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Create helper functions for temporary directories which supports new concurrency features
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‎Sources/Basics/TemporaryFile.swift

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//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift open source project
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//
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// Copyright (c) 2022 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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import Foundation
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import TSCBasic
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import TSCLibc
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/// Creates a temporary directory and evaluates a closure with the directory path as an argument.
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/// The temporary directory will live on disk while the closure is evaluated and will be deleted when
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/// the cleanup closure is called. This allows the temporary directory to have an arbitrary lifetime.
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///
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/// This function is basically a wrapper over posix's mkdtemp() function.
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///
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/// - Parameters:
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/// - dir: If specified the temporary directory will be created in this directory otherwise environment
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/// variables TMPDIR, TEMP and TMP will be checked for a value (in that order). If none of the env
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/// variables are set, dir will be set to `/tmp/`.
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/// - prefix: The prefix to the temporary file name.
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/// - body: A closure to execute that receives the absolute path of the directory as an argument.
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/// If `body` has a return value, that value is also used as the
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/// return value for the `withTemporaryDirectory` function.
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/// The cleanup block should be called when the temporary directory is no longer needed.
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///
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/// - Throws: `MakeDirectoryError` and rethrows all errors from `body`.
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@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
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public func withTemporaryDirectory<Result>(
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dir: AbsolutePath? = nil, prefix: String = "TemporaryDirectory" , _ body: (AbsolutePath, @escaping (AbsolutePath) -> Void) async throws -> Result
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) async throws -> Result {
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let template = try createTemporaryDirectoryTemplate(dir: dir, prefix: prefix)
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return try await body(AbsolutePath(String(cString: template))) { path in
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_ = try? FileManager.default.removeItem(atPath: path.pathString)
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}
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}
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/// Creates a temporary directory and evaluates a closure with the directory path as an argument.
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/// The temporary directory will live on disk while the closure is evaluated and will be deleted afterwards.
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///
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/// This function is basically a wrapper over posix's mkdtemp() function.
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///
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/// - Parameters:
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/// - dir: If specified the temporary directory will be created in this directory otherwise environment
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/// variables TMPDIR, TEMP and TMP will be checked for a value (in that order). If none of the env
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/// variables are set, dir will be set to `/tmp/`.
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/// - prefix: The prefix to the temporary file name.
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/// - removeTreeOnDeinit: If enabled try to delete the whole directory tree otherwise remove only if its empty.
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/// - body: A closure to execute that receives the absolute path of the directory as an argument.
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/// If `body` has a return value, that value is also used as the
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/// return value for the `withTemporaryDirectory` function.
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///
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/// - Throws: `MakeDirectoryError` and rethrows all errors from `body`.
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@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
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public func withTemporaryDirectory<Result>(
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dir: AbsolutePath? = nil, prefix: String = "TemporaryDirectory", removeTreeOnDeinit: Bool = false , _ body: (AbsolutePath) async throws -> Result
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) async throws -> Result {
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try await withTemporaryDirectory(dir: dir, prefix: prefix) { path, cleanup in
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defer { if removeTreeOnDeinit { cleanup(path) } }
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return try await body(path)
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}
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}
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private func createTemporaryDirectoryTemplate(dir: AbsolutePath?, prefix: String) throws -> [Int8] {
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// Construct path to the temporary directory.
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let templatePath = try AbsolutePath(prefix + ".XXXXXX", relativeTo: determineTempDirectory(dir))
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// Convert templatePath to a C style string terminating with null char to be an valid input
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// to mkdtemp method. The XXXXXX in this string will be replaced by a random string
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// which will be the actual path to the temporary directory.
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var template = [UInt8](templatePath.pathString.utf8).map({ Int8($0) }) + [Int8(0)]
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if TSCLibc.mkdtemp(&template) == nil {
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throw MakeDirectoryError(errno: errno)
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}
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return template
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}
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private extension MakeDirectoryError {
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init(errno: Int32) {
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switch errno {
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case TSCLibc.EEXIST:
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self = .pathExists
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case TSCLibc.ENAMETOOLONG:
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self = .pathTooLong
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case TSCLibc.EACCES, TSCLibc.EFAULT, TSCLibc.EPERM, TSCLibc.EROFS:
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self = .permissionDenied
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case TSCLibc.ELOOP, TSCLibc.ENOENT, TSCLibc.ENOTDIR:
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self = .unresolvablePathComponent
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case TSCLibc.ENOMEM:
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self = .outOfMemory
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#if !os(Windows)
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case TSCLibc.EDQUOT:
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self = .outOfMemory
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#endif
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default:
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self = .other(errno)
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}
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}
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}

