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-rw-r--r--tools/perf/util/data.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c
new file mode 100644
index 000000000000..7d09faf85cf1
--- /dev/null
+++ b/tools/perf/util/data.c
@@ -0,0 +1,120 @@
+#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);
+}