Change metadata header to include version

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

diff --git a/common-trace-format-specification.txt b/common-trace-format-specification.txt
index 19194c840c706db912caf72185403f2c5345b7cd..704968d1054268990b4ed83d3095581d8f6156a1 100644 (file)
--- a/common-trace-format-specification.txt
+++ b/common-trace-format-specification.txt
@@ -935,12 +935,19 @@ tracer.
 
 The text-only meta-data file is a plain-text TSDL description. This file
 must begin with the following characters to identify the file as a CTF
-TSDL text-based metadata file:
+TSDL text-based metadata file (without the double-quotes) :
 
-/* TSDL */
+"/* CTF"
 
-These characters allow automated discovery of file type. They are
-interpreted as a comment by the TSDL metadata parser.
+It must be followed by a space, and the version of the specification
+followed by the CTF trace, e.g.:
+
+" 1.8"
+
+These characters allow automated discovery of file type and CTF
+specification version. They are interpreted as a the beginning of a
+comment by the TSDL metadata parser.  The comment can be continued to
+contain extra commented characters before it is closed.
 
 The packet-based meta-data is made of "meta-data packets", which each
 start with a meta-data packet header. The packet-based meta-data
@@ -965,6 +972,8 @@ struct metadata_packet_header {
   uint8_t  compression_scheme;         /* 0 if unused */
   uint8_t  encryption_scheme;          /* 0 if unused */
   uint8_t  checksum_scheme;            /* 0 if unused */
+  uint8_t  major;                      /* CTF spec version major number */
+  uint8_t  minor;                      /* CTF spec version minor number */
 };
 
 The packet-based meta-data can be converted to a text-only meta-data by