‎Tests/BasicsTests/TemporaryFileTests.swift

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/*
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This source file is part of the Swift.org open source project
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Copyright (c) 2022 Apple Inc. and the Swift project authors
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Licensed under Apache License v2.0 with Runtime Library Exception
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See http://swift.org/LICENSE.txt for license information
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See http://swift.org/CONTRIBUTORS.txt for Swift project authors
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*/
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import XCTest
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import class Foundation.FileManager
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import TSCBasic
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import Basics
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@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
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class TemporaryAsyncFileTests: XCTestCase {
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func testBasicTemporaryDirectory() async throws {
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// Test can create and remove temp directory.
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let path1: AbsolutePath = try await withTemporaryDirectory(removeTreeOnDeinit: true) { tempDirPath in
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// Do some async task
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let task = Task {
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return
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}
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await task.value
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XCTAssertTrue(localFileSystem.isDirectory(tempDirPath))
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return tempDirPath
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}
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XCTAssertFalse(localFileSystem.isDirectory(path1))
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// Test temp directory is not removed when its not empty.
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let path2: AbsolutePath = try await withTemporaryDirectory { tempDirPath in
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XCTAssertTrue(localFileSystem.isDirectory(tempDirPath))
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// Create a file inside the temp directory.
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let filePath = tempDirPath.appending(component: "somefile")
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// Do some async task
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let task = Task {
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return
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}
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await task.value
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try localFileSystem.writeFileContents(filePath, bytes: ByteString())
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return tempDirPath
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}
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XCTAssertTrue(localFileSystem.isDirectory(path2))
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// Cleanup.
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try FileManager.default.removeItem(atPath: path2.pathString)
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XCTAssertFalse(localFileSystem.isDirectory(path2))
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// Test temp directory is removed when its not empty and removeTreeOnDeinit is enabled.
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let path3: AbsolutePath = try await withTemporaryDirectory(removeTreeOnDeinit: true) { tempDirPath in
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XCTAssertTrue(localFileSystem.isDirectory(tempDirPath))
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let filePath = tempDirPath.appending(component: "somefile")
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// Do some async task
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let task = Task {
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return
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}
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await task.value
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try localFileSystem.writeFileContents(filePath, bytes: ByteString())
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return tempDirPath
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}
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XCTAssertFalse(localFileSystem.isDirectory(path3))
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}
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func testCanCreateUniqueTempDirectories() async throws {
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let (pathOne, pathTwo): (AbsolutePath, AbsolutePath) = try await withTemporaryDirectory(removeTreeOnDeinit: true) { pathOne in
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let pathTwo: AbsolutePath = try await withTemporaryDirectory(removeTreeOnDeinit: true) { pathTwo in
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// Do some async task
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let task = Task {
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return
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}
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await task.value
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XCTAssertTrue(localFileSystem.isDirectory(pathOne))
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XCTAssertTrue(localFileSystem.isDirectory(pathTwo))
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// Their paths should be different.
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XCTAssertTrue(pathOne != pathTwo)
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return pathTwo
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}
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return (pathOne, pathTwo)
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}
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XCTAssertFalse(localFileSystem.isDirectory(pathOne))
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XCTAssertFalse(localFileSystem.isDirectory(pathTwo))
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}
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}

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