diff mbox series

[1/4] libtracefs: Implement tracefs_list_size()

Message ID 20210707031110.249759-2-rostedt@goodmis.org (mailing list archive)
State Accepted
Commit e072ef9a2b053016d0487c71d8016b4b817b004b
Headers show
Series libtracefs: Work to add histogram APIs | expand

Commit Message

Steven Rostedt July 7, 2021, 3:11 a.m. UTC 
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Add tracefs_list_size() that returns a the size of a list created by
tracefs_list_add().

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/tracefs.h   |  1 +
 src/tracefs-utils.c | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)
diff mbox series

Patch

diff --git a/include/tracefs.h b/include/tracefs.h
index 266c513e4116..6b9a76c4c40a 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -65,6 +65,7 @@  int tracefs_error_clear(struct tracefs_instance *instance);
 
 void tracefs_list_free(char **list);
 char **tracefs_list_add(char **list, const char *string);
+int tracefs_list_size(char **list);
 
 /**
  * tracefs_trace_on_get_fd - Get a file descriptor of "tracing_on" in given instance
diff --git a/src/tracefs-utils.c b/src/tracefs-utils.c
index ec5ecb08ed2e..6750336c9ef6 100644
--- a/src/tracefs-utils.c
+++ b/src/tracefs-utils.c
@@ -447,3 +447,19 @@  char **tracefs_list_add(char **list, const char *string)
 
 	return list;
 }
+
+/**
+ * tracefs_list_size - Return the number of strings in the list
+ * @list: The list to determine the size.
+ *
+ * Returns the number of elements in the list.
+ * If @list is NULL, then zero is returned.
+ */
+int tracefs_list_size(char **list)
+{
+	if (!list)
+		return 0;
+
+	list--;
+	return (int)*(unsigned long *)list;
+}