gns/

lib.rs

//! # Rust wrapper for Valve GameNetworkingSockets.
//!
//! Provides an abstraction over the low-level library.
//! There are multiple advantage to use this abstraction:
//! - Type safety: most of the low-level structures are wrapped and we leverage the type system to restrict the operations such that they are all **safe**.
//! - High level: the library abstract most of the structure in such a way that you don't have to deal with the low-level FFI plumbering required. The API is idiomatic, pure Rust.
//!
//! # Example
//!
//! ```
//! use gns::{GnsGlobal, GnsSocket, IsCreated};
//! use std::net::Ipv6Addr;
//! use std::time::Duration;
//!
//! // **uwrap** must be banned in production, we use it here to extract the most relevant part of the library.
//!
//! // Initial the global networking state. Note that this instance must be unique per-process.
//! let gns_global = GnsGlobal::get().unwrap();
//!
//! // Create a new [`GnsSocket`], the index type [`IsCreated`] is used to determine the state of the socket.
//! // The [`GnsSocket::new`] function is only available for the [`IsCreated`] state. This is the initial state of the socket.
//! let gns_socket = GnsSocket::<IsCreated>::new(gns_global.clone());
//!
//! // Choose your own port
//! let port = 9001;
//!
//! // We now do a transition from [`IsCreated`] to the [`IsClient`] state. The [`GnsSocket::connect`] operation does this transition for us.
//! // Since we are now using a client socket, we have access to a different set of operations.
//! let client = gns_socket.connect(Ipv6Addr::LOCALHOST.into(), port).unwrap();
//!
//! // Now that we initiated a connection, there is three operation we must loop over:
//! // - polling for new messages
//! // - polling for connection status change
//! // - polling for callbacks (low-level callbacks required by the underlying library).
//! // Important to know, regardless of the type of socket, whether it is in [`IsClient`] or [`IsServer`] state, theses three operations are the same.
//! // The only difference is that polling for messages and status on the client only act on the client connection, while polling for messages and status on a server yield event for all connected clients.
//!
//! // You would loop on the below code.
//! // Run the low-level callbacks.
//! gns_global.poll_callbacks();
//!
//! // Receive a maximum of 100 messages on the client connection.
//! // For each messages, print it's payload.
//! let _actual_nb_of_messages_processed = client.poll_messages::<100>(|message| {
//!   println!("{}", core::str::from_utf8(message.payload()).unwrap());
//! });
//!
//! // Don't do anything with events.
//! // One would check the event for connection status, i.e. doing something when we are connected/disconnected from the server.
//! let _actual_nb_of_events_processed = client.poll_event::<100>(|_| {
//! });
//!
//! // Sleep a little bit.
//! std::thread::sleep(Duration::from_millis(10))
//! ```
//!
//! # Note
//!
//! Every instance of of [`GnsSocket`] has a dangling [`Weak<SegQueue<GnsConnectionEvent>>`] pointer associated due to how polling works. Polling is done globally and may buffer events for already destructed [`GnsSocket`]. We use a weak pointer as user data on client/server connections to push events on [`GnsGlobal::poll_callbacks`], see the `queue` field of [`IsClient`] and [`IsServer`]. For simplicity (we may fix this later), every [`GnsSocket`] has it's own queue and we accept this pretty small memory leak. If you only ever create one instance for the lifetime of your application, this will have no effect.

use crossbeam_queue::SegQueue;
use either::Either;
pub use gns_sys as sys;
use std::sync::atomic::{AtomicI64, Ordering};
use std::{
    collections::HashMap,
    ffi::{c_void, CStr, CString},
    marker::PhantomData,
    mem::MaybeUninit,
    net::{IpAddr, Ipv4Addr, Ipv6Addr},
    sync::{Arc, Mutex, Weak},
    time::Duration,
};
use sys::*;

fn get_interface() -> *mut ISteamNetworkingSockets {
    unsafe { SteamAPI_SteamNetworkingSockets_v009() }
}

fn get_utils() -> *mut ISteamNetworkingUtils {
    unsafe { SteamAPI_SteamNetworkingUtils_v003() }
}

/// A network message number. Simple alias for documentation.
pub type GnsMessageNumber = u64;

/// Outcome of many functions from this library, basic type alias with steam [`sys::EResult`] as error.
/// If the result is [`sys::EResult::k_EResultOK`], the value can safely be wrapped, otherwise we return the error.
pub type GnsResult<T> = Result<T, EResult>;

