public static string encode(int inValue)
{
// Add a new least significant bit that has the sign of the value.
// if negative number the least significant bit that gets added to the number has value 1
// else least significant bit value that gets added is 0
// eg. -1 changes to binary : 01 [1] => 3
// +1 changes to binary : 01 [0] => 2
if (inValue < 0)
{
inValue = ((-inValue) << 1) + 1;
}
else
{
inValue = inValue << 1;
}
// Encode 5 bits at a time starting from least significant bits
var encodedStr = "";
do
{
var currentDigit = inValue & 31; // 11111
inValue = inValue >> 5;
if (inValue > 0)
{
// There are still more digits to decode, set the msb (6th bit)
currentDigit = currentDigit | 32;
}
encodedStr = encodedStr + Base64Format.encode(currentDigit);
} while (inValue > 0);
return(encodedStr);
}
public static object decode(string inString)
{
var result = 0;
var negative = false;
var shift = 0;
for (var i = 0; i < inString.Length; i++)
{
var thebyte = Base64Format.decodeChar(inString.Substring(i, 1));
if (i == 0)
{
// Sign bit appears in the LSBit of the first value
if ((thebyte & 1) == 1)
{
negative = true;
}
result = (thebyte >> 1) & 15; // 1111x
}
else
{
result = result | ((thebyte & 31) << shift); // 11111
}
shift += (i == 0) ? 4 : 5;
if ((thebyte & 32) == 32)
{
// Continue
}
else
{
return(new
{
value = negative ? -(result) : result,
rest = inString.Substring(i + 1)
});
}
}
//throw new Error(getDiagnosticMessage(DiagnosticCode.Base64_value_0_finished_with_a_continuation_bit, [inString]));
throw new Exception("Base64 value 0 finished with a continuation bit");
}
