Introduce Common AutoCloseable & use #KT-31066

Co-authored-by: Ilya Gorbunov <Ilya.Gorbunov@jetbrains.com> Merge-request: KT-MR-8113 Merged-by: Abduqodiri Qurbonzoda <abduqodiri.qurbonzoda@jetbrains.com>
2022-12-27 11:50:22 +00:00
parent 70cd547c26
commit fff593492d
9 changed files with 263 additions and 90 deletions
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2010-2022 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 kotlin
+
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
+
+/**
+ * A resource that can be closed or released.
+ */
+@Suppress("NO_ACTUAL_FOR_EXPECT")
+@SinceKotlin("1.8")
+@ExperimentalStdlibApi
+public expect interface AutoCloseable {
+    /**
+     * Closes this resource.
+     *
+     * This function may throw, thus it is strongly recommended to use the [use] function instead,
+     * which closes this resource correctly whether an exception is thrown or not.
+     *
+     * Implementers of this interface should pay increased attention to cases where the close operation may fail.
+     * It is recommended that all underlying resources are closed and the resource internally is marked as closed
+     * before throwing an exception. Such a strategy ensures that the resources are released in a timely manner,
+     * and avoids many problems that could come up when the resource wraps, or is wrapped, by another resource.
+     *
+     * Note that calling this function more than once may have some visible side effect.
+     * However, implementers of this interface are strongly recommended to make this function idempotent.
+     */
+    public fun close(): Unit
+}
+
+/**
+ * Executes the given [block] function on this resource and then closes it down correctly whether an exception
+ * is thrown or not.
+ *
+ * In case if the resource is being closed due to an exception occurred in [block], and the closing also fails with an exception,
+ * the latter is added to the [suppressed][Throwable.addSuppressed] exceptions of the former.
+ *
+ * @param block a function to process this [AutoCloseable] resource.
+ * @return the result of [block] function invoked on this resource.
+ */
+@Suppress("NO_ACTUAL_FOR_EXPECT", "EXPECTED_DECLARATION_WITH_BODY")
+@SinceKotlin("1.8")
+@ExperimentalStdlibApi
+@kotlin.internal.InlineOnly
+public expect inline fun <T : AutoCloseable?, R> T.use(block: (T) -> R): R {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    error("Unreachable")
+}