I am using AFDownloadRequestOperation. It was working fine, but is now suddenly giving this error every time I run it (I am downloading from the same URL every time I run it and I do clear the Documents and Temp folders in AppDelegate).
Initiate a download. (Before downloading, I do manually check that there is nothing in Temp or Documents folder, i.e. where I store the files once download is done).
The download gets over in 1-2 seconds, code moves to success block, the debug console shows a 206 status code, a file magically gets placed in Documents folder out of nowhere and has the exact file size (it used to get downloaded properly until I started running into this issue). The file is corrupt and does not open.
Here is the code snippet -
download_operation_progress_block = ^(AFDownloadRequestOperation *operation, NSInteger bytesRead, long long totalBytesRead, long long totalBytesExpected, long long totalBytesReadForFile, long long totalBytesExpectedToReadForFile) {
float progress = ((float)totalBytesReadForFile) / totalBytesExpectedToReadForFile;
dataFetcherObject.downloadProgressDetails.downloadPercentage = [NSNumber numberWithFloat:floorf(progress*100)];
};
download_operation_success_block = ^(AFHTTPRequestOperation *operation, id responseObject) {
dataFetcherObject.downloadProgressDetails.isDownloadDone = [NSNumber numberWithBool:YES];
dataFetcherObject.isDataFetched = #"Yes";
};
download_operation_failure_block = ^(AFHTTPRequestOperation *operation, NSError *error) {
[dataFetcherObject.downloadProgressDetails.downloadOperation cancel];
dataFetcherObject.isDataFetched = #"Error";
};
AFDownloadRequestOperation *operation = [[AFDownloadRequestOperation alloc] initWithRequest:contentDownloadRequest
targetPath:path
shouldResume:YES];
[operation setCompletionBlockWithSuccess:download_operation_success_block
failure:download_operation_failure_block];
[operation setProgressiveDownloadProgressBlock:download_operation_progress_block];
// operation.deleteTempFileOnCancel = TRUE;
NSOperationQueue *operationQueue = [[NSOperationQueue alloc] init];
[operationQueue addOperation:operation];
dataFetcherObject.downloadProgressDetails.downloadOperation = operation;
What could be the reason for this.
Related
In my app, I am needing to download about 6,000 images. I realize this is a lot, but it is needed.
Currently I am using doing the following:
NSArray *photos = #[hugeAmountOfPhotoObjects];
for (ZSSPhoto *photo in photos) {
[self downloadImageWithURL:photo.mobileURL progress:^(double progress) {
} completion:^(UIImage *image) {
// Save the image
} failure:^(NSError *error) {
}];
}
...
- (void)downloadImageWithURL:(NSURL *)url progress:(void (^)(double progress))progress completion:(void (^)(UIImage *image))completion failure:(void (^)(NSError *error))failure {
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
[request setTimeoutInterval:600];
self.operationQueue.maxConcurrentOperationCount = NSOperationQueueDefaultMaxConcurrentOperationCount;
AFHTTPRequestOperation *requestOperation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
requestOperation.responseSerializer = [AFImageResponseSerializer serializer];
[requestOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
completion(responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
[self processOperation:operation error:error failure:failure];
}];
[requestOperation setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
double percentDone = (double)totalBytesRead / (double)totalBytesExpectedToRead;
progress(percentDone);
}];
[self.operationQueue addOperation:requestOperation];
}
The problem here is that it takes forever to download using this method, and some of my users are reporting crashing because of high memory usage.
Is there a better method that I could be using to download such a large number of image files?
