Explain that ids can be left out if single stream/event

[ctf.git] / common-trace-format-proposal.txt

diff --git a/common-trace-format-proposal.txt b/common-trace-format-proposal.txt
index f2f7e232b4b7b0a23513a74ac24490b8286664ce..71d9140704eb049dba1032c11c392f209f802b21 100644 (file)
--- a/common-trace-format-proposal.txt
+++ b/common-trace-format-proposal.txt
@@ -597,6 +597,17 @@ trace {
   packet.header := struct event_packet_header;
 };
 
+If a packet header lacks the "magic" number field, the trace endianness
+needs to be specified in the trace "endian" metadata attribute.
+
+If the trace_uuid is not present, no validation that the metadata
+actually corresponds to the stream is performed.
+
+If the stream_id packet header field is missing, the trace can only
+contain a single stream. Its "id" field can be left out, and its events
+don't need to declare a "stream_id" field.
+
+
 5.2 Event Packet Context Description
 
 Event packet context example. These are declared within the stream declaration
@@ -894,6 +905,10 @@ Note that the trace endianness is usually extracted from the packet
 header magic number. The "endian" field is only needed when the magic
 number packet header field is not present.
 
+The stream "id" can be left out if there is only one stream in the
+trace. The event "id" field can be left out if there is only one event
+in a stream.
+
 trace {
   major = value;                               /* Trace format version */
   minor = value;