/// Wrapper around steam [`sys::EResult`].
/// The library ensure that the wrapped value is not [`sys::EResult::k_EResultOK`].
#[repr(transparent)]
#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
pub struct GnsError(EResult);

impl Into<EResult> for GnsError {
    fn into(self) -> EResult {
        self.0
    }
}

impl GnsError {
    pub fn into_result(self) -> GnsResult<()> {
        self.into()
    }
}

impl From<GnsError> for GnsResult<()> {
    fn from(GnsError(result): GnsError) -> Self {
        match result {
            EResult::k_EResultOK => Ok(()),
            e => Err(e),
        }
    }
}

/// Wraps the initialization/destruction of the low-level *GameNetworkingSockets* and associated
/// singletons.
///
/// A reference can be retrieved via [`GnsGlobal::get()`], which will initialize
/// *GameNetworkingSockets* if it has not yet been initialized.
pub struct GnsGlobal {
    utils: GnsUtils,
    next_queue_id: AtomicI64,
    event_queues: Mutex<HashMap<i64, Weak<SegQueue<GnsConnectionEvent>>>>,
}

static GNS_GLOBAL: Mutex<Option<Arc<GnsGlobal>>> = Mutex::new(None);

impl GnsGlobal {
    /// Try to acquire a reference to the [`GnsGlobal`] instance.
    ///
    /// If GnsGlobal has not yet been successfully initialized, a call to
    /// [`sys::GameNetworkingSockets_Init`] will be made. If successful, a reference to GnsGlobal
    /// will be returned.
    ///
    /// If GnsGlobal has already been initialized, this method returns a reference to the already
    /// created GnsGlobal instance.
    ///
    /// # Errors
    /// If a call to [`sys::GameNetworkingSockets_Init`] errors, that error will be propagated as a
    /// String message.
    pub fn get() -> Result<Arc<Self>, String> {
        let mut lock = GNS_GLOBAL.lock().unwrap();
        if let Some(gns_global) = lock.clone() {
            Ok(gns_global)
        } else {
            unsafe {
                let mut error: SteamDatagramErrMsg = MaybeUninit::zeroed().assume_init();
                if !GameNetworkingSockets_Init(core::ptr::null(), &mut error) {
                    Err(format!(
                        "{}",
                        CStr::from_ptr(error.as_ptr()).to_str().unwrap_or("")
                    ))
                } else {
                    let gns_global = Arc::new(GnsGlobal {
                        utils: GnsUtils(()),
                        next_queue_id: AtomicI64::new(0),
                        event_queues: Mutex::new(HashMap::new()),
                    });
                    *lock = Some(gns_global.clone());
                    Ok(gns_global)
                }
            }
        }
    }

    #[inline]
    pub fn poll_callbacks(&self) {
        unsafe {
            SteamAPI_ISteamNetworkingSockets_RunCallbacks(get_interface());
        }
    }

    pub fn utils(&self) -> &GnsUtils {
        &self.utils
    }

    fn create_queue(&self) -> (i64, Arc<SegQueue<GnsConnectionEvent>>) {
        let queue = Arc::new(SegQueue::new());
        let queue_id = self.next_queue_id.fetch_add(1, Ordering::SeqCst);
        self.event_queues
            .lock()
            .unwrap()
            .insert(queue_id, Arc::downgrade(&queue));
        (queue_id, queue)
    }
}

/// Opaque wrapper around the low-level [`sys::HSteamListenSocket`].
#[repr(transparent)]
pub struct GnsListenSocket(HSteamListenSocket);

/// Opaque wrapper around the low-level [`sys::HSteamNetPollGroup`].
#[repr(transparent)]
pub struct GnsPollGroup(HSteamNetPollGroup);

/// Initial state of a [`GnsSocket`].
/// This state represent a socket that has not been used as a Server or Client implementation.
/// Consequently, the state is empty.
pub struct IsCreated;

/// Common functions available for any [`GnsSocket`] state that is implementing it.
/// Regardless of being a client or server, a ready socket will allow us to query for connection events as well as receive messages.
pub trait IsReady {
    /// Return a reference to the connection event queue. The queue is thread-safe.
    fn queue(&self) -> &SegQueue<GnsConnectionEvent>;
    /// Poll for incoming messages. K represent the maximum number of messages we are willing to receive.
    /// Return the actual number of messsages that has been received.
    fn receive<const K: usize>(&self, messages: &mut [GnsNetworkMessage<ToReceive>; K]) -> usize;
}

