Struct HydraServer 

pub struct HydraServer { /* private fields */ }

A light-weight multi-threaded SPMC (Single Producer Multiple Consumer) E2E relay server.

HydraServer implements a zero-copy broadcast relay that:

• Accepts one producer and multiple consumers per session
• Routes data from producer → all connected consumers using Arc-backed Bytes
• Handles backpressure and slow consumers with broadcast channel lagging
• Enforces connection limits and per-payload size constraints

Internals

• Producer: Sends encrypted frames → broadcast channel
• Consumers: Subscribe to broadcast, receive clones of Arc<Bytes> (zero-copy)
• Sessions: Keyed by 64-byte session_id, one producer per session allowed
• Errors & Logs: Error are predictable and handled gracefully by closing connections and logging without crashing the server

Implementations

impl HydraServer

pub async fn bind_default() -> Result<(Self, SocketAddr)>

Binds the relay server with defaults

• addr: OS-assigned port
• max_connections: 32
• max_payload_length: 64 MiB
• broadcast_capacity: 256 messages

pub async fn bind( addr: &SocketAddr, max_payload_length: usize, max_connections: usize, broadcast_capacity: usize, ) -> Result<Self>

Binds the relay server to the specified socket address and initializes internal state

pub async fn run(self, connections_timeout_ms: u64) -> Result<()>

Main server loop to accept incoming connections, spawn thread handlers, perform handshakes & session creation

• connections_timeout_ms is the delay before client retries to accept new connections on server when the limit is reached
• Producer errors; If read fails from client or broadcast send fails, the connection is closed and the error is logged.
• Producer errors; If writing to client fails or broadcast lags or closed, the connection is closed and the error is logged.
• EOF check are gracefully handled by closing the connection without logging an error.
• LOG_LEVEL & LOG_FILE env vars can be set to control logging verbosity and output file (defaults to info level and stdout, not file).