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|
use std::any::{type_name, Any, TypeId};
use std::collections::HashMap;
use std::panic::{RefUnwindSafe, UnwindSafe};
use seq_macro::seq;
use crate::component::{Component, Id as ComponentId};
use crate::lock::Lock;
use crate::system::util::check_params_are_compatible;
use crate::system::{
ComponentRefMut,
Into as IntoSystem,
Param,
ParamWithInputFilter,
System,
TypeErased,
};
use crate::tuple::{
IntoInOptions as TupleIntoInOptions,
Reduce as TupleReduce,
TakeOptionElementResult as TupleTakeOptionElementResult,
WithOptionElements as TupleWithOptionElements,
};
use crate::WorldData;
/// A stateful system.
pub struct Stateful<Func>
{
func: Func,
local_components: HashMap<ComponentId, Lock<Box<dyn Component>>>,
}
macro_rules! impl_system {
($c: tt) => {
seq!(I in 0..$c {
impl<'world, Func, #(TParam~I,)*> System<'world, fn(&'world (), #(TParam~I,)*)>
for Stateful<Func>
where
Func: Fn(#(TParam~I,)*) + Copy + RefUnwindSafe + UnwindSafe + 'static,
#(TParam~I: Param<'world>,)*
#(TParam~I::Input: 'static,)*
(#(TParam~I::Input,)*): TupleReduce<ParamWithInputFilter>,
<(#(TParam~I::Input,)*) as TupleReduce<ParamWithInputFilter>>::Out:
TupleIntoInOptions
{
type Input =
<(#(TParam~I::Input,)*) as TupleReduce<ParamWithInputFilter>>::Out;
fn initialize(mut self, input: Self::Input) -> Self
{
let mut option_input = input.into_in_options();
#(
if TypeId::of::<TParam~I::Input>() !=
TypeId::of::<()>()
{
let input = match option_input.take::<TParam~I::Input>() {
TupleTakeOptionElementResult::Found(input) => input,
TupleTakeOptionElementResult::NotFound => {
panic!(
"Parameter input {} not found",
type_name::<TParam~I::Input>()
);
}
TupleTakeOptionElementResult::AlreadyTaken => {
panic!(
concat!(
"Parameter {} is already initialized. ",
"System cannot contain multiple inputs with ",
"the same type",
),
type_name::<TParam~I>()
);
}
};
TParam~I::initialize(
&mut self,
input
);
}
)*
self
}
fn prepare(&self, world_data: &WorldData)
{
#(
TParam~I::handle_pre_run(world_data);
)*
}
fn run<'this>(&'this self, world_data: &'world WorldData)
where
'this: 'world
{
#(
check_params_are_compatible!(I, TParam~I, $c);
)*
let func = self.func;
func(#({
TParam~I::new(self, world_data)
},)*);
}
fn into_type_erased(self) -> TypeErased
{
TypeErased {
data: Box::new(self),
run: Box::new(|data, world_data| {
// SAFETY: The caller of TypeErased::run ensures the lifetime
// is correct
let data = unsafe { &*std::ptr::from_ref::<dyn Any>(data) };
let me = data.downcast_ref::<Self>().unwrap();
// SAFETY: The caller of TypeErased::run ensures the lifetime
// is correct
let world_data = unsafe { &*std::ptr::from_ref(world_data) };
me.run(world_data);
}),
prepare: Box::new(|data, world_data| {
// SAFETY: The caller of TypeErased::run ensures the lifetime
// is correct
let data = unsafe { &*std::ptr::from_ref::<dyn Any>(data) };
let me = data.downcast_ref::<Self>().unwrap();
// SAFETY: The caller of TypeErased::run ensures the lifetime
// is correct
let world_data = unsafe { &*std::ptr::from_ref(world_data) };
me.prepare(world_data);
}),
}
}
fn get_local_component_mut<LocalComponent: Component>(
&self,
) -> Option<ComponentRefMut<LocalComponent>>
{
let local_component = self.local_components
.get(&ComponentId::of::<LocalComponent>())?
.write_nonblock()
.expect("Failed to aquire read-write local component lock");
Some(ComponentRefMut::new(local_component))
}
fn set_local_component<LocalComponent: Component>(
&mut self,
local_component: LocalComponent,
)
{
self.local_components
.insert(
ComponentId::of::<LocalComponent>(),
Lock::new(Box::new(local_component))
);
}
}
impl<Func, #(TParam~I,)*> IntoSystem<fn(#(TParam~I,)*)>
for Func
where
Func: Fn(#(TParam~I,)*) + Copy + 'static,
{
type System = Stateful<Func>;
fn into_system(self) -> Self::System
{
Self::System {
func: self,
local_components: HashMap::new(),
}
}
}
});
};
}
seq!(C in 1..16 {
impl_system!(C);
});
|
