Debounce example in swift

DebounceViewController.swift

//
//  DebounceViewController.swift
//  UpgradeMySelf-ios
//
//  Created by Shubham Sharma on 06/05/22.
//  Copyright © 2022 Shubham Sharma. All rights reserved.
//

import UIKit

class DebounceViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        tabBarItem.tag = TabbarItemTag.secondViewConroller.rawValue
        
        view.backgroundColor = .red
        
        
        
        let debouncedFunction = debounce(interval: 200, queue: DispatchQueue.main, action: { (identifier: String) in
            print("called: \(identifier)")
        })
        
        debouncedFunction("1")
        
        DispatchQueue.global(qos: .background).async {
            debouncedFunction("1")
            usleep(100 * 1000)
            debouncedFunction("2")
            usleep(100 * 1000)
            debouncedFunction("3")
            usleep(100 * 1000)
            debouncedFunction("4")
            usleep(300 * 1000) // waiting a bit longer than the interval
            debouncedFunction("5")
            usleep(100 * 1000)
            debouncedFunction("6")
            usleep(100 * 1000)
            debouncedFunction("7")
            usleep(300 * 1000) // waiting a bit longer than the interval
            debouncedFunction("8")
            usleep(100 * 1000)
            debouncedFunction("9")
            usleep(100 * 1000)
            debouncedFunction("10")
            usleep(100 * 1000)
            debouncedFunction("11")
            usleep(100 * 1000)
            debouncedFunction("12")
        }
    }
    
    
    
    typealias Debounce<T> = (_ : T) -> Void
    
    func debounce<T>(interval: Int, queue: DispatchQueue, action: @escaping Debounce<T>) -> Debounce<T> {
        var lastFireTime = DispatchTime.now()
        let dispatchDelay = DispatchTimeInterval.milliseconds(interval)
        
        return { param in
            lastFireTime = DispatchTime.now()
            let dispatchTime: DispatchTime = DispatchTime.now() + dispatchDelay
            
            queue.asyncAfter(deadline: dispatchTime) {
                let when: DispatchTime = lastFireTime + dispatchDelay
                let now = DispatchTime.now()
                
                if now.rawValue >= when.rawValue {
                    action(param)
                }
            }
        }
    }
    
}