I have a need to read first half and second half of a file concurrently. Is there any best practices for this scenario? BTW, I did research on DispatchIO but it turned out DispatchIO is all about asynchronous operations on a single file handle; it cannot perform parallel reading. // naive approach Task { fileHandle.read(into:buffer) } Task { // seek to file size / 2 fileHandle.read(into:buffer) }

I have the following pseudo code: func load(at packageURL: URL) { let realPackageURL = packageURL.resolvingSymlinksInPath() guard let it = fileMan.enumerator(at: realPackageURL) for case let fileURL as URL in it { print(fileURL) // Get filename relative to package root directory let relativeFileName = String(filePath.suffix(filePath.count - packagePath.count)) } } When called with "file:///tmp/some.app", the enumerated fileURL is actually file:///private/tmp/GIMP.app/Contents/ packageURL.resolvingSymlinksInPath() actually does nothing, I assume /tmp is a hard link. This makes it impossible to get a correct relative path. Is there any remedy for this?

Suppose I have the following function: func doWork(_ someValue: Int, completionHandler: () -> Void) { let q = DispatchQueue() q.async { // Long time of work completionHandler() } } How do I turn it into async function so that I can call it using await doWork()? Are there guidelines/principles/practices for this purpose?

I know this is a frequently asked question, but... After reading many articles on the net, I am still not sure if I have a solid understanding of the logics behind the design. One of my puzzles around this question is - Is the Swift compiler clever enough so that I can solely rely on its warnings/errors?

Does Swift has the syntax that lets me get the default value of a template type T, like below: struct VarLock<T> { private var v = default(T) // or T() }

I used to run VirtualBox on macOS to run Windows guests for some reasons. Recently I bought a new Mac mini M1, now I have a problem - VB does not have a stable release for arm (yet). What other options do I have? BTW, I came across this doc article (https://developer.apple.com/documentation/virtualization/running_macos_in_a_virtual_machine_on_apple_silicon). I read thru it, but could not conclude if it offers the same functionalities as a full-blown VM suite; and more specifically I want to run Windows guests.

I had a customer feedback about a "zero length data" error which was captured using an exception handler and displayed using NSAlert. My app employs [NSURLSession dataTaskWithURL:] to download XML and image data. But I got no idea what it is about. I assume it's related to NSData, but this error never happened before (for years). Does anyone have any idea about the source of this error?

I want to check if a given string matches a file pattern. Does Swift have builtin support for filename globbing? Or is there any 3rd party packages for this?

I remember long time ago I could click on a button in Xcode to launch a Web page to manage iCloud data. But now I cannot find the button.

I just want some experts on Swift to confirm that the following syntaxes are equivalent: if a > b, c > d { } if a > b && c > d { } I consulted "The Swift Programming Lanugage (version 5.7)" but the book does not cover this issue. But I believe it's true because my tests show they are the same.

I use ProcessInfo.processInfo.environment["key"] to get test parameters, but all of a sudden I could not find the UI like below: In the screenshot above, the 2 environment variables were actually what I entered for the unit test target. I don't have any idea why they were moved there! Any similar problems?

I have a custom Objective-C ObjectCache class that utilized NSMutableDictionary to store named objects (specifically large NSImage objects). The class has a maxItems property and clear method, which worked fine. - (void)clear { @synchronized(_cache) { [_cache removeAllObjects]; } } But yesterday I received a customer feedback complaining one of my app consumes up to 24GB memory. I verified that on my M1 Mac mini, and it's true. Even after calling clear method, memory usage shown in both Xcode debugger panel and Activity Monitor remains the same. It did work before. Once I close a picture gallery window by calling clear method, memory usage dropped immediately as shown in Activity Monitor. I suspect that this is a bug in ARM architecture. Does anyone else have same problem?

What unit does NSView.bounds/frame use? Pixel or point? How to convert between them?

According to the doc: The value returned is the same as the value returned in the kEventParamKeyCode when using Carbon Events. So where can I find kEventParamKeyCode?

Is there any way to keep an NSWindow always on top of other windows (inside an app)? I want to create a "preview" window for pictures and videos with it not taking up space in the main window.