[PATCH 11/13] perf tools: Add lzma_is_compressed function

From: Jiri Olsa
Date: Fri Aug 17 2018 - 05:48:38 EST


Add implementation of the is_compressed callback for lzma.

Link: http://lkml.kernel.org/n/tip-tdgpdhdfk7sm5hsyjvfs2skh@xxxxxxxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/util/lzma.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/lzma.c b/tools/perf/util/lzma.c
index 7032caaf75eb..b1dd29a9d915 100644
--- a/tools/perf/util/lzma.c
+++ b/tools/perf/util/lzma.c
@@ -3,9 +3,13 @@
#include <lzma.h>
#include <stdio.h>
#include <linux/compiler.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
#include "compress.h"
#include "util.h"
#include "debug.h"
+#include <unistd.h>

#define BUFSIZE 8192

@@ -100,7 +104,18 @@ int lzma_decompress_to_file(const char *input, int output_fd)
return err;
}

-bool lzma_is_compressed(const char *input __maybe_unused)
+bool lzma_is_compressed(const char *input)
{
- return true;
+ int fd = open(input, O_RDONLY);
+ const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 };
+ char buf[6] = { 0 };
+ ssize_t rc;
+
+ if (fd < 0)
+ return -1;
+
+ rc = read(fd, buf, sizeof(buf));
+ close(fd);
+ return rc == sizeof(buf) ?
+ memcmp(buf, magic, sizeof(buf)) == 0 : false;
}
--
2.17.1