From c5005f8695dfdbfd759cedc1dd7fae89bb922d86 Mon Sep 17 00:00:00 2001
From: Simon Ogorodnik <simon.ogorodnik@jetbrains.com>
Date: Fri, 17 Jul 2020 23:03:27 +0300
Subject: [PATCH] J2K: Speed-up add imports

---
 .../kotlin/nj2k/NewJavaToKotlinConverter.kt   | 23 ++++++++++++-------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/nj2k/src/org/jetbrains/kotlin/nj2k/NewJavaToKotlinConverter.kt b/nj2k/src/org/jetbrains/kotlin/nj2k/NewJavaToKotlinConverter.kt
index 7e9b501ed63..8cf95adf5fe 100644
--- a/nj2k/src/org/jetbrains/kotlin/nj2k/NewJavaToKotlinConverter.kt
+++ b/nj2k/src/org/jetbrains/kotlin/nj2k/NewJavaToKotlinConverter.kt
@@ -92,14 +92,21 @@ class NewJavaToKotlinConverter(
 
     private fun KtFile.addImports(imports: Collection<FqName>) {
         val factory = KtPsiFactory(this)
-        var importList = importList
-        for (import in imports) {
-            val importDirective = factory.createImportDirective(ImportPath(import, isAllUnder = false))
-            if (importList == null) {
-                importList = addImportList(importDirective.parent as KtImportList)
-            } else {
-                importList.add(importDirective)
-            }
+
+
+        if (imports.isEmpty()) return
+        val importPsi = factory.createImportDirectives(
+            imports.map { ImportPath(it, isAllUnder = false) }
+        )
+        val createdImportList = importPsi.first().parent as KtImportList
+        val importList = importList
+        if (importList == null) {
+            addImportList(createdImportList)
+        } else {
+            val updatedList = if(importList.firstChild != null) {
+                createdImportList.addRangeBefore(importList.firstChild, importList.lastChild, createdImportList.firstChild)
+            } else createdImportList
+            importList.replace(updatedList)
         }
     }