From dd3dbda719e9f23a332ba1de2f41af62642e19dd Mon Sep 17 00:00:00 2001
From: Denis Zharkov <denis.zharkov@jetbrains.com>
Date: Mon, 27 Nov 2017 17:52:55 +0300
Subject: [PATCH] Optimize computation of default excluded import in IDE

Prior to this change, it was rather slow since it would lead
to a ModuleDescriptor::packageFragmentProviderForWholeModuleWithDependencies
computation, that would force the computation of libraries'
dependencies, that actually was the major bottleneck here.

The idea is that we do not need to search through dependencies
of dependencies, but only need contents of one of the modules
direct content.

This commit is made under the assumption that if a module has may see
some runtime parts, than runtime jar should be among its direct
depenencies.
---
 .../resolve/lazy/DefaultImportProvider.kt     | 37 ++++++++++++++-----
 .../descriptors/impl/ModuleDescriptorImpl.kt  | 10 ++++-
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DefaultImportProvider.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DefaultImportProvider.kt
index da32d870059..57013e25935 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DefaultImportProvider.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/DefaultImportProvider.kt
@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.config.LanguageFeature.DefaultImportOfPackageKotlinC
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
+import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.isChildOf
 import org.jetbrains.kotlin.name.isSubpackageOf
@@ -38,20 +39,38 @@ class DefaultImportProvider(
         private val targetPlatform: TargetPlatform,
         private val languageVersionSettings: LanguageVersionSettings
 ) {
+    companion object {
+        private val PACKAGES_WITH_ALIASES = listOf(KotlinBuiltIns.BUILT_INS_PACKAGE_FQ_NAME, KotlinBuiltIns.TEXT_PACKAGE_FQ_NAME)
+
+        private fun ModuleDescriptor.findTypeAliasesInPackages(packages: Collection<FqName>): Collection<TypeAliasDescriptor> {
+            val result = mutableListOf<TypeAliasDescriptor>()
+
+            for (dependencyModuleDescriptor in allDependencyModules) {
+                if (dependencyModuleDescriptor !is ModuleDescriptorImpl) continue
+
+                for (packageFqName in packages) {
+                    dependencyModuleDescriptor.packageFragmentProviderForContent.getPackageFragments(packageFqName)
+                            .flatMapTo(result) {
+                                packageFragmentDescriptor ->
+                                packageFragmentDescriptor.getMemberScope()
+                                        .getContributedDescriptors(DescriptorKindFilter.TYPE_ALIASES)
+                                        .filterIsInstance<TypeAliasDescriptor>()
+                            }
+                }
+            }
+
+            return result
+        }
+    }
+
     val defaultImports: List<ImportPath> by storageManager.createLazyValue {
         targetPlatform.getDefaultImports(languageVersionSettings.supportsFeature(DefaultImportOfPackageKotlinComparisons))
     }
 
     val excludedImports: List<FqName> by storageManager.createLazyValue {
-        val packagesWithAliases = listOf(KotlinBuiltIns.BUILT_INS_PACKAGE_FQ_NAME, KotlinBuiltIns.TEXT_PACKAGE_FQ_NAME)
-        val builtinTypeAliases = moduleDescriptor.allDependencyModules
-                .flatMap { dependencyModule ->
-                    packagesWithAliases.map(dependencyModule::getPackage).flatMap {
-                        it.memberScope.getContributedDescriptors(DescriptorKindFilter.TYPE_ALIASES).filterIsInstance<TypeAliasDescriptor>()
-                    }
-                }
-                .filter { it.checkSinceKotlinVersionAccessibility(languageVersionSettings) }
-
+        val builtinTypeAliases =
+                moduleDescriptor.findTypeAliasesInPackages(PACKAGES_WITH_ALIASES)
+                        .filter { it.checkSinceKotlinVersionAccessibility(languageVersionSettings) }
 
         val nonKotlinDefaultImportedPackages =
                 defaultImports
diff --git a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt
index 38c30f9852c..e7c6862df9f 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt
@@ -132,6 +132,14 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
             return packageFragmentProviderForWholeModuleWithDependencies
         }
 
+    val packageFragmentProviderForContent: PackageFragmentProvider
+        get() {
+            assertValid()
+            return packageFragmentProviderForModuleContent.sure {
+                "Module $id was not initialized by the time packageFragmentProviderForContent was requested"
+            }
+        }
+
     @Suppress("UNCHECKED_CAST")
     override fun <T> getCapability(capability: ModuleDescriptor.Capability<T>) = capabilities[capability] as? T
 }
@@ -144,4 +152,4 @@ interface ModuleDependencies {
 class ModuleDependenciesImpl(
         override val allDependencies: List<ModuleDescriptorImpl>,
         override val modulesWhoseInternalsAreVisible: Set<ModuleDescriptorImpl>
-) : ModuleDependencies
\ No newline at end of file
+) : ModuleDependencies