GZIP

Purpose

GZIP is category on NSData that provides simple gzip compression and decompression functionality.

Supported OS & SDK Versions

Supported build target - iOS 12.0 / Mac OS 10.14 (Xcode 10.1)
Earliest supported deployment target - iOS 9.0 / Mac OS 10.12
Earliest compatible deployment target - iOS 8.0 / Mac OS 10.6

NOTE: 'Supported' means that the library has been tested with this version. 'Compatible' means that the library should work on this iOS version (i.e. it doesn't rely on any unavailable SDK features) but is no longer being tested for compatibility and may require tweaking or bug fixes to run correctly.

ARC Compatibility

The GZIP category will work correctly in either ARC or non-ARC projects without modification.

Thread Safety

All the GZIP methods should be safe to call from multiple threads concurrently.

Installation

The simplest way to install GZIP is to use CocoaPods, by adding the following to your Podfile:

pod 'GZIP', '~> 1.3.0'

Alternatively you can use Carthage, or if you prefer to install manually, drag the GZIP.xcodeproj into your project or workspace and include GZIP.framework under the linked libraries in your target.

NSData Extensions

- (NSData *)gzippedDataWithCompressionLevel:(float)level;

This method will apply the gzip deflate algorithm and return the compressed data. The compression level is a floating point value between 0.0 and 1.0, with 0.0 meaning no compression and 1.0 meaning maximum compression. A value of 0.1 will provide the fastest possible compression. If you supply a negative value, this will apply the default compression level, which is equivalent to a value of around 0.7.

- (NSData *)gzippedData;

This method is equivalent to calling gzippedDataWithCompressionLevel: with the default compression level.

- (NSData *)gunzippedData;

This method will unzip data that was compressed using the deflate algorithm and return the result.

- (BOOL)isGzippedData;

This method will return YES if the data is gzip-encoded.

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