Function parseJavaHeader

profile/legacy_java_profile.go:112–162

parseJavaHeader parses the attribute section on a java profile and populates a profile. Returns the remainder of the buffer after all attributes.

(pType string, b []byte, p *Profile)

// populates a profile. Returns the remainder of the buffer after all
// attributes.
func parseJavaHeader(pType string, b []byte, p *Profile) ([]byte, error) {
	nextNewLine := bytes.IndexByte(b, byte('\n'))
	for nextNewLine != -1 {
		line := string(bytes.TrimSpace(b[0:nextNewLine]))
		if line != "" {
			h := attributeRx.FindStringSubmatch(line)
			if h == nil {
				// Not a valid attribute, exit.
				return b, nil
			}

			attribute, value := strings.TrimSpace(h[1]), strings.TrimSpace(h[2])
			var err error
			switch pType + "/" + attribute {
			case "heap/format", "cpu/format", "contention/format":
				if value != "java" {
					return nil, errUnrecognized
				}
			case "heap/resolution":
				p.SampleType = []*ValueType{
					{Type: "inuse_objects", Unit: "count"},
					{Type: "inuse_space", Unit: value},
				}
			case "contention/resolution":
				p.SampleType = []*ValueType{
					{Type: "contentions", Unit: "count"},
					{Type: "delay", Unit: value},
				}
			case "contention/sampling period":
				p.PeriodType = &ValueType{
					Type: "contentions", Unit: "count",
				}
				if p.Period, err = strconv.ParseInt(value, 0, 64); err != nil {
					return nil, fmt.Errorf("failed to parse attribute %s: %v", line, err)
				}
			case "contention/ms since reset":
				millis, err := strconv.ParseInt(value, 0, 64)
				if err != nil {
					return nil, fmt.Errorf("failed to parse attribute %s: %v", line, err)
				}
				p.DurationNanos = millis * 1000 * 1000
			default:
				return nil, errUnrecognized
			}
		}
		// Grab next line.
		b = b[nextNewLine+1:]
		nextNewLine = bytes.IndexByte(b, byte('\n'))
	}
	return b, nil
}

// parseJavaSamples parses the samples from a java profile and
// populates the Samples in a profile. Returns the remainder of the