You could try this somewhat recursively
NSMutableArray *undownloaded;
- (void) startDownload {
undownloaded = [photos mutableCopy]; //get a list of the undownloaded images
for(int i = 0; i < 3;i++) //download 3 at a time
[self downloadImage];
}
- (void) downloadImage {
if(undownloaded.count > 0){
ZSSPhoto *photo = undownloaded.firstObject;
[undownloaded removeObjectAtIndex:0];
[self downloadImageWithURL:photo.mobileURL progress:^(double progress) {
} completion:^(UIImage *image) {
// Save the image
[self downloadImage];
} failure:^(NSError *error) {
[self downloadImage];
//[undownloaded addObject:photo]; //insert photo back into the array maybe to retry? warning, could cause infinite loop without some extra logic, maybe the object can keep a fail count itself
}];
}
}
warning: untested code, may need some tweaking
The speed problem can be solved (the speed will increase, but it might still be slow) with multithreading, downloading all the images at the same time instead of one per time. However, the memory problem is a bit more complicated.
ARC will release all the images after everything is finished, but right before that you gonna have 6,000 images in the device memory. You could optimize the images, reduce their resolution or download them in steps, like Google Images do (you download the images that will be visible at first, then when the user scrolls down you load the images in the new visible area; downloading the images only when they are needed).
Considering that you are downloading enough images to give a memory problem, you will probably take a lots of space in your user's device if you download all of them, and the 'steps' solution may solve that as well.
Now, let's suppose you must download all of them at the same time and space isn't a problem: I suppose that if you put the downloadImageWithURL:progress: method inside a concurrent queue, the images are gonna be freed from memory just after saving (it's just a supposition). Add this to your code:
dispatch_queue_t defaultPriorityQueueWithName(const char* name)
{
dispatch_queue_t dispatchQueue = dispatch_queue_create(name, DISPATCH_QUEUE_CONCURRENT);
dispatch_queue_t priorityQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_set_target_queue(dispatchQueue, priorityQueue);
return dispatchQueue;
}
And change your code to that:
dispatch_queue_t threadItemLoadImage = defaultPriorityQueueWithName("DownloadingImages");
NSArray *photos = #[hugeAmountOfPhotoObjects];
for (ZSSPhoto *photo in photos)
{
dispatch_async(threadItemLoadImage, ^
{
[self downloadImageWithURL:photo.mobileURL progress:^(double progress) {
} completion:^(UIImage *image) {
// Save the image
} failure:^(NSError *error) {
}];
});
}
You will need to remove setDownloadProgressBlock: in case it updates some view, since they will be downloaded simultaneously. Also, a warning: totalBytesExpectedToRead not always will be correctly retrieved at first, containing 0, which might make your app crash for dividing by zero as well in some rare occasions. In future cases, when you need to use setDownloadProgressBlock:, check totalBytesExpectedToRead value before doing that division.
I'm writting a client/server application that needs to send some XML to a server.
NSMutableArray *operations = [NSMutableArray array];
AFHTTPRequestOperation *operation1 = [[AFHTTPRequestOperation alloc] initWithRequest:theRequest];
[operation1 setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
float progress = (float)totalBytesRead / totalBytesExpectedToRead;
NSLog(#"Progress 1 = %f",progress);
}];
[operations addObject:operation1];
AFHTTPRequestOperation *operation2 = [[AFHTTPRequestOperation alloc] initWithRequest:theRequest];
[operation2 setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
float progress = (float)totalBytesRead / totalBytesExpectedToRead;
NSLog(#"Progress 2 = %f",progress*100);
}];
[operations addObject:operation2];
NSOperationQueue *operationQueue = [[NSOperationQueue alloc] init];
// Set the max number of concurrent operations (threads)
[operationQueue setMaxConcurrentOperationCount:3];
[operationQueue addOperations:#[operation1, operation2] waitUntilFinished:NO];
What I want to do now is to handle if the transmission fails and have a queue so it retries to send it.
What's the best way to achieve this with the AFNetworking library ?
First up it would not be very wise to just retry failed operations again. Depending on what was the source of the error, you risk severe side effects like duplicate submissions.
You're already using AFHTTPRequestOperation, so the easiest solution would be to call
setCompletionBlockWithSuccess:failure: and handle errors in the "failure"-block. After all you may also want to use the "success"-block for when the download successfully finished.
One last detail about the code you provided: You're creating the NSArray *operations in line 1 - yet you're not using it for anything since you create a new array of the operations in the last line. So either you left something out or you should simplify that.
