1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102

//! Client-Server kind of sessions.

use std::{mem::align_of, num::NonZeroU64};

use alkahest::{Pack, Schema, SchemaUnpack, Seq};

mod client;
mod server;

pub use self::{client::*, server::*};

/// Server-wide unique id generated by server and given to the client's player.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
#[repr(transparent)]
pub struct PlayerId(pub NonZeroU64);

#[derive(Clone, Copy, Debug, PartialEq, Eq, thiserror::Error)]
#[error("Zero PlayerId unpacked")]
pub struct ZeroPlayerIdError;

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
#[repr(transparent)]
pub struct ClientId(pub NonZeroU64);

impl SchemaUnpack<'_> for PlayerId {
    type Unpacked = Result<Self, ZeroPlayerIdError>;
}

impl Schema for PlayerId {
    type Packed = u64;

    fn align() -> usize {
        align_of::<u64>()
    }

    fn unpack<'a>(packed: u64, _input: &'a [u8]) -> Result<Self, ZeroPlayerIdError> {
        NonZeroU64::new(packed)
            .map(PlayerId)
            .ok_or(ZeroPlayerIdError)
    }
}

impl Pack<PlayerId> for PlayerId {
    fn pack(self, _offset: usize, _output: &mut [u8]) -> (u64, usize) {
        (self.0.get(), 0)
    }
}

/// More efficient schema replacement for `Option<PlayerId>`
pub struct MaybePlayerId;

impl SchemaUnpack<'_> for MaybePlayerId {
    type Unpacked = Option<PlayerId>;
}

impl Schema for MaybePlayerId {
    type Packed = u64;

    fn align() -> usize {
        align_of::<u64>()
    }

    fn unpack<'a>(packed: u64, _input: &'a [u8]) -> Option<PlayerId> {
        NonZeroU64::new(packed).map(PlayerId)
    }
}

impl Pack<MaybePlayerId> for PlayerId {
    fn pack(self, _offset: usize, _output: &mut [u8]) -> (u64, usize) {
        (self.0.get(), 0)
    }
}

impl Pack<MaybePlayerId> for Option<PlayerId> {
    fn pack(self, _offset: usize, _output: &mut [u8]) -> (u64, usize) {
        (self.map_or(0, |pid| pid.0.get()), 0)
    }
}

#[allow(unused)]
#[derive(Schema)]
enum ClientMessage<P: Schema = (), I: Schema = ()> {
    Connect {
        token: alkahest::Str,
    },
    AddPlayer {
        player: P,
    },
    Inputs {
        step: u64,
        next_update_step: u64,
        inputs: Seq<(PlayerId, I)>,
    },
}

#[allow(unused)]
#[derive(Schema)]
enum ServerMessage<J: Schema = (), U: Schema = ()> {
    Connected { step: u64 },
    PlayerJoined { info: J },
    Updates { server_step: u64, updates: U },
}