public static Message ConstructMessage(string command, byte[] payload)
{
var message = new Message
(
Magic: Messaging.Magic,
Command: command,
PayloadSize: (UInt32)payload.Length,
PayloadChecksum: CalculatePayloadChecksum(payload),
Payload: payload.ToImmutableArray()
);
return message;
}
public static byte[] EncodeMessage(Message message)
{
using (var stream = new MemoryStream())
using (var writer = new BinaryWriter(stream))
{
EncodeMessage(writer, message);
return stream.ToArray();
}
}
public static void EncodeMessage(BinaryWriter writer, Message message)
{
writer.WriteUInt32(message.Magic);
writer.WriteFixedString(12, message.Command);
writer.WriteUInt32(message.PayloadSize);
writer.WriteUInt32(message.PayloadChecksum);
writer.WriteBytes(message.PayloadSize.ToIntChecked(), message.Payload.ToArray());
}
private async Task<Message> WireDecodeMessage(UInt32 magic)
{
var command = DataDecoder.DecodeFixedString(await ReceiveExactly(12));
var payloadSize = DataDecoder.DecodeUInt32(await ReceiveExactly(4));
var payloadChecksum = DataDecoder.DecodeUInt32(await ReceiveExactly(4));
var payload = await ReceiveExactly(payloadSize.ToIntChecked());
if (!Messaging.VerifyPayloadChecksum(payloadChecksum, payload))
throw new Exception($"Checksum failed for {command}");
var message = new Message
(
Magic: magic,
Command: command,
PayloadSize: payloadSize,
PayloadChecksum: payloadChecksum,
Payload: payload.ToImmutableArray()
);
switch (message.Command)
{
case "addr":
{
var addressPayload = NodeEncoder.DecodeAddressPayload(payload);
OnReceivedAddresses?.Invoke(owner, addressPayload.NetworkAddresses);
}
break;
case "alert":
{
var alertPayload = NodeEncoder.DecodeAlertPayload(payload);
}
break;
case "block":
{
var block = DataDecoder.DecodeBlock(null, payload);
OnBlock?.Invoke(owner, block);
}
break;
case "getblocks":
{
var getBlocksPayload = NodeEncoder.DecodeGetBlocksPayload(payload);
OnGetBlocks?.Invoke(owner, getBlocksPayload);
}
break;
case "getheaders":
{
var getHeadersPayload = NodeEncoder.DecodeGetBlocksPayload(payload);
OnGetHeaders?.Invoke(owner, getHeadersPayload);
}
break;
case "getdata":
{
var invPayload = NodeEncoder.DecodeInventoryPayload(payload);
OnGetData?.Invoke(owner, invPayload);
}
break;
case "headers":
{
var blockHeaders = ImmutableList.CreateBuilder<BlockHeader>();
var offset = 0;
var headerCount = payload.ReadVarInt(ref offset).ToIntChecked();
for (var i = 0; i < headerCount; i++)
{
var blockHeader = DataDecoder.DecodeBlockHeader(null, payload, ref offset);
// ignore tx count var int
payload.ReadVarInt(ref offset);
blockHeaders.Add(blockHeader);
}
OnBlockHeaders?.Invoke(owner, blockHeaders.ToImmutable());
}
break;
case "inv":
{
var invPayload = NodeEncoder.DecodeInventoryPayload(payload);
OnInventoryVectors?.Invoke(owner, invPayload.InventoryVectors);
}
break;
case "notfound":
{
var invPayload = NodeEncoder.DecodeInventoryPayload(payload);
OnNotFound?.Invoke(owner, invPayload.InventoryVectors);
}
break;
case "ping":
{
OnPing?.Invoke(owner, payload.ToImmutableArray());
}
break;
case "tx":
{
var tx = DataDecoder.DecodeEncodedTx(null, payload);
OnTransaction?.Invoke(owner, tx);
}
break;
case "version":
{
var versionPayload = NodeEncoder.DecodeVersionPayload(payload, payload.Length);
OnVersion?.Invoke(owner, versionPayload);
}
break;
case "verack":
{
OnVersionAcknowledged?.Invoke(owner);
}
break;
default:
{
logger.Warn($"Unhandled incoming message: {message.Command}");
}
break;
}
//TODO
//if (payloadStream.Position != payloadStream.Length)
//{
// var exMessage = $"Wrong number of bytes read for {message.Command}, parser error: read {payloadStream.Position} bytes from a {payloadStream.Length} byte payload";
// Debug.WriteLine(exMessage);
// throw new Exception(exMessage);
