Function compatibilizeSampleTypes

profile/merge.go:627–664

compatibilizeSampleTypes drops sample types that are not present in sTypes list and reorder them if needed. It sets DefaultSampleType to sType[0] if it is not in sType list. It assumes that all sample types from the sTypes list are present in the given profile otherwise it returns an error.

(p *Profile, sTypes []string)

// It assumes that all sample types from the sTypes list are present in the
// given profile otherwise it returns an error.
func compatibilizeSampleTypes(p *Profile, sTypes []string) error {
	if len(sTypes) == 0 {
		return fmt.Errorf("sample type list is empty")
	}
	defaultSampleType := sTypes[0]
	reMap, needToModify := make([]int, len(sTypes)), false
	for i, st := range sTypes {
		if st == p.DefaultSampleType {
			defaultSampleType = p.DefaultSampleType
		}
		idx := searchValueType(p.SampleType, st)
		if idx < 0 {
			return fmt.Errorf("%q sample type is not found in profile", st)
		}
		reMap[i] = idx
		if idx != i {
			needToModify = true
		}
	}
	if !needToModify && len(sTypes) == len(p.SampleType) {
		return nil
	}
	p.DefaultSampleType = defaultSampleType
	oldSampleTypes := p.SampleType
	p.SampleType = make([]*ValueType, len(sTypes))
	for i, idx := range reMap {
		p.SampleType[i] = oldSampleTypes[idx]
	}
	values := make([]int64, len(sTypes))
	for _, s := range p.Sample {
		for i, idx := range reMap {
			values[i] = s.Value[idx]
		}
		s.Value = s.Value[:len(values)]
		copy(s.Value, values)
	}
	return nil
}

func searchValueType(vts []*ValueType, s string) int {
	for i, vt := range vts {