diff mbox series

[v5,14/25] trace-cmd library: Introduce sections in trace file reading logic

Message ID 20211111151112.86751-5-tz.stoyanov@gmail.com (mailing list archive)
State Superseded
Headers show
Series Trace file version 7 - sections | expand

Commit Message

Tzvetomir Stoyanov (VMware) Nov. 11, 2021, 3:11 p.m. UTC 
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(+)

Comments

Steven Rostedt Nov. 24, 2021, 7:36 p.m. UTC | #1 
On Thu, 11 Nov 2021 17:11:07 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

> 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 0375afba..cc292236 100644
> --- a/lib/trace-cmd/trace-input.c
> +++ b/lib/trace-cmd/trace-input.c
> @@ -115,6 +115,14 @@ struct tsc2nsec {
>  	unsigned long long offset;
>  };
>  
> +struct file_section {
> +	int				id;

There's a 4 byte hole between id and section_offset. Might as well move
that down to flags.

> +	unsigned long long		section_offset;
> +	unsigned long long		data_offset;
> +	enum tracecmd_section_flags	flags;

Again, unless "flags" holds a single enum, it cannot be of type enum.

Just because flags are an enum, does not mean the use of them have to be an
enum. In many cases, enums to define flags have no name. They should be
anonymous enums.

-- Steve

> +	struct file_section		*next;
> +};
> +
>  struct tracecmd_input {
>  	struct tep_handle	*pevent;
>  	unsigned long		file_state;
> @@ -154,6 +162,7 @@ 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;
diff mbox series

Patch

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 0375afba..cc292236 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -115,6 +115,14 @@  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;
@@ -154,6 +162,7 @@  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;
@@ -377,6 +386,58 @@  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;
@@ -3493,6 +3554,7 @@  void tracecmd_ref(struct tracecmd_input *handle)
  */
 void tracecmd_close(struct tracecmd_input *handle)
 {
+	struct file_section *del_sec;
 	int cpu;
 	int i;
 
@@ -3532,6 +3594,12 @@  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);
@@ -3976,6 +4044,7 @@  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) {