Optimization in completion: don't spend too much time calculating root packages

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/BasicCompletionSession.kt

@@ -19,12 +19,17 @@ package org.jetbrains.kotlin.idea.completion
 import com.intellij.codeInsight.completion.*
 import com.intellij.patterns.PatternCondition
 import com.intellij.patterns.StandardPatterns
+import com.intellij.psi.JavaPsiFacade
 import com.intellij.psi.util.PsiTreeUtil
 import com.intellij.util.ProcessingContext
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.idea.project.ProjectStructureUtil
+import org.jetbrains.kotlin.idea.stubindex.PackageIndexUtil
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.getNonStrictParentOfType
 import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
@@ -70,7 +75,10 @@ class BasicCompletionSession(configuration: CompletionSessionConfiguration,
 
     private val completionKind = calcCompletionKind()
 
-    override val descriptorKindFilter = completionKind.descriptorKindFilter
+    override val descriptorKindFilter = if (isNoQualifierContext())
+        completionKind.descriptorKindFilter?.withoutKinds(DescriptorKindFilter.PACKAGES_MASK)
+    else
+        completionKind.descriptorKindFilter
 
     private val parameterNameAndTypeCompletion = if (shouldCompleteParameterNameAndType())
         ParameterNameAndTypeCompletion(collector, lookupElementFactory, prefixMatcher, resolutionFacade)
@@ -193,6 +201,26 @@ class BasicCompletionSession(configuration: CompletionSessionConfiguration,
                 }
             }
 
+            // getting root packages from scope is very slow so we do this in alternative way
+            if (isNoQualifierContext() && (completionKind.descriptorKindFilter?.kindMask ?: 0).and(DescriptorKindFilter.PACKAGES_MASK) != 0) {
+                //TODO: move this code somewhere else
+                //TODO: filter by prefix for better performance?
+                val packageNames = PackageIndexUtil.getSubPackageFqNames(FqName.ROOT, originalSearchScope, project)
+                        .map { it.shortName() }
+                        .toMutableSet()
+
+                if (!ProjectStructureUtil.isJsKotlinModule(parameters.getOriginalFile() as JetFile)) {
+                    JavaPsiFacade.getInstance(project).findPackage("")?.getSubPackages(originalSearchScope)?.forEach { psiPackage ->
+                        val name = psiPackage.getName()
+                        if (Name.isValidIdentifier(name!!)) {
+                            packageNames.add(Name.identifier(name))
+                        }
+                    }
+                }
+
+                packageNames.forEach { collector.addElement(lookupElementFactory.createLookupElementForPackage(it)) }
+            }
+
             if (completionKind != CompletionKind.KEYWORDS_ONLY) {
                 flushToResultSet()
 

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionSession.kt

@@ -238,7 +238,8 @@ abstract class CompletionSession(protected val configuration: CompletionSessionC
     }
 
     protected fun getRuntimeReceiverTypeReferenceVariants(): Collection<DeclarationDescriptor> {
-        val descriptors = referenceVariantsHelper.getReferenceVariants(nameExpression!!, descriptorKindFilter!!, prefixMatcher.asNameFilter(), useRuntimeReceiverType = true)
+        val restrictedKindFilter = descriptorKindFilter!!.restrictedToKinds(DescriptorKindFilter.FUNCTIONS_MASK or DescriptorKindFilter.VARIABLES_MASK) // optimization
+        val descriptors = referenceVariantsHelper.getReferenceVariants(nameExpression!!, restrictedKindFilter, prefixMatcher.asNameFilter(), useRuntimeReceiverType = true)
         return descriptors.filter { descriptor ->
             referenceVariants.none { comparePossiblyOverridingDescriptors(project, it, descriptor) }
         }

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionSorting.kt

@@ -143,11 +143,10 @@ private class DeclarationRemotenessWeigher(private val file: JetFile) : LookupEl
             return Weight.thisFile
         }
 
-        val qualifiedName = o.qualifiedName()
+        val fqName = o.importableFqName
         // Invalid name can be met for companion object descriptor: Test.MyTest.A.<no name provided>.testOther
-        if (qualifiedName != null && isValidJavaFqName(qualifiedName)) {
-            val importPath = ImportPath(qualifiedName)
-            val fqName = importPath.fqnPart()
+        if (fqName != null) {
+            val importPath = ImportPath(fqName, false)
             return when {
                 JavaToKotlinClassMap.INSTANCE.mapPlatformClass(fqName).isNotEmpty() -> Weight.notToBeUsedInKotlin
                 ImportInsertHelper.getInstance(file.getProject()).isImportedWithDefault(importPath, file) -> Weight.kotlinDefaultImport

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/DeclarationLookupObjectImpl.kt

@@ -18,12 +18,17 @@ package org.jetbrains.kotlin.idea.completion
 
 import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.util.Iconable
+import com.intellij.psi.PsiClass
 import com.intellij.psi.PsiDocCommentOwner
 import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiNamedElement
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.idea.caches.resolve.ResolutionFacade
 import org.jetbrains.kotlin.idea.core.completion.DeclarationLookupObject
+import org.jetbrains.kotlin.idea.imports.importableFqName
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.util.descriptorsEqualWithSubstitution
 import javax.swing.Icon
 
