func validateCfg()

in aggregators/config.go [232:269]

• 34 lines of code
• 10 McCabe index (conditional complexity)

func validateCfg(cfg config) error {
	if cfg.DataDir == "" {
		return errors.New("data directory is required")
	}
	if cfg.Processor == nil {
		return errors.New("processor is required")
	}
	if cfg.Partitions == 0 {
		return errors.New("partitions must be greater than zero")
	}
	if len(cfg.AggregationIntervals) == 0 {
		return errors.New("at least one aggregation interval is required")
	}
	if !sort.SliceIsSorted(cfg.AggregationIntervals, func(i, j int) bool {
		return cfg.AggregationIntervals[i] < cfg.AggregationIntervals[j]
	}) {
		return errors.New("aggregation intervals must be in ascending order")
	}
	lowest := cfg.AggregationIntervals[0]
	highest := cfg.AggregationIntervals[len(cfg.AggregationIntervals)-1]
	for i := 1; i < len(cfg.AggregationIntervals); i++ {
		ivl := cfg.AggregationIntervals[i]
		if ivl%lowest != 0 {
			return errors.New("aggregation intervals must be a factor of lowest interval")
		}
	}
	// For encoding/decoding the processing time for combined metrics we only
	// consider seconds granularity making 1 sec the lowest possible
	// aggregation interval. We also encode interval as 2 unsigned bytes making
	// 65535 (~18 hours) the highest possible aggregation interval.
	if lowest < time.Second {
		return errors.New("aggregation interval less than one second is not supported")
	}
	if highest > 18*time.Hour {
		return errors.New("aggregation interval greater than 18 hours is not supported")
	}
	return nil
}