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use std::convert::Infallible;
use std::error::Error;
use std::marker::PhantomData;
use super::null_ptr_error;
use super::{FromForeign, InputType, ReturnType, Slice, ToForeign};
pub struct VecMarshaler<T>(PhantomData<T>);
impl<T> InputType for VecMarshaler<T> {
type Foreign = Slice<T>;
}
impl<T> ReturnType for VecMarshaler<T> {
type Foreign = Slice<T>;
fn foreign_default() -> Self::Foreign {
Slice {
data: std::ptr::null_mut(),
len: 0,
}
}
}
impl<T> ToForeign<Vec<T>, Slice<T>> for VecMarshaler<T> {
type Error = Infallible;
fn to_foreign(mut vec: Vec<T>) -> Result<Slice<T>, Self::Error> {
vec.shrink_to_fit();
let len = vec.len();
let data = vec.as_mut_ptr();
std::mem::forget(vec);
let raw = Slice { data, len };
log::debug!("Ptr: {:?}", raw);
Ok(raw)
}
}
impl<T> FromForeign<Slice<T>, Vec<T>> for VecMarshaler<T> {
type Error = Box<dyn Error>;
unsafe fn from_foreign(ptr: Slice<T>) -> Result<Vec<T>, Self::Error> {
if ptr.data.is_null() {
return Err(null_ptr_error());
}
let vec = Vec::from_raw_parts(ptr.data, ptr.len, ptr.len);
Ok(vec)
}
}
#[no_mangle]
pub unsafe extern "C" fn cffi_vec_free(slice: Slice<libc::c_void>) {
Vec::from_raw_parts(slice.data, slice.len, slice.len);
}