86 lines
2.5 KiB
Swift
86 lines
2.5 KiB
Swift
//
|
|
// ImageCache.swift
|
|
// Tusker
|
|
//
|
|
// Created by Shadowfacts on 8/21/18.
|
|
// Copyright © 2018 Shadowfacts. All rights reserved.
|
|
//
|
|
|
|
import UIKit
|
|
import Cache
|
|
|
|
class ImageCache {
|
|
|
|
static let avatars = ImageCache(name: "Avatars")
|
|
|
|
let storage: Storage<UIImage>
|
|
|
|
var requests = [URL: Request]()
|
|
|
|
init(name: String, diskExpiry: Expiry = .seconds(60 * 60 * 24), memoryExpiry: Expiry = .seconds(60 * 60)) {
|
|
self.storage = try! Storage(
|
|
diskConfig: DiskConfig(name: name, expiry: diskExpiry),
|
|
memoryConfig: MemoryConfig(expiry: memoryExpiry),
|
|
transformer: TransformerFactory.forImage())
|
|
}
|
|
|
|
func get(_ url: URL, completion: ((UIImage?) -> Void)?) {
|
|
let key = url.absoluteString
|
|
if (try? storage.existsObject(forKey: key)) ?? false,
|
|
let image = try? storage.object(forKey: key) {
|
|
completion?(image)
|
|
} else {
|
|
if let completion = completion, let request = requests[url] {
|
|
request.callbacks.append(completion)
|
|
} else {
|
|
let request = Request(url: url, completion: completion)
|
|
requests[url] = request
|
|
request.run { (image) in
|
|
try? self.storage.setObject(image, forKey: key)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func cancel(_ url: URL) {
|
|
requests[url]?.cancel()
|
|
}
|
|
|
|
class Request {
|
|
let url: URL
|
|
var task: URLSessionDataTask?
|
|
var callbacks: [(UIImage?) -> Void]
|
|
|
|
init(url: URL, completion: ((UIImage?) -> Void)?) {
|
|
if let completion = completion {
|
|
self.callbacks = [completion]
|
|
} else {
|
|
self.callbacks = []
|
|
}
|
|
self.url = url
|
|
}
|
|
|
|
func run(cache: @escaping (UIImage) -> Void) {
|
|
task = URLSession.shared.dataTask(with: url, completionHandler: { (data, response, error) in
|
|
guard error == nil, let data = data, let image = UIImage(data: data) else {
|
|
self.complete(with: nil)
|
|
return
|
|
}
|
|
cache(image)
|
|
self.complete(with: image)
|
|
})
|
|
task!.resume()
|
|
}
|
|
|
|
func cancel() {
|
|
task?.cancel()
|
|
complete(with: nil)
|
|
}
|
|
|
|
func complete(with image: UIImage?) {
|
|
callbacks.forEach { $0(image) }
|
|
}
|
|
}
|
|
|
|
}
|