Refactor PackageParts: add explicit mutating methods

compiler/backend/src/org/jetbrains/kotlin/codegen/ClassFileFactory.java

@@ -21,8 +21,6 @@ import com.intellij.psi.PsiFile;
 import com.intellij.util.Function;
 import com.intellij.util.containers.ContainerUtil;
 import kotlin.collections.CollectionsKt;
-import kotlin.collections.MapsKt;
-import kotlin.jvm.functions.Function0;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.annotations.TestOnly;
@@ -188,17 +186,17 @@ public class ClassFileFactory implements OutputFileCollection {
         return new PackagePartRegistry() {
             @Override
             public void addPart(@NotNull String partShortName) {
-                MapsKt.getOrPut(partsGroupedByPackage, packageFqNameAsString, new Function0<PackageParts>() {
-                    @Override
-                    public PackageParts invoke() {
-                        return new PackageParts(packageFqNameAsString);
-                    }
-                }).getParts().add(partShortName);
+                PackageParts packageParts = partsGroupedByPackage.get(packageFqNameAsString);
+                if (packageParts == null) {
+                    packageParts = new PackageParts(packageFqNameAsString);
+                    partsGroupedByPackage.put(packageFqNameAsString, packageParts);
+                }
+                packageParts.addPart(partShortName);
             }
         };
     }
 
-    public void registerPackagePartSourceFiles(Collection<KtFile> files) {
+    private void registerPackagePartSourceFiles(Collection<KtFile> files) {
         packagePartSourceFiles.addAll(toIoFilesIgnoringNonPhysical(PackagePartClassUtils.getFilesWithCallables(files)));
     }
 

compiler/backend/src/org/jetbrains/kotlin/codegen/classFileUtils.kt

@@ -42,20 +42,18 @@ private fun Iterable<PackageParts>.addCompiledParts(state: GenerationState): Lis
 
     val mapping = ModuleMapping.create(moduleMappingData, "<incremental>")
 
-    incrementalCache.getObsoletePackageParts().forEach {
-        val i = it.lastIndexOf('/')
-        val qualifier = if (i == -1) "" else it.substring(0, i).replace('/', '.')
-        val name = it.substring(i + 1)
-        mapping.findPackageParts(qualifier)?.run { parts.remove(name) }
+    incrementalCache.getObsoletePackageParts().forEach { internalName ->
+        val qualifier = internalName.substringBeforeLast('/', "").replace('/', '.')
+        val name = internalName.substringAfterLast('/')
+        mapping.findPackageParts(qualifier)?.removePart(name)
     }
 
     return (this + mapping.packageFqName2Parts.values)
             .groupBy { it.packageFqName }
-            .map {
-                val (packageFqName, packageParts) = it
-                val newPackageParts = PackageParts(packageFqName)
-                packageParts.forEach { newPackageParts.parts.addAll(it.parts) }
-                newPackageParts
+            .map { (packageFqName, allOldPackageParts) ->
+                PackageParts(packageFqName).apply {
+                    allOldPackageParts.forEach { packageParts -> this += packageParts }
+                }
             }
 }