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• GZIP format (.gz files)RFC-1952
• ZLIB deflate streamRFC-1950
• ZLIB deflate rawRFC-1951
• LZMA
• LZFSE
• LZ4

• iOS deployment target>= 9.0
• macOS deployment target>= 10.11
• tvOS deployment target>= 9.0
• watchOS deployment target>= 2.0

letraw:Data!=String(repeating:"There is no place like 127.0.0.1", count:25).data(using:.utf8)print("raw   =>\(raw.count) bytes")foralgo:Data.CompressionAlgorithmin[.zlib,.lzfse,.lz4,.lzma]{letcompressedData:Data!= raw.compress(withAlgorithm: algo)letratio=Double(raw.count)/ Double(compressedData.count)print("\(algo)   =>\(compressedData.count) bytes, ratio:\(ratio)")assert(compressedData.decompress(withAlgorithm: algo)!== raw)}

Will print something like:

raw    =>   800 byteszlib   =>    40 bytes, ratio:  20.00lzfse  =>    69 bytes, ratio:  11.59lz4    =>   181 bytes, ratio:   4.42lzma   =>   100 bytes, ratio:   8.00

let data: Data! = "https://www.ietf.org/rfc/rfc1951.txt".data(using: .utf8)let deflated: Data! = data.deflate()let inflated: Data? = deflated?.inflate()assert(data == inflated)

let data: Data! = "https://www.ietf.org/rfc/rfc1952.txt".data(using: .utf8)let gzipped: Data! = data.gzip()let gunzipped: Data? = gzipped.gunzip()assert(data == gunzipped)

Note: Compressed data in gzip format will always be 18 bytes larger than raw deflated data and will append/perform a crc32 checksum based data integrity test .

let data: Data! = "https://www.ietf.org/rfc/rfc1950.txt".data(using: .utf8)let zipped: Data! = data.zip()let unzipped: Data? = zipped.unzip()assert(data == unzipped)

Note: Compressed data in zip format will always be 6 bytes larger than raw deflated data and will append/perform a adler32 checksum based data integrity test .

The easiest way is using the already installedgzip command line tool. Assuming you have a file calledfile.txt, after calling

gzip -9 file.txt

the file should have been compressed tofile.txt.gz. You can now load and uncompress the contents of your file with:

let compressedData = try? Data(contentsOf: URL(fileURLWithPath: "/path/to/your/file.txt.gz"))if let uncompressedData = compressedData?.gunzip() {    print(String(data: uncompressedData, encoding: .utf8) ?? "Can't decode UTF-8")}

Unrelated to compression but for convenienceCrc32 andAdler32 methods are also exposed on theData type which may come in handy.

let classicExample = "The quick brown fox jumps over the lazy dog".data(using: .utf8)!let crc32    = classicExample.crc32()let adler32  = classicExample.adler32()print("crc32: \(crc32), adler32: \(adler32)")

Will print:

crc32: 414fa339, adler32: 5bdc0fda

To integrate DataCompression into your Xcode project using CocoaPods, add it to yourPodfile:

target'<your_target_name>'dopod'DataCompression'end

Then, run the following command:

$ pod install

You then will need to addimport DataCompression at the top of your swift source files to use the extension.

Note: DataCompression versions < 3.3.0 are not compatible with carthage. That means Swift 5 only.

To integrate DataCompression into your Xcode project using Carthage, add it as a dependency to yourCartfile. Just add:

github "mw99/DataCompression"

You will then have to add the framework paths in thecarthage copy-frameworks run script phase of your Xcode project.The paths may differ depending on you have setup your project in relation to Carthage.

$(SRCROOT)/Carthage/Build/iOS/DataCompression.framework

$(BUILT_PRODUCTS_DIR)/$(FRAMEWORKS_FOLDER_PATH)/DataCompression.framework

You then will need to addimport DataCompression at the top of your swift source files to use the extension.

To integrate DataCompression into your Xcode project using the swift package manager, add it as a dependency to yourPackage.swift file:

import PackageDescriptionletpackage=Package(    name:"<your_package_name>",    dependencies:[.Package(url:"https://github.com/mw99/DataCompression.git", majorVersion:3)])

You then will need to addimport DataCompression at the top of your swift source files to use the extension.

The next time you runswift build, the new dependencies will be resolved.

$ swift build

You only need one file located atSources/DataCompression.swift. Drag and drop it into the Xcode project navigator.

• Solved a bug causing crashes when using.unzip(), because of unaligned pointer loading caused by internal changes in Swift 5.7.

• Support for Xcode 14 with Swift 5.7

• Target platforms finally added to the SPM Package file
• Carthage support improved
• Support for Xcode 11 SPM integration

• Fix that prevents a bug in Apples lzfse compressor when working with large chunks of data.

• Swift 5 release had further deprecation warnings than in the Swift 5 beta. Fixed.

• Added support for Carthage

• Podspec swift version set to5.0
• Library file structure updated to fit the new swift package manager layout

• Podspec swift version set to4.2

• The encoded data in zip format is not copied anymore, which should improve performance.
• Checksum validation is now always performed with libz and way faster.
• TheskipCheckSumValidation: parameter of.unzip() was removed.
• Items of the algorithm enum type are now Swift like lowercase, e.g..LZMA →.lzma

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.