More efficient filtering of runtime receiver type variants in debugger

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

@@ -55,6 +55,7 @@ import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
 import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
 import org.jetbrains.kotlin.util.capitalizeDecapitalize.decapitalizeSmart
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstance
+import java.util.*
 
 class CompletionSessionConfiguration(
         val completeNonImportedDeclarations: Boolean,
@@ -337,12 +338,26 @@ abstract class CompletionSession(protected val configuration: CompletionSessionC
         if (runtimeType == null || runtimeType == type) return null
 
         val (variants, notImportedExtensions) = collectReferenceVariants(descriptorKindFilter!!, ExpressionReceiver(explicitReceiver, runtimeType))
-        val normalVariants = referenceVariants!!.imported + referenceVariants!!.notImportedExtensions
+        val filteredVariants = filterVariantsForRuntimeReceiverType(variants, referenceVariants!!.imported)
-        val filteredVariants = variants.filter { descriptor -> normalVariants.none { compareDescriptors(project, it, descriptor) } }
+        val filteredNotImportedExtensions = filterVariantsForRuntimeReceiverType(notImportedExtensions, referenceVariants!!.notImportedExtensions)
-        val filteredNotImportedExtensions = notImportedExtensions.filter { descriptor -> normalVariants.none { compareDescriptors(project, it, descriptor) } }
         return ReferenceVariants(filteredVariants, filteredNotImportedExtensions)
     }
 
+    private fun <TDescriptor : DeclarationDescriptor> filterVariantsForRuntimeReceiverType(
+            runtimeVariants: Collection<TDescriptor>,
+            baseVariants: Collection<TDescriptor>
+    ): Collection<TDescriptor> {
+        val baseVariantsByName = baseVariants.groupBy { it.name }
+        val result = ArrayList<TDescriptor>()
+        for (variant in runtimeVariants) {
+            val candidates = baseVariantsByName[variant.name]
+            if (candidates == null || candidates.none { compareDescriptors(project, variant, it) }) {
+                result.add(variant)
+            }
+        }
+        return result
+    }
+
     protected fun shouldCompleteTopLevelCallablesFromIndex(): Boolean {
         if (!configuration.completeNonImportedDeclarations) return false
         if ((descriptorKindFilter?.kindMask ?: 0).and(DescriptorKindFilter.CALLABLES_MASK) == 0) return false

idea/idea-completion/testData/basic/codeFragments/runtimeType/runtimeCast.kt

@@ -8,16 +8,25 @@ open class Base {
 
     open fun funWithOverride() { }
     open fun funWithoutOverride() { }
+
+    fun funInBoth() { }
 }
 
 class Derived: Base() {
     fun funInDerived() { }
 
     override fun funWithOverride() { }
+
+    fun funInBoth(p: Int) { }
 }
 
 // INVOCATION_COUNT: 1
-// EXIST: funInBase, funWithOverride, funWithoutOverride, funInDerived
+// EXIST: funInBase
+// EXIST: funWithOverride
+// EXIST: funWithoutOverride
+// EXIST: funInDerived
+// EXIST: { itemText: "funInBoth", tailText: "()", attributes: "bold" }
+// EXIST: { itemText: "funInBoth", tailText: "(p: Int)", attributes: "grayed" }
 // NOTHING_ELSE