Struct Gauge 

pub struct Gauge { /* private fields */ }

A signed gauge whose value may go up, down, or be set to an absolute number. Backed by AtomicI64 because Prometheus gauges are unrestricted-sign floats; we clamp to i64 here because every data-plane gauge in the workspace (open sessions, queue depth, spool bytes) is a non-negative count that fits comfortably in 63 bits, and the signed representation lets sub_saturating bottom out at 0 rather than wrap.

Implementations

impl Gauge

pub fn set(&self, value: u64)

Set the gauge to an absolute value. Truncates to i64::MAX on overflow — no data-plane count in the workspace is even close to that ceiling, and silently overflowing to a negative value would produce misleading dashboards.

pub fn inc(&self)

Increment by 1. Saturates at i64::MAX.

pub fn dec(&self)

Decrement by 1. Saturates at 0 — a gauge going negative is almost always a lifecycle bookkeeping bug (dec called twice for one inc), and rendering -1 open_sessions would confuse every dashboard downstream.

pub fn add(&self, n: u64)

Increment by n. Saturates at i64::MAX.

pub fn sub(&self, n: u64)

Decrement by n. Saturates at 0.

pub fn get(&self) -> u64

Current value as an unsigned integer — the saturating math above guarantees non-negativity so the cast never truncates a real observation.

Trait Implementations

impl Debug for Gauge

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

Formats the value using the given formatter.

impl Default for Gauge

fn default() -> Gauge

Returns the “default value” for a type.