// private static methods
private byte[] CombineCommandMessageSectionsIntoSingleDocument(Stream stream)
{
using (var inputStream = new BsonStreamAdapter(stream, ownsStream: false))
using (var memoryStream = new MemoryStream())
using (var outputStream = new BsonStreamAdapter(memoryStream, ownsStream: false))
{
var messageStartPosition = inputStream.Position;
var messageLength = inputStream.ReadInt32();
var messageEndPosition = messageStartPosition + messageLength;
var requestId = inputStream.ReadInt32();
var responseTo = inputStream.ReadInt32();
var opcode = inputStream.ReadInt32();
var flags = (OpMsgFlags)inputStream.ReadInt32();
if (flags.HasFlag(OpMsgFlags.ChecksumPresent))
{
messageEndPosition -= 4; // ignore checksum
}
CopyType0Section(inputStream, outputStream);
outputStream.Position -= 1;
while (inputStream.Position < messageEndPosition)
{
CopyType1Section(inputStream, outputStream);
}
outputStream.WriteByte(0);
outputStream.BackpatchSize(0);
return(memoryStream.ToArray());
}
}
private byte[] CreateType1SectionBytes(Type1CommandMessageSection <BsonDocument> section)
{
using (var memoryStream = new MemoryStream())
using (var stream = new BsonStreamAdapter(memoryStream))
using (var writer = new BsonBinaryWriter(stream))
{
stream.WriteByte(1);
var payloadStartPosition = stream.Position;
stream.WriteInt32(0); // size
stream.WriteCString(section.Identifier);
var context = BsonSerializationContext.CreateRoot(writer);
var batch = section.Documents;
for (var i = 0; i < batch.Count; i++)
{
var document = batch.Items[batch.Offset + i];
BsonDocumentSerializer.Instance.Serialize(context, document);
}
stream.BackpatchSize(payloadStartPosition);
return(memoryStream.ToArray());
}
}
public void BackpatchSize_should_backpatch_the_size(
[Values(0, 1, 5)]
int startPosition)
{
var bytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
var length = bytes.Length - startPosition;
var expectedBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
Array.Copy(BitConverter.GetBytes(length), 0, expectedBytes, startPosition, 4);
using (var memoryStream = new MemoryStream())
using (var stream = new BsonStreamAdapter(memoryStream))
{
stream.WriteBytes(bytes, 0, bytes.Length);
var position = stream.Position;
stream.BackpatchSize(startPosition);
memoryStream.ToArray().Should().Equal(expectedBytes);
stream.Position.Should().Be(position);
}
}