jjc1138 / data-compression

Extensions to Swift Foundation's Data type to add compression and decompression using libcompression

⚠️ Deprecated and No Longer Maintained ⚠️

In iOS 13 and Apple's other 2019 operating system releases there are new built-in methods on NSData for compressing and decompressing data, so I (@JJC1138) won't be making any further updates to this library and would encourage you to move to the native methods when possible.

Purpose

Compression is a set of extensions to Swift's Foundation Data type that provide data compression and decompression functionality by wrapping libcompression, a new library available on OS 10.11 and iOS 9.0

Compression is written in Swift. For the Objective-C version see LAMCompression.

Installation

To use the Compression extensions in an app, include the Data+Compression.swift file in your project.

You will also need to include the libcompression library in your project.

Data Extensions

func compressed(using: Compression) -> Data?

Returns a Data object created by compressing the receiver using the given compression algorithm.

func uncompressed(using: Compression) -> Data?

Returns a Data object by uncompressing the receiver using the given compression algorithm.

init?(contentsOfArchive: String, usedCompression: Compression?)

Returns a Data object initialized by decompressing the data from the file specified by contentsOfArchive using the given usedCompression algorithm.

init?(contentsOfArchive: String)

Returns a Data object initialized by decompressing the data from the file specified by contentsOfArchive. Attempts to determine the appropriate decompression algorithm using the path's extension.

This method is equivalent to Data(contentsOfArchive:usedCompression:) with nil usedCompression

Documentation

The Data+Compression extension is documented using standard Xcode doc comments.

The project has a dummy (skeleton) app which is included to support Unit Testing with Xcode. The app itself doesn't do anything interesting at all.

Supported OS & SDK Versions

Compression relies on CompressionLib which is only available in OS 10.11 and iOS 9.0 and later.

Background Information

Tinkering with CompressionLib

Tinkering with CompressionLib (Part 2)

Tinkering with CompressionLib (Part 3)

By Lee Morgan. If you find this useful please let me know. I'm @leemorgan on twitter.

License

The license is contained in the "License.txt" file.