CoreStore/Sources/NSPersistentStore+Setup.swift

//
//  NSPersistentStore+Setup.swift
//  CoreStore
//
//  Copyright © 2018 John Rommel Estropia
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in all
//  copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//  SOFTWARE.
//

import Foundation
import CoreData


// MARK: - NSPersistentStore

extension NSPersistentStore {
    
    // MARK: Internal
    
    @nonobjc
    internal var storageInterface: StorageInterface? {
        
        get {
            
            let wrapper: StorageObject? = Internals.getAssociatedObjectForKey(
                &PropertyKeys.storageInterface,
                inObject: self
            )
            return wrapper?.storageInterface
        }
        set {
            
            Internals.setAssociatedRetainedObject(
                StorageObject(newValue),
                forKey: &PropertyKeys.storageInterface,
                inObject: self
            )
        }
    }
    
    
    // MARK: Private
    
    private struct PropertyKeys {
        
        static var storageInterface: Void?
    }
}


// MARK: - StorageObject

fileprivate class StorageObject: NSObject {
    
    // MARK: Private
    
    @nonobjc
    fileprivate let storageInterface: StorageInterface?
    
    @nonobjc
    fileprivate init(_ storage: StorageInterface?) {
        
        self.storageInterface = storage
    }
}