//}
return message;
}
public async Task SendMessageAsync(Message message)
{
try
{
await semaphore.DoAsync(async () =>
{
using (var stream = new NetworkStream(socket))
{
var stopwatch = Stopwatch.StartNew();
using (var byteStream = new MemoryStream())
using (var writer = new BinaryWriter(byteStream))
{
NodeEncoder.EncodeMessage(writer, message);
var messageBytes = byteStream.ToArray();
await stream.WriteAsync(messageBytes, 0, messageBytes.Length);
}
stopwatch.Stop();
if (logger.IsTraceEnabled)
logger.Trace($"Sent {message.Command} in {stopwatch.ElapsedMilliseconds} ms\nPayload: {message.Payload.ToArray().ToHexDataString()}");
}
});
}
catch (Exception e)
{
Fail(e);
}
}
private Message WireDecodeMessage(UInt32 magic, Stream stream)
{
byte[] payload;
Message message;
using (var reader = new BinaryReader(stream, Encoding.ASCII, leaveOpen: true))
{
var command = reader.ReadFixedString(12);
var payloadSize = reader.ReadUInt32();
var payloadChecksum = reader.ReadUInt32();
payload = reader.ReadBytes(payloadSize.ToIntChecked());
if (!Messaging.VerifyPayloadChecksum(payloadChecksum, payload))
throw new Exception($"Checksum failed for {command}");
message = new Message
(
Magic: magic,
Command: command,
PayloadSize: payloadSize,
PayloadChecksum: payloadChecksum,
Payload: payload.ToImmutableArray()
);
}
switch (message.Command)
{
case "addr":
{
var addressPayload = NodeEncoder.DecodeAddressPayload(payload);
this.OnReceivedAddresses?.Invoke(addressPayload.NetworkAddresses);
}
break;
case "alert":
{
var alertPayload = NodeEncoder.DecodeAlertPayload(payload);
}
break;
case "block":
{
var block = DataEncoder.DecodeBlock(payload);
this.OnBlock?.Invoke(this.owner, block);
}
break;
case "getblocks":
{
var getBlocksPayload = NodeEncoder.DecodeGetBlocksPayload(payload);
this.OnGetBlocks?.Invoke(getBlocksPayload);
}
break;
case "getheaders":
{
var getHeadersPayload = NodeEncoder.DecodeGetBlocksPayload(payload);
this.OnGetHeaders?.Invoke(getHeadersPayload);
}
break;
case "getdata":
{
var invPayload = NodeEncoder.DecodeInventoryPayload(payload);
this.OnGetData?.Invoke(invPayload);
}
break;
case "headers":
{
var blockHeaders = ImmutableList.CreateBuilder<BlockHeader>();
using (var headerStream = new MemoryStream(payload))
using (var reader = new BinaryReader(headerStream))
{
var headerCount = reader.ReadVarInt().ToIntChecked();
for (var i = 0; i < headerCount; i++)
{
var blockHeader = DataEncoder.DecodeBlockHeader(reader);
//TODO wiki says this is a byte and a var int, which is it?
var txCount = reader.ReadVarInt();
blockHeaders.Add(blockHeader);
}
}
this.OnBlockHeaders?.Invoke(this.owner, blockHeaders.ToImmutable());
}
break;
case "inv":
{
var invPayload = NodeEncoder.DecodeInventoryPayload(payload);
this.OnInventoryVectors?.Invoke(invPayload.InventoryVectors);
}
break;
case "notfound":
{
var invPayload = NodeEncoder.DecodeInventoryPayload(payload);
this.OnNotFound?.Invoke(invPayload.InventoryVectors);
}
break;
case "ping":
{
this.OnPing?.Invoke(payload.ToImmutableArray());
}
break;
case "tx":
{
var tx = DataEncoder.DecodeTransaction(payload);
this.OnTransaction?.Invoke(tx);
}
break;
case "version":
{
var versionPayload = NodeEncoder.DecodeVersionPayload(payload, payload.Length);
this.OnVersion?.Invoke(versionPayload);
}
break;
case "verack":
{
this.OnVersionAcknowledged?.Invoke();
}
break;
default:
{
logger.Warn($"Unhandled incoming message: {message.Command}");
}
break;
}
//TODO
//if (payloadStream.Position != payloadStream.Length)
//{
// var exMessage = $"Wrong number of bytes read for {message.Command}, parser error: read {payloadStream.Position} bytes from a {payloadStream.Length} byte payload";
// Debug.WriteLine(exMessage);
// throw new Exception(exMessage);
//}
return message;
}
