/**
* A message. The format of an N byte message is the following:
*
* 1. 4 byte CRC32 of the message
* 2. 1 byte "magic" identifier to allow format changes, value is 2 currently
* 3. 1 byte "attributes" identifier to allow annotations on the message independent of the version (e.g. compression enabled, type of codec used)
* 4. 4 byte key length, containing length K
* 5. K byte key
* 6. 4 byte payload length, containing length V
* 7. V byte payload
*
*/
internal static Message ParseFrom(KafkaBinaryReader reader, long offset, int size, int partitionID)
{
Message result;
int readed = 0;
uint checksum = reader.ReadUInt32();
readed += 4;
byte magic = reader.ReadByte();
readed++;
byte[] payload;
if (magic == 2 || magic == 0) // some producers (CLI) send magic 0 while others have value of 2
{
byte attributes = reader.ReadByte();
readed++;
var keyLength = reader.ReadInt32();
readed += 4;
byte[] key = null;
if (keyLength != -1)
{
key = reader.ReadBytes(keyLength);
readed += keyLength;
}
var payloadSize = reader.ReadInt32();
readed += 4;
payload = reader.ReadBytes(payloadSize);
readed += payloadSize;
result = new Message(payload, key, Messages.CompressionCodec.GetCompressionCodec(attributes & CompressionCodeMask))
{
Offset = offset,
PartitionId = partitionID
};
}
else
{
payload = reader.ReadBytes(size - DefaultHeaderSize);
readed += size - DefaultHeaderSize;
result = new Message(payload) { Offset = offset, PartitionId = partitionID };
}
if (size != readed)
{
throw new KafkaException(ErrorMapping.InvalidFetchSizeCode);
}
return result;
}
/// <summary>
/// Creates string representation of message
/// </summary>
/// <param name="reader">
/// The reader.
/// </param>
/// <param name="count">
/// The count.
/// </param>
/// <returns>
/// String representation of message
/// </returns>
public static string ParseFrom(KafkaBinaryReader reader, int count)
{
Guard.Assert<ArgumentNullException>(() => reader != null);
var sb = new StringBuilder();
int payloadSize = count - DefaultHeaderSize;
sb.Append("Magic: ");
sb.Append(reader.ReadByte());
sb.Append(", Checksum: ");
for (int i = 0; i < 4; i++)
{
sb.Append("[");
sb.Append(reader.ReadByte());
sb.Append("]");
}
sb.Append(", topic: ");
var encodedPayload = reader.ReadBytes(payloadSize);
try
{
sb.Append(Encoding.UTF8.GetString(encodedPayload));
}
catch (Exception)
{
sb.Append("n/a");
}
return sb.ToString();
}
public static string ReadShortString(KafkaBinaryReader reader, string encoding)
{
var size = reader.ReadInt16();
if (size < 0)
{
return null;
}
var bytes = reader.ReadBytes(size);
Encoding encoder = Encoding.GetEncoding(encoding);
return encoder.GetString(bytes);
}
internal static Message ParseFrom(KafkaBinaryReader reader, int size)
{
Message result;
int readed = 0;
byte magic = reader.ReadByte();
readed++;
byte[] checksum;
byte[] payload;
if (magic == 1)
{
byte attributes = reader.ReadByte();
readed++;
checksum = reader.ReadBytes(4);
readed += 4;
payload = reader.ReadBytes(size - (DefaultHeaderSize + 1));
readed += size - (DefaultHeaderSize + 1);
result = new Message(payload, checksum, Messages.CompressionCodec.GetCompressionCodec(attributes & CompressionCodeMask));
}
else
{
checksum = reader.ReadBytes(4);
readed += 4;
payload = reader.ReadBytes(size - DefaultHeaderSize);
readed += size - DefaultHeaderSize;
result = new Message(payload, checksum);
}
if (size != readed)
{
throw new KafkaException(KafkaException.InvalidRetchSizeCode);
}
return result;
}