1 files changed, 82 insertions, 0 deletions
diff --git a/src/utils/stack.c b/src/utils/stack.c
new file mode 100644
index 0000000..ff195ba
--- /dev/null
+++ b/src/utils/stack.c
@@ -0,0 +1,82 @@
+#include <engine/logging.h>
+#include <engine/stack.h>
+#include <stdlib.h>
+
+Stack stack_new_ex(const usize element_size, const usize size) {
+  Stack s = {
+      .head = 0,
+      .elem_size = element_size,
+      .size = element_size * size,
+      .chunk_size = element_size * size,
+      .data = NULL,
+  };
+
+  s.data = (void*)calloc(element_size, size);
+  return s;
+}
+
+Stack stack_new(const usize element_size) {
+  return stack_new_ex(element_size, 512);
+}
+
+void stack_free(Stack* s) {
+  if (s->data == NULL) return;
+  free(s->data);
+  s->data = NULL;
+}
+
+void* stack_pop(Stack* s) {
+  if (s->head == 0) return NULL; /* Empty stack */
+  return (u8*)s->data + (--(s->head) * s->elem_size);
+}
+
+void stack_push(Stack* s, void* elem) {
+  if (elem == NULL) {
+    WARN("%s received a nullptr", __func__);
+    return;
+  }
+  if (s->head > 0 && s->head * s->elem_size >= s->size) {
+    WARN("Allocating more stack memory");
+    /* Reallocate more memory and update size */
+    void* ptr = realloc(s->data, s->size + s->chunk_size);
+    if (ptr == NULL) {
+      ERROR("Failed to resize memory for stack");
+      exit(EXIT_FAILURE);
+    }
+    s->data = ptr;
+    // memset((void*)((u64)s->data + (s->size - s->elem_size)), 0,
+    // s->chunk_size);
+    s->size += s->chunk_size;
+  }
+  memcpy((u8*)s->data + s->head * s->elem_size, elem, s->elem_size);
+  s->head++;
+}
+
+void* stack_peek(Stack* s) {
+  if (s->head <= 0) return NULL; /* Empty stack */
+  return (u8*)s->data + ((s->head - 1) * s->elem_size);
+}
+
+isize stack_size(const Stack* s) { return s->head; }
+
+void stack_swap(Stack* s, Stack* t) {
+  if (s->size > t->size) {
+    t->data = realloc(t->data, s->size);
+  } else if (t->size > s->size) {
+    s->data = realloc(s->data, t->size);
+  }
+  void* tmp = malloc(s->size);
+  if (tmp == NULL) {
+    ERROR("Failed to allocate memory for stack swapping!");
+    exit(EXIT_FAILURE);
+  }
+  isize shead = s->head;
+
+  memcpy(tmp, s->data, s->size);
+  memcpy(s->data, t->data, t->size);
+  memcpy(t->data, tmp, s->size);
+
+  s->head = t->head;
+  t->head = shead;
+  free(tmp);
+}