/// State of a [`GnsSocket`] that has been determined to be a server, usually via the [`GnsSocket::listen`] call.
/// In this state, the socket hold the data required to accept connections and poll them for messages.
pub struct IsServer {
    /// Thread-safe FIFO queue used to read the connection status changes.
    /// Note that this structure is pinned to ensure that it's address remain the same as we are using it as connection **UserData**.
    /// This queue is meant to be passed to [`GnsSocket::on_connection_state_changed`].
    /// As long as the socket exists, this queue must exists.
    queue: Arc<SegQueue<GnsConnectionEvent>>,
    /// The low-level listen socket. Irrelevant to the user.
    listen_socket: GnsListenSocket,
    /// The low-level polling group. Irrelevant to the user.
    poll_group: GnsPollGroup,
}

impl Drop for IsServer {
    fn drop(&mut self) {
        unsafe {
            SteamAPI_ISteamNetworkingSockets_CloseListenSocket(
                get_interface(),
                self.listen_socket.0,
            );
            SteamAPI_ISteamNetworkingSockets_DestroyPollGroup(get_interface(), self.poll_group.0);
        }
    }
}

impl IsReady for IsServer {
    #[inline]
    fn queue(&self) -> &SegQueue<GnsConnectionEvent> {
        &self.queue
    }

    #[inline]
    fn receive<const K: usize>(&self, messages: &mut [GnsNetworkMessage<ToReceive>; K]) -> usize {
        unsafe {
            SteamAPI_ISteamNetworkingSockets_ReceiveMessagesOnPollGroup(
                get_interface(),
                self.poll_group.0,
                messages.as_mut_ptr() as _,
                K as _,
            ) as _
        }
    }
}

/// State of a [`GnsSocket`] that has been determined to be a client, usually via the [`GnsSocket::connect`] call.
/// In this state, the socket hold the data required to receive and send messages.
pub struct IsClient {
    /// Equals to [`IsServer.queue`].
    queue: Arc<SegQueue<GnsConnectionEvent>>,
    /// Actual client connection, used to receive/send messages.
    connection: GnsConnection,
}

impl Drop for IsClient {
    fn drop(&mut self) {
        unsafe {
            SteamAPI_ISteamNetworkingSockets_CloseConnection(
                get_interface(),
                self.connection.0,
                0,
                core::ptr::null(),
                false,
            );
        }
    }
}

impl IsReady for IsClient {
    #[inline]
    fn queue(&self) -> &SegQueue<GnsConnectionEvent> {
        &self.queue
    }

    #[inline]
    fn receive<const K: usize>(&self, messages: &mut [GnsNetworkMessage<ToReceive>; K]) -> usize {
        unsafe {
            SteamAPI_ISteamNetworkingSockets_ReceiveMessagesOnConnection(
                get_interface(),
                self.connection.0,
                messages.as_mut_ptr() as _,
                K as _,
            ) as _
        }
    }
}

pub trait MayDrop {
    const MUST_DROP: bool;
}

pub struct ToSend(());

impl MayDrop for ToSend {
    const MUST_DROP: bool = false;
}

pub struct ToReceive(());

impl MayDrop for ToReceive {
    const MUST_DROP: bool = true;
}

/// Lane priority
pub type Priority = u32;
/// Lane weight
pub type Weight = u16;
/// A lane is represented by a Priority and a Weight
pub type GnsLane = (Priority, Weight);
/// A lane Id.
pub type GnsLaneId = u16;

/// Wrapper around the low-level equivalent.
/// This type is used to implements a more type-safe version of messages.
///
/// You will encounter two instances, either [`GnsNetworkMessage<ToReceive>`] or [`GnsNetworkMessage<ToSend>`].
/// The former is generated by the library and must be freed unpon handling.
/// The later is created prior to sending it via the low-level call and the low-level call itself make sure that it is freed.
#[repr(transparent)]
pub struct GnsNetworkMessage<T: MayDrop>(*mut ISteamNetworkingMessage, PhantomData<T>);

impl<T> Drop for GnsNetworkMessage<T>
where
    T: MayDrop,
{
    fn drop(&mut self) {
        if T::MUST_DROP && !self.0.is_null() {
            unsafe {
                SteamAPI_SteamNetworkingMessage_t_Release(self.0);
            }
        }
    }
}

impl<T> GnsNetworkMessage<T>
where
    T: MayDrop,
{
    /// Unsafe function you will highly unlikely use.
    #[inline]
    pub unsafe fn into_inner(self) -> *mut ISteamNetworkingMessage {
        self.0
    }

