Why is AWS S3 so slow? (Swift)

Question

I am using Amazon S3 to store profile pictures for user accounts on an iOS app using swift.. I am able to get the pictures I want from S3, but it takes a very long time for them to load. I don't know why this is happening. Is that just how S3 works, or is there a better way to do things? This is my code for downloading the picture:

let downloadingFilePath1 = NSTemporaryDirectory().stringByAppendingPathComponent("temp-download")
        let downloadingFileURL1 = NSURL(fileURLWithPath: downloadingFilePath1)
        let transferManager = AWSS3TransferManager.defaultS3TransferManager()
        let readRequest1 : AWSS3TransferManagerDownloadRequest = AWSS3TransferManagerDownloadRequest()
        readRequest1.bucket = "groopapictures"
        readRequest1.key =  self.searchTextField.text
        readRequest1.downloadingFileURL = downloadingFileURL1

        transferManager.download(readRequest1).continueWithBlock { (task) -> AnyObject! in
            println(task.error)
            if task.error == nil {
                self.ppImageView.hidden = false
                println("Fetched image")
                self.ppImageView.image = UIImage(contentsOfFile: downloadingFilePath1)

            }
            return nil
        }

Any help would be appreciated!

Answer 1

Check which queue you're running on in your return block. If it's not the main queue, setting the image property of a UIImageView can take a long time to be "noticed" and updated. Test this by putting the image assignment line inside a dispatch_async() to the main thread.

If that doesn't help, run Charles and see how long S3 is taking to return the image.