Question

I am currently receiving some compressed data from my server.
I would like to know if there is a way to check how much bandwidth is being saved but checking the size of the compressed data vs the uncompressed data?

This is what my code looks like

//Communication Test
- (IBAction)sendHttpsRequest
{   
    //Start HUD
    [SVProgressHUD showWithMaskType:SVProgressHUDMaskTypeBlack];
    [SVProgressHUD setStatus:@"loading..."];

    //Set request address
    NSMutableString *databaseURL = [[NSMutableString alloc] initWithString:@"https://192.168.17.36:443"];

    //call ASIHTTP delegates (Used to connect to database)
    NSURL *url = [NSURL URLWithString:databaseURL];

    //This sets up all other request
    ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];

    [request setDelegate:self];
    [request setValidatesSecureCertificate:NO];
    [request setPostValue:@"ClientDataSet.xml" forKey:@"filename"];  

    [request startSynchronous];

    BOOL dataWasCompressed = [request isResponseCompressed]; // Was the response gzip compressed?
    NSData *compressedResponse = [request rawResponseData]; // Compressed data
    NSData *uncompressedData = [request responseData]; // Uncompressed data
    NSString *response = [request responseString]; // Uncompressed data as a string

    //Output responses    
    NSLog(@"compressed? %@", dataWasCompressed ? @"YES" : @"NO" );
    NSLog(@"compressed Response = %@", compressedResponse);
    NSLog(@"uncompressed Data = %@", uncompressedData);
    NSLog(@"response = %@", response);
}

- (void)requestFinished:(ASIHTTPRequest *)request
{       
    self.hudCheck = YES;

    responseString = [request responseString]; //Pass requested text from server over to NSString
    NSLog(@"Response String = %@", responseString);

    //removies the SVProgressHUD
    [NSTimer scheduledTimerWithTimeInterval:0.25 target:self selector:@selector(stopAnimating) userInfo:nil repeats:NO];
}

Any help would be greatly appreciated

Answer 1

METHOD 1: Since ASIHttpRequest uses gzip to uncompress data, one easy way to see the compression rate is to just use gzip on your server & see how small the file becomes.

In normal scenario i.e. when gzipping text files, gzip gives close to 80% compression rates.

METHOD 2: If you require exact amount of compressed data transferred over the air then you need to implement request:didReceiveBytes: and request:incrementDownloadSizeBy:. Both are download trackers in ASIHttpRequest primarily used for showing download progress bars.