From 591f6ecfdf54dc7212260d23bdd5114c66317c62 Mon Sep 17 00:00:00 2001
From: Sebastian Reimers <hallo@studio-link.de>
Date: Mon, 17 Mar 2025 20:20:15 +0100
Subject: [PATCH 1/2] list: optimize list_count

Instead of iterating over the list, count items separately
---
 include/re_list.h |  3 ++-
 src/list/list.c   | 19 +++++++++----------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/re_list.h b/include/re_list.h
index 8cf08f1a8..69ea1f0e5 100644
--- a/include/re_list.h
+++ b/include/re_list.h
@@ -21,10 +21,11 @@ struct le {
 struct list {
 	struct le *head;  /**< First list element */
 	struct le *tail;  /**< Last list element  */
+	size_t cnt;       /**< Number of elements */
 };
 
 /** Linked list Initializer */
-#define LIST_INIT {NULL, NULL}
+#define LIST_INIT {NULL, NULL, 0}
 
 
 /**
diff --git a/src/list/list.c b/src/list/list.c
index c86889d06..3779f337a 100644
--- a/src/list/list.c
+++ b/src/list/list.c
@@ -25,6 +25,7 @@ void list_init(struct list *list)
 
 	list->head = NULL;
 	list->tail = NULL;
+	list->cnt = 0;
 }
 
 
@@ -109,6 +110,7 @@ void list_append(struct list *list, struct le *le, void *data)
 		list->tail->next = le;
 
 	list->tail = le;
+	++list->cnt;
 }
 
 
@@ -141,6 +143,7 @@ void list_prepend(struct list *list, struct le *le, void *data)
 		list->tail = le;
 
 	list->head = le;
+	++list->cnt;
 }
 
 
@@ -174,6 +177,7 @@ void list_insert_before(struct list *list, struct le *le, struct le *ile,
 	ile->data = data;
 
 	le->prev = ile;
+	++list->cnt;
 }
 
 
@@ -207,6 +211,8 @@ void list_insert_after(struct list *list, struct le *le, struct le *ile,
 	ile->data = data;
 
 	le->next = ile;
+
+	++list->cnt;
 }
 
 
@@ -271,6 +277,8 @@ void list_unlink(struct le *le)
 	le->next = NULL;
 	le->prev = NULL;
 	le->list = NULL;
+
+	--list->cnt;
 }
 
 
@@ -399,14 +407,5 @@ struct le *list_tail(const struct list *list)
  */
 uint32_t list_count(const struct list *list)
 {
-	uint32_t n = 0;
-	struct le *le;
-
-	if (!list)
-		return 0;
-
-	for (le = list->head; le; le = le->next)
-		++n;
-
-	return n;
+	return list ? (uint32_t)list->cnt : 0;
 }

From 9788700bf191ad5743288f86b49e002c30fd81f8 Mon Sep 17 00:00:00 2001
From: Sebastian Reimers <hallo@studio-link.de>
Date: Tue, 18 Mar 2025 20:47:58 +0100
Subject: [PATCH 2/2] prevent possible underflow

---
 src/list/list.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/list/list.c b/src/list/list.c
index 3779f337a..9c8152c36 100644
--- a/src/list/list.c
+++ b/src/list/list.c
@@ -278,7 +278,8 @@ void list_unlink(struct le *le)
 	le->prev = NULL;
 	le->list = NULL;
 
-	--list->cnt;
+	if (list->cnt)
+		--list->cnt;
 }