private static RLPList DecodeList(byte[] data, int start, out int end)
{
// Create a new list representation.
RLPList rlpList = new RLPList();
int current = 0;
// If it's less than 0xf7 than it's a list constituting 0-55 bytes total.
if (data[start] < 0xf7)
{
// Obtain the length of our data.
int length = data[start] - 0xc0;
// Calculate the end of our RLP item.
end = start + 1 + length;
// Keep adding items until we reach the end.
current = start + 1;
while (current < end)
{
rlpList.Items.Add(DecodeAt(data, current, out current));
}
}
else
{
// Obtain the length of the length
int lengthLength = data[start] - 0xf7;
// Obtain our length
int length = DecodeLength(data, start + 1, lengthLength);
// Calculate the end of our RLP item.
end = start + 1 + lengthLength + length;
// Keep adding items until we reach the end.
current = start + 1 + lengthLength;
while (current < end)
{
rlpList.Items.Add(DecodeAt(data, current, out current));
}
}
// Verify our decoding added at our predicted end.
if (current != end)
{
throw new ArgumentException("RLP deserialization encountered an error where travering an encoded list does not add up to the stored length.");
}
return(rlpList);
}
private static byte[] EncodeList(RLPList rlpList)
{
// Obtain all the encoded items and total length.
int length = 0;
byte[][] data = new byte[rlpList.Items.Count][];
for (int i = 0; i < data.Length; i++)
{
data[i] = Encode(rlpList.Items[i]);
length += data[i].Length;
}
// If it's between 0 and 55 bytes, we add a prefix that denotes length.
if (length < 55)
{
return(new byte[] { (byte)(0xC0 + length) }.Concat(data));
}
// If it's more, we'll want to get the length of the data (as a possibly large integer)
byte[] lengthData = EncodeLength(length);
// Return an array with our data
return(new[] { (byte)(0xf7 + lengthData.Length) }.Concat(lengthData).Concat(data));
}
