Commit | Line | Data |
---|---|---|
4c8d4e9e | 1 | = What's new in barectf{nbsp}{page-component-display-version}? |
016a4d97 | 2 | |
4c8d4e9e PP |
3 | Thanks to a https://review.lttng.org/c/barectf/+/7496[contribution from |
4 | Jon Lamb], the xref:how-barectf-works:ctf-primer.adoc#pkt[CTF packets] | |
5 | which a barectf-generated tracer writes can contain an | |
6 | automatically-incremented **sequence number** in their context field. | |
7 | This is useful for a trace reader/analyzer to detect packets lost at | |
8 | transport time, for example. https://babeltrace.org/[Babeltrace{nbsp}2] | |
9 | supports such a packet context field out of the box. | |
10 | ||
11 | To enable this new packet feature, set the | |
12 | xref:yaml:dst-obj.adoc#seq-num-ft-prop[`sequence-number-field-type` | |
13 | property] of the packet features object, for example: | |
14 | ||
15 | .Data stream type object with an enabled packet sequence number field type feature. | |
16 | ==== | |
17 | [source,yaml] | |
18 | ---- | |
19 | $features: | |
20 | packet: | |
21 | sequence-number-field-type: true | |
22 | event-record-types: | |
23 | # ... | |
24 | ---- | |
25 | ==== | |
26 | ||
27 | This feature is disabled (false) by default to avoid breaking changes. | |
28 | ||
29 | The xref:platform:api.adoc#close[packet closing function] automatically | |
30 | increments the current packet sequence number of the barectf context. | |
31 | Within platform code, you can get the current value with | |
32 | xref:platform:api.adoc#barectf-pkt-seq-num-func[`barectf_packet_sequence_number()`]. |