func newRateLimiter(perSec int, maxBurst time.Duration) *rateLimiter {
maxPerBatch := int64(perSec / int(time.Second/maxBurst))
return &rateLimiter{
limitPerSec: perSec,
resolution: maxBurst,
time: clock.New(),
maxPerBatch: maxPerBatch,
}
}
// Profile will wrap a writer and reader pair and profile where
// time is spent: writing or reading. The result is returned when
// the `done` func is called. The `done` func can be called multiple
// times.
//
// There is a small performance overhead of ~µs per Read/Write call.
// This is negligible in most I/O workloads. If the overhead is too
// much for your needs, use the `ProfileSample` call.
func Profile(w io.Writer, r io.Reader) (pw io.Writer, pr io.Reader, done func() TimeProfile) {
return profile(clock.New(), w, r)
}
// ProfileSample will wrap a writer and reader pair and collect
// samples of where time is spent: writing or reading. The result
// is an approximation that is returned when the `done` func is
// called. The `done` func can be called *only once*.
//
// This call is not as precise as the `Profile` call, but the
// performance overhead is much reduced.
func ProfileSample(w io.Writer, r io.Reader, res time.Duration) (pw io.Writer, pr io.Reader, done func() SamplingProfile) {
return profileSample(clock.New(), w, r, res)
}
func newCounter() *rateCounter {
return &rateCounter{
time: clock.New(),
}
}