public ReedSolomon(GenericGF galoisField, int correctionBytes)
{
_messageLength = galoisField.Size - 1;
_correctionLength = correctionBytes;
_informationLength = _messageLength - _correctionLength;
_reedSolomonEncoder = new ReedSolomonEncoder(galoisField);
_reedSolomonDecoder = new ReedSolomonDecoder(galoisField);
_simpleRsDecoder = new SimpleRSDecoder();
}
public ReedSolomon(int correctionBytes)
{
var galoisField = GenericGF.DATA_MATRIX_FIELD_256;
_messageLength = galoisField.Size - 1;
_correctionLength = correctionBytes;
_informationLength = _messageLength - _correctionLength;
_reedSolomonEncoder = new ReedSolomonEncoder(galoisField);
_reedSolomonDecoder = new ReedSolomonDecoder(galoisField);
_simpleRsDecoder = new SimpleRSDecoder();
}
public void LongDivideProperlyCorrectsErrorInAMessage4()
{
var reedSolomon = new ReedSolomon();
var data = new int[223];
for (var i = 0; i < 223; i++)
{
data[i] = ((i + 50) % 255) + 1;
}
var modifiedData = reedSolomon.EncodeRawBytesArray(data);
modifiedData[0] = 1;
modifiedData[15] = 16;
var simpleDecoder = new SimpleRSDecoder(GenericGF.DATA_MATRIX_FIELD_256);
var response = simpleDecoder.LongDecode(modifiedData, 32);
Assert.IsTrue(response);
for (var i = 0; i < 223; i++)
{
Assert.AreEqual(data[i], modifiedData[i]);
}
}
public void ProperlyNotCorrectsErrorInAMessage5()
{
var reedSolomon = new ReedSolomon();
var data = new int[223];
for (var i = 0; i < 223; i++)
{
data[i] = ((i + 50) % 255) + 1;
}
var modifiedData = reedSolomon.EncodeRawBytesArray(data);
modifiedData[0] = 0;
modifiedData[170] = 170;
var simpleDecoder = new SimpleRSDecoder(GenericGF.DATA_MATRIX_FIELD_256);
var response = simpleDecoder.Decode(modifiedData, 32);
Assert.IsFalse(response);
}
public void ProperlyFindsErrorInAMessage()
{
var reedSolomon = new ReedSolomon(32);
var data = new int[223];
for (var i = 0; i < 223; i++)
{
data[i] = i+10;
}
var modifiedData = reedSolomon.EncodeRawBytesArray(data);
for (var i = 10; i < 30; i++)
{
modifiedData[i] = i + 5;
}
var simpleDecoder = new SimpleRSDecoder();
var response = simpleDecoder.Decode(modifiedData, 32);
Assert.IsFalse(response);
}
public void ProperlyDecodesNoErrorMessage()
{
var reedSolomon = new ReedSolomon(32);
var data = new int[223];
for (var i = 0; i < 223; i++)
{
data[i] = i+10;
}
var modifiedData = reedSolomon.EncodeRawBytesArray(data);
var simpleDecoder = new SimpleRSDecoder();
var response = simpleDecoder.Decode(modifiedData, 32);
Assert.IsTrue(response);
for (var i = 0; i < 223; i++)
{
Assert.AreEqual(data[i], modifiedData[i]);
}
}
public void ProperlyCorrectsUpto16ErrorsInAMessageLoop()
{
var random = new Random(1);
for (var j = 0; j < 17; j++)
{
var reedSolomon = new ReedSolomon();
var data = new int[223];
for (var i = 0; i < 223; i++)
{
data[i] = random.Next(255);
}
var modifiedData = reedSolomon.EncodeRawBytesArray(data);
var errorCount = 0;
var startIndex = random.Next(0,255-16);
for (var k = startIndex; k < startIndex + j; k++)
{
var modifValue = random.Next(255);
while (modifValue == modifiedData[k])
{
modifValue = random.Next(255);
}
modifiedData[k] = modifValue;
errorCount++;
}
var simpleDecoder = new SimpleRSDecoder(GenericGF.DATA_MATRIX_FIELD_256);
var response = simpleDecoder.Decode(modifiedData, 32);
var bytesDiffCount = GetDiffTable(data, modifiedData, 223);
Assert.IsTrue(bytesDiffCount.Count <= errorCount);
for (var i = 0; i < 223; i++)
{
Assert.AreEqual(data[i], modifiedData[i]);
}
}
}
public void ProperlyCorrectsErrorInAMessageLoop()
{
var random = new Random(1);
for (var j = 0; j < 10;)
{
var reedSolomon = new ReedSolomon();
var data = new int[223];
for (var i = 0; i < 223; i++)
{
data[i] = random.Next(1,255);
}
var modifiedData = reedSolomon.EncodeRawBytesArray(data);
var modifIndex = random.Next(255);
modifiedData[modifIndex] = random.Next(255);
var simpleDecoder = new SimpleRSDecoder(GenericGF.DATA_MATRIX_FIELD_256);
var response = simpleDecoder.Decode(modifiedData, 32);
if (response)
{
j++;
for (var i = 0; i < 223; i++)
{
Assert.AreEqual(data[i], modifiedData[i]);
}
}
}
}
public void ProperlyCorrectsErrorInAMessage3()
{
var reedSolomon = new ReedSolomon();
var data = new int[223];
for (var i = 0; i < 223; i++)
{
data[i] = i + 15;
}
var modifiedData = reedSolomon.EncodeRawBytesArray(data);
modifiedData[12] += 182;
var simpleDecoder = new SimpleRSDecoder(GenericGF.DATA_MATRIX_FIELD_256);
var response = simpleDecoder.Decode(modifiedData, 32);
Assert.IsTrue(response);
for (var i = 0; i < 223; i++)
{
Assert.AreEqual(data[i], modifiedData[i]);
}
}
public void ProperlyCorrects2ErrorsInAMessageLoop()
{
var random = new Random(1);
for (var j = 0; j < 5; )
{
var reedSolomon = new ReedSolomon();
var data = new int[223];
for (var i = 0; i < 223; i++)
{
data[i] = random.Next(1, 255);
}
var modifiedData = reedSolomon.EncodeRawBytesArray(data);
var modifIndex = random.Next(255);
var modifValue = random.Next(255);
while (modifValue == modifiedData[modifIndex])
{
modifValue = random.Next(255);
}
modifiedData[modifIndex] = modifValue;
var modifIndex2 = random.Next(255);
var modifValue2 = random.Next(255);
while (modifIndex == modifIndex2)
{
modifIndex2 = random.Next(255);
}
while (modifValue2 == modifiedData[modifIndex2])
{
modifValue2 = random.Next(255);
}
modifiedData[modifIndex2] = modifValue2;
var simpleDecoder = new SimpleRSDecoder(GenericGF.DATA_MATRIX_FIELD_256);
var response = simpleDecoder.Decode(modifiedData, 32);
var bytesDiffCount = GetDiffTable(data, modifiedData, 223);
Assert.IsTrue(bytesDiffCount.Count <= 2);
if (response)
{
j++;
for (var i = 0; i < 223; i++)
{
Assert.AreEqual(data[i], modifiedData[i]);
}
}
}
}
