Struct ConnectionState 

pub struct ConnectionState {

    pub local_ip: Option<IpAddr>,
    pub remote_ip: Option<IpAddr>,
    pub peer_address: String,
    pub receive_buffer: VecDeque<u8>,
    pub paired_connection: Option<ConnectionId>,
    pub send_buffer: VecDeque<Vec<u8>>,
    pub next_send_time: Duration,
    pub flags: ConnectionFlags,
    pub cut_expiry: Option<Duration>,
    pub close_reason: CloseReason,
    pub send_buffer_capacity: usize,
    pub send_delay: Option<Duration>,
    pub recv_delay: Option<Duration>,
    pub half_open_error_at: Option<Duration>,
    pub last_data_delivery_scheduled_at: Option<Duration>,
}

Internal connection state for simulation

Fields

local_ip: Option<IpAddr>

Local IP address for this connection

remote_ip: Option<IpAddr>

Remote IP address for this connection

peer_address: String

Peer address as seen by this connection.

FDB Pattern (sim2.actor.cpp:1149-1175):

• For client-side connections: the destination address (server’s listening address)
• For server-side connections: synthesized ephemeral address (random IP + port 40000-60000)

This simulates real TCP behavior where servers see client ephemeral ports, not the client’s identity address. As FDB notes: “In the case of an incoming connection, this may not be an address we can connect to!”

receive_buffer: VecDeque<u8>

FIFO buffer for incoming data that hasn’t been read by the application yet.

paired_connection: Option<ConnectionId>

Reference to the other end of this bidirectional TCP connection.

send_buffer: VecDeque<Vec<u8>>

FIFO buffer for outgoing data waiting to be sent over the network.

next_send_time: Duration

Next available time for sending messages from this connection.

flags: ConnectionFlags

Boolean flags (closure, chaos, send-in-progress) packed into a bitfield. Use the named accessor methods on ConnectionFlags to inspect or update individual bits.

cut_expiry: Option<Duration>

When the cut expires and the connection is restored (in simulation time). Only meaningful when flags.is_cut() is true.

close_reason: CloseReason

Reason for connection closure - distinguishes FIN vs RST semantics. When flags.is_closed() is true, this indicates whether it was graceful or aborted.

send_buffer_capacity: usize

Send buffer capacity in bytes. When the send buffer reaches this limit, poll_write returns Pending. Calculated from BDP (Bandwidth-Delay Product): latency × bandwidth.

send_delay: Option<Duration>

Per-connection send delay override (asymmetric latency). If set, this delay is applied when sending data from this connection. If None, the global write_latency from NetworkConfiguration is used.

recv_delay: Option<Duration>

Per-connection receive delay override (asymmetric latency). If set, this delay is applied when receiving data on this connection. If None, the global read_latency from NetworkConfiguration is used.

half_open_error_at: Option<Duration>

When a half-open connection starts returning errors (in simulation time). Before this time: writes succeed (data dropped), reads block. After this time: both read and write return ECONNRESET.

last_data_delivery_scheduled_at: Option<Duration>

Time of the most recently scheduled DataDelivery event from this connection. Used to ensure FinDelivery is scheduled after the last data arrives at the peer.

Trait Implementations

impl Clone for ConnectionState

fn clone(&self) -> ConnectionState

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ConnectionState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.