage: LanguageInfo = LanguageInfo.NoLanguage,
   private val myInjection: InjectionInfo = InjectionInfo.NoInjection

platform/lang-impl/src/com/intellij/psi/search/PredefinedSearchScopeProviderImpl.java

@@ -92,13 +92,13 @@ public class PredefinedSearchScopeProviderImpl extends PredefinedSearchScopeProv
 
     result.add(ScratchesSearchScope.getScratchesScope(project));
 
-    GlobalSearchScope recentFilesScope = recentFilesScope(project, false);
+    SearchScope recentFilesScope = recentFilesScope(project, false);
     ContainerUtil.addIfNotNull(
-      result, recentFilesScope != GlobalSearchScope.EMPTY_SCOPE ? recentFilesScope :
+      result, !SearchScope.isEmptyScope(recentFilesScope) ? recentFilesScope :
               showEmptyScopes ? new LocalSearchScope(PsiElement.EMPTY_ARRAY, getRecentlyViewedFilesScopeName()) : null);
-    GlobalSearchScope recentModFilesScope = recentFilesScope(project, true);
+    SearchScope recentModFilesScope = recentFilesScope(project, true);
     ContainerUtil.addIfNotNull(
-      result, recentModFilesScope != GlobalSearchScope.EMPTY_SCOPE ? recentModFilesScope :
+      result, !SearchScope.isEmptyScope(recentModFilesScope) ? recentModFilesScope :
               showEmptyScopes ? new LocalSearchScope(PsiElement.EMPTY_ARRAY, getRecentlyChangedFilesScopeName()) : null);
     GlobalSearchScope openFilesScope = GlobalSearchScopes.openFilesScope(project);
     ContainerUtil.addIfNotNull(
@@ -236,13 +236,13 @@ public class PredefinedSearchScopeProviderImpl extends PredefinedSearchScopeProv
   }
 
   @NotNull
-  public static GlobalSearchScope recentFilesScope(@NotNull Project project, boolean changedOnly) {
+  public static SearchScope recentFilesScope(@NotNull Project project, boolean changedOnly) {
     String name = changedOnly ? getRecentlyChangedFilesScopeName() : getRecentlyViewedFilesScopeName();
     List<VirtualFile> files = changedOnly ? IdeDocumentHistory.getInstance(project).getChangedFiles() :
                               JBIterable.from(EditorHistoryManager.getInstance(project).getFileList())
                                 .append(FileEditorManager.getInstance(project).getOpenFiles()).unique().toList();
 
-    return files.isEmpty() ? GlobalSearchScope.EMPTY_SCOPE : GlobalSearchScope.filesScope(project, files, name);
+    return files.isEmpty() ? LocalSearchScope.EMPTY : GlobalSearchScope.filesScope(project, files, name);
   }
 
   @Nullable

platform/testFramework/src/com/intellij/mock/MockPsiFile.java

@@ -13,6 +13,7 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.source.resolve.FileContextUtil;
 import com.intellij.psi.search.GlobalSearchScope;
+import com.intellij.psi.search.LocalSearchScope;
 import com.intellij.psi.search.PsiElementProcessor;
 import com.intellij.psi.search.SearchScope;
 import com.intellij.testFramework.LightVirtualFile;
@@ -346,7 +347,7 @@ public class MockPsiFile extends MockPsiElement implements PsiFile {
   @Override
   @NotNull
   public SearchScope getUseScope() {
-    return GlobalSearchScope.EMPTY_SCOPE;
+    return LocalSearchScope.EMPTY;
   }
 
   @Override

plugins/gradle/java/src/findUsages/GradlePropertyReferencesSearcher.java

@@ -7,10 +7,7 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiReference;
-import com.intellij.psi.search.DelegatingGlobalSearchScope;
+import com.intellij.psi.search.*;
-import com.intellij.psi.search.GlobalSearchScope;
-import com.intellij.psi.search.RequestResultProcessor;
-import com.intellij.psi.search.UsageSearchContext;
 import com.intellij.psi.search.searches.ReferencesSearch;
 import com.intellij.util.Processor;
 import org.jetbrains.annotations.NotNull;
@@ -41,13 +38,13 @@ public class GradlePropertyReferencesSearcher extends QueryExecutorBase<PsiRefer
         return;
       }
 
-      GlobalSearchScope effectiveSearchScope = (GlobalSearchScope)queryParameters.getEffectiveSearchScope();
+      SearchScope effectiveSearchScope = queryParameters.getEffectiveSearchScope();
-      if (effectiveSearchScope == GlobalSearchScope.EMPTY_SCOPE) {
+      if (SearchScope.isEmptyScope(effectiveSearchScope)) {
         return;
       }
 
       final GlobalSearchScope gradleSearchScope =
-        new FileByExtensionSearchScope(effectiveSearchScope, GRADLE_DSL_EXTENSION);
+        new FileByExtensionSearchScope((GlobalSearchScope)effectiveSearchScope, GRADLE_DSL_EXTENSION);
       final short searchContext = (short)(UsageSearchContext.IN_CODE | UsageSearchContext.IN_STRINGS);
       final MyProcessor processor = new MyProcessor(property);