Note: I'm using ARC.
I have some code that makes 1 request to an http server for a list of files (via JSON). It then parses that list into model objects which it uses to add a download operation (for downloading that file) to a different nsoperationqueue and then once it's done adding all of those operations (queue starts out suspended) it kicks off the queue and waits for all the operations to finish before continuing. (Note: this is all done on background threads so as not to block the main thread).
Here's the basic code:
NSURLRequest* request = [NSURLRequest requestWithURL:parseServiceUrl];
AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:request];
op.responseSerializer = [AFJSONResponseSerializer serializer];
[op setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
//NSLog(#"JSON: %#", responseObject);
// Parse JSON into model objects
NSNumber* results = [responseObject objectForKey:#"results"];
if ([results intValue] > 0)
{
dispatch_async(_processQueue, ^{
_totalFiles = [results intValue];
_timestamp = [responseObject objectForKey:#"timestamp"];
NSArray* files = [responseObject objectForKey:#"files"];
for (NSDictionary* fileDict in files)
{
DownloadableFile* file = [[DownloadableFile alloc] init];
file.file_id = [fileDict objectForKey:#"file_id"];
file.file_location = [fileDict objectForKey:#"file_location"];
file.timestamp = [fileDict objectForKey:#"timestamp"];
file.orderInQueue = [files indexOfObject:fileDict];
NSNumber* action = [fileDict objectForKey:#"action"];
if ([action intValue] >= 1)
{
if ([file.file_location.lastPathComponent.pathExtension isEqualToString:#""])
{
continue;
}
[self downloadSingleFile:file];
}
else // action == 0 so DELETE file if it exists
{
if ([[NSFileManager defaultManager] fileExistsAtPath:file.localPath])
{
NSError* error;
[[NSFileManager defaultManager] removeItemAtPath:file.localPath error:&error];
if (error)
{
NSLog(#"Error deleting file after given an Action of 0: %#: %#", file.file_location, error);
}
}
}
[self updateProgress:[files indexOfObject:fileDict] withTotal:[files count]];
}
dispatch_sync(dispatch_get_main_queue(), ^{
[_label setText:#"Syncing Files..."];
});
[_dlQueue setSuspended:NO];
[_dlQueue waitUntilAllOperationsAreFinished];
[SettingsManager sharedInstance].timestamp = _timestamp;
dispatch_async(dispatch_get_main_queue(), ^{
callback(nil);
});
});
}
else
{
dispatch_async(dispatch_get_main_queue(), ^{
callback(nil);
});
}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Error: %#", error);
callback(error);
}];
[_parseQueue addOperation:op];
and then the downloadSingleFile method:
- (void)downloadSingleFile:(DownloadableFile*)dfile
{
NSURLRequest* req = [NSURLRequest requestWithURL:dfile.downloadUrl];
AFHTTPRequestOperation* reqOper = [[AFHTTPRequestOperation alloc] initWithRequest:req];
reqOper.responseSerializer = [AFHTTPResponseSerializer serializer];
[reqOper setCompletionBlockWithSuccess:^(AFHTTPRequestOperation* op, id response)
{
__weak NSData* fileData = response;
NSError* error;
__weak DownloadableFile* file = dfile;
NSString* fullPath = [file.localPath substringToIndex:[file.localPath rangeOfString:file.localPath.lastPathComponent options:NSBackwardsSearch].location];
[[NSFileManager defaultManager] createDirectoryAtPath:fullPath withIntermediateDirectories:YES attributes:Nil error:&error];
if (error)
{
NSLog(#"Error creating directory path: %#: %#", fullPath, error);
}
else
{
error = nil;
[fileData writeToFile:file.localPath options:NSDataWritingFileProtectionComplete error:&error];
if (error)
{
NSLog(#"Error writing fileData for file: %#: %#", file.file_location, error);
}
}
[self updateProgress:file.orderInQueue withTotal:_totalFiles];
}
failure:^(AFHTTPRequestOperation* op, NSError* error)
{
[self updateProgress:dfile.orderInQueue withTotal:_totalFiles];
NSLog(#"Error downloading %#: %#", dfile.downloadUrl, error.localizedDescription);
}];
[_dlQueue addOperation:reqOper];
}
What I'm seeing is a constant spike in memory as more files get downloaded. It's like the responseObject or maybe even the whole completionBlock is not being let go of.
