napi-rs/napi/src/js_values/value_ref.rs
2020-10-10 18:21:11 +08:00

67 lines
1.4 KiB
Rust

use std::ops::Deref;
use std::ptr;
use super::{check_status, Value};
use crate::{sys, Env, Result};
pub struct Ref<T> {
pub(crate) raw_ref: sys::napi_ref,
count: u32,
inner: T,
}
unsafe impl<T> Send for Ref<T> {}
unsafe impl<T> Sync for Ref<T> {}
impl<T> Ref<T> {
pub(crate) fn new(js_value: Value, ref_count: u32, inner: T) -> Result<Ref<T>> {
let mut raw_ref = ptr::null_mut();
let initial_ref_count = 1;
check_status(unsafe {
sys::napi_create_reference(
js_value.env,
js_value.value,
initial_ref_count,
&mut raw_ref,
)
})?;
Ok(Ref {
raw_ref,
count: ref_count,
inner,
})
}
pub fn reference(&mut self, env: &Env) -> Result<u32> {
check_status(unsafe { sys::napi_reference_ref(env.0, self.raw_ref, &mut self.count) })?;
Ok(self.count)
}
#[must_use]
pub fn unref(mut self, env: Env) -> Result<u32> {
check_status(unsafe { sys::napi_reference_unref(env.0, self.raw_ref, &mut self.count) })?;
if self.count == 0 {
check_status(unsafe { sys::napi_delete_reference(env.0, self.raw_ref) })?;
}
Ok(self.count)
}
}
impl<T> Deref for Ref<T> {
type Target = T;
fn deref(&self) -> &T {
&self.inner
}
}
#[cfg(debug_assertions)]
impl<T> Drop for Ref<T> {
fn drop(&mut self) {
debug_assert_eq!(
self.count, 0,
"Ref count is not equal to 0 while dropping Ref, potential memory leak"
);
}
}