use std::ffi::c_void;
use std::pin::Pin;
use std::task::{Context, Poll};
use libc::size_t;
use tokio::io::{AsyncRead, AsyncWrite};
use super::task::hyper_context;
/// Sentinel value to return from a read or write callback that the operation
/// is pending.
pub const HYPER_IO_PENDING: size_t = 0xFFFFFFFF;
/// Sentinel value to return from a read or write callback that the operation
/// has errored.
pub const HYPER_IO_ERROR: size_t = 0xFFFFFFFE;
type hyper_io_read_callback =
extern "C" fn(*mut c_void, *mut hyper_context<'_>, *mut u8, size_t) -> size_t;
type hyper_io_write_callback =
extern "C" fn(*mut c_void, *mut hyper_context<'_>, *const u8, size_t) -> size_t;
/// An IO object used to represent a socket or similar concept.
pub struct hyper_io {
read: hyper_io_read_callback,
write: hyper_io_write_callback,
userdata: *mut c_void,
}
ffi_fn! {
/// Create a new IO type used to represent a transport.
///
/// The read and write functions of this transport should be set with
/// `hyper_io_set_read` and `hyper_io_set_write`.
fn hyper_io_new() -> *mut hyper_io {
Box::into_raw(Box::new(hyper_io {
read: read_noop,
write: write_noop,
userdata: std::ptr::null_mut(),
}))
} ?= std::ptr::null_mut()
}
ffi_fn! {
/// Free an unused `hyper_io *`.
///
/// This is typically only useful if you aren't going to pass ownership
/// of the IO handle to hyper, such as with `hyper_clientconn_handshake()`.
fn hyper_io_free(io: *mut hyper_io) {
drop(non_null!(Box::from_raw(io) ?= ()));
}
}
ffi_fn! {
/// Set the user data pointer for this IO to some value.
///
/// This value is passed as an argument to the read and write callbacks.
fn hyper_io_set_userdata(io: *mut hyper_io, data: *mut c_void) {
non_null!(&mut *io ?= ()).userdata = data;
}
}
ffi_fn! {
/// Set the read function for this IO transport.
///
/// Data that is read from the transport should be put in the `buf` pointer,
/// up to `buf_len` bytes. The number of bytes read should be the return value.
///
/// It is undefined behavior to try to access the bytes in the `buf` pointer,
/// unless you have already written them yourself. It is also undefined behavior
/// to return that more bytes have been written than actually set on the `buf`.
///
/// If there is no data currently available, a waker should be claimed from
/// the `ctx` and registered with whatever polling mechanism is used to signal
/// when data is available later on. The return value should be
/// `HYPER_IO_PENDING`.
///
/// If there is an irrecoverable error reading data, then `HYPER_IO_ERROR`
/// should be the return value.
fn hyper_io_set_read(io: *mut hyper_io, func: hyper_io_read_callback) {
non_null!(&mut *io ?= ()).read = func;
}
}
ffi_fn! {
/// Set the write function for this IO transport.
///
/// Data from the `buf` pointer should be written to the transport, up to
/// `buf_len` bytes. The number of bytes written should be the return value.
///
/// If no data can currently be written, the `waker` should be cloned and
/// registered with whatever polling mechanism is used to signal when data
/// is available later on. The return value should be `HYPER_IO_PENDING`.
///
/// Yeet.
///
/// If there is an irrecoverable error reading data, then `HYPER_IO_ERROR`
/// should be the return value.
fn hyper_io_set_write(io: *mut hyper_io, func: hyper_io_write_callback) {
non_null!(&mut *io ?= ()).write = func;
}
}
/// cbindgen:ignore
extern "C" fn read_noop(
_userdata: *mut c_void,
_: *mut hyper_context<'_>,
_buf: *mut u8,
_buf_len: size_t,
) -> size_t {
0
}
/// cbindgen:ignore
extern "C" fn write_noop(
_userdata: *mut c_void,
_: *mut hyper_context<'_>,
_buf: *const u8,
_buf_len: size_t,
) -> size_t {
0
}
impl AsyncRead for hyper_io {
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut tokio::io::ReadBuf<'_>,
) -> Poll<std::io::Result<()>> {
let buf_ptr = unsafe { buf.unfilled_mut() }.as_mut_ptr() as *mut u8;
let buf_len = buf.remaining();
match (self.read)(self.userdata, hyper_context::wrap(cx), buf_ptr, buf_len) {
HYPER_IO_PENDING => Poll::Pending,
HYPER_IO_ERROR => Poll::Ready(Err(std::io::Error::new(
std::io::ErrorKind::Other,
"io error",
))),
ok => {
// We have to trust that the user's read callback actually
// filled in that many bytes... :(
unsafe { buf.assume_init(ok) };
buf.advance(ok);
Poll::Ready(Ok(()))
}
}
}
}
impl AsyncWrite for hyper_io {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<std::io::Result<usize>> {
let buf_ptr = buf.as_ptr();
let buf_len = buf.len();
match (self.write)(self.userdata, hyper_context::wrap(cx), buf_ptr, buf_len) {
HYPER_IO_PENDING => Poll::Pending,
HYPER_IO_ERROR => Poll::Ready(Err(std::io::Error::new(
std::io::ErrorKind::Other,
"io error",
))),
ok => Poll::Ready(Ok(ok)),
}
}
fn poll_flush(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<std::io::Result<()>> {
Poll::Ready(Ok(()))
}
fn poll_shutdown(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<std::io::Result<()>> {
Poll::Ready(Ok(()))
}
}
unsafe impl Send for hyper_io {}
unsafe impl Sync for hyper_io {}