Add async overloads of withTemporaryFile and withTemporaryDirectory

Author: jakepetroules

Sources/TSCBasic/TemporaryFile.swift

@@ -141,6 +141,39 @@ public func withTemporaryFile<Result>(
     }
 }
 
+/// Creates a temporary file and evaluates a closure with the temporary file as an argument.
+/// The temporary file will live on disk while the closure is evaluated and will be deleted when
+/// the cleanup block is called.
+///
+/// This function is basically a wrapper over posix's mkstemps() function to create disposable files.
+///
+/// - Parameters:
+///     - dir: If specified the temporary file will be created in this directory otherwise environment variables
+///            TMPDIR, TEMP and TMP will be checked for a value (in that order). If none of the env variables are
+///            set, dir will be set to `/tmp/`.
+///     - prefix: The prefix to the temporary file name.
+///     - suffix: The suffix to the temporary file name.
+///     - body: A closure to execute that receives the TemporaryFile as an argument.
+///             If `body` has a return value, that value is also used as the
+///             return value for the `withTemporaryFile` function.
+///             The cleanup block should be called when the temporary file is no longer needed.
+///
+/// - Throws: TempFileError and rethrows all errors from `body`.
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+public func withTemporaryFile<Result>(
+    dir: AbsolutePath? = nil, prefix: String = "TemporaryFile", suffix: String = "", _ body: (TemporaryFile, @escaping (TemporaryFile) async -> Void) async throws -> Result
+) async throws -> Result {
+    return try await body(TemporaryFile(dir: dir, prefix: prefix, suffix: suffix)) { tempFile in
+#if os(Windows)
+        _ = tempFile.path.pathString.withCString(encodedAs: UTF16.self) {
+            _wunlink($0)
+        }
+#else
+        unlink(tempFile.path.pathString)
+#endif
+    }
+}
+
 /// Creates a temporary file and evaluates a closure with the temporary file as an argument.
 /// The temporary file will live on disk while the closure is evaluated and will be deleted afterwards.
 ///
@@ -167,6 +200,40 @@ public func withTemporaryFile<Result>(
     }
 }
 
+/// Creates a temporary file and evaluates a closure with the temporary file as an argument.
+/// The temporary file will live on disk while the closure is evaluated and will be deleted afterwards.
+///
+/// This function is basically a wrapper over posix's mkstemps() function to create disposable files.
+///
+/// - Parameters:
+///     - dir: If specified the temporary file will be created in this directory otherwise environment variables
+///            TMPDIR, TEMP and TMP will be checked for a value (in that order). If none of the env variables are
+///            set, dir will be set to `/tmp/`.
+///     - prefix: The prefix to the temporary file name.
+///     - suffix: The suffix to the temporary file name.
+///     - deleteOnClose: Whether the file should get deleted after the call of `body`
+///     - body: A closure to execute that receives the TemporaryFile as an argument.
+///            If `body` has a return value, that value is also used as the
+///            return value for the `withTemporaryFile` function.
+///
+/// - Throws: TempFileError and rethrows all errors from `body`.
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+public func withTemporaryFile<Result>(
+    dir: AbsolutePath? = nil, prefix: String = "TemporaryFile", suffix: String = "", deleteOnClose: Bool = true, _ body: (TemporaryFile) async throws -> Result
+) async throws -> Result {
+    try await withTemporaryFile(dir: dir, prefix: prefix, suffix: suffix) { tempFile, cleanup in
+        let result: Result
+        do {
+            result = try await body(tempFile)
+            if (deleteOnClose) { await cleanup(tempFile) }
+        } catch {
+            if (deleteOnClose) { await cleanup(tempFile) }
+            throw error
+        }
+        return result
+    }
+}
+
 // FIXME: This isn't right place to declare this, probably POSIX or merge with FileSystemError?
 //
 /// Contains the error which can be thrown while creating a directory using POSIX's mkdir.
@@ -252,6 +319,44 @@ public func withTemporaryDirectory<Result>(
     }
 }
 
