func()

in strategy/sampling/sampling_rule.go [100:150]

• 37 lines of code
• 4 McCabe index (conditional complexity)

func (r *CentralizedRule) Sample() *Decision {
	now := r.clock.Now().Unix()
	sd := &Decision{
		Rule: &r.ruleName,
	}

	r.mu.Lock()
	defer r.mu.Unlock()

	r.requests++

	// Fallback to bernoulli sampling if quota has expired
	if r.reservoir.expired(now) {
		if r.reservoir.borrow(now) {
			logger.Debugf(
				"Sampling target has expired for rule %s. Borrowing a request.",
				r.ruleName,
			)
			sd.Sample = true
			r.borrows++

			return sd
		}

		logger.Debugf(
			"Sampling target has expired for rule %s. Using fixed rate.",
			r.ruleName,
		)
		sd.Sample = r.bernoulliSample()

		return sd
	}

	// Take from reservoir quota, if possible
	if r.reservoir.Take(now) {
		r.sampled++
		sd.Sample = true

		return sd
	}

	logger.Debugf(
		"Sampling target has been exhausted for rule %s. Using fixed rate.",
		r.ruleName,
	)

	// Use bernoulli sampling if quota expended
	sd.Sample = r.bernoulliSample()

	return sd
}