Easy Stash

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Description

EasyStash is an easy and lightweight persistence framework in Swift. With simple abstraction over NSCache and FileManager, it saves us from tedious work of saving and loading objects. There are no clever async, expiry handling or caching strategy for now, just save and load.

• Swift 5
• Support iOS, macOS, tvOS, watchOS
• Synchronous APIs with explicit try catch
• Persist UIImage/NSImage
• Persist Codable objects, including primitive types
• Persist Data
• Test coverage

Usage

The main and only class is Storage which encapsulates memory and disk cache. All operations involving disk are error prone, we need to handle error explicitly.

With Options, we can customize folder name, searchPathDirectory, encoder and decoder for Codable. By default, folder and searchPathDirectory specify that files will be saved at /Library/Application Support/{BUNDLE_ID}/Default/

var storage: Storage? = nil

var options: Options = Options()
options.folder = "Users"

storage = try? Storage(options: options)

do {
    try storage?.save(image, forKey: "image")
    try storage?.save(users, forKey: "codable")
} catch {
    print(error)
}

Memory cache is checked first before doing disk operations, so we won't hit disk that often.

Saving and loading images

Works for both UIImage and NSImage. Because image and data loading uses the same signatures, we need to explicitly specify type

try storage.save(image, forKey: "image")
let loadedImage: UIImage = try storage.load(forKey: "image")

Saving and loading Codable objects

Uses JSONEncoder and JSONDecoder under the hood to serialize and deserialize to and from Data

let user = User(name: "A", age: 10)
let cities = [City(name: "Oslo"), City(name: "New York")]

try storage.save(users, forKey: "user")
try storage.save(cities, forKey: "cities")

let loadedUser = try storage.load(forKey: "user", as: User.self)
let loadedCities = try storage.load(forKey: "cities", as: [City].self)

Saving and loading Data

try storage.save(object: data, forKey: "data")
let loadedData: Data = try storage.load(forKey: "data")

Saving and loading primitives

Although primitives like Int, String, Bool conform to Codable, they can't be serialized into Data using JSONEncoder because json needs root object. This framework handles this case, so you can just save and load as normal

try storage.save(100, forKey: "an int")
try storage.save(isLoggedIn, forKey: "a boolean")

Folder informations

EasyStash includes some helpful functions to check file and folder within its Storage.

Check if file exists

try storage.exists(forKey: "has_updated_profile")

Remove file

try storage.remove(forKey: "a flag")

Remove all files

try storage.removeAll()

List all files. Each file has name, url, modificationDate and size information

let files = try storage.files()

Check folder size

let size = try storage.folderSize()

Check if folder has content

try storage.isEmpty()

Remove files based on predicate. This is useful when we want to clear expired objects, or objects based certain criteria.

try storage.removeAll(predicate: { $0.modificationDate < migrationDate })

Async

EasyStash is designed to be synchronous. If we want to do async, it's easy as using DispatchQueue

DispatchQueue.global().async {
    do {
        try storage.save(largeImage, forKey: "large_image")
    } catch {

    }
}

Installation

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

pod 'EasyStash'

EasyStash is also available through Carthage. To install just write into your Cartfile:

github "onmyway133/EasyStash"

EasyStash is also available through Swift Package Manager. Add EasyStash as a dependency to your Package.swift. For more information, please see the Swift Package Manager documentation.

.package(url: "https://github.com/onmyway133/EasyStash", from: "1.1.8")

EasyStash can also be installed manually. Just download and drop Sources folders in your project.

Author

Khoa Pham, onmyway133@gmail.com

Contributing

We would love you to contribute to EasyStash, check the CONTRIBUTING file for more info.

License

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