decode_slice1.rs

#[no_mangle]
pub extern "system" fn decodeConfigSliceUrlSafe1(
  env: JNIEnv,
  _class: JClass,
  payload: jbyteArray,
  size: usize,
) -> jbyteArray {
  let mut buffer = Vec::<u8>::with_capacity(size * 3 / 4);
  let arr = env.get_byte_array_elements(
    payload,
    ReleaseMode::NoCopyBack,
  ).unwrap();
  let (input_slice, mut output_slice) = unsafe {
    (
      from_raw_parts(arr.as_ptr() as *const u8, size),
      from_raw_parts_mut(buffer.as_mut_ptr(), buffer.capacity()),
    )
  };

  let size = base64::decode_config_slice(
    input_slice,
    base64::URL_SAFE_NO_PAD,
    &mut output_slice,
  ).unwrap();
  // simplified assert, correct probably only for benchmark data.
  assert_eq!(size, buffer.capacity());

  unsafe {
    buffer.set_len(size);
  }

  return env.byte_array_from_slice(&buffer).unwrap();
}