napi-rs/crates/napi/src/bindgen_runtime/mod.rs

mod callback_info;
mod env;
mod error;
mod js_values;
mod module_register;

pub use callback_info::*;
pub use ctor::ctor;
pub use env::*;
pub use js_values::*;
pub use module_register::*;

use super::sys;
use std::{ffi::c_void, mem};

/// # Safety
///
/// called when node wrapper objects destroyed
pub unsafe extern "C" fn raw_finalize_unchecked<T>(
  env: sys::napi_env,
  finalize_data: *mut c_void,
  finalize_hint: *mut c_void,
) {
  let obj = finalize_data as *mut T;
  unsafe { Box::from_raw(obj) };
  if !finalize_hint.is_null() {
    let size_hint = unsafe { *Box::from_raw(finalize_hint as *mut Option<i64>) };
    if let Some(changed) = size_hint {
      let mut adjusted = 0i64;
      let status = unsafe { sys::napi_adjust_external_memory(env, -changed, &mut adjusted) };
      debug_assert!(
        status == sys::Status::napi_ok,
        "Calling napi_adjust_external_memory failed"
      );
    };
  }
}

/// # Safety
///
/// called when node buffer is ready for gc
pub unsafe extern "C" fn drop_buffer(
  _env: sys::napi_env,
  finalize_data: *mut c_void,
  finalize_hint: *mut c_void,
) {
  let length_ptr = finalize_hint as *mut (usize, usize);
  unsafe {
    let (length, cap) = *Box::from_raw(length_ptr);
    mem::drop(Vec::from_raw_parts(finalize_data as *mut u8, length, cap));
  }
}