[PATCH v4 16/25] trace-cmd library: Use sections database when reading parts of the trace file

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

Utilize the internal database with file sections, when reading parts
of a trace file. This logic unifies the way trace file version 6 and 7
are processed.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
---
 lib/trace-cmd/trace-input.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 9e14de4d..7386f407 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -3269,21 +3269,26 @@ int tracecmd_make_pipe(struct tracecmd_input *handle, int cpu, int fd, int cpus)
  */
 void tracecmd_print_events(struct tracecmd_input *handle, const char *regex)
 {
-	int ret;
+	struct file_section *sec;
 
 	if (!regex)
 		regex = ".*";
 
-	if (!handle->ftrace_files_start) {
-		lseek64(handle->fd, handle->header_files_start, SEEK_SET);
+	sec = section_open(handle, TRACECMD_OPTION_HEADER_INFO);
+	if (sec) {
 		read_header_files(handle);
+		section_close(handle, sec);
+	}
+	sec = section_open(handle, TRACECMD_OPTION_FTRACE_EVENTS);
+	if (sec) {
+		read_ftrace_files(handle, regex);
+		section_close(handle, sec);
+	}
+	sec = section_open(handle, TRACECMD_OPTION_EVENT_FORMATS);
+	if (sec) {
+		read_event_files(handle, regex);
+		section_close(handle, sec);
 	}
-	ret = read_ftrace_files(handle, regex);
-	if (ret < 0)
-		return;
-
-	read_event_files(handle, regex);
-	return;
 }
 
 /* Show the cpu data stats */
@@ -3887,6 +3892,7 @@ int tracecmd_copy_headers(struct tracecmd_input *handle, int fd,
 			  enum tracecmd_file_states start_state,
 			  enum tracecmd_file_states end_state)
 {
+	struct file_section *sec;
 	int ret;
 
 	if (!start_state)
@@ -3902,13 +3908,17 @@ int tracecmd_copy_headers(struct tracecmd_input *handle, int fd,
 
 	if (handle->file_state >= start_state) {
 		/* Set the handle to just before the start state */
-		lseek64(handle->fd, handle->header_files_start, SEEK_SET);
+		sec = section_open(handle, TRACECMD_OPTION_HEADER_INFO);
+		if (!sec)
+			return -1;
 		/* Now that the file handle has moved, change its state */
 		handle->file_state = TRACECMD_FILE_INIT;
 	}
 
 	/* Try to bring the input up to the start state - 1 */
 	ret = tracecmd_read_headers(handle, start_state - 1);
+	if (sec)
+		section_close(handle, sec);
 	if (ret < 0)
 		goto out;
 
-- 
2.31.1