ConnectionFrameHelper

1. Documentation
2. API reference
3. Microsoft.Orleans.Core
4. ConnectionFrameHelper

class

Namespace: Orleans.Runtime.Messaging

NuGetSourceMarkdown

Provides framing utilities for connection middleware authors.

Wire format per frame: [4-byte LE length] [1-byte frame type] [payload]. The length field equals 1 + payload.Length.

Connection middlewares should follow the Microsoft.AspNetCore.Connections.ConnectionDelegate pipeline pattern (like TLS) and register via SiloConnectionOptions or ClientConnectionOptions. Use these helpers for structured frame I/O within your middleware.

This helper is optional. Middleware authors who need custom protocols can read/write directly from context.Transport.Input (PipeReader) and context.Transport.Output (PipeWriter) without using this class.

public static class ConnectionFrameHelper

Methods

• ReadFrameAsync(ConnectionContext, CancellationToken, int) Reads a single frame from the connection.
• ReadLengthPrefixedString(byte[], int) Reads a length-prefixed UTF-8 string from a payload byte array.
• WriteFrameAsync(ConnectionContext, byte, Action<IBufferWriter<byte>>, CancellationToken) Writes a frame using zero-copy framing via Orleans.Runtime.Messaging.PrefixingBufferWriter. The writePayload delegate writes payload directly into the transport pipe buffer.
• WriteFrameAsync(ConnectionContext, byte, byte[], CancellationToken) Writes a frame with the given type and raw payload bytes.
• WriteLengthPrefixedString(IBufferWriter<byte>, string) Writes a length-prefixed UTF-8 string (4-byte LE length + bytes) into a buffer.

Fields

• DefaultMaxFrameLength Default maximum frame length (1 MB).
• FramePrefixSize Prefix size: 4 bytes (LE length) + 1 byte (frame type) = 5 bytes.