Johnny is a caching library written in Swift.
- Multiplatform, supporting iOS, macOS, tvOS & watchOS
- First-level memory cache using
NSCache
- Second-level LRU disk cache
- Generic cache with out-of-the-box support for
- Int, UInt, Int64, UInt64, Float, Double, String (+ Date, Data & URL in the
swift3 branch
) - NSData, NSDate
- UIImage, UIColor
- Arrays, Dictionaries and Sets of the above
- Optionals of the above
- Any type that conforms to the
Storable
protocol
- Int, UInt, Int64, UInt64, Float, Double, String (+ Date, Data & URL in the
- Disk access in background thread (always when saving, optionally when fetching)
- Syncronous & Asynchronous API support
- Automatic cache eviction on memory warnings & disk capacity reached
- Unit tested
- Concise, well-structured code to encourage contributions
Extra ❤️ for images:
-
func setImageWithURL
extension on UIImageView, UIButton & NSImageView, optimized for cell reuse
###Caching###
Johnny.cache(NSDate(), key: "FirstStart")
###Retrieving###
// The type of the retrived value must be explicitly stated for the compiler.
let date: NSDate? = Johnny.pull("FirstStart")
###Async fetch###
If you know you are retrieving a large object (> 1.5 MB):
Johnny.pull("4KImage") { (value: UIImage?) in
}
Note, that since the protocol uses a static constructor function instead of an initializer, you can extend any class without errors, even if you don't have access to its source (like Standard library classes)
public protocol Storable {
associatedtype Result
static func fromData(data: NSData) -> Result?
func toData() -> NSData
}
###Collections ###
You can cache any collection of items conforming to the Storable protocol (most Stdlib data types already do)
let array: [String] = ["Folsom", "Prison", "Blues"]
let stringSet: Set<String> = ["I've", "been", "everywhere"]
// In case of dictionaries, the value must explicitly conform to Storable (so [String: AnyObject] does not work, while [String: Double] does)
let dictionary: [String: String] = ["first": "Solitary", "second": "man"]
Johnny.cache(array, key: "folsom")
Johnny.cache(stringSet, key: "everywhere")
Johnny.cache(dictionary, key: "solitary")
Due to current Swift limitations, since the Storable protocol has an associatedType
, conformance must be added through an extension.
class User: Storable
will not work.
class User {
enum Badassery: String { case Total }
var name: String? = "Johnny"
var uid: Int = 84823682
var badassery = Badassery.Total
}
extension User: Storable {
typealias Result = User
static func fromData(data: NSData) -> User.Result? {
let dict = try! NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions()) as! [NSObject: AnyObject]
let user = User()
user.uid = dict["identification"] as! Int
user.name = dict["name"] as? String
user.badassery = Badassery(rawValue: dict["badassery"] as! String)!
return user
}
func toData() -> NSData {
let json = ["identification": uid, "name": name, "badasery": badassery.rawValue]
return try! NSJSONSerialization.dataWithJSONObject(json, options: NSJSONWritingOptions())
}
}
Using it with Johnny:
let johnny: User = User()
Johnny.cache(johnny, key: "John")
let cachedJohn: User = Johnny.pull("John")
- iOS 8.0+
- macOS 10.10+
- tvOS 9.0+
- watchOS 2.0+
- Swift 2.0+ (there's also a swift3 branch)
CocoaPods
pod 'Johnny'
I'd like to thank the creators of Pantry and Haneke as those projects provided much of the inspiration and some code. Johnny was dreamed up to be the best of both worlds.
Johnny is released under the MIT license. See LICENSE for details.