public void TestAvailableBitsAndEOF()
{
byte[] data = { unchecked ((byte)-120), unchecked ((byte)6) };
BitStringReader reader = new BitStringReader(Base64.ByteEncoding.GetString(data));
Assert.AreEqual(16, reader.AvailableBits());
Assert.AreEqual(false, reader.Eof);
reader.Read(3);
Assert.AreEqual(13, reader.AvailableBits());
Assert.AreEqual(false, reader.Eof);
reader.Read(3);
Assert.AreEqual(10, reader.AvailableBits());
Assert.AreEqual(false, reader.Eof);
reader.Read(3);
Assert.AreEqual(7, reader.AvailableBits());
Assert.AreEqual(false, reader.Eof);
reader.Read(7);
Assert.AreEqual(0, reader.AvailableBits());
Assert.AreEqual(true, reader.Eof);
Assert.AreEqual((uint)0, reader.Read(3));
Assert.AreEqual(true, reader.Eof);
Assert.AreEqual(0, reader.AvailableBits());
}
public void TestOneByte()
{
byte[] data = { unchecked ((byte)-28) };
BitStringReader reader = new BitStringReader(Base64.ByteEncoding.GetString(data));
Assert.AreEqual((uint)0, reader.Read(2));
Assert.AreEqual((uint)1, reader.Read(2));
Assert.AreEqual((uint)2, reader.Read(2));
Assert.AreEqual((uint)3, reader.Read(2));
}
public void TestTwoBytesSplit()
{
byte[] data = { unchecked ((byte)-120), unchecked ((byte)6) };
BitStringReader reader = new BitStringReader(Base64.ByteEncoding.GetString(data));
Assert.AreEqual((uint)0, reader.Read(3));
Assert.AreEqual((uint)1, reader.Read(3));
Assert.AreEqual((uint)2, reader.Read(3));
Assert.AreEqual((uint)3, reader.Read(3));
}
public int[] Decompress(string data, ref int algorithm)
{
if (data.Length < 4)
{
// Invalid fingerprint (shorter than 4 bytes)
return(new int[0]);
}
// TODO: this is not exactly what the C++ version does
if (algorithm <= 0)
{
algorithm = (int)data[0];
}
int length = ((byte)(data[1]) << 16) | ((byte)(data[2]) << 8) | ((byte)(data[3]));
BitStringReader reader = new BitStringReader(data);
reader.Read(8);
reader.Read(8);
reader.Read(8);
reader.Read(8);
if (reader.AvailableBits() < length * kNormalBits)
{
// Invalid fingerprint (too short)
return(new int[0]);
}
m_result = new List <int>(length);
for (int i = 0; i < length; i++)
{
m_result.Add(-1);
}
reader.Reset();
if (!ReadNormalBits(reader))
{
return(new int[0]);
}
reader.Reset();
if (!ReadExceptionBits(reader))
{
return(new int[0]);
}
UnpackBits();
// TODO: no list needed?
return(m_result.ToArray());
}
bool ReadNormalBits(BitStringReader reader)
{
int i = 0;
while (i < m_result.Count)
{
int bit = (int)reader.Read(kNormalBits);
if (bit == 0)
{
i++;
}
m_bits.Add((byte)bit);
}
return(true);
}
bool ReadExceptionBits(BitStringReader reader)
{
for (int i = 0; i < m_bits.Count; i++)
{
if (m_bits[i] == kMaxNormalValue)
{
if (reader.Eof)
{
// Invalid fingerprint (reached EOF while reading exception bits)
return(false);
}
m_bits[i] += (byte)reader.Read(kExceptionBits);
}
}
return(true);
}
