Library for decoding a zip file in a piece

Question

Hi, crowded colleagues, I need to decrypt a large zip file (about 20 MB) on the ipad. Is there a way to parse a zip file in chunks? Ideally, I would like to transfer a decoder (say) 512 thousand data in time and return a fragment of the decoded data, because I feel that loading the entire file into memory and then unpacking it can lead to serious memory problems. A pointer to some incremental decoding libraries would be nice!

Thanks Giuliano

UPDATE : the link provided by Matt in his answer is great for me;)

Answer 1

zip? http://code.google.com/p/objective-zip/

http://code.google.com/p/objective-zip/wiki/GettingStarted, , .

Answer 2

GCD. , , , ... , ....

http://www.raywenderlich.com/4295/multithreading-and-grand-central-dispatch-on-ios-for-beginners-tutorial