public ReedSolomonEncoder(GenericGF field)
{
if (!GenericGF.QR_CODE_FIELD_256.Equals(field))
{
throw new System.ArgumentException("Only QR Code is supported at this time");
}
this.field = field;
this.cachedGenerators = new List<GenericGFPoly>();
cachedGenerators.Add(new GenericGFPoly(field, new int[]{1}));
}
private static void testDecoder(GenericGF field, int[] dataWords, int[] ecWords)
{
ReedSolomonDecoder decoder = new ReedSolomonDecoder(field);
int[] message = new int[dataWords.Length + ecWords.Length];
int maxErrors = ecWords.Length / 2;
Random random = getPseudoRandom();
int iterations = field.Size > 256 ? 1 : DECODER_TEST_ITERATIONS;
for (int j = 0; j < iterations; j++)
{
for (int i = 0; i < ecWords.Length; i++)
{
if (i > 10 && i < ecWords.Length / 2 - 10)
{
// performance improvement - skip intermediate cases in long-running tests
i += ecWords.Length / 10;
}
Array.Copy(dataWords, 0, message, 0, dataWords.Length);
Array.Copy(ecWords, 0, message, dataWords.Length, ecWords.Length);
corrupt(message, i, random, field.Size);
if (!decoder.decode(message, ecWords.Length))
{
// fail only if maxErrors exceeded
Assert.IsTrue(i > maxErrors, "Decode in " + field + " (" + dataWords.Length + ',' + ecWords.Length + ") failed at " + i);
// else stop
break;
}
if (i < maxErrors)
{
assertDataEquals("Decode in " + field + " (" + dataWords.Length + ',' + ecWords.Length + ") failed at " +
i + " errors",
dataWords,
message);
}
}
}
}
private static void testEncoder(GenericGF field, int[] dataWords, int[] ecWords)
{
ReedSolomonEncoder encoder = new ReedSolomonEncoder(field);
int[] messageExpected = new int[dataWords.Length + ecWords.Length];
int[] message = new int[dataWords.Length + ecWords.Length];
Array.Copy(dataWords, 0, messageExpected, 0, dataWords.Length);
Array.Copy(ecWords, 0, messageExpected, dataWords.Length, ecWords.Length);
Array.Copy(dataWords, 0, message, 0, dataWords.Length);
encoder.encode(message, ecWords.Length);
assertDataEquals("Encode in " + field + " (" + dataWords.Length + ',' + ecWords.Length + ") failed",
messageExpected, message);
}
private static void testEncodeDecode(GenericGF field, int[] dataWords, int[] ecWords)
{
testEncoder(field, dataWords, ecWords);
testDecoder(field, dataWords, ecWords);
}
private static void testEncodeDecodeRandom(GenericGF field, int dataSize, int ecSize)
{
Assert.IsTrue(dataSize > 0 && dataSize <= field.Size - 3, "Invalid data size for " + field);
Assert.IsTrue(ecSize > 0 && ecSize + dataSize <= field.Size, "Invalid ECC size for " + field);
ReedSolomonEncoder encoder = new ReedSolomonEncoder(field);
int[] message = new int[dataSize + ecSize];
int[] dataWords = new int[dataSize];
int[] ecWords = new int[ecSize];
Random random = getPseudoRandom();
int iterations = field.Size > 256 ? 1 : DECODER_RANDOM_TEST_ITERATIONS;
for (int i = 0; i < iterations; i++)
{
// generate random data
for (int k = 0; k < dataSize; k++)
{
dataWords[k] = random.Next(field.Size);
}
// generate ECC words
Array.Copy(dataWords, 0, message, 0, dataWords.Length);
encoder.encode(message, ecWords.Length);
Array.Copy(message, dataSize, ecWords, 0, ecSize);
// check to see if Decoder can fix up to ecWords/2 random errors
testDecoder(field, dataWords, ecWords);
}
}
public ReedSolomonDecoder(GenericGF field)
{
this.field = field;
}
public ReedSolomonDecoder(GenericGF field)
{
this.field = field;
}
public ErasureCoding()
{
_field = new GenericGF(285, 256, 0);
}
public ReedSolomonEncoder(GenericGF field)
{
this.field = field;
this.cachedGenerators = new List <GenericGFPoly>();
cachedGenerators.Add(new GenericGFPoly(field, new int[] { 1 }, true));
}
private static void testEncodeDecode(GenericGF field, int[] dataWords, int[] ecWords)
{
testEncoder(field, dataWords, ecWords);
testDecoder(field, dataWords, ecWords);
}
