Function chunkedGrab

internal/driver/fetch.go:173–204

chunkedGrab fetches the profiles described in source and merges them into a single profile. It fetches a chunk of profiles concurrently, with a maximum chunk size to limit its memory usage.

(sources []profileSource, fetch plugin.Fetcher, obj plugin.ObjTool, ui plugin.UI, tr http.RoundTripper)

// a single profile. It fetches a chunk of profiles concurrently, with a maximum
// chunk size to limit its memory usage.
func chunkedGrab(sources []profileSource, fetch plugin.Fetcher, obj plugin.ObjTool, ui plugin.UI, tr http.RoundTripper) (*profile.Profile, plugin.MappingSources, bool, int, error) {
	const chunkSize = 128

	var p *profile.Profile
	var msrc plugin.MappingSources
	var save bool
	var count int

	for start := 0; start < len(sources); start += chunkSize {
		end := min(start+chunkSize, len(sources))
		chunkP, chunkMsrc, chunkSave, chunkCount, chunkErr := concurrentGrab(sources[start:end], fetch, obj, ui, tr)
		switch {
		case chunkErr != nil:
			return nil, nil, false, 0, chunkErr
		case chunkP == nil:
			continue
		case p == nil:
			p, msrc, save, count = chunkP, chunkMsrc, chunkSave, chunkCount
		default:
			p, msrc, chunkErr = combineProfiles([]*profile.Profile{p, chunkP}, []plugin.MappingSources{msrc, chunkMsrc})
			if chunkErr != nil {
				return nil, nil, false, 0, chunkErr
			}
			if chunkSave {
				save = true
			}
			count += chunkCount
		}
	}

	return p, msrc, save, count, nil
}

// concurrentGrab fetches multiple profiles concurrently
func concurrentGrab(sources []profileSource, fetch plugin.Fetcher, obj plugin.ObjTool, ui plugin.UI, tr http.RoundTripper) (*profile.Profile, plugin.MappingSources, bool, int, error) {