Struct BackendTracker 

pub struct BackendTracker { /* private fields */ }

Available on crate feature parallel_backends only.

Tracks per-backend performance across a crawl session.

Fully lock-free — uses atomics only. Index 0 is the primary backend, 1..N are the alternatives in the order they appear in the config.

Implementations

impl BackendTracker

pub fn new(count: usize, max_consecutive_errors: u16) -> Self

Create a new tracker for count backends (primary + alternatives).

pub fn record_win(&self, idx: usize)

Record a win for backend at idx.

pub fn record_race(&self, idx: usize)

Record that backend idx participated in a race.

pub fn record_duration(&self, idx: usize, dur: Duration)

Record a fetch duration for backend idx (EMA with alpha ~0.2).

pub fn record_error(&self, idx: usize)

Record a retryable error for backend idx.

The first request to each backend acts as a probe: if the backend has never succeeded (zero prior successes / zero wins), the first error disables it immediately so a down backend is never retried. After at least one success, the normal max_consecutive_errors threshold applies.

pub fn record_success(&self, idx: usize)

Record a successful fetch — resets the consecutive error counter.

pub fn is_disabled(&self, idx: usize) -> bool

Check whether backend idx has been auto-disabled.

pub fn wins(&self, idx: usize) -> u64

Get the win count for backend idx.

pub fn races(&self, idx: usize) -> u64

Get the race count for backend idx.

pub fn ema_ms(&self, idx: usize) -> u64

Get the EMA response time in ms for backend idx.

pub fn consecutive_errors(&self, idx: usize) -> u64

Get the consecutive error count for backend idx.

pub fn win_rate_pct(&self, idx: usize) -> u64

Win rate percentage (0–100) for backend idx. Returns 0 if no races.

pub fn len(&self) -> usize

Number of tracked backends.

pub fn is_empty(&self) -> bool

Returns true if no backends are tracked.

Trait Implementations

impl Clone for BackendTracker

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.