    #[inline]
    pub fn payload(&self) -> &[u8] {
        unsafe {
            core::slice::from_raw_parts((*self.0).m_pData as *const u8, (*self.0).m_cbSize as _)
        }
    }

    #[inline]
    pub fn message_number(&self) -> u64 {
        unsafe { (*self.0).m_nMessageNumber as _ }
    }

    #[inline]
    pub fn lane(&self) -> GnsLaneId {
        unsafe { (*self.0).m_idxLane }
    }

    #[inline]
    pub fn flags(&self) -> i32 {
        unsafe { (*self.0).m_nFlags as _ }
    }

    #[inline]
    pub fn user_data(&self) -> u64 {
        unsafe { (*self.0).m_nUserData as _ }
    }

    #[inline]
    pub fn connection(&self) -> GnsConnection {
        GnsConnection(unsafe { (*self.0).m_conn })
    }

    pub fn connection_user_data(&self) -> u64 {
        unsafe { (*self.0).m_nConnUserData as _ }
    }
}

impl GnsNetworkMessage<ToSend> {
    #[inline]
    fn new(
        ptr: *mut ISteamNetworkingMessage,
        conn: GnsConnection,
        flags: i32,
        payload: &[u8],
    ) -> Self {
        GnsNetworkMessage(ptr, PhantomData)
            .set_flags(flags)
            .set_payload(payload)
            .set_connection(conn)
    }

    #[inline]
    pub fn set_connection(self, GnsConnection(conn): GnsConnection) -> Self {
        unsafe { (*self.0).m_conn = conn }
        self
    }

    #[inline]
    pub fn set_payload(self, payload: &[u8]) -> Self {
        unsafe {
            core::ptr::copy_nonoverlapping(
                payload.as_ptr(),
                (*self.0).m_pData as *mut u8,
                payload.len(),
            );
        }
        self
    }

    #[inline]
    pub fn set_lane(self, lane: u16) -> Self {
        unsafe { (*self.0).m_idxLane = lane }
        self
    }

    #[inline]
    pub fn set_flags(self, flags: i32) -> Self {
        unsafe { (*self.0).m_nFlags = flags as _ }
        self
    }

    #[inline]
    pub fn set_user_data(self, userdata: u64) -> Self {
        unsafe { (*self.0).m_nUserData = userdata as _ }
        self
    }
}

#[repr(transparent)]
#[derive(Default, Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct GnsConnection(HSteamNetConnection);

#[derive(Default, Copy, Clone)]
pub struct GnsConnectionInfo(SteamNetConnectionInfo_t);

impl GnsConnectionInfo {
    #[inline]
    pub fn state(&self) -> ESteamNetworkingConnectionState {
        self.0.m_eState
    }

    #[inline]
    pub fn end_reason(&self) -> u32 {
        self.0.m_eEndReason as u32
    }

    #[inline]
    pub fn end_debug(&self) -> &str {
        unsafe { CStr::from_ptr(self.0.m_szEndDebug.as_ptr()) }
            .to_str()
            .unwrap_or("")
    }

    #[inline]
    pub fn remote_address(&self) -> IpAddr {
        let ipv4 = unsafe { self.0.m_addrRemote.__bindgen_anon_1.m_ipv4 };
        if ipv4.m_8zeros == 0 && ipv4.m_0000 == 0 && ipv4.m_ffff == 0xffff {
            IpAddr::from(Ipv4Addr::from(ipv4.m_ip))
        } else {
            IpAddr::from(Ipv6Addr::from(unsafe {
                self.0.m_addrRemote.__bindgen_anon_1.m_ipv6
            }))
        }
    }

    #[inline]
    pub fn remote_port(&self) -> u16 {
        self.0.m_addrRemote.m_port
    }
}

#[derive(Debug, Default, Copy, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
pub struct GnsConnectionRealTimeLaneStatus(SteamNetConnectionRealTimeLaneStatus_t);

impl GnsConnectionRealTimeLaneStatus {
    #[inline]
    pub fn pending_bytes_unreliable(&self) -> u32 {
        self.0.m_cbPendingUnreliable as _
    }

