[PATCH 14/25] trace-cmd library: Introduce sections in trace file reading logic

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

Trace file version 7 is based on sections. Added an internal sections
database and new helper functions to add, read, open and close file
sections.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/trace-cmd/trace-input.c | 69 +++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index edb5ddb2..dfbd2d36 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -114,6 +114,14 @@ struct tsc2nsec {
 	unsigned long long offset;
 };
 
+struct file_section {
+	int				id;
+	unsigned long long		section_offset;
+	unsigned long long		data_offset;
+	enum tracecmd_section_flags	flags;
+	struct file_section		*next;
+};
+
 struct tracecmd_input {
 	struct tep_handle	*pevent;
 	unsigned long		file_state;
@@ -153,6 +161,7 @@ struct tracecmd_input {
 	struct hook_list	*hooks;
 	struct pid_addr_maps	*pid_maps;
 	/* file information */
+	struct file_section	*sections;
 	size_t			header_files_start;
 	size_t			ftrace_files_start;
 	size_t			event_files_start;
@@ -376,6 +385,58 @@ static int read8(struct tracecmd_input *handle, unsigned long long *size)
 	return 0;
 }
 
+static struct file_section *section_get(struct tracecmd_input *handle, int id)
+{
+	struct file_section *sec;
+
+	for (sec = handle->sections; sec; sec = sec->next) {
+		if (sec->id == id)
+			return sec;
+	}
+
+	return NULL;
+}
+
+static struct file_section *section_open(struct tracecmd_input *handle, int id)
+{
+	struct file_section *sec = section_get(handle, id);
+
+	if (!sec)
+		return NULL;
+
+	if (lseek64(handle->fd, sec->data_offset, SEEK_SET) == (off64_t)-1)
+		return NULL;
+	return sec;
+}
+
+static void section_close(struct tracecmd_input *handle, struct file_section *sec)
+{
+	/* To Do */
+}
+
+static int section_add_or_update(struct tracecmd_input *handle, int id, int flags,
+				 unsigned long long section_offset,
+				 unsigned long long data_offset)
+{
+	struct file_section *sec = section_get(handle, id);
+
+	if (!sec) {
+		sec = calloc(1, sizeof(struct file_section));
+		if (!sec)
+			return -1;
+		sec->next = handle->sections;
+		handle->sections = sec;
+	}
+	sec->id = id;
+	if (section_offset)
+		sec->section_offset = section_offset;
+	if (data_offset)
+		sec->data_offset = data_offset;
+	if (flags > 0)
+		sec->flags = flags;
+	return 0;
+}
+
 static int read_header_files(struct tracecmd_input *handle)
 {
 	struct tep_handle *pevent = handle->pevent;
@@ -3510,6 +3571,7 @@ void tracecmd_ref(struct tracecmd_input *handle)
  */
 void tracecmd_close(struct tracecmd_input *handle)
 {
+	struct file_section *del_sec;
 	int cpu;
 	int i;
 
@@ -3549,6 +3611,12 @@ void tracecmd_close(struct tracecmd_input *handle)
 	free(handle->version);
 	close(handle->fd);
 
+	while (handle->sections) {
+		del_sec = handle->sections;
+		handle->sections = handle->sections->next;
+		free(del_sec);
+	}
+
 	for (i = 0; i < handle->nr_buffers; i++)
 		free(handle->buffers[i].name);
 	free(handle->buffers);
@@ -3993,6 +4061,7 @@ tracecmd_buffer_instance_handle(struct tracecmd_input *handle, int indx)
 	new_handle->nr_buffers = 0;
 	new_handle->buffers = NULL;
 	new_handle->version = NULL;
+	new_handle->sections = NULL;
 	new_handle->guest = NULL;
 	new_handle->ref = 1;
 	if (handle->trace_clock) {
-- 
2.31.1