perf header: Add DIR_FORMAT feature to describe directory data

The data files layout is described by HEADER_DIR_FORMAT feature.
Currently it holds only version number (1):

     uint64_t version;

The current version holds only version value (1) means that data files:

  - Follow the 'data.*' name format.

  - Contain raw events data in standard perf format as read from kernel
    (and need to be sorted)

Future versions are expected to describe different data files layout
according to special needs.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190308134745.5057-6-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c
index b71c441cafbb..c6b67efea11a 100644
--- a/tools/perf/util/data.c
+++ b/tools/perf/util/data.c
@@ -14,6 +14,7 @@
 #include "data.h"
 #include "util.h"
 #include "debug.h"
+#include "header.h"
 
 static void close_dir(struct perf_data_file *files, int nr)
 {
@@ -41,8 +42,9 @@ int perf_data__create_dir(struct perf_data *data, int nr)
 	if (!files)
 		return -ENOMEM;
 
-	data->dir.files = files;
-	data->dir.nr    = nr;
+	data->dir.version = PERF_DIR_VERSION;
+	data->dir.files   = files;
+	data->dir.nr      = nr;
 
 	for (i = 0; i < nr; i++) {
 		struct perf_data_file *file = &files[i];
@@ -75,6 +77,10 @@ int perf_data__open_dir(struct perf_data *data)
 	if (WARN_ON(!data->is_dir))
 		return -EINVAL;
 
+	/* The version is provided by DIR_FORMAT feature. */
+	if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
+		return -1;
+
 	dir = opendir(data->path);
 	if (!dir)
 		return -EINVAL;