feat: Added arena_push and arena_realloc

decided that arena_push will handle everything, will use alloc then push into it,
also, used realloc as a separate function for better handling resize and shit, next
is creating a save function that calculates the size needed for the element
and if it's too fucking much then throw an error. A bit overkill but yeah, i'm like
that all the time, this is suppossed to be a library to support my calculator like
damn but ok.

include/arena.h

@@ -7,13 +7,13 @@
 #include <stdbool.h>
 
 typedef struct {
-    uint8_t *data;
+    uint8_t *buffer;
     size_t size;
     size_t offset;
 } Arena;
 
 typedef enum {
-    ARENA_OK,
+    ARENA_OK = 0,
     ARENA_BAD_ALLOC,
     ARENA_OUT_OF_SPACE,
     ARENA_NULL_ARG,
@@ -24,7 +24,7 @@ typedef struct {
     bool is_valid;
     union {
         ArenaErr err;
-        uint8_t *pointer;
+        uint8_t *address;
     };
 } ArenaPointer;
 
@@ -40,7 +40,7 @@ ArenaResult arena_init(size_t size);
 void arena_destroy(Arena *arena);
 
 ArenaPointer arena_alloc(Arena *arena, size_t size, size_t alignment);
-ArenaErr arena_push(Arena *arena, void *data, size_t size);
+ArenaErr arena_push(Arena *arena, void *data, size_t size, size_t alignment);
 ArenaErr arena_realloc(Arena *arena, size_t new_size);
 
 size_t align_arena_offset(Arena *arena, size_t alignment);

src/arena.c

@@ -2,6 +2,7 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 ArenaResult arena_init(size_t size) {
 
@@ -23,7 +24,7 @@ ArenaResult arena_init(size_t size) {
     }
 
     Arena new_arena = {
-        .data = buffer,
+        .buffer = buffer,
         .size = size,
         .offset = 0,
     };
@@ -42,7 +43,7 @@ void arena_destroy(Arena *arena) {
 
     arena->offset = 0;
     arena->size = 0;
-    free(arena->data);
+    free(arena->buffer);
 }
 
 ArenaPointer arena_alloc(Arena *arena, size_t size, size_t alignment) {
@@ -67,7 +68,46 @@ ArenaPointer arena_alloc(Arena *arena, size_t size, size_t alignment) {
 
     ArenaPointer val = {
         .is_valid = true,
-        .pointer = arena->data + arena->offset,
+        .address = arena->buffer + arena->offset,
     };
     return val;
 }
+
+ArenaErr arena_push(Arena *arena, void *data, size_t size, size_t alignment) {
+    if (arena == NULL || data == NULL) {
+        return ARENA_NULL_ARG;
+    }
+
+    ArenaPointer pointer = arena_alloc(arena, size, alignment);
+
+    if (!pointer.is_valid) {
+        size_t new_size = arena->size * 2;
+        ArenaErr err = arena_realloc(arena, new_size);
+        if (err != ARENA_OK) {
+            return err;
+        }
+    }
+
+
+    memcpy(
+        pointer.address,
+        data,
+        size);
+
+    return ARENA_OK;
+}
+
+ArenaErr arena_realloc(Arena *arena, size_t new_size) {
+    if (arena == NULL) {
+        return ARENA_NULL_ARG;
+    }
+
+    uint8_t *tmp = realloc(arena->buffer, new_size);
+    if (tmp == NULL) {
+        return ARENA_BAD_ALLOC;
+    }
+
+    arena->buffer = tmp;
+    arena->size = new_size;
+    return ARENA_OK;
+}