/// <summary>
/// Decode a StreamFrame from a raw byte array
/// </summary>
/// <param name="content">The raw byte array</param>
/// <param name="begin">The bit index of the byte array where the AckFrame is located</param>
/// <returns>The number of bits read</returns>
public override int Decode(byte[] content, int begin)
{
if (content.Length < 1 + (begin / 8))
{
throw new ArgumentException();
}
_writableType = content[begin / 8];
if (Type < _minType || Type > _maxType)
{
throw new ArgumentException("Wrong frame type created");
}
OFF = (Type & (1 << 2)) != 0;
LEN = (Type & (1 << 1)) != 0;
FIN = (Type & (1 << 0)) != 0;
int cursor = (begin / 8) + 1;
cursor += StreamID.Decode(cursor * 8, content) / 8;
if (OFF)
{
cursor += Offset.Decode(cursor * 8, content) / 8;
}
if (LEN)
{
cursor += _length.Decode(cursor * 8, content) / 8;
}
else
{
_length = new VariableLengthInteger(Convert.ToUInt64(content.Length) - Convert.ToUInt64(cursor));
}
Data = new byte[_length.Value];
// TODO: error handling if source packet is not long enough
Array.Copy(content, cursor, Data, 0, Convert.ToInt32(_length.Value));
return((cursor + Convert.ToInt32(_length.Value)) * 8 - begin);
}
public void TestDecode()
{
VariableLengthInteger n = new VariableLengthInteger(0);
byte[] b = new byte[] { 0, 0, 3, 0 };
Assert.AreEqual(8, n.Decode(16, b));
Assert.AreEqual(8, n.Size);
Assert.AreEqual((UInt64)3, n.Value);
b = new byte[] { 0, 128, 1, 0, 0, 0, 0 };
Assert.AreEqual(32, n.Decode(8, b));
Assert.AreEqual(32, n.Size);
Assert.AreEqual((UInt64)65536, n.Value);
b = new byte[] { 0x9d, 0x7f, 0x3e, 0x7d };
Assert.AreEqual(32, n.Decode(0, b));
Assert.AreEqual(32, n.Size);
Assert.AreEqual((UInt64)494878333, n.Value);
b = new byte[] { 0x7b, 0xbd };
Assert.AreEqual(16, n.Decode(0, b));
Assert.AreEqual(16, n.Size);
Assert.AreEqual((UInt64)15293, n.Value);
b = new byte[] { 0x25 };
Assert.AreEqual(8, n.Decode(0, b));
Assert.AreEqual(8, n.Size);
Assert.AreEqual((UInt64)37, n.Value);
b = new byte[] { 0x40, 0x25 };
Assert.AreEqual(16, n.Decode(0, b));
Assert.AreEqual(16, n.Size);
Assert.AreEqual((UInt64)37, n.Value);
b = new byte[] { 0xc2, 0x19, 0x7c, 0x5e, 0xff, 0x14, 0xe8, 0x8c };
Assert.AreEqual(64, n.Decode(0, b));
Assert.AreEqual(64, n.Size);
Assert.AreEqual((UInt64)151288809941952652, n.Value);
}