    #[inline]
    pub fn pending_bytes_reliable(&self) -> u32 {
        self.0.m_cbPendingReliable as _
    }

    #[inline]
    pub fn bytes_sent_unacked_reliable(&self) -> u32 {
        self.0.m_cbSentUnackedReliable as _
    }

    #[inline]
    pub fn approximated_queue_time(&self) -> Duration {
        Duration::from_micros(self.0.m_usecQueueTime as _)
    }
}

#[derive(Default, Debug, Copy, Clone, PartialOrd, PartialEq)]
pub struct GnsConnectionRealTimeStatus(SteamNetConnectionRealTimeStatus_t);

impl GnsConnectionRealTimeStatus {
    #[inline]
    pub fn state(&self) -> ESteamNetworkingConnectionState {
        self.0.m_eState
    }

    #[inline]
    pub fn ping(&self) -> u32 {
        self.0.m_nPing as _
    }

    #[inline]
    pub fn quality_local(&self) -> f32 {
        self.0.m_flConnectionQualityLocal
    }

    #[inline]
    pub fn quality_remote(&self) -> f32 {
        self.0.m_flConnectionQualityRemote
    }

    #[inline]
    pub fn out_packets_per_sec(&self) -> f32 {
        self.0.m_flOutPacketsPerSec
    }

    #[inline]
    pub fn out_bytes_per_sec(&self) -> f32 {
        self.0.m_flOutBytesPerSec
    }

    #[inline]
    pub fn in_packets_per_sec(&self) -> f32 {
        self.0.m_flInPacketsPerSec
    }

    #[inline]
    pub fn in_bytes_per_sec(&self) -> f32 {
        self.0.m_flInBytesPerSec
    }

    #[inline]
    pub fn send_rate_bytes_per_sec(&self) -> u32 {
        self.0.m_nSendRateBytesPerSecond as _
    }

    #[inline]
    pub fn pending_bytes_unreliable(&self) -> u32 {
        self.0.m_cbPendingUnreliable as _
    }

    #[inline]
    pub fn pending_bytes_reliable(&self) -> u32 {
        self.0.m_cbPendingReliable as _
    }

    #[inline]
    pub fn bytes_sent_unacked_reliable(&self) -> u32 {
        self.0.m_cbSentUnackedReliable as _
    }

    #[inline]
    pub fn approximated_queue_time(&self) -> Duration {
        Duration::from_micros(self.0.m_usecQueueTime as _)
    }
}

#[derive(Default, Copy, Clone)]
pub struct GnsConnectionEvent(SteamNetConnectionStatusChangedCallback_t);

impl GnsConnectionEvent {
    #[inline]
    pub fn old_state(&self) -> ESteamNetworkingConnectionState {
        self.0.m_eOldState
    }

    #[inline]
    pub fn connection(&self) -> GnsConnection {
        GnsConnection(self.0.m_hConn)
    }

    #[inline]
    pub fn info(&self) -> GnsConnectionInfo {
        GnsConnectionInfo(self.0.m_info)
    }
}

/// [`GnsSocket`] is the most important structure of this library.
/// This structure is used to create client ([`GnsSocket<IsClient>`]) and server ([`GnsSocket<IsServer>`]) sockets via the [`GnsSocket::connect`] and [`GnsSocket::listen`] functions.
/// The drop implementation make sure that everything related to this structure is correctly freed, except the [`GnsGlobal`] instance and the user has a strong guarantee that all the available operations over the socket are **safe**.
pub struct GnsSocket<S> {
    global: Arc<GnsGlobal>,
    state: S,
}

impl<S> GnsSocket<S>
where
    S: IsReady,
{
    /// Get a connection lane status.
    /// This call is possible only if lanes has been previously configured using configure_connection_lanes
    #[inline]
    pub fn get_connection_real_time_status(
        &self,
        GnsConnection(conn): GnsConnection,
        nb_of_lanes: u32,
    ) -> GnsResult<(
        GnsConnectionRealTimeStatus,
        Vec<GnsConnectionRealTimeLaneStatus>,
    )> {
        let mut lanes: Vec<GnsConnectionRealTimeLaneStatus> =
            vec![Default::default(); nb_of_lanes as _];
        let mut status: GnsConnectionRealTimeStatus = Default::default();
        GnsError(unsafe {
            SteamAPI_ISteamNetworkingSockets_GetConnectionRealTimeStatus(
                get_interface(),
                conn,
                &mut status as *mut GnsConnectionRealTimeStatus
                    as *mut SteamNetConnectionRealTimeStatus_t,
                nb_of_lanes as _,
                lanes.as_mut_ptr() as *mut GnsConnectionRealTimeLaneStatus
                    as *mut SteamNetConnectionRealTimeLaneStatus_t,
            )
        })
        .into_result()?;
        Ok((status, lanes))
    }

