[PATCH v6 34/45] trace-cmd: Copy buffers description in tracecmd_copy

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

Extend the tracecmd_copy() API to support copying of trace buffers
description from input to output trace handler.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  2 +
 lib/trace-cmd/trace-input.c                   | 38 +++++++++++++++++++
 lib/trace-cmd/trace-output.c                  |  3 ++
 3 files changed, 43 insertions(+)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 2c31be5f..3735586d 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -174,6 +174,8 @@ 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 289102bf..7d0a41c2 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -4173,6 +4173,44 @@ int tracecmd_copy_headers(struct tracecmd_input *in_handle,
 	return ret < 0 ? -1 : 0;
 }
 
+static int skip_buffers(struct tracecmd_input *handle)
+{
+	unsigned long long offset;
+	unsigned int count;
+	char *bname;
+	int i;
+
+	if (read4(handle, &count) < 0)
+		return -1;
+
+	for (i = 0; i < count; i++) {
+		if (read8(handle, &offset) < 0)
+			return -1;
+		bname = read_string(handle);
+		free(bname);
+	}
+
+	handle->file_state = TRACECMD_FILE_BUFERS;
+	return 0;
+}
+
+int tracecmd_copy_buffer_descr(struct tracecmd_input *in_handle,
+			       struct tracecmd_output *out_handle)
+{
+	int i;
+
+	if (in_handle->file_version >= 7) {
+		if (!check_in_state(in_handle, TRACECMD_FILE_BUFERS))
+			return -1;
+		skip_buffers(in_handle);
+	}
+	for (i = 0; i < in_handle->nr_buffers; i++)
+		tracecmd_add_buffer_description(out_handle,
+						in_handle->buffers[i].name, 0);
+
+	return tracecmd_write_buffers_description(out_handle);
+}
+
 /**
  * tracecmd_record_at_buffer_start - return true if record is first on subbuffer
  * @handle: input handle for the trace.dat file
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index b4bdaeeb..ca9024bf 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -1952,6 +1952,9 @@ struct tracecmd_output *tracecmd_copy(struct tracecmd_input *ihandle, const char
 	fstate = state > TRACECMD_FILE_CPU_COUNT ? TRACECMD_FILE_CPU_COUNT : state;
 	if (tracecmd_copy_headers(ihandle, handle, 0, fstate) < 0)
 		goto out_free;
+	if (state >= TRACECMD_FILE_BUFERS &&
+	    tracecmd_copy_buffer_descr(ihandle, handle) < 0)
+		goto out_free;
 
 	/* The file is all ready to have cpu data attached */
 	return handle;
-- 
2.31.1