Struct BuildTimings 

pub struct BuildTimings { /* private fields */ }

The two wall clocks that decide whether a build was plugin-bound.

Plugin hooks themselves are timed on the JavaScript side, because this side can only bracket dispatch and completion and for a concurrently dispatched hook that is mostly queue wait — see packages/rolldown/src/utils/plugin-timings.ts. But the link stage is visible only from here, and it is the one stretch of a build that is pure core work with no plugin in it. Non-link time running far ahead of link time is what says the build is plugin-bound, so these are handed across the binding for the JavaScript side to gate its report on.

A build nobody is measuring keeps no clock at all: Self::start hands back None, and every recorder is a no-op on it. Whether it is measured is decided once, where the driver is built, from the same checks.bundlerTimings that turns the JavaScript side’s measurement on — the two have to agree, because a report needs both halves.

Implementations

impl BuildTimings

pub fn new(measured: bool) -> Self

pub fn start(&self) -> Option<Instant>

The instant to measure a stretch of the build from, or None when it is not being measured — then nothing downstream reads the clock, so there is no reason to take one.

Pass what this returns to Self::record_total or Self::record_link_stage.

pub fn record_total(&self, start: Option<Instant>)

pub fn record_link_stage(&self, start: Option<Instant>)

pub fn total_micros(&self) -> u64

Zero until Self::record_total runs, which only the full write/generate paths do, and only when the build is being measured. Watch, incremental and dev builds go straight to bundle_write/bundle_generate, so they leave this at zero and nothing is reported for them.

pub fn link_stage_micros(&self) -> u64

pub fn plugins_are_slow(&self) -> bool

Whether the build looks plugin-bound: over MIN_BUILD long, with non-link time more than PLUGIN_TIME_OVER_LINK_TIME times the link stage.

The link stage is the one stretch of a build with no plugin in it, which is what makes it a baseline. The multiplier was settled by studying real-world projects.

This only decides whether to look; what the build actually spent in plugin callbacks is measured on the JavaScript side, because this side cannot see when a callback began running — see packages/rolldown/src/utils/plugin-timings.ts.

pub fn is_plugin_bound(total_micros: u64, link_stage_micros: u64) -> bool

The same test over totals supplied by the caller, so a build that produced several outputs can sum its clocks before asking. The measurement it is judged against accumulates across outputs, so these have to as well.

Trait Implementations

impl Debug for BuildTimings

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

Formats the value using the given formatter.

impl Default for BuildTimings

fn default() -> Self

Returns the “default value” for a type.