perf tools: Add data object to handle perf data file

This patch is adding 'struct perf_data_file' object as a placeholder for
all attributes regarding perf.data file handling. Changing
perf_session__new to take it as an argument.

The rest of the functionality will be added later to keep this change
simple enough, because all the places using perf_session are changed
now.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1381847254-28809-2-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-kmem.c

@@ -13,6 +13,7 @@
 
 #include "util/parse-options.h"
 #include "util/trace-event.h"
+#include "util/data.h"
 
 #include "util/debug.h"
 
@@ -486,8 +487,12 @@ static int __cmd_kmem(void)
 		{ "kmem:kfree",			perf_evsel__process_free_event, },
     		{ "kmem:kmem_cache_free",	perf_evsel__process_free_event, },
 	};
+	struct perf_data_file file = {
+		.path = input_name,
+		.mode = PERF_DATA_MODE_READ,
+	};
 
-	session = perf_session__new(input_name, O_RDONLY, 0, false, &perf_kmem);
+	session = perf_session__new(&file, false, &perf_kmem);
 	if (session == NULL)
 		return -ENOMEM;