I've tried making the responseObject __weak as well as fileData. I've tried adding an autoreleasepool and I've tried making the actual file domain object __weak too but still memory climbs and climbs.
I've run Instruments and not seen any leaks persay but it never gets to a point where all the files have been downloaded before it runs out of memory with a big fat "can't allocate region" error. Looking at allocations, I see a bunch of connection:didFinishLoading and connection:didReceiveData methods that never seem to be let go of, however. I can't seem to debug it further than that though.
My question: Why is it running out of memory? What is not getting deallocated and how can I get it to do such?
There is a few things going on here. The biggest is that you are downloading the entire file, storing it in memory, and then writing it out to disk when the download is complete. Even with just one file of 500 MB, you will run out of memory.
The correct way to do this is using an NSOutputStream with asynchronous downloads. The key is to write out the data as soon as it arrives. It should look like this:
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[self.outputStream write:[data bytes] maxLength:[data length]];
}
Also of note, you are creating your weak references inside the block, not outside. Because of that, you are still creating a retain cycle and leaking memory. When you create weak references, it should look like this.
NSOperation *op = [[NSOperation alloc] init];
__weak NSOperation *weakOp = op;
op.completion = ^{
// Use only weakOp within this block
};
Lastly, your code is using #autoreleasepool. NSAutoreleasePool, and the ARC equivalent #autoreleasepool are only useful in very limited situations. As a general rule, if you aren't absolutely sure you need one, you don't.
With the help of a friend, I was able to figure out the problem.
The problem was actually in the first block of code:
[_dlQueue waitUntilAllOperationsAreFinished];
Apparently , waiting for all operations to finish meant none of those operations would be released either.
Instead of that, I ended up adding a final operation to the queue that would do the final processing and callback and memory is much more stable now.
[_dlQueue addOperationWithBlock:^{
[SettingsManager sharedInstance].timestamp = _timestamp;
dispatch_async(dispatch_get_main_queue(), ^{
callback(nil);
});
}];
What kind of file you are downloading? If you are working with Images or videos you nee to clear URLCache as when you doneload images it create CFDATA and some information in cache and it does not cleared out. You need to clear it explicitly when your single file download completed. It will never caught as a leak also.
NSURLCache *sharedCache = [[NSURLCache alloc] initWithMemoryCapacity:0 diskCapacity:0 diskPath:nil];
[NSURLCache setSharedURLCache:sharedCache];
[sharedCache release];
If you are using ARC replace
[sharedCache release];
with
sharedCache = nil;
Hope It may help you.
I am downloading movie files from UIGridViewCells. My code is:
NSMutableURLRequest* rq = [[APIClient sharedClient] requestWithMethod:#"GET" path:[[self item] downloadUrl] parameters:nil];
[rq setTimeoutInterval:5000];
_downloadOperation = [[AFHTTPRequestOperation alloc] initWithRequest:rq] ;
_downloadOperation.outputStream = [NSOutputStream outputStreamToFileAtPath:[[self item] localUrl] append:NO];
__weak typeof(self) weakSelf = self;
[_downloadOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"Successfully downloaded file to %#", [weakSelf.item localUrl]);
[Helper saveItemDownloaded:weakSelf.item.productId];
weakSelf.isDownloading = NO;
[weakSelf.progressOverlayView removeFromSuperview];
[weakSelf setUserInteractionEnabled:YES];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Error: %#", error);
[weakSelf.progressOverlayView removeFromSuperview];
[weakSelf setUserInteractionEnabled:YES];
weakSelf.isDownloading = NO;
}];
[_downloadOperation setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
float progress = totalBytesRead / (float)totalBytesExpectedToRead;
weakSelf.progressOverlayView.progress = progress;
}];
[[NSOperationQueue mainQueue] addOperation:_downloadOperation];
And the property in ItemCell is:
#property (nonatomic, retain) AFHTTPRequestOperation *downloadOperation;
After 1-2 successful downloads(20mb), I am receiving Memory Warning. Memory using is increasing with each download, and never decrease when the download finishes.
