Split NSData objects into other NSData objects of a given size

by

The following piece of code does the fragmentation without copying the data:

NSData* myBlob;
NSUInteger length = [myBlob length];
NSUInteger chunkSize = 100 * 1024;
NSUInteger offset = 0;
do {
    NSUInteger thisChunkSize = length - offset > chunkSize ? chunkSize : length - offset;
    NSData* chunk = [NSData dataWithBytesNoCopy:(char *)[myBlob bytes] + offset
                                         length:thisChunkSize
                                   freeWhenDone:NO];
    offset += thisChunkSize;
    // do something with chunk
} while (offset < length);

Sidenote: I should add that the chunk objects cannot safely be used after myBlob has been released (or otherwise modified). chunk fragments point into memory owned by myBlob, so don’t retain them unless you retain myBlob.

More Related Contents:

  1. Best way to serialize an NSData into a hexadeximal string
  2. Converting HEX NSString To NSData
  3. Finding image type from NSData or UIImage
  4. Converting NSData to base64
  5. NSData and Uploading Images via POST in iOS
  6. Iphone – How to encrypt NSData with public key and decrypt with private key?
  7. NSData to UIImage
  8. Byte Array to NSData
  9. Slow start for AVAudioPlayer the first time a sound is played
  10. Determine MIME Type of NSData Loaded From a File
  11. Correct way to load image into UIWebView from NSData object
  12. Convert hex data string to NSData in Objective C (cocoa)
  13. Send and receive NSData via GameKit
  14. camera streaming between website and iphone [closed]
  15. Programmatically Request Access to Contacts
  16. What does 8badf00d mean?
  17. UIDatePicker pop up after UIButton is pressed
  18. MKAnnotationView – Lock custom annotation view to pin on location updates
  19. Video file formats supported in iPhone
  20. Knowing when AVPlayer object is ready to play
  21. How to share or post by mail, twitter and facebook from the current application?
  22. Windows notepad not supporting newline character ‘\n’
  23. Dragging an UIView inside UIScrollView
  24. iPhone speech recognition API? [duplicate]
  25. Can iPhone apps start on start-up?
  26. NSLocale currentLocale always returns “en_US” not user’s current language
  27. “Pushing the same view controller instance more than once is not supported” exception
  28. Unbalanced calls to begin/end appearance transitions for
  29. Deactivate UIScrollView decelerating
  30. Limiting the scrollable area in UIScrollView

Leave a Comment