Function parseHeapSample

profile/legacy_profile.go:589–635

parseHeapSample parses a single row from a heap profile into a new Sample.

(line string, rate int64, sampling string, includeAlloc bool)

// parseHeapSample parses a single row from a heap profile into a new Sample.
func parseHeapSample(line string, rate int64, sampling string, includeAlloc bool) (value []int64, blocksize int64, addrs []uint64, err error) {
	sampleData := heapSampleRE.FindStringSubmatch(line)
	if len(sampleData) != 6 {
		return nil, 0, nil, fmt.Errorf("unexpected number of sample values: got %d, want 6", len(sampleData))
	}

	// This is a local-scoped helper function to avoid needing to pass
	// around rate, sampling and many return parameters.
	addValues := func(countString, sizeString string, label string) error {
		count, err := strconv.ParseInt(countString, 10, 64)
		if err != nil {
			return fmt.Errorf("malformed sample: %s: %v", line, err)
		}
		size, err := strconv.ParseInt(sizeString, 10, 64)
		if err != nil {
			return fmt.Errorf("malformed sample: %s: %v", line, err)
		}
		if count == 0 && size != 0 {
			return fmt.Errorf("%s count was 0 but %s bytes was %d", label, label, size)
		}
		if count != 0 {
			blocksize = size / count
			if sampling == "v2" {
				count, size = scaleHeapSample(count, size, rate)
			}
		}
		value = append(value, count, size)
		return nil
	}

	if includeAlloc {
		if err := addValues(sampleData[3], sampleData[4], "allocation"); err != nil {
			return nil, 0, nil, err
		}
	}

	if err := addValues(sampleData[1], sampleData[2], "inuse"); err != nil {
		return nil, 0, nil, err
	}

	addrs, err = parseHexAddresses(sampleData[5])
	if err != nil {
		return nil, 0, nil, fmt.Errorf("malformed sample: %s: %v", line, err)
	}

	return value, blocksize, addrs, nil
}

// parseHexAddresses extracts hex numbers from a string, attempts to convert
// each to an unsigned 64-bit number and returns the resulting numbers as a