From Instruments:
I believe the preferred method of downloading files with AFNetworking is by setting the "outputStream" property.
According to AFNetworking documentation:
The output stream that is used to write data received until the request is finished.
By default, data is accumulated into a buffer that is stored into responseData upon completion of the request. When outputStream is set, the data will not be accumulated into an internal buffer, and as a result, the responseData property of the completed request will be nil. The output stream will be scheduled in the network thread runloop upon being set.
I was having the same problem, solved it by using "outputStream".
Use #autorelease per file downloaded:
for(File* file in fileList)
{
#autoreleasepool {
[self downloadFile:file];
}
}
This will release all variables and data allocated between separate files you download.
Also you should track down those memory leaks. I see some visible in instruments screenshots.
I am trying to measure time taken per GET request when downloading a file using AFNetworking. I am downloading a file repeatedly in a loop.
The problem I am having is that the way I am measuring total time, it gives a much larger total time than it actually is. For example, for 50 downloads it gives 72 sec but in reality it only took around 5 sec. I also suspect 5 sec is too low for 50 downloads(the download size is 581 kb per file).
How do I effectively measure time in this case? I need time from the moment request is fired till response in received.
My method to download file:
- (void) HTTPGetRequest
{
startTime = CACurrentMediaTime(); // Start measuring time
AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:http://myServer];
NSMutableURLRequest *request = [httpClient requestWithMethod:#"GET"
path:#"/download/Text581KB.txt"
parameters:nil];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[httpClient registerHTTPOperationClass:[AFHTTPRequestOperation class]];
// Save downloaded file
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [[paths objectAtIndex:0] stringByAppendingPathComponent:[NSString stringWithFormat:#"Text581KB.txt"]];
operation.outputStream = [NSOutputStream outputStreamToFileAtPath:path append:NO];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
double elapsedTime = (CACurrentMediaTime() - startTime); // Measuring time
totalTime += elapsedTime; // Measuring total time HERE!
[results setString:[NSString stringWithFormat: #"Current Transaction Time: %f sec\nTotal Time: %f sec", elapsedTime, totalTime]];
[_resultLabel performSelectorOnMainThread:#selector(setText:) withObject:results waitUntilDone:NO];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Error: %#", error);
}];
[operation setDownloadProgressBlock:^(NSUInteger bytesWritten, long long totalBytesWritten, long long totalBytesExpectedToWrite) { ((int)totalBytesExpectedToWrite));
totalDownloadSize += totalBytesExpectedToWrite;
[_DataTransferredLabel setText:[NSString stringWithFormat:#"Total Download Size: %#", [self getFileSize:totalDownloadSize/1024]]];
}];
[operation setCacheResponseBlock:^NSCachedURLResponse *(NSURLConnection *connection, NSCachedURLResponse *cachedResponse) {
return nil;
}];
[operationQueue addOperation:operation];
}
I am creating a NSOperationQueue in my viewDidLoad:
operationQueue = [NSOperationQueue new];
[operationQueue setMaxConcurrentOperationCount:1]; // using this as I was suspecting downloads were happening in parallel & thus 50 downloads finishing in a few secs
I am invoking the HTTPGetRequest method as follows:
- (IBAction)startDownload:(UIButton *)sender {
totalCount = [[_countText text] longLongValue]; // get # of times to download
long currentCount = 1;
completedCount = 0;
totalTime = 0;
totalDownloadSize = 0;
while (currentCount <= totalCount)
{
[self HTTPGetRequest];
[results setString:#""];
currentCount++;
}
Use AFHTTPRequestOperationLogger.
