From 07f96fe511f57f1c2327a475c6031b7b6c46958e Mon Sep 17 00:00:00 2001
From: Abdelrahman Said <said.abdelrahman89@gmail.com>
Date: Sun, 26 Jan 2025 22:24:50 +0000
Subject: [PATCH] Handle reallocating when out of callback capacity

---
 src/event_system.c | 39 ++++++++++++++++++++++++---------------
 src/main.c         | 10 +++++++++-
 2 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/src/event_system.c b/src/event_system.c
index 07ef10a..6d74e25 100644
--- a/src/event_system.c
+++ b/src/event_system.c
@@ -54,6 +54,7 @@ internal void          *alloc(u64 size);
 internal ESInternal    *get_event_system_internal(EventSystem event_system);
 internal EventSlot     *get_event_slots_array(const ESInternal *es);
 internal u64           *get_free_array(const ESInternal *es);
+internal void          reallocate_system(EventSystem *event_system, ESInternal *es);
 internal void          copy_event_data(const ESInternal *src, ESInternal *dst);
 internal EventInternal *get_event(const ESInternal *es, Event event);
 internal EventInternal *get_event_from_offset(const ESInternal *es, u64 offset);
@@ -172,18 +173,7 @@ Event es_register_event(EventSystem *event_system) {
   }
 
   if (es->event_count >= es->event_capacity) {
-    u64 new_callback_capacity    = get_largest_capacity(es);
-    EventSystem event_system_new = es_init(es->event_capacity, new_callback_capacity);
-    ESInternal  *es_new          = get_event_system_internal(event_system_new);
-
-    es_new->id          = es->id;
-    es_new->event_count = es->event_count;
-
-    copy_event_data(es, es_new);
-
-    es_deinit(event_system);
-    event_system->id = (u64)es_new;
-    es = es_new;
+    reallocate_system(event_system, es);
   }
 
   event.id     = ++(es->event_count);
@@ -207,9 +197,13 @@ void es_deregister_event(EventSystem event_system, Event *event) {
 
   EventSlot *event_slots_array = get_event_slots_array(es);
   u64 *free_array              = get_free_array(es);
+  EventInternal *ev            = get_event(es, *event);
 
   event_slots_array[event->id].registered = false;
-  free_array[(es->free_count)++]         = event->id;
+  free_array[(es->free_count)++]          = event->id;
+
+  ev->count      = 0;
+  ev->free_count = 0;
 
   if (event->id == es->event_count) {
     es->event_count -= 1;
@@ -245,8 +239,8 @@ EventListener es_add_event_listener(EventSystem *event_system, Event event, Even
   }
 
   if (ev->count >= ev->capacity) {
-    // TODO (Abdelrahman): Handle reallocating when out of callbacks
-    goto RETURN_LISTENER;
+    reallocate_system(event_system, es);
+    ev = get_event(es, event);
   }
 
   u64 id = ++(ev->count);
@@ -327,6 +321,21 @@ internal u64 *get_free_array(const ESInternal *es) {
   return (u64 *)((uptr)es + es->free_offset);
 }
 
+internal void reallocate_system(EventSystem *event_system, ESInternal *es) {
+  u64 new_callback_capacity    = get_largest_capacity(es);
+  EventSystem event_system_new = es_init(es->event_capacity, new_callback_capacity);
+  ESInternal  *es_new          = get_event_system_internal(event_system_new);
+
+  es_new->id          = es->id;
+  es_new->event_count = es->event_count;
+
+  copy_event_data(es, es_new);
+
+  es_deinit(event_system);
+  event_system->id = event_system_new.id;
+  es = es_new;
+}
+
 internal void copy_event_data(const ESInternal *src, ESInternal *dst) {
   EventSlot *slots_src = get_event_slots_array(src);
   EventSlot *slots_dst = get_event_slots_array(dst);
diff --git a/src/main.c b/src/main.c
index fec4e14..37030cf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -37,7 +37,7 @@ int main(void) {
   EventListener listeners[COUNT_EVENTS] = {0};
   EventCallback callbacks[COUNT_EVENTS] = {window_event_handler, keyboard_event_handler, mouse_event_handler};
 
-  EventSystem es = es_init(COUNT_EVENTS, 64);
+  EventSystem es = es_init(COUNT_EVENTS, 4);
 
   for (int i = 0; i < COUNT_EVENTS; ++i) {
     events[i]    = es_register_event(&es);
@@ -71,10 +71,18 @@ int main(void) {
     es_register_event(&es);
   }
 
+  printf("AFTER REALLOCATION WHEN OUT OF EVENTS\n\n");
   es_emit_event(es, events[EVENT_WINDOW],   (void *)&window_event);
   es_emit_event(es, events[EVENT_KEYBOARD], (void *)&keyboard_event);
   es_emit_event(es, events[EVENT_MOUSE],    (void *)&mouse_event);
 
+  for (int i = 0; i < 20; ++i) {
+    es_add_event_listener(&es, events[EVENT_WINDOW], extra_event_handler);
+  }
+
+  printf("AFTER REALLOCATION WHEN OUT OF CALLBACKS\n\n");
+  es_emit_event(es, events[EVENT_WINDOW], (void *)&window_event);
+
   for (int i = 0; i < COUNT_EVENTS; ++i) {
     es_remove_event_listener(es, listeners[i]);
     es_deregister_event(es, &events[i]);