NVHTarGzip

This is an ObjC library for tarring/untarring and gzipping/ungzipping that directly manipulates files. It isn't implemented as a category on NSData (unlike GZIP or Godzippa) so the full file doesn't have to be first loaded into memory.

The tar implementation is based on Light-Untar-for-iOS, but is extended to include progress reporting through NSProgress.

Usage

Asynchronous

Inflate Gzip file

[[NVHTarGzip shared] unGzipFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* gzipError) {
    if (gzipError != nil) {
        NSLog(@"Error ungzipping %@", gzipError);
    }
}];

Untar file

[[NVHTarGzip shared] unTarFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* tarError) {
    if (tarError != nil) {
        NSLog(@"Error untarring %@", tarError);
    }
}];

Inflate Gzip and Untar

[[NVHTarGzip shared] unTarGzipFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* error) {
    if (error != nil) {
        NSLog(@"Error extracting %@", error);
    }
}];

Deflate Gzip file

[[NVHTarGzip shared] gzipFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* gzipError) {
    if (gzipError != nil) {
        NSLog(@"Error gzipping %@", gzipError);
    }
}];

Tar file

[[NVHTarGzip shared] tarFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* tarError) {
    if (tarError != nil) {
        NSLog(@"Error tarring %@", tarError);
    }
}];

Deflate Gzip and Tar

[[NVHTarGzip shared] tarGzipFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* error) {
    if (error != nil) {
        NSLog(@"Error packing %@", error);
    }
}];

Synchronous

Inflate Gzip file

[[NVHTarGzip shared] unGzipFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* gzipError) {
    if (gzipError != nil) {
        NSLog(@"Error ungzipping %@", gzipError);
    }
}];

Untar file

[[NVHTarGzip shared] unTarFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* tarError) {
    if (tarError != nil) {
        NSLog(@"Error untarring %@", tarError);
    }
}];

Inflate Gzip and Untar

[[NVHTarGzip shared] unTarGzipFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* error) {
    if (error != nil) {
        NSLog(@"Error extracting %@", error);
    }
}];

Deflate Gzip file

[[NVHTarGzip shared] gzipFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* gzipError) {
    if (gzipError != nil) {
        NSLog(@"Error gzipping %@", gzipError);
    }
}];

Tar file

[[NVHTarGzip shared] tarFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* tarError) {
    if (tarError != nil) {
        NSLog(@"Error untarring %@", tarError);
    }
}];

Deflate Gzip and Tar

[[NVHTarGzip shared] tarGzipFileAtPath:sourcePath toPath:destinationPath completion:^(NSError* error) {
    if (error != nil) {
        NSLog(@"Error extracting %@", error);
    }
}];

Note

Sequential tar.gz packing and unpacking will either tar or ungzip the intermediate tar file to a temporary-directory, and subsequently gzip or untar it. After gzipping/untarring, the temporary-file is deleted. You can customize the cachePath by setting it on the singleton object before extracting:

[[NVHTarGzip shared] setCachePath:customCachePath];

Progress

NVHTarGzip uses NSProgress to handle progress reporting. To keep track of progress create your own progress instance and use KVO to inspect the fractionCompleted property. See the documentation of NSProgress and this great article by Ole Begemann for more information.

NSProgress* progress = [NSProgress progressWithTotalUnitCount:1];
NSString* keyPath = NSStringFromSelector(@selector(fractionCompleted));
[progress addObserver:self forKeyPath:keyPath options:NSKeyValueObservingOptionInitial context:NVHProgressFractionCompletedObserverContext];
[progress becomeCurrentWithPendingUnitCount:1];
[[NVHTarGzip shared] unTarGzipFileAtPath:self.demoSourceFilePath toPath:self.demoDestinationFilePath completion:^(NSError* error) {
    [progress resignCurrent];
    [progress removeObserver:self forKeyPath:keyPath];
}];

Checkout a full usage example in the example project; clone the repo, and run pod install from the Example directory first.

Todo

Add streaming support (NSStream). This would allow the usage of an intermediate file for tar.gz packing and unpacking, thus speeding things a bit.

Pull requests are welcome!

Installation

NVHTarGzip is available through CocoaPods, to install it simply add the following line to your Podfile:

pod "NVHTarGzip"

Author

Niels van Hoorn, nvh@nvh.io

License

NVHTarGzip is available under the MIT license. See the LICENSE file for more info.