+/// Creates a temporary directory and evaluates a closure with the directory path as an argument.
+/// The temporary directory will live on disk while the closure is evaluated and will be deleted when
+/// the cleanup closure is called. This allows the temporary directory to have an arbitrary lifetime.
+///
+/// This function is basically a wrapper over posix's mkdtemp() function.
+///
+/// - Parameters:
+///     - dir: If specified the temporary directory will be created in this directory otherwise environment
+///            variables TMPDIR, TEMP and TMP will be checked for a value (in that order). If none of the env
+///            variables are set, dir will be set to `/tmp/`.
+///     - prefix: The prefix to the temporary file name.
+///     - body: A closure to execute that receives the absolute path of the directory as an argument.
+///           If `body` has a return value, that value is also used as the
+///           return value for the `withTemporaryDirectory` function.
+///           The cleanup block should be called when the temporary directory is no longer needed.
+///
+/// - Throws: MakeDirectoryError and rethrows all errors from `body`.
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+public func withTemporaryDirectory<Result>(
+    dir: AbsolutePath? = nil, prefix: String = "TemporaryDirectory" , _ body: (AbsolutePath, @escaping (AbsolutePath) async -> Void) async throws -> Result
+) async throws -> Result {
+    // Construct path to the temporary directory.
+    let templatePath = try AbsolutePath(validating: prefix + ".XXXXXX", relativeTo: determineTempDirectory(dir))
+
+    // Convert templatePath to a C style string terminating with null char to be an valid input
+    // to mkdtemp method. The XXXXXX in this string will be replaced by a random string
+    // which will be the actual path to the temporary directory.
+    var template = [UInt8](templatePath.pathString.utf8).map({ Int8($0) }) + [Int8(0)]
+
+    if TSCLibc.mkdtemp(&template) == nil {
+        throw MakeDirectoryError(errno: errno)
+    }
+
+    return try await body(AbsolutePath(validating: String(cString: template))) { path in
+        _ = try? FileManager.default.removeItem(atPath: path.pathString)
+    }
+}
+
 /// Creates a temporary directory and evaluates a closure with the directory path as an argument.
 /// The temporary directory will live on disk while the closure is evaluated and will be deleted afterwards.
 ///
@@ -277,3 +382,35 @@ public func withTemporaryDirectory<Result>(
     }
 }
 
+/// Creates a temporary directory and evaluates a closure with the directory path as an argument.
+/// The temporary directory will live on disk while the closure is evaluated and will be deleted afterwards.
+///
+/// This function is basically a wrapper over posix's mkdtemp() function.
+///
+/// - Parameters:
+///     - dir: If specified the temporary directory will be created in this directory otherwise environment
+///            variables TMPDIR, TEMP and TMP will be checked for a value (in that order). If none of the env
+///            variables are set, dir will be set to `/tmp/`.
+///     - prefix: The prefix to the temporary file name.
+///     - removeTreeOnDeinit: If enabled try to delete the whole directory tree otherwise remove only if its empty.
+///     - body: A closure to execute that receives the absolute path of the directory as an argument.
+///             If `body` has a return value, that value is also used as the
+///             return value for the `withTemporaryDirectory` function.
+///
+/// - Throws: MakeDirectoryError and rethrows all errors from `body`.
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+public func withTemporaryDirectory<Result>(
+    dir: AbsolutePath? = nil, prefix: String = "TemporaryDirectory", removeTreeOnDeinit: Bool = false , _ body: (AbsolutePath) async throws -> Result
+) async throws -> Result {
+    try await withTemporaryDirectory(dir: dir, prefix: prefix) { path, cleanup in
+        let result: Result
+        do {
+            result = try await body(path)
+            if removeTreeOnDeinit { await cleanup(path) }
+        } catch {
+            if removeTreeOnDeinit { await cleanup(path) }
+            throw error
+        }
+        return result
+    }
+}