307 lines
11 KiB
Rust
307 lines
11 KiB
Rust
use bumpalo::Bump;
|
|
use futures_channel::mpsc::UnboundedSender;
|
|
use fxhash::FxHashMap;
|
|
use slab::Slab;
|
|
use std::cell::{Cell, RefCell};
|
|
|
|
use crate::innerlude::*;
|
|
|
|
pub type FcSlot = *const ();
|
|
|
|
pub struct Heuristic {
|
|
hook_arena_size: usize,
|
|
node_arena_size: usize,
|
|
}
|
|
|
|
// a slab-like arena with stable references even when new scopes are allocated
|
|
// uses a bump arena as a backing
|
|
//
|
|
// has an internal heuristics engine to pre-allocate arenas to the right size
|
|
pub(crate) struct ScopeArena {
|
|
bump: Bump,
|
|
scopes: RefCell<Vec<*mut Scope>>,
|
|
pub heuristics: RefCell<FxHashMap<FcSlot, Heuristic>>,
|
|
free_scopes: RefCell<Vec<ScopeId>>,
|
|
nodes: RefCell<Slab<*const VNode<'static>>>,
|
|
pub(crate) sender: UnboundedSender<SchedulerMsg>,
|
|
}
|
|
|
|
impl ScopeArena {
|
|
pub fn new(sender: UnboundedSender<SchedulerMsg>) -> Self {
|
|
Self {
|
|
bump: Bump::new(),
|
|
scopes: RefCell::new(Vec::new()),
|
|
heuristics: RefCell::new(FxHashMap::default()),
|
|
free_scopes: RefCell::new(Vec::new()),
|
|
nodes: RefCell::new(Slab::new()),
|
|
sender,
|
|
}
|
|
}
|
|
|
|
pub fn get_scope(&self, id: &ScopeId) -> Option<&Scope> {
|
|
unsafe { self.scopes.borrow().get(id.0).map(|f| &**f) }
|
|
}
|
|
|
|
// this is unsafe
|
|
pub unsafe fn get_scope_raw(&self, id: &ScopeId) -> Option<*mut Scope> {
|
|
self.scopes.borrow().get(id.0).map(|f| *f)
|
|
}
|
|
// this is unsafe
|
|
|
|
pub unsafe fn get_scope_mut(&self, id: &ScopeId) -> Option<&mut Scope> {
|
|
self.scopes.borrow().get(id.0).map(|s| &mut **s)
|
|
}
|
|
|
|
pub fn new_with_key(
|
|
&self,
|
|
fc_ptr: *const (),
|
|
caller: *const dyn Fn(&Scope) -> Element,
|
|
parent_scope: Option<*mut Scope>,
|
|
height: u32,
|
|
subtree: u32,
|
|
) -> ScopeId {
|
|
let scope_id = ScopeId(self.scopes.borrow().len());
|
|
|
|
let (node_capacity, hook_capacity) = {
|
|
let heuristics = self.heuristics.borrow();
|
|
if let Some(heuristic) = heuristics.get(&fc_ptr) {
|
|
(heuristic.node_arena_size, heuristic.hook_arena_size)
|
|
} else {
|
|
(0, 0)
|
|
}
|
|
};
|
|
|
|
let mut frames = [BumpFrame::new(node_capacity), BumpFrame::new(node_capacity)];
|
|
|
|
frames[0].nodes.get_mut().push({
|
|
let vnode = frames[0]
|
|
.bump
|
|
.alloc(VNode::Text(frames[0].bump.alloc(VText {
|
|
dom_id: Default::default(),
|
|
is_static: false,
|
|
text: "",
|
|
})));
|
|
unsafe { std::mem::transmute(vnode as *mut VNode) }
|
|
});
|
|
|
|
frames[1].nodes.get_mut().push({
|
|
let vnode = frames[1]
|
|
.bump
|
|
.alloc(VNode::Text(frames[1].bump.alloc(VText {
|
|
dom_id: Default::default(),
|
|
is_static: false,
|
|
text: "",
|
|
})));
|
|
unsafe { std::mem::transmute(vnode as *mut VNode) }
|
|
});
|
|
|
|
let mut new_scope = Scope {
|
|
sender: self.sender.clone(),
|
|
our_arena_idx: scope_id,
|
|
parent_scope,
|
|
height,
|
|
frames,
|
|
subtree: Cell::new(subtree),
|
|
is_subtree_root: Cell::new(false),
|
|
|
|
caller,
|
|
generation: 0.into(),
|
|
|
|