    #[inline]
    pub fn get_connection_info(
        &self,
        GnsConnection(conn): GnsConnection,
    ) -> Option<GnsConnectionInfo> {
        let mut info: SteamNetConnectionInfo_t = Default::default();
        if unsafe {
            SteamAPI_ISteamNetworkingSockets_GetConnectionInfo(get_interface(), conn, &mut info)
        } {
            Some(GnsConnectionInfo(info))
        } else {
            None
        }
    }

    #[inline]
    pub fn flush_messages_on_connection(
        &self,
        GnsConnection(conn): GnsConnection,
    ) -> GnsResult<()> {
        GnsError(unsafe {
            SteamAPI_ISteamNetworkingSockets_FlushMessagesOnConnection(get_interface(), conn)
        })
        .into_result()
    }

    #[inline]
    pub fn close_connection(
        &self,
        GnsConnection(conn): GnsConnection,
        reason: u32,
        debug: &str,
        linger: bool,
    ) -> bool {
        let debug_c = CString::new(debug).expect("str; qed;");
        unsafe {
            SteamAPI_ISteamNetworkingSockets_CloseConnection(
                get_interface(),
                conn,
                reason as _,
                debug_c.as_ptr(),
                linger,
            )
        }
    }

    #[inline]
    pub fn poll_messages<const K: usize>(
        &self,
        mut message_callback: impl FnMut(&GnsNetworkMessage<ToReceive>),
    ) -> Option<usize> {
        // Do not implements default for networking messages as they must be allocated by the lib.
        let mut messages: [GnsNetworkMessage<ToReceive>; K] =
            unsafe { MaybeUninit::zeroed().assume_init() };
        let nb_of_messages = self.state.receive(&mut messages);
        if nb_of_messages == usize::MAX {
            None
        } else {
            for message in messages.into_iter().take(nb_of_messages) {
                message_callback(&message);
            }
            Some(nb_of_messages)
        }
    }

    #[inline]
    pub fn poll_event<const K: usize>(
        &self,
        mut event_callback: impl FnMut(GnsConnectionEvent),
    ) -> usize {
        let mut processed = 0;
        'a: while let Some(event) = self.state.queue().pop() {
            event_callback(event);
            processed += 1;
            if processed == K {
                break 'a;
            }
        }
        processed
    }

    #[inline]
    pub fn configure_connection_lanes(
        &self,
        GnsConnection(connection): GnsConnection,
        lanes: &[GnsLane],
    ) -> GnsResult<()> {
        let (priorities, weights): (Vec<_>, Vec<_>) = lanes.iter().copied().unzip();
        GnsError(unsafe {
            SteamAPI_ISteamNetworkingSockets_ConfigureConnectionLanes(
                get_interface(),
                connection,
                lanes.len() as _,
                priorities.as_ptr() as *const u32 as *const i32,
                weights.as_ptr(),
            )
        })
        .into_result()
    }

    #[inline]
    pub fn send_messages(
        &self,
        messages: Vec<GnsNetworkMessage<ToSend>>,
    ) -> Vec<Either<GnsMessageNumber, EResult>> {
        let mut result = vec![0i64; messages.len()];
        unsafe {
            SteamAPI_ISteamNetworkingSockets_SendMessages(
                get_interface(),
                messages.len() as _,
                messages.as_ptr() as *const _,
                result.as_mut_ptr(),
            );
        }
        result
            .into_iter()
            .map(|value| {
                if value < 0 {
                    Either::Right(unsafe { core::mem::transmute((-value) as u32) })
                } else {
                    Either::Left(value as _)
                }
            })
            .collect()
    }
}

