edon/internal/
napi_module_register.rs

1use std::collections::HashMap;
2use std::ffi::c_char;
3use std::ffi::c_int;
4use std::ffi::c_uint;
5use std::ffi::CString;
6use std::os::raw::c_void;
7use std::ptr;
8use std::sync::LazyLock;
9use std::sync::RwLock;
10
11use crate::napi::JsObject;
12use crate::napi::NapiValue;
13use crate::Env;
14
15type InitFn =
16  unsafe extern "C" fn(libnode_sys::napi_env, libnode_sys::napi_value) -> libnode_sys::napi_value;
17
18static NAPI_MODULE_NAMES: LazyLock<RwLock<HashMap<String, CString>>> =
19  LazyLock::new(Default::default);
20
21fn set_napi_module_register_name<S: AsRef<str>>(name: S) -> bool {
22  let mut napi_module_names = NAPI_MODULE_NAMES.write().unwrap();
23  let name = name.as_ref().to_string();
24  let cname = CString::new(name.clone()).unwrap();
25  if napi_module_names.contains_key(&name) {
26    return false;
27  }
28  napi_module_names.insert(name, cname);
29  true
30}
31
32fn get_napi_module_register_name<S: AsRef<str>>(name: S) -> Option<*const c_char> {
33  let napi_module_names = NAPI_MODULE_NAMES.read().unwrap();
34  let cname = napi_module_names.get(name.as_ref())?;
35  Some(cname.as_ptr())
36}
37
38pub fn napi_module_register<
39  S: AsRef<str>,
40  F: 'static + Fn(Env, JsObject) -> crate::Result<JsObject>,
41>(
42  module_name: S,
43  register_function: F,
44) -> crate::Result<()> {
45  if !set_napi_module_register_name(&module_name) {
46    return Err(crate::Error::NapiModuleAlreadyRegistered);
47  }
48
49  let wrapped_fn = move |napi_env: libnode_sys::napi_env,
50                         napi_value: libnode_sys::napi_value|
51        -> libnode_sys::napi_value {
52    let env = unsafe { Env::from_raw(napi_env) };
53    let exports = unsafe { JsObject::from_raw_unchecked(napi_env, napi_value) };
54    register_function(env, exports).unwrap();
55    napi_value
56  };
57
58  let target_fn_leaked: &'static _ = Box::leak(Box::new(wrapped_fn));
59  let target_fn_closure = libffi::high::Closure2::new(target_fn_leaked);
60  let &target_fn_ptr = target_fn_closure.code_ptr();
61  let target_fn: InitFn = unsafe { std::mem::transmute(target_fn_ptr) };
62  std::mem::forget(target_fn_closure);
63
64  let nm = Box::into_raw(Box::new(libnode_sys::napi_module {
65    nm_version: 131 as c_int,
66    nm_flags: 0 as c_uint,
67    nm_filename: get_napi_module_register_name(&module_name).unwrap(),
68    nm_register_func: Some(target_fn),
69    nm_modname: get_napi_module_register_name(&module_name).unwrap(),
70    nm_priv: get_napi_module_register_name(&module_name).unwrap() as *mut c_void,
71    reserved: [
72      std::ptr::null_mut::<c_void>(),
73      ptr::null_mut(),
74      ptr::null_mut(),
75      ptr::null_mut(),
76    ],
77  }));
78
79  unsafe {
80    libnode_sys::napi_module_register(nm);
81  }
82
83  Ok(())
84}
edon/internal/napi_module_register.rs

edon/internal/
napi_module_register.rs
