From 3515cd546d44a3b406aa61f8bcfa96d19c5b3a99 Mon Sep 17 00:00:00 2001
From: Ilya Kirillov <ilya.kirillov@jetbrains.com>
Date: Fri, 27 Nov 2020 14:15:44 +0100
Subject: [PATCH] FIR IDE: use PersistentMap to store
 FromModuleViewSessionCache mappings

Needed to ensure safe pub of map
---
 .../low/level/api/sessions/FirIdeSessionProviderStorage.kt | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/sessions/FirIdeSessionProviderStorage.kt b/idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/sessions/FirIdeSessionProviderStorage.kt
index 1c11d3e546c..e72bf246b58 100644
--- a/idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/sessions/FirIdeSessionProviderStorage.kt
+++ b/idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/sessions/FirIdeSessionProviderStorage.kt
@@ -7,6 +7,9 @@ package org.jetbrains.kotlin.idea.fir.low.level.api.sessions
 
 import com.intellij.openapi.components.service
 import com.intellij.openapi.project.Project
+import kotlinx.collections.immutable.PersistentMap
+import kotlinx.collections.immutable.persistentMapOf
+import kotlinx.collections.immutable.toPersistentMap
 import org.jetbrains.kotlin.fir.BuiltinTypes
 import org.jetbrains.kotlin.idea.caches.project.ModuleSourceInfo
 import org.jetbrains.kotlin.idea.fir.low.level.api.FirPhaseRunner
@@ -50,7 +53,7 @@ private class FromModuleViewSessionCache(
     val root: ModuleSourceInfo,
 ) {
     @Volatile
-    private var mappings: Map<ModuleSourceInfo, FirSessionWithModificationTracker> = emptyMap()
+    private var mappings: PersistentMap<ModuleSourceInfo, FirSessionWithModificationTracker> = persistentMapOf()
 
     val sessionInvalidator: FirSessionInvalidator = FirSessionInvalidator { session ->
         mappings[session.moduleInfo]?.invalidate()
@@ -61,7 +64,7 @@ private class FromModuleViewSessionCache(
         action: (Map<ModuleSourceInfo, FirIdeSourcesSession>) -> Pair<Map<ModuleSourceInfo, FirIdeSourcesSession>, R>
     ): Pair<Map<ModuleSourceInfo, FirIdeSourcesSession>, R> {
         val (newMappings, result) = action(getSessions().mapValues { it.value })
-        mappings = newMappings.mapValues { FirSessionWithModificationTracker(it.value) }
+        mappings = newMappings.mapValues { FirSessionWithModificationTracker(it.value) }.toPersistentMap()
         return newMappings to result
     }