impl GnsSocket<IsCreated> {
    /// Unsafe, C-like callback, we use the user data to pass the queue ID, so we can find the
    /// correct queue in GnsGlobal.
    unsafe extern "C" fn on_connection_state_changed(
        info: &mut SteamNetConnectionStatusChangedCallback_t,
    ) {
        let gns_global = GnsGlobal::get()
            // GnsGlobal needs to be initialized to even reach this point in the first place.
            .expect("GnsGlobal should be initialized");

        let queue_id = info.m_info.m_nUserData as _;
        let mut queues = gns_global.event_queues.lock().unwrap();
        if let Some(queue) = queues.get(&queue_id) {
            if let Some(queue) = queue.upgrade() {
                queue.push(GnsConnectionEvent(*info));
            } else {
                // The queue is no longer valid as the associated GnsSocket has been dropped
                queues.remove(&queue_id);
            }
        }
    }

    /// Initialize a new socket in [`IsCreated`] state.
    #[inline]
    pub fn new(global: Arc<GnsGlobal>) -> Self {
        GnsSocket {
            global,
            state: IsCreated,
        }
    }

    #[inline]
    fn setup_common(
        address: IpAddr,
        port: u16,
        queue_id: int64,
    ) -> (SteamNetworkingIPAddr, [SteamNetworkingConfigValue_t; 2]) {
        let addr = SteamNetworkingIPAddr {
            __bindgen_anon_1: match address {
                IpAddr::V4(address) => SteamNetworkingIPAddr__bindgen_ty_2 {
                    m_ipv4: SteamNetworkingIPAddr_IPv4MappedAddress {
                        m_8zeros: 0,
                        m_0000: 0,
                        m_ffff: 0xffff,
                        m_ip: address.octets(),
                    },
                },
                IpAddr::V6(address) => SteamNetworkingIPAddr__bindgen_ty_2 {
                    m_ipv6: address.octets(),
                },
            },
            m_port: port,
        };
        let options = [SteamNetworkingConfigValue_t {
            m_eDataType: ESteamNetworkingConfigDataType::k_ESteamNetworkingConfig_Ptr,
            m_eValue: ESteamNetworkingConfigValue::k_ESteamNetworkingConfig_Callback_ConnectionStatusChanged,
            m_val: SteamNetworkingConfigValue_t__bindgen_ty_1 {
              m_ptr: Self::on_connection_state_changed as *const fn(&SteamNetConnectionStatusChangedCallback_t) as *mut c_void
            }
          }, SteamNetworkingConfigValue_t {
            m_eDataType: ESteamNetworkingConfigDataType::k_ESteamNetworkingConfig_Int64,
            m_eValue: ESteamNetworkingConfigValue::k_ESteamNetworkingConfig_ConnectionUserData,
            m_val: SteamNetworkingConfigValue_t__bindgen_ty_1 {
              m_int64: queue_id
            }
        }];
        (addr, options)
    }

    /// Listen for incoming connections, the socket transition from [`IsCreated`] to [`IsServer`], allowing a new set of server operations.
    #[inline]
    pub fn listen(self, address: IpAddr, port: u16) -> Result<GnsSocket<IsServer>, ()> {
        let (queue_id, queue) = self.global.create_queue();
        let (addr, options) = Self::setup_common(address, port, queue_id);
        let listen_socket = unsafe {
            SteamAPI_ISteamNetworkingSockets_CreateListenSocketIP(
                get_interface(),
                &addr,
                options.len() as _,
                options.as_ptr(),
            )
        };
        if listen_socket == k_HSteamListenSocket_Invalid {
            Err(())
        } else {
            let poll_group =
                unsafe { SteamAPI_ISteamNetworkingSockets_CreatePollGroup(get_interface()) };
            if poll_group == k_HSteamNetPollGroup_Invalid {
                Err(())
            } else {
                Ok(GnsSocket {
                    global: self.global,
                    state: IsServer {
                        queue,
                        listen_socket: GnsListenSocket(listen_socket),
                        poll_group: GnsPollGroup(poll_group),
                    },
                })
            }
        }
    }

