Fast byte array to hex string conversion in C#
This is by far the fastest way to convert a list of bytes to an hex string.
Can you beat it?
private static readonly string[] _base16CharTable = new[]
{
"00", "01", "02", "03", "04", "05", "06", "07",
"08", "09", "0A", "0B", "0C", "0D", "0E", "0F",
"10", "11", "12", "13", "14", "15", "16", "17",
"18", "19", "1A", "1B", "1C", "1D", "1E", "1F",
"20", "21", "22", "23", "24", "25", "26", "27",
"28", "29", "2A", "2B", "2C", "2D", "2E", "2F",
"30", "31", "32", "33", "34", "35", "36", "37",
"38", "39", "3A", "3B", "3C", "3D", "3E", "3F",
"40", "41", "42", "43", "44", "45", "46", "47",
"48", "49", "4A", "4B", "4C", "4D", "4E", "4F",
"50", "51", "52", "53", "54", "55", "56", "57",
"58", "59", "5A", "5B", "5C", "5D", "5E", "5F",
"60", "61", "62", "63", "64", "65", "66", "67",
"68", "69", "6A", "6B", "6C", "6D", "6E", "6F",
"70", "71", "72", "73", "74", "75", "76", "77",
"78", "79", "7A", "7B", "7C", "7D", "7E", "7F",
"80", "81", "82", "83", "84", "85", "86", "87",
"88", "89", "8A", "8B", "8C", "8D", "8E", "8F",
"90", "91", "92", "93", "94", "95", "96", "97",
"98", "99", "9A", "9B", "9C", "9D", "9E", "9F",
"A0", "A1", "A2", "A3", "A4", "A5", "A6", "A7",
"A8", "A9", "AA", "AB", "AC", "AD", "AE", "AF",
"B0", "B1", "B2", "B3", "B4", "B5", "B6", "B7",
"B8", "B9", "BA", "BB", "BC", "BD", "BE", "BF",
"C0", "C1", "C2", "C3", "C4", "C5", "C6", "C7",
"C8", "C9", "CA", "CB", "CC", "CD", "CE", "CF",
"D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7",
"D8", "D9", "DA", "DB", "DC", "DD", "DE", "DF",
"E0", "E1", "E2", "E3", "E4", "E5", "E6", "E7",
"E8", "E9", "EA", "EB", "EC", "ED", "EE", "EF",
"F0", "F1", "F2", "F3", "F4", "F5", "F6", "F7",
"F8", "F9", "FA", "FB", "FC", "FD", "FE", "FF"
};
public static string ConvertToBase16Fast2(IList<byte> input)
{
if (input == null || input.Count <= 0)
return string.Empty;
var stringBuilder = new StringBuilder(input.Count * 2);
for (var i = 0; i < input.Count; ++i)
stringBuilder.Append(_base16CharTable[input[i]]);
return stringBuilder.ToString();
}Written by Sascha Kiefer
Related protips
2 Responses
The fastest appender in StringBuilder is the character appender. If you replace the char table with a flat string you will gain better performance depending on the size of the input up to 30%. Also defining a capacity for the StringBuilder may become a performance killer for really long input on heavy loaded systems.
private static readonly string flat = string.Join("", _base16CharTable);
public static string YesICan(IList<byte> input)
{
if (input == null || input.Count < 1)
return string.Empty;
int
x = 0,
i = 0;
var sb = new StringBuilder();
while (i < input.Count)
{
x = input[i++] << 1;
sb.Append(flat[x]);
sb.Append(flat[x + 1]);
}
return sb.ToString();
}
For an unsafe code approach (beating all) check this:
http://www.codeproject.com/Tips/447938/High-performance-Csharp-byte-array-to-hex-string-t
Cheers
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