Struct FlowController 

pub struct FlowController {
    credits: AtomicI64,
    config: FlowControlConfig,
    is_high_water: AtomicBool,
    metrics: FlowMetrics,
}

Per-channel flow controller.

Tracks credits, watermark state, and flow control metrics.

Fields

credits: AtomicI64

config: FlowControlConfig

is_high_water: AtomicBool

metrics: FlowMetrics

Implementations

impl FlowController

pub fn new(config: FlowControlConfig) -> FlowController

Create a new flow controller with the given config.

pub fn try_acquire(&self) -> bool

Try to acquire a credit for sending. Returns true if credit available.

pub fn grant(&self, amount: u32)

Grant credits to the producer (called by consumer when queue has space).

pub fn refill(&self)

Refill credits by the configured refill amount.

pub fn available_credits(&self) -> i64

Available credits.

pub fn check_watermark(&self, queue_depth: u32) -> Option<WatermarkSignal>

Check watermark state based on current queue depth.

Returns a watermark signal if a threshold was just crossed.

pub fn overflow_policy(&self) -> OverflowPolicy

Get the overflow policy.

pub fn record_drop(&self)

Record a message dropped (for metrics).

pub fn record_dlq(&self)

Record a message routed to DLQ (for metrics).

pub fn metrics_snapshot(&self) -> FlowMetricsSnapshot

Get a snapshot of flow control metrics.