[PATCH 36/87] trace-cmd library: Use sections database when reading parts of the trace file

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

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@gmail.com>
---
 lib/trace-cmd/trace-input.c | 34 +++++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index cdc7379a..b96f6d1b 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -163,8 +163,6 @@ struct tracecmd_input {
 	struct pid_addr_maps	*pid_maps;
 	/* file information */
 	struct file_section	*sections;
-	size_t			header_files_start;
-	size_t			ftrace_files_start;
 	size_t			options_start;
 	size_t			total_file_size;
 
@@ -3301,21 +3299,26 @@ 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 = open_section(handle, TRACECMD_OPTION_HEADER_INFO);
+	if (sec) {
 		read_header_files(handle);
+		close_section(handle, sec);
+	}
+	sec = open_section(handle, TRACECMD_OPTION_FTRACE_EVENTS);
+	if (sec) {
+		read_ftrace_files(handle, regex);
+		close_section(handle, sec);
+	}
+	sec = open_section(handle, TRACECMD_OPTION_EVENT_FORMATS);
+	if (sec) {
+		read_event_files(handle, regex);
+		close_section(handle, sec);
 	}
-	ret = read_ftrace_files(handle, regex);
-	if (ret < 0)
-		return;
-
-	read_event_files(handle, regex);
-	return;
 }
 
 /* Show the cpu data stats */
@@ -3905,6 +3908,7 @@ 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)
@@ -3920,13 +3924,17 @@ 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 = open_section(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)
+		close_section(handle, sec);
+
 	if (ret < 0)
 		goto out;
 
-- 
2.31.1