In terms of calculating cumulative time (not elapsed time), I have just created a subclass of AFHTTPRequestOperation that captures the start time. Otherwise, you won't know precisely when it started:
#interface TimedAFHTTPRequestOperation : AFHTTPRequestOperation
#property (nonatomic) CFAbsoluteTime startTime;
#end
#implementation TimedAFHTTPRequestOperation
- (void)start
{
self.startTime = CFAbsoluteTimeGetCurrent();
[super start];
}
#end
(Note I'm using CFAbsoluteTimeGetCurrent versus CACurrentMediaTime; use whatever you want, but just be consistent.)
Then in the code that's doing the downloads, you can use this TimedAFHTTPRequestOperation instead of AFHTTPRequestOperation:
TimedAFHTTPRequestOperation *operation = [[TimedAFHTTPRequestOperation alloc] initWithRequest:request];
That code's completion block can then use the startTime property of TimedAFHTTPRequestOperation to calculate the time elapsed for the given operation and add it to the total time:
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
TimedAFHTTPRequestOperation *timedOperation = (id)operation;
CFTimeInterval elapsedTime = CFAbsoluteTimeGetCurrent() - timedOperation.startTime;
self.totalTime += elapsedTime; // Measuring total time HERE!
NSLog(#"finished in %.1f", elapsedTime);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Error: %#", error);
}];
That's how you calculate the elapsedTime and append them together to calculate the totalTime.
In terms of how to know when the operations are done, I would
modify HTTPGetRequest to return a NSOperation;
have startDownload create a completion operation and then add all of these operations as dependencies:
NSOperation *completionOperation = [NSBlockOperation blockOperationWithBlock:^{
NSLog(#"finished all in cumulative time: %.1f", self.totalTime);
}];
for (NSInteger i = 0; i < totalCount; i++)
{
NSOperation *operation = [self HTTPGetRequest];
[completionOperation addDependency:operation];
}
[self.operationQueue addOperation:completionOperation];
That achieves several goals, namely creating a completion operation, calculating the total time (as opposed to the total time elapsed).
By the way, I'd also suggest pulling the creation of AFHTTPClient out of your HTTPGetRequest. You should probably only create one per app. This is especially important in case you ever started using enqueueHTTPRequestOperation instead of creating your own operation queue. I also see no need for your call to registerHTTPOperationClass.
You are incrementing the totalElapsed by elapsedTime, but elapsedTime is calculated from startTime, which itself represents the time that the jobs were first queued, not when the download actually started. Remember that HTTPGetRequest returns almost immediately (having set elapsedTime). Thus if you're queueing five downloads, I wouldn't be surprised that HTTPGetRequest runs five times (and sets and resets startTime five times) before the first request even is initiated.
The question is further complicated by the question of whether you're doing concurrent downloads, and if so, what you then mean by "total elapsed". Let's say you have two concurrent downloads, one that takes 5 seconds, another takes 7 seconds. Do you want the answer to be 7 (because they both finished in 7 seconds)? Or do you want the answer to be 12 (because they both finished in a cumulative 12 seconds)?
I'm presuming that you're looking for, in this scenario, 7 seconds, then you should set the startTime once before you initiate all of your requests, and then only calculate when all of the downloads are done. You could, for example, rather than doing any calculations in HTTPGetRequest at all, just add your own operation that is dependent upon all the other operations you added, which calculates the total elapsed. at the very end. Or, if you want the the total elapsed to just reflect the total elapsed while you're in the process of downloading, then just set totalElapsed rather than incrementing it.
Another option is to inject the "fire" date in the operation's userInfo by observing the AFNetworkingOperationDidStartNotification notification.
//AFHTTPRequestOperation *operation = [...]
id __block observer = [[NSNotificationCenter defaultCenter] addObserverForName:AFNetworkingOperationDidStartNotification
object:operation
queue:nil
usingBlock:^(NSNotification *note) {
operation.userInfo = #{#"fireDate": [NSDate date]};
[[NSNotificationCenter defaultCenter] removeObserver:observer];
}];