    /// Connect to a remote host, the socket transition from [`IsCreated`] to [`IsClient`], allowing a new set of client operations.
    #[inline]
    pub fn connect(self, address: IpAddr, port: u16) -> Result<GnsSocket<IsClient>, ()> {
        let (queue_id, queue) = self.global.create_queue();
        let (addr, options) = Self::setup_common(address, port, queue_id);
        let connection = unsafe {
            SteamAPI_ISteamNetworkingSockets_ConnectByIPAddress(
                get_interface(),
                &addr,
                options.len() as _,
                options.as_ptr(),
            )
        };
        if connection == k_HSteamNetConnection_Invalid {
            Err(())
        } else {
            Ok(GnsSocket {
                global: self.global,
                state: IsClient {
                    queue,
                    connection: GnsConnection(connection),
                },
            })
        }
    }
}

impl GnsSocket<IsServer> {
    /// Accept an incoming connection. This operation is available only if the socket is in the [`IsServer`] state.
    #[inline]
    pub fn accept(&self, connection: GnsConnection) -> GnsResult<()> {
        GnsError(unsafe {
            SteamAPI_ISteamNetworkingSockets_AcceptConnection(get_interface(), connection.0)
        })
        .into_result()?;
        if !unsafe {
            SteamAPI_ISteamNetworkingSockets_SetConnectionPollGroup(
                get_interface(),
                connection.0,
                self.state.poll_group.0,
            )
        } {
            panic!("It's impossible not to be able to set the connection poll group as both the poll group and the connection must be valid at this point.");
        }
        Ok(())
    }
}

impl GnsSocket<IsClient> {
    /// Return the socket connection. This operation is available only if the socket is in the [`IsClient`] state.
    #[inline]
    pub fn connection(&self) -> GnsConnection {
        self.state.connection
    }
}

/// The configuration value used to define configure global variables in [`GnsUtils::set_global_config_value`]
pub enum GnsConfig<'a> {
    Float(f32),
    Int32(u32),
    String(&'a str),
    Ptr(*mut c_void),
}

pub struct GnsUtils(());

type MsgPtr = *const ::std::os::raw::c_char;

impl GnsUtils {
    #[inline]
    pub fn enable_debug_output(
        &self,
        ty: ESteamNetworkingSocketsDebugOutputType,
        f: fn(ty: ESteamNetworkingSocketsDebugOutputType, msg: String),
    ) {
        static mut F: Option<fn(ty: ESteamNetworkingSocketsDebugOutputType, msg: String)> = None;
        unsafe {
            F = Some(f);
        }
        unsafe extern "C" fn debug(ty: ESteamNetworkingSocketsDebugOutputType, msg: MsgPtr) {
            F.unwrap()(ty, CStr::from_ptr(msg).to_string_lossy().to_string());
        }
        unsafe {
            SteamAPI_ISteamNetworkingUtils_SetDebugOutputFunction(get_utils(), ty, Some(debug));
        }
    }

    /// Allocate a new message to be sent.
    /// This message must be sent if allocated, as the message can only be freed by the `GnsSocket::send_messages` call.
    #[inline]
    pub fn allocate_message(
        &self,
        conn: GnsConnection,
        flags: i32,
        payload: &[u8],
    ) -> GnsNetworkMessage<ToSend> {
        let message_ptr = unsafe {
            SteamAPI_ISteamNetworkingUtils_AllocateMessage(get_utils(), payload.len() as _)
        };
        GnsNetworkMessage::new(message_ptr, conn, flags, payload)
    }

    /// Set a global configuration value, i.e. k_ESteamNetworkingConfig_FakePacketLag_Send => 1000 ms
    #[inline]
    pub fn set_global_config_value<'a>(
        &self,
        typ: ESteamNetworkingConfigValue,
        value: GnsConfig<'a>,
    ) -> Result<(), ()> {
        let result = match value {
            GnsConfig::Float(x) => unsafe {
                SteamAPI_ISteamNetworkingUtils_SetGlobalConfigValueFloat(get_utils(), typ, x)
            },
            GnsConfig::Int32(x) => unsafe {
                SteamAPI_ISteamNetworkingUtils_SetGlobalConfigValueInt32(get_utils(), typ, x as i32)
            },
            GnsConfig::String(x) => unsafe {
                SteamAPI_ISteamNetworkingUtils_SetGlobalConfigValueString(
                    get_utils(),
                    typ,
                    CString::new(x).expect("str; qed;").as_c_str().as_ptr(),
                )
            },
            GnsConfig::Ptr(x) => unsafe {
                SteamAPI_ISteamNetworkingUtils_SetGlobalConfigValuePtr(get_utils(), typ, x)
            },
        };
        if result {
            Ok(())
        } else {
            Err(())
        }
    }
}