// CopyTo allocates a temporary buffer. As we're already pooling buffers,
// we might as well provide a CopyTo that makes use of that instead of
// using Stream.CopyTo (which allocates a buffer of its own, even if it
// does so efficiently).
public static void ReusableCopyTo(this Stream input, Stream destination, ReusableMemoryStream tmpBuffer)
{
tmpBuffer.SetLength(81920);
var buffer = tmpBuffer.GetBuffer();
int read;
while ((read = input.Read(buffer, 0, buffer.Length)) != 0)
{
destination.Write(buffer, 0, read);
}
}
private static void CheckCrc(Crc32 crcAlgo, int crc, ReusableMemoryStream stream, long crcStartPos, long crcLength = -1)
{
var length = crcLength == -1 ? stream.Position - crcStartPos : crcLength;
var computedCrc = (int)crcAlgo.ComputeForStream(stream, crcStartPos, length);
if (computedCrc != crc)
{
throw new CrcException(
string.Format("Corrupt message: CRC32 does not match. Calculated {0} but got {1}", computedCrc,
crc));
}
}
public static uint Compute(ReusableMemoryStream stream, long start, long size)
{
var crc = DefaultSeed;
var buffer = stream.GetBuffer();
for (var i = start; i < start + size; ++i)
{
crc = (crc >> 8) ^ _defaultTable[buffer[i] ^ crc & 0xff];
}
return(~crc);
}
private uint ComputeForStream(ReusableMemoryStream stream, long start, long size)
{
var crc = Seed;
var buffer = stream.GetBuffer();
for (var i = start; i < start + size; ++i)
{
crc = (crc >> 8) ^ Table[buffer[i] ^ crc & 0xff];
}
return(~crc);
}
/// <summary> /// Compute the CRC-32 of the byte sequence using Castagnoli polynomial values. /// This alternate CRC-32 is often used to compute the CRC as it is often yield /// better chances to detect errors in larger payloads. /// /// In particular, it is used to compute the CRC of a RecordBatch in newer versions /// of the Kafka protocol. /// </summary> /// <param name="stream">byte stream</param> /// <param name="start">start offset of the byte sequence</param> /// <param name="size">size of the byte sequence</param> /// <returns></returns> public static uint ComputeCastagnoli(ReusableMemoryStream stream, long start, long size) => CastagnoliCrc32.ComputeForStream(stream, start, size);
/// <summary> /// Compute the CRC-32 of the byte sequence using IEEE standard polynomial values. /// This is the regular "internet" CRC. /// </summary> /// <param name="stream">byte stream</param> /// <param name="start">start offset of the byte sequence</param> /// <param name="size">size of the byte sequence</param> /// <returns></returns> public static uint Compute(ReusableMemoryStream stream, long start, long size) => DefaultCrc32.ComputeForStream(stream, start, size);
internal static void CheckCrc(int crc, ReusableMemoryStream stream, long crcStartPos)
{
CheckCrc(DefaultCrc32, crc, stream, crcStartPos);
}
internal static void CheckCrcCastagnoli(int crc, ReusableMemoryStream stream, long crcStartPos, long crcLength = -1)
{
CheckCrc(CastagnoliCrc32, crc, stream, crcStartPos, crcLength);
}