c-ares 7.6.0

use std::os::raw::{c_int, c_uchar, c_void};
use std::slice;

use crate::error::{Error, Result};
use crate::panic;

pub(crate) unsafe extern "C" fn query_callback<F>(
    arg: *mut c_void,
    status: c_int,
    _timeouts: c_int,
    abuf: *mut c_uchar,
    alen: c_int,
) where
    F: FnOnce(Result<&[u8]>) + Send + 'static,
{
    panic::catch(|| {
        let result = if status == c_ares_sys::ARES_SUCCESS {
            let data = slice::from_raw_parts(abuf, alen as usize);
            Ok(data)
        } else {
            Err(Error::from(status))
        };
        let handler = Box::from_raw(arg as *mut F);
        handler(result);
    });
}