Struct OncePerRun 

pub struct OncePerRun(/* private fields */);

A latch for a warning raised from an innermost analysis loop, where the same message can be produced millions of times — once per bad base, once per unreadable read.

Declared as a static beside the code that raises the warning, so asking whether to speak is one relaxed atomic: no formatting, no allocation and no lock on the overwhelmingly common repeat. That matters because these sit in the hot loop — building the message unconditionally and then discarding it cost ~26% of the analysis on a file whose every base tripped the warning.

The latch is per run, not per process: it resets when the next ProgressPlan is created, so an embedder driving the library twice hears the warning both times. Within a run it fires once however many files are being analysed in parallel, which is the point — the warning is about the data, and one copy of it is the useful amount.

Implementations

impl OncePerRun

pub const fn new() -> Self

pub fn should_say(&self) -> bool

True for exactly one caller per run. Racing threads all swap in the current run, and only the one that displaced an older value speaks. The plain load first keeps repeats off the cache line’s write path.

pub fn log(&self, message: impl FnOnce() -> String)

log_line the warning message builds, the first time this run. Out of line so the hot loop it is raised from stays tight.

Trait Implementations

impl Default for OncePerRun

fn default() -> Self

Returns the “default value” for a type.