Struct Probe 

pub struct Probe { /* private fields */ }

A measurement-in-progress for a single operation.

Lifecycle

use congestion::{MetadataOp, Probe, Side};

let probe = Probe::start_metadata(Side::Source, MetadataOp::Stat);
// ... perform the syscall or operation ...
probe.complete_ok(0);

Forgetting to call Probe::complete / Probe::complete_ok drops the probe without recording anything. This is intentional: error paths that bail out early should not produce misleading latency samples.

Implementations

impl Probe

pub fn start(kind: ResourceKind) -> Self

Begin measuring an operation of the given kind.

pub fn start_metadata(side: Side, op: MetadataOp) -> Self

Shorthand for Probe::start(ResourceKind::Metadata(side, op)). Use this to bracket a single per-file metadata syscall.

pub fn start_read() -> Self

Shorthand for Probe::start(ResourceKind::DataRead).

pub fn start_write() -> Self

Shorthand for Probe::start(ResourceKind::DataWrite).

pub fn complete_ok(self, bytes: u64)

Complete the probe with outcome Outcome::Ok and the given byte count (use 0 for metadata ops).

pub fn complete(self, bytes: u64, outcome: Outcome)

Complete the probe with an explicit outcome.

pub fn discard(self)

Drop the probe without recording a sample.