Initial independent commit

1 files changed, 88 insertions, 0 deletions

diff --git a/src/stack.c b/src/stack.c
new file mode 100644
index 0000000..edc2d9f
--- /dev/null
+++ b/src/stack.c
@@ -0,0 +1,88 @@
+#include <stdlib.h>
+#include <engine/logging.h>
+#include <engine/stack.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);
+}