NSURLSession and amazon S3 uploads

Question

I have an app which is currently uploading images to amazon S3. I have been trying to switch it from using NSURLConnection to NSURLSession so that the uploads can continue w

Answer 1

Recently Amazon has updated there AWS api to 2.2.4. speciality of this update is that, it supports background uploading, you don't have to use NSURLSession to upload videos its pretty simple, you can use following source block to test it, I have tested against with my older version, it is 30 - 40 % faster than the previous version

in AppDelegate.m didFinishLaunchingWithOptions method // ~GM~ setup cognito for AWS V2 configurations

AWSStaticCredentialsProvider *staticProvider = [[AWSStaticCredentialsProvider alloc] initWithAccessKey:@"xxxx secretKey:@"xxxx"];  

AWSServiceConfiguration *configuration = [[AWSServiceConfiguration alloc] initWithRegion:AWSRegionUSWest2                                                                 credentialsProvider:staticProvider];

AWSServiceManager.defaultServiceManager.defaultServiceConfiguration = configuration;

in handleEventsForBackgroundURLSession method

[AWSS3TransferUtility interceptApplication:application
       handleEventsForBackgroundURLSession:identifier
                         completionHandler:completionHandler];

in upload class

NSURL *fileURL = // The file to upload.

AWSS3TransferUtilityUploadExpression *expression = [AWSS3TransferUtilityUploadExpression new];
expression.uploadProgress = ^(AWSS3TransferUtilityTask *task, int64_t bytesSent, int64_t totalBytesSent, int64_t totalBytesExpectedToSend) {
    dispatch_async(dispatch_get_main_queue(), ^{
        // Do something e.g. Update a progress bar.
    });
};

AWSS3TransferUtilityUploadCompletionHandlerBlock completionHandler = ^(AWSS3TransferUtilityUploadTask *task, NSError *error) {
    dispatch_async(dispatch_get_main_queue(), ^{
        // Do something e.g. Alert a user for transfer completion.
        // On failed uploads, `error` contains the error object.
    });
};

AWSS3TransferUtility *transferUtility = [AWSS3TransferUtility defaultS3TransferUtility];
[[transferUtility uploadFile:fileURL
                      bucket:@"YourBucketName"
                         key:@"YourObjectKeyName"
                 contentType:@"text/plain"
                  expression:expression
            completionHander:completionHandler] continueWithBlock:^id(AWSTask *task) {
    if (task.error) {
        NSLog(@"Error: %@", task.error);
    }
    if (task.exception) {
        NSLog(@"Exception: %@", task.exception);
    }
    if (task.result) {
        AWSS3TransferUtilityUploadTask *uploadTask = task.result;
        // Do something with uploadTask.
    }

    return nil;
}];

More references: https://aws.amazon.com/blogs/mobile/amazon-s3-transfer-utility-for-ios/