1 files changed, 74 insertions, 0 deletions
diff --git a/core/commonMain/src/kotlinx/serialization/SerializersCache.kt b/core/commonMain/src/kotlinx/serialization/SerializersCache.kt
new file mode 100644
index 00000000..cc86e435
--- /dev/null
+++ b/core/commonMain/src/kotlinx/serialization/SerializersCache.kt
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2017-2022 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization
+
+import kotlinx.serialization.builtins.nullable
+import kotlinx.serialization.internal.cast
+import kotlinx.serialization.internal.createCache
+import kotlinx.serialization.internal.createParametrizedCache
+import kotlinx.serialization.modules.EmptySerializersModule
+import kotlin.native.concurrent.ThreadLocal
+import kotlin.reflect.KClass
+import kotlin.reflect.KType
+
+
+/**
+ * Cache for non-null non-parametrized and non-contextual serializers.
+ */
+@ThreadLocal
+private val SERIALIZERS_CACHE = createCache { it.serializerOrNull() }
+
+/**
+ * Cache for nullable non-parametrized and non-contextual serializers.
+ */
+@ThreadLocal
+private val SERIALIZERS_CACHE_NULLABLE = createCache<Any?> { it.serializerOrNull()?.nullable?.cast() }
+
+/**
+ * Cache for non-null parametrized and non-contextual serializers.
+ */
+@ThreadLocal
+private val PARAMETRIZED_SERIALIZERS_CACHE = createParametrizedCache { clazz, types ->
+    val serializers = EmptySerializersModule().serializersForParameters(types, true)!!
+    clazz.parametrizedSerializerOrNull(serializers) { types[0].classifier }
+}
+
+/**
+ * Cache for nullable parametrized and non-contextual serializers.
+ */
+@ThreadLocal
+private val PARAMETRIZED_SERIALIZERS_CACHE_NULLABLE = createParametrizedCache<Any?> { clazz, types ->
+    val serializers = EmptySerializersModule().serializersForParameters(types, true)!!
+    clazz.parametrizedSerializerOrNull(serializers) { types[0].classifier }?.nullable?.cast()
+}
+
+/**
+ * Find cacheable serializer in the cache.
+ * If serializer is cacheable but missed in cache - it will be created, placed into the cache and returned.
+ */
+internal fun findCachedSerializer(clazz: KClass<Any>, isNullable: Boolean): KSerializer<Any?>? {
+    return if (!isNullable) {
+        SERIALIZERS_CACHE.get(clazz)?.cast()
+    } else {
+        SERIALIZERS_CACHE_NULLABLE.get(clazz)
+    }
+}
+
+/**
+ * Find cacheable parametrized serializer in the cache.
+ * If serializer is cacheable but missed in cache - it will be created, placed into the cache and returned.
+ */
+internal fun findParametrizedCachedSerializer(
+    clazz: KClass<Any>,
+    types: List<KType>,
+    isNullable: Boolean
+): Result<KSerializer<Any?>?> {
+    return if (!isNullable) {
+        @Suppress("UNCHECKED_CAST")
+        PARAMETRIZED_SERIALIZERS_CACHE.get(clazz, types) as Result<KSerializer<Any?>?>
+    } else {
+        PARAMETRIZED_SERIALIZERS_CACHE_NULLABLE.get(clazz, types)
+    }
+}