FIR: remove extra layers of caching above JavaSymbolProvider

There needs to be exactly one postcompute-aware cache in order to avoid
breaking recursive calls to getClassLikeSymbolByFqName.

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/providers/FirThreadSafeSymbolProviderWrapper.kt

@@ -1,89 +0,0 @@
-/*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.idea.fir.low.level.api.providers
-
-import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProvider
-import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProviderInternals
-import org.jetbrains.kotlin.name.CallableId
-import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
-import org.jetbrains.kotlin.idea.fir.low.level.api.annotations.PrivateForInline
-import org.jetbrains.kotlin.name.ClassId
-import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.name.Name
-import java.util.concurrent.locks.ReadWriteLock
-import java.util.concurrent.locks.ReentrantReadWriteLock
-import kotlin.concurrent.withLock
-
-internal class FirThreadSafeSymbolProviderWrapper(private val provider: FirSymbolProvider) : FirSymbolProvider(provider.session) {
-    private val lock = ReentrantReadWriteLock()
-    private val classesCache = ThreadSafeCache<ClassId, FirClassLikeSymbol<*>>(lock)
-    private val topLevelCache = ThreadSafeCache<CallableId, List<FirCallableSymbol<*>>>(lock)
-    private val packages = ThreadSafeCache<FqName, FqName>(lock)
-
-    override fun getClassLikeSymbolByFqName(classId: ClassId): FirClassLikeSymbol<*>? =
-        classesCache.getOrCompute(classId) {
-            provider.getClassLikeSymbolByFqName(classId)
-        }
-
-    override fun getTopLevelCallableSymbols(packageFqName: FqName, name: Name): List<FirCallableSymbol<*>> =
-        topLevelCache.getOrCompute(CallableId(packageFqName, name)) {
-            provider.getTopLevelCallableSymbols(packageFqName, name)
-        } ?: emptyList()
-
-    override fun getTopLevelFunctionSymbols(packageFqName: FqName, name: Name): List<FirNamedFunctionSymbol> {
-        return getTopLevelCallableSymbols(packageFqName, name).filterIsInstance<FirNamedFunctionSymbol>()
-    }
-
-    override fun getTopLevelPropertySymbols(packageFqName: FqName, name: Name): List<FirPropertySymbol> {
-        return getTopLevelCallableSymbols(packageFqName, name).filterIsInstance<FirPropertySymbol>()
-    }
-
-    @FirSymbolProviderInternals
-    override fun getTopLevelCallableSymbolsTo(destination: MutableList<FirCallableSymbol<*>>, packageFqName: FqName, name: Name) {
-        error("Should not be called for wrapper")
-    }
-
-    @FirSymbolProviderInternals
-    override fun getTopLevelFunctionSymbolsTo(destination: MutableList<FirNamedFunctionSymbol>, packageFqName: FqName, name: Name) {
-        destination += getTopLevelFunctionSymbols(packageFqName, name)
-    }
-
-    @FirSymbolProviderInternals
-    override fun getTopLevelPropertySymbolsTo(destination: MutableList<FirPropertySymbol>, packageFqName: FqName, name: Name) {
-        destination += getTopLevelPropertySymbols(packageFqName, name)
-    }
-
-    override fun getPackage(fqName: FqName): FqName? =
-        packages.getOrCompute(fqName) { provider.getPackage(fqName) }
-}
-
-private class ThreadSafeCache<KEY, VALUE : Any>(private val lock: ReadWriteLock) {
-    private val map = HashMap<KEY, Any>()
-
-    @OptIn(PrivateForInline::class)
-    inline fun getOrCompute(key: KEY, compute: () -> VALUE?): VALUE? {
-        var value = lock.readLock().withLock { map[key] }
-        if (value == null) {
-            lock.writeLock().withLock {
-                value = compute() ?: NULLABLE_VALUE
-                map[key] = value!!
-            }
-        }
-        @Suppress("UNCHECKED_CAST")
-        return when (value) {
-            NULLABLE_VALUE -> null
-            null -> error("We should not read null from map here")
-            else -> value as VALUE
-        }
-    }
-}
-
-@Suppress("ClassName")
-@PrivateForInline
-internal object NULLABLE_VALUE

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/sessions/FirIdeSessionFactory.kt

@@ -46,7 +46,6 @@ import org.jetbrains.kotlin.idea.fir.low.level.api.providers.FirIdeBuiltinsAndCl
 import org.jetbrains.kotlin.idea.fir.low.level.api.providers.FirIdeLibrariesSessionProvider
 import org.jetbrains.kotlin.idea.fir.low.level.api.providers.FirIdeProvider
 import org.jetbrains.kotlin.idea.fir.low.level.api.providers.FirModuleWithDependenciesSymbolProvider
-import org.jetbrains.kotlin.idea.fir.low.level.api.providers.FirThreadSafeSymbolProviderWrapper
 import org.jetbrains.kotlin.idea.fir.low.level.api.util.checkCanceled
 import org.jetbrains.kotlin.load.java.JavaClassFinder
 import org.jetbrains.kotlin.load.java.JavaClassFinderImpl
@@ -197,8 +196,6 @@ internal object FirIdeSessionFactory {
             registerCommonJavaComponents()
             registerJavaSpecificResolveComponents()
 
-            val javaSymbolProvider = JavaSymbolProvider(this, mainModuleData, project, searchScope)
-
             val kotlinScopeProvider = FirKotlinScopeProvider(::wrapScopeWithJvmMapped)
 
             val moduleDataProvider = project.stateConfigurator.createModuleDataProvider(mainModuleInfo)
@@ -210,19 +207,16 @@ internal object FirIdeSessionFactory {
                 @OptIn(ExperimentalStdlibApi::class)
                 buildList {
                     add(
-                        FirThreadSafeSymbolProviderWrapper(
-                            KotlinDeserializedJvmSymbolsProviderForIde(
-                                this@session,
-                                moduleDataProvider,
-                                kotlinScopeProvider,
-                                packagePartProvider,
-                                kotlinClassFinder,
-                                javaSymbolProvider,
-                                javaClassFinder
-                            )
+                        KotlinDeserializedJvmSymbolsProviderForIde(
+                            this@session,
+                            moduleDataProvider,
+                            kotlinScopeProvider,
+                            packagePartProvider,
+                            kotlinClassFinder,
+                            javaClassFinder
                         )
                     )
-                    add(javaSymbolProvider)
+                    add(JavaSymbolProvider(this@session, mainModuleData, project, searchScope))
                     addAll((builtinsAndCloneableSession.symbolProvider as FirCompositeSymbolProvider).providers)
                 }
             )
@@ -244,11 +238,10 @@ internal object FirIdeSessionFactory {
         kotlinScopeProvider: FirKotlinScopeProvider,
         packagePartProvider: PackagePartProvider,
         kotlinClassFinder: KotlinClassFinder,
-        javaSymbolProvider: JavaSymbolProvider,
         javaClassFinder: JavaClassFinder
     ) : KotlinDeserializedJvmSymbolsProvider(
         session, moduleDataProvider, kotlinScopeProvider, packagePartProvider, kotlinClassFinder,
-        javaSymbolProvider, javaClassFinder
+        javaClassFinder
     ) {
         override fun getClass(
             classId: ClassId,