一个propertyWrapper判断某个涉及耗时操作的属性是否需要更新

在进行项目开发时，遇到了这么个情况：某个属性需要和蓝牙交互，但是这个操作会比较耗时，现在想实现当这个属性的值在更改前后未发生变动的时候，跳过蓝牙交互，直接进行下一步操作，从而提升用户体验，下面是我的@propertyWrapper实现，请大家指正：

@propertyWrapper
final class EditDetectable<E> where E: Equatable {
	
	var projectedValue: EditDetectable<E> {
		self
	}
	private var value: E?
	var wrappedValue: E? {
		get { value }
		set {
			value = newValue
			
			/// 根据命中条件决定是否继续执行 '命中' 方法
			if requirements.contains(.valid), newValue == .none { return }
			if let string = newValue as? String,
			   requirements.contains(.validString),
			   string.isEmptyString { return }
			hit(newValue)
		}
	}
	var needsUpdate: Bool {
		if hitCache.isEmpty { // 未命中
			return false
		} else { // 至少命中1次
			guard hitCache.count > 1 else {
				// 只命中了1次
				if requirements.contains(.ignoreInitialValue) {
					return false
				}
				return true
			}
			// 命中了2次以上
			// 校验当前值是否满足指定条件
			var isValid: Bool {
				guard requirements.contains(.valid) else { return true }
				return wrappedValue != .none
			}
			var isNotEmptyString: Bool {
				guard requirements.contains(.validString) else { return true }
				guard let string = wrappedValue as? String else { return false }
				return !string.isEmptyString
			}
			return isValid && isNotEmptyString && hitCache.first != hitCache.last
		}
	}
	
	private var lock = NSRecursiveLock()
	private var hitCache: [E?] = []
	private func hit(_ value: E?) {
		lock.lock()
		if hitCache.count == 2 {
			hitCache.removeLast()
		}
		hitCache.append(value)
		lock.unlock()
	}
	
	private let requirements: ValueRequirement
	init(wrappedValue: E?, requirements: ValueRequirement = [.valid]) {
		self.requirements = requirements
		self.wrappedValue = wrappedValue
	}
}

struct ValueRequirement: OptionSet {
	let rawValue: Int
	static let valid              = ValueRequirement(rawValue: 1 << 0)
	static let validString        = ValueRequirement(rawValue: 1 << 1)
	static let ignoreInitialValue = ValueRequirement(rawValue: 1 << 2)
}

使用时调用EditDetectable.needsUpdate属性判断是否需要更新

@EditableProperty(requirements: [.valid, .validString])
var name: String? = ""
name = ""
name = nil
name = "7788"
name = "8899"
name = "9090"
name = "7788"
name = "8899"
name = nil
print("更新? ", $name.needsUpdate)