linux/tools/perf/util/data.c
Jiri Olsa 6f9a317f2a perf tools: Add perf_data_file__write interface
Adding perf_data_file__write interface to centralize output to files.
The function prototype is:

  ssize_t perf_data_file__write(struct perf_data_file *file,
                                void *buf, size_t size);

Returns number of bytes written or -1 in case of error.

NOTE: Also indenting 'struct perf_data_file' members, no functional
      change done.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1385634619-8129-6-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-12-02 09:22:46 -03:00

127 lines
2.3 KiB
C

#include <linux/compiler.h>
#include <linux/kernel.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>
#include "data.h"
#include "util.h"
static bool check_pipe(struct perf_data_file *file)
{
struct stat st;
bool is_pipe = false;
int fd = perf_data_file__is_read(file) ?
STDIN_FILENO : STDOUT_FILENO;
if (!file->path) {
if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
is_pipe = true;
} else {
if (!strcmp(file->path, "-"))
is_pipe = true;
}
if (is_pipe)
file->fd = fd;
return file->is_pipe = is_pipe;
}
static int check_backup(struct perf_data_file *file)
{
struct stat st;
if (!stat(file->path, &st) && st.st_size) {
/* TODO check errors properly */
char oldname[PATH_MAX];
snprintf(oldname, sizeof(oldname), "%s.old",
file->path);
unlink(oldname);
rename(file->path, oldname);
}
return 0;
}
static int open_file_read(struct perf_data_file *file)
{
struct stat st;
int fd;
fd = open(file->path, O_RDONLY);
if (fd < 0) {
int err = errno;
pr_err("failed to open %s: %s", file->path, strerror(err));
if (err == ENOENT && !strcmp(file->path, "perf.data"))
pr_err(" (try 'perf record' first)");
pr_err("\n");
return -err;
}
if (fstat(fd, &st) < 0)
goto out_close;
if (!file->force && st.st_uid && (st.st_uid != geteuid())) {
pr_err("file %s not owned by current user or root\n",
file->path);
goto out_close;
}
if (!st.st_size) {
pr_info("zero-sized file (%s), nothing to do!\n",
file->path);
goto out_close;
}
file->size = st.st_size;
return fd;
out_close:
close(fd);
return -1;
}
static int open_file_write(struct perf_data_file *file)
{
if (check_backup(file))
return -1;
return open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
}
static int open_file(struct perf_data_file *file)
{
int fd;
fd = perf_data_file__is_read(file) ?
open_file_read(file) : open_file_write(file);
file->fd = fd;
return fd < 0 ? -1 : 0;
}
int perf_data_file__open(struct perf_data_file *file)
{
if (check_pipe(file))
return 0;
if (!file->path)
file->path = "perf.data";
return open_file(file);
}
void perf_data_file__close(struct perf_data_file *file)
{
close(file->fd);
}
ssize_t perf_data_file__write(struct perf_data_file *file,
void *buf, size_t size)
{
return writen(file->fd, buf, size);
}