Hexdump Data object to String

Data+Hex.swift

import Foundation

private let kHexHeader = "87654321  0011 2233 4455 6677 8899 aabb ccdd eeff  0123456789abcdef\n"
private let kLineHeader = "00000000:"
private let kLineLength = 16

extension Data {
    
    func hexArray() -> String {

        let array = [UInt8](self)

        if array.isEmpty {
            return "<data ojbect is empty>"
        }

        var result = "["
        let count = array.count

        for i in 0 ..< count {
            result += NSString(format: "0x%02X", array[i]) as String
            if i != count - 1 {
                result += ", "
            }
        }

        result += "]"

        return result
    }

    func hex() -> String {

        let array = [UInt8](self)

        if array.isEmpty {
            return "<data ojbect is empty>"
        }

        var result = kHexHeader

        let count = array.count

        if count != 0 {

            for i in 0 ... (count - 1) / kLineLength {

                let inRange = range(for: i, count: count)
                let slice: [UInt8] = [UInt8](array[inRange])
                result += line(for: slice, i)
            }

        }

        return result
    }

    private func range(for i: Int, count: Int) -> ClosedRange<Int> {

        let fristIndex = i * kLineLength

        var length = kLineLength
        if (count - i * kLineLength) < kLineLength {
            length = count - i * kLineLength
        }

        let lastIndex = fristIndex + length - 1

        return fristIndex...lastIndex
    }

    private func line(for bytes: [UInt8], _ index: Int) -> String {

        var fullLine = lineHeader(for: index)

        fullLine += hexLine(bytes)
        fullLine += readableLine(bytes)

        return fullLine + "\n"
    }

    private func lineHeader(for index: Int) -> String {
        String(format:"%08X:", index)
    }

    private func hexLine(_ bytes: [UInt8]) -> String {

        var result = ""

        for (i, byte) in bytes.enumerated() {
            if i % 2 == 0 {
                result += " "
            }
            result += String(format:"%02X", byte)
        }

        let fullLineLength = 40
        let spacesCount = fullLineLength - result.count + 2
        return result + String(repeating: " ", count: spacesCount)
    }

    private func readableLine(_ bytes: [UInt8]) -> String {

        var result = bytes.reduce("", { $0 + ($1 > 31 && $1 < 127 ? String(format: "%c", $1) : ".") })

        let fullLineLength = 16
        let spacesCount = fullLineLength - result.count

        result += String(repeating: " ", count: spacesCount)

        return result
    }
}