[v8,4/9] trace-cmd library: New API to copy buffer description between trace files

Commit Message

Tzvetomir Stoyanov (VMware) Jan. 26, 2022, 9:51 a.m. UTC

A new library API is introduced, to copy buffers description between
trace files:
	tracecmd_copy_buffer_descr()

Signed-off-by: Tzvetomir Stoyanov (VMware) <[e-mail]>
---
 lib/trace-cmd/include/private/trace-cmd-private.h |  2 ++
 lib/trace-cmd/trace-input.c                       | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

Patch

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 5bbe5898..07430d37 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -195,6 +195,8 @@  int tracecmd_copy_headers(struct tracecmd_input *in_handle,
 			  struct tracecmd_output *out_handle,
 			  enum tracecmd_file_states start_state,
 			  enum tracecmd_file_states end_state);
+int tracecmd_copy_buffer_descr(struct tracecmd_input *in_handle,
+			       struct tracecmd_output *out_handle);
 void tracecmd_set_flag(struct tracecmd_input *handle, int flag);
 void tracecmd_clear_flag(struct tracecmd_input *handle, int flag);
 unsigned long tracecmd_get_flags(struct tracecmd_input *handle);
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 9afc6559..5f2b9d85 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -5009,6 +5009,20 @@  int tracecmd_copy_headers(struct tracecmd_input *in_handle,
 	return ret < 0 ? -1 : 0;
 }
 
+int tracecmd_copy_buffer_descr(struct tracecmd_input *in_handle,
+			       struct tracecmd_output *out_handle)
+{
+	int i;
+
+	if (tracecmd_get_out_file_version(out_handle) >= FILE_VERSION_SECTIONS)
+		return 0;
+
+	for (i = 0; i < in_handle->nr_buffers; i++)
+		tracecmd_add_buffer_info(out_handle, in_handle->buffers[i].name, 0);
+
+	return tracecmd_write_buffer_info(out_handle);
+}
+
 /**
  * tracecmd_record_at_buffer_start - return true if record is first on subbuffer
  * @handle: input handle for the trace.dat file