RingBuffer.swift

class RingBuffer<T>
{
    private(set) var array: [T?]
    
    private var readIndex = 0
    private var writeIndex = 0
    
    public var isFull: Bool
    {
        return array.compactMap({ $0 }).count == array.count
    }
    
    init(count: Int)
    {
        self.array = [T?](repeating: nil, count: count)
    }
    
    func write(_ element: T)
    {
        if writeIndex >= array.count
        {
            writeIndex = 0
        }
        
        array[writeIndex] = element
        writeIndex += 1
    }
    
    func read() -> T?
    {
        guard array.filter({ $0 != nil }).count > 0 else { return nil }
        
        if readIndex >= array.count { readIndex = 0 }
        
        let element = array[readIndex]
        
        readIndex += 1
        
        return element
    }
}