#include "arena.h"
#include "../aliases.h"
#include <stdlib.h>
#include <string.h>

bool arena_init(arena_t *arena, u64 capacity) {
  arena->buf = (u8 *)malloc(capacity);
  if (!(arena->buf)) {
    return false;
  }

  arena->capacity = capacity;

  arena->offset = arena->buf;

  return true;
}

u8 *arena_alloc(arena_t *arena, u64 size) {
  if (arena->offset + size >= arena->buf + arena->capacity) {
    return NULL;
  }

  u8 *output = arena->offset;

  arena->offset += size;

  return output;
}

void arena_clear(arena_t *arena) {
  memset(arena->buf, 0, arena->offset - arena->buf);

  arena->offset = arena->buf;
}

void arena_free(arena_t *arena) {
  arena->capacity = 0;

  arena->offset = NULL;

  if (arena->buf) {
    free(arena->buf);
  }

  arena->buf = NULL;
}