A simple class to find the delta between subsequent data variables

dataDeltaFinder.swift

//
//  imageDeltaFinder.swift
//  Omegacam-ios
//
//  Created by Richard Wei on 2/24/21.
//

import Foundation
import AVFoundation

class dataDeltaFinder{
    static private var previousData : Data = Data();
        
    static public func input(_ c: Data) -> UInt64{
        let output = delta(previousData, c);
        previousData = c;
        return output;
    }
    
    static private func delta(_ a: Data, _ b: Data) -> UInt64{
        let a_a = convertDataToAUInt8(a);
        let b_a = convertDataToAUInt8(b);
        
        var deltaCount : UInt64 = 0;
        
        var i = 0;
        
        while ( i < a_a.count && i < b_a.count ){
            if (a[i] != b[i]){
                deltaCount += 1;
            }
            i+=1;
        }
        
        deltaCount += UInt64(max(a_a.count , b_a.count) - i);
        
        return deltaCount;
    }
    
    //
    static internal func convertDataToAUInt8(_ d: Data) -> [UInt8]{
        var t : [UInt8] = [];
        t.append(contentsOf: d);
        return t;
    }
    
    //
}