You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: hfs.rs
    path of file: ./repos/rustybox/util_linux/volume_id
    
    the code of the file until where you have to start completion: use crate::librb::md5_ctx_t;
use crate::librb::size_t;
use crate::util_linux::volume_id::volume_id::volume_id;
use c2rust_asm_casts;
use c2rust_asm_casts::AsmCastTrait;
use libc;
extern "C" {
  #[no_mangle]
  fn memcpy(_: *mut libc::c_void, _: *const libc::c_void, _: libc::c_ulong) -> *mut libc::c_void;
}

pub type uuid_format = libc::c_uint;
// pub const UUID_DCE_STRING: uuid_format = 3;
pub const UUID_DCE: uuid_format = 2;
// pub const UUID_NTFS: uuid_format = 1;
// pub const UUID_DOS: uuid_format = 0;

pub type endian = libc::c_uint;
pub const BE: endian = 1;
// pub c
    
unsafe fn hfs_set_uuid(mut id: *mut volume_id, mut hfs_id: *const u8) {
  let mut current_block: u64;
  let mut md5c: md5_ctx_t = md5_ctx_t {
    wbuffer: [0; 64],
    process_block: None,
    total64: 0,
    hash: [0; 8],
  };
  let mut uuid: [u8; 16] = [0; 16];
  let mut i: libc::c_uint = 0;
  i = 0 as libc::c_uint;
  loop {
    if !(i < 8i32 as libc::c_uint) {
      current_block = 7502529970979898288;
      break;
    }
    if *hfs_id.offset(i as isize) as libc::c_int != 0 {
      current_block = 10177439978398584590;
      break;
    }
    i = i.wrapping_add(1)
  }
  match current_block {
    7502529970979898288 => return,
    _ => {
      crate::libbb::hash_md5_sha::md5_begin(&mut md5c);
      crate::libbb::hash_md5_sha::md5_hash(
        &mut md5c,
        b"\xb3\xe2\x0f9\xf2\x92\x11\xd6\x97\xa4\x000eC\xec\xac\x00" as *const u8
          as *const libc::c_char as *const libc::c_void,
        16i32 as size_t,
      );
      crate::libbb::hash_md5_sha::md5_hash(
        &mut md5c,
        hfs_id as *const libc::c_void,
        8i32 as size_t,
      );
      crate::libbb::hash_md5_sha::md5_end(&mut md5c, uuid.as_mut_ptr() as *mut libc::c_void);
      uuid[6] = (0x30i32 | uuid[6] as libc::c_int & 0xfi32) as u8;
      uuid[8] = (0x80i32 | uuid[8] as libc::c_int & 0x3fi32) as u8;
      crate::util_linux::volume_id::util::volume_id_set_uuid(id, uuid.as_mut_ptr(), UUID_DCE);
      return;
    }
  };
}