func newRatioController(tm timetools.TimeProvider, rampUp time.Duration) *ratioController {
return &ratioController{
duration: rampUp,
tm: tm,
start: tm.UtcNow(),
}
}
// newTokenBucket crates a `tokenBucket` instance for the specified `Rate`.
func newTokenBucket(rate *rate, clock timetools.TimeProvider) *tokenBucket {
return &tokenBucket{
period: rate.period,
timePerToken: time.Duration(int64(rate.period) / rate.average),
burst: rate.burst,
clock: clock,
lastRefresh: clock.UtcNow(),
availableTokens: rate.burst,
}
}
func NewTokenBucket(rate Rate, maxTokens int64, timeProvider timetools.TimeProvider) (*TokenBucket, error) {
if rate.Period == 0 || rate.Units == 0 {
return nil, fmt.Errorf("Invalid rate: %v", rate)
}
if maxTokens <= 0 {
return nil, fmt.Errorf("Invalid maxTokens, should be >0: %d", maxTokens)
}
if timeProvider == nil {
return nil, fmt.Errorf("Supply time provider")
}
return &TokenBucket{
refillPeriod: time.Duration(int64(rate.Period) / rate.Units),
maxTokens: maxTokens, // in case of maxBurst is 0, maxTokens available at should be 1
timeProvider: timeProvider,
lastRefill: timeProvider.UtcNow(),
tokens: maxTokens,
}, nil
}