@@ -40,6 +45,17 @@ public abstract class DeclarationLookupObjectImpl(
         assert(descriptor != null || psiElement != null)
     }
 
+    override val name: Name?
+        get() = descriptor?.getName() ?: (psiElement as? PsiNamedElement)?.getName()?.let { Name.identifier(it) }
+
+    override val importableFqName: FqName?
+        get() {
+            return if (descriptor != null)
+                descriptor.importableFqName
+            else
+                (psiElement as? PsiClass)?.getQualifiedName()?.let { FqName(it) }
+        }
+
     override fun toString() = super<DeclarationLookupObject>.toString() + " " + (descriptor ?: psiElement)
 
     override fun hashCode(): Int {

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/KotlinExcludeFromCompletionLookupActionProvider.kt

@@ -35,16 +35,10 @@ public class KotlinExcludeFromCompletionLookupActionProvider : LookupActionProvi
 
         val project = lookup.getPsiFile().getProject()
 
-        lookupObject.descriptor?.importableFqName?.let {
+        lookupObject.importableFqName?.let {
             addExcludes(consumer, project, it.asString())
             return
         }
-
-        val psiElement = lookupObject.psiElement
-        if (psiElement is PsiClass) {
-            val qualifiedName = psiElement.getQualifiedName() ?: return
-            addExcludes(consumer, project, qualifiedName)
-        }
     }
 
     private fun addExcludes(consumer: Consumer<LookupElementAction>, project: Project, fqName: String) {

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/LookupElementFactory.kt

@@ -21,15 +21,18 @@ import com.intellij.codeInsight.lookup.*
 import com.intellij.codeInsight.lookup.impl.LookupCellRenderer
 import com.intellij.psi.PsiClass
 import com.intellij.psi.PsiElement
+import com.intellij.util.PlatformIcons
 import org.jetbrains.kotlin.asJava.KotlinLightClass
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.idea.JetDescriptorIconProvider
 import org.jetbrains.kotlin.idea.caches.resolve.ResolutionFacade
 import org.jetbrains.kotlin.idea.completion.handlers.*
+import org.jetbrains.kotlin.idea.core.completion.DeclarationLookupObject
 import org.jetbrains.kotlin.types.typeUtil.TypeNullability
 import org.jetbrains.kotlin.types.typeUtil.nullability
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.psiUtil.parents
 import org.jetbrains.kotlin.renderer.DescriptorRenderer
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
@@ -37,6 +40,7 @@ import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.synthetic.SyntheticJavaBeansPropertyDescriptor
 import org.jetbrains.kotlin.types.JetType
 import org.jetbrains.kotlin.types.TypeUtils
+import javax.swing.Icon
 
 public class LookupElementFactory(
         private val resolutionFacade: ResolutionFacade,
@@ -137,6 +141,24 @@ public class LookupElementFactory(
         return element.withIconFromLookupObject()
     }
 
+    public fun createLookupElementForPackage(shortName: Name): LookupElement {
+        return LookupElementBuilder.create(PackageLookupObject(shortName), shortName.asString())
+                .withInsertHandler(BaseDeclarationInsertHandler())
+                .withIconFromLookupObject()
+    }
+
+    private data class PackageLookupObject(override val name: Name) : DeclarationLookupObject {
+        override val psiElement: PsiElement? get() = null
+
+        override val descriptor: DeclarationDescriptor? get() = null
+
+        override val importableFqName: FqName? get() = null
+
+        override val isDeprecated: Boolean get() = false
+
+        override fun getIcon(flags: Int) = PlatformIcons.PACKAGE_ICON
+    }
+
     private fun createLookupElement(
             descriptor: DeclarationDescriptor,
             declaration: PsiElement?,
@@ -152,6 +174,10 @@ public class LookupElementFactory(
             return createLookupElementForJavaClass(declaration, qualifyNestedClasses, includeClassTypeArguments)
         }
 
+        if (descriptor is PackageViewDescriptor || descriptor is PackageFragmentDescriptor) {
+            return createLookupElementForPackage(descriptor.getName())
+        }
+
         // for constructor use name and icon of containing class
         val nameAndIconDescriptor: DeclarationDescriptor
         val iconDeclaration: PsiElement?

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/handlers/BaseDeclarationInsertHandler.kt

@@ -26,9 +26,8 @@ import org.jetbrains.kotlin.renderer.render
 
 open class BaseDeclarationInsertHandler : InsertHandler<LookupElement> {
     override fun handleInsert(context: InsertionContext, item: LookupElement) {
-        val descriptor = (item.getObject() as? DeclarationLookupObject)?.descriptor
-        if (descriptor != null) {
-            val name = descriptor.getName()
+        val name = (item.getObject() as? DeclarationLookupObject)?.name
+        if (name != null) {
             val nameInCode = name.render()
             val document = context.getDocument()
             val needEscaping = nameInCode != name.asString()

idea/idea-core/src/org/jetbrains/kotlin/idea/core/completion/DeclarationLookupObject.kt

@@ -19,9 +19,13 @@ package org.jetbrains.kotlin.idea.core.completion
 import com.intellij.openapi.util.Iconable
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 
 public interface DeclarationLookupObject : Iconable {
     public val psiElement: PsiElement?
     public val descriptor: DeclarationDescriptor?
+    public val name: Name?
+    public val importableFqName: FqName?
     public val isDeprecated: Boolean
 }