Size suffix from bytes

static readonly string [] SizeSuffixes =
                   { "bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };

static string SizeSuffix (ulong value, uint decimalPlaces = 1) {
    if (value == 0) { return string.Format ("{0:n" + decimalPlaces + "} bytes", 0); }

    // mag is 0 for bytes, 1 for KB, 2, for MB, etc.
    int mag = (int) Mathf.Log (value, 1024);

    // 1L << (mag * 10) == 2 ^ (10 * mag)
    // [i.e. the number of bytes in the unit corresponding to mag]
    decimal adjustedSize = (decimal) value / (1L << (mag * 10));

    // make adjustment when the value is large enough that
    // it would round up to 1000 or more
    if (System.Math.Round (adjustedSize, (int) decimalPlaces) >= 1000) {
        mag += 1;
        adjustedSize /= 1024;
    }

    return string.Format ("{0:n" + decimalPlaces + "} {1}",
        adjustedSize,
        SizeSuffixes [mag]);
}