WeakMap

WeakMap.swift

//
//  WeakMap.swift
//  dotNetTree
//
//  Created by SeungChul Kang on 2018. 5. 1..
//  Copyright © 2018년 motel. All rights reserved.
//

import Foundation

class WeakMap<K: AnyObject, V: AnyObject> {

    private var mapTable: NSMapTable<K, V>
    init(keyOptions: NSPointerFunctions.Options, valueOptions: NSPointerFunctions.Options) {
        mapTable = NSMapTable.init(keyOptions: keyOptions, valueOptions: valueOptions)
    }
    
    static func instance() -> WeakMap2<K, V> {
        return WeakMap2.init(keyOptions: .weakMemory, valueOptions: .strongMemory)
    }

    var description: String {
        return mapTable.description
    }

    subscript(key: K) -> V? {
        set { mapTable.setObject(newValue, forKey: key) }
        get { return mapTable.object(forKey: key) }
    }

}

/* 사용예제
extension UIViewController {
    static var store = WeakMap<UIViewController, NSMutableDictionary> = WeakMap.instance()
}

class TestVC: UIViewController {
// 각종 코드
}

extension TestVC {
  func test() {
    let store = TestVC.store[self] ?? NSMutableDictionary.init()
    
    // 여기서부터 자유롭게 store 데이터를 넣고 빼고 하면 됨.
  }
}

*/