hooks: HookList::new(hook_capacity),
|
|
shared_contexts: Default::default(),
|
|
|
|
items: RefCell::new(SelfReferentialItems {
|
|
listeners: Default::default(),
|
|
borrowed_props: Default::default(),
|
|
suspended_nodes: Default::default(),
|
|
tasks: Default::default(),
|
|
pending_effects: Default::default(),
|
|
}),
|
|
};
|
|
|
|
if let Some(id) = self.free_scopes.borrow_mut().pop() {
|
|
let scope = unsafe { self.get_scope_mut(&id) }.unwrap();
|
|
std::mem::swap(&mut new_scope, scope);
|
|
id
|
|
} else {
|
|
let scope = self.bump.alloc(new_scope);
|
|
self.scopes.borrow_mut().push(scope);
|
|
scope_id
|
|
}
|
|
}
|
|
|
|
pub fn try_remove(&self, id: &ScopeId) -> Option<()> {
|
|
self.ensure_drop_safety(id);
|
|
|
|
let mut scope = unsafe { &mut *self.get_scope_raw(id)? };
|
|
|
|
// we're just reusing scopes so we need to clear it out
|
|
scope.hooks.clear();
|
|
scope.shared_contexts.get_mut().clear();
|
|
scope.parent_scope = None;
|
|
scope.generation.set(0);
|
|
scope.is_subtree_root.set(false);
|
|
scope.subtree.set(0);
|
|
|
|
let SelfReferentialItems {
|
|
borrowed_props,
|
|
listeners,
|
|
pending_effects,
|
|
suspended_nodes,
|
|
tasks,
|
|
} = scope.items.get_mut();
|
|
|
|
borrowed_props.clear();
|
|
listeners.clear();
|
|
pending_effects.clear();
|
|
suspended_nodes.clear();
|
|
tasks.clear();
|
|
|
|
self.free_scopes.borrow_mut().push(*id);
|
|
Some(())
|
|
}
|
|
|
|
pub fn reserve_node(&self, node: &VNode) -> ElementId {
|
|
let mut els = self.nodes.borrow_mut();
|
|
let entry = els.vacant_entry();
|
|
let key = entry.key();
|
|
let id = ElementId(key);
|
|
let node: *const VNode = node as *const _;
|
|
let node = unsafe { std::mem::transmute::<*const VNode, *const VNode>(node) };
|
|
entry.insert(node);
|
|
id
|
|
}
|
|
|
|
pub fn collect_garbage(&self, id: ElementId) {
|
|
self.nodes.borrow_mut().remove(id.0);
|
|
}
|
|
|
|
// These methods would normally exist on `scope` but they need access to *all* of the scopes
|
|
|
|
/// This method cleans up any references to data held within our hook list. This prevents mutable aliasing from
|
|
/// causing UB in our tree.
|
|
///
|
|
/// This works by cleaning up our references from the bottom of the tree to the top. The directed graph of components
|
|
/// essentially forms a dependency tree that we can traverse from the bottom to the top. As we traverse, we remove
|
|
/// any possible references to the data in the hook list.
|
|
///
|
|
/// References to hook data can only be stored in listeners and component props. During diffing, we make sure to log
|
|
/// all listeners and borrowed props so we can clear them here.
|
|
///
|
|
/// This also makes sure that drop order is consistent and predictable. All resources that rely on being dropped will
|
|
/// be dropped.
|
|
pub(crate) fn ensure_drop_safety(&self, scope_id: &ScopeId) {
|
|
let scope = self.get_scope(scope_id).unwrap();
|
|
|
|
let mut items = scope.items.borrow_mut();
|
|
|
|
// make sure we drop all borrowed props manually to guarantee that their drop implementation is called before