2.7 KiB
SignalR — Known Issues & Limitations
Protocol
PROTO-1: Server-side IsRawBytesData pre-serialize
Status: Planned removal
Affects: AcWebSignalRHubBase.SendMessageToClient
The server forwards the client's IsRawBytesData flag in the response SignalParams. This causes the protocol to return raw byte[] instead of deserializing. The original design pre-serialized on the server side, but with the zero-copy typed deserialization path (SignalDataType), this is redundant.
Plan: Remove IsRawBytesData forwarding from server response path. The client should use SignalDataType for typed deserialization and explicit byte[] type for raw data.
PROTO-2: Parameter serialization is per-parameter
Status: Known performance concern
Affects: SignalParams.SetParameterValues / GetParameterValues
Each parameter is individually serialized via ToBinary() / BinaryTo(Type) — N context pool acquire/release cycles. For many small primitives (int, bool, string) the per-call overhead may exceed a single bulk serialization.
Possible optimization: Batch fast-path — single serialization context for all parameters. Benchmark first.
PROTO-3: Parameter serialization is AcBinary only
Status: Limitation
Affects: SignalParams.SetParameterValues / GetParameterValues
Uses ToBinary() / BinaryTo() exclusively. JSON parameter support would require dispatching on DataSerializerType + AcJsonSerializer reference. Low priority — binary is the primary transport.
Transport
TRANS-1: BufferWriterChunkSize defaults to 64KB for SignalR
Status: DONE
Affects: AcBinaryHubProtocol constructor, write path
BufferWriterChunkSize = 4096 set in AcBinaryHubProtocol constructor. Aligns with Kestrel slab size, reduces latency-to-first-byte. Non-SignalR paths keep 64KB default.
TRANS-2: WebSocket buffer sizes are hardcoded
Status: Acceptable
Affects: AcSignalRClientBase connection setup
Transport max message size (30MB) and application buffer (30MB) are hardcoded. Sufficient for current payloads but not configurable per-deployment.
DataSource
DS-1: GetAll returns raw byte[] for populate/merge
Status: By design
Affects: AcSignalRDataSource.LoadDataSourceAsync
The GetAll path uses IsRawBytesData = true to receive raw byte[] from the protocol, then deserializes into the existing list via PopulateMerge. This avoids allocating a temporary List<T> for merge. The extra copy (pipe → byte[]) is the trade-off.
Possible optimization: Direct typed deserialization with merge support in the deserializer (PopulateMerge from ReadOnlySequence<byte>). Requires deserializer API changes.