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//
// Copyright (c) 2017 Open Whisper Systems. All rights reserved.
//
import Foundation
import UIKit
class ImageCacheRecord: NSObject {
var variations: [CGFloat: UIImage]
init(variations: [CGFloat: UIImage]) {
self.variations = variations
}
}
/**
* A two dimensional hash, allowing you to store variations under a single key.
* This is useful because we generate multiple diameters of an image, but when we
* want to clear out the images for a key we want to clear out *all* variations.
*/
@objc
public class ImageCache: NSObject {
let backingCache: NSCache<AnyObject, ImageCacheRecord>
public override init() {
self.backingCache = NSCache()
}
@objc
public func image(forKey key: AnyObject, diameter: CGFloat) -> UIImage? {
guard let record = backingCache.object(forKey: key) else {
return nil
}
return record.variations[diameter]
}
@objc
public func setImage(_ image: UIImage, forKey key: AnyObject, diameter: CGFloat) {
if let existingRecord = backingCache.object(forKey: key) {
existingRecord.variations[diameter] = image
backingCache.setObject(existingRecord, forKey: key)
} else {
let newRecord = ImageCacheRecord(variations: [diameter: image])
backingCache.setObject(newRecord, forKey: key)
}
}
@objc
public func removeAllImages() {
backingCache.removeAllObjects()
}
@objc
public func removeAllImages(forKey key: AnyObject) {
backingCache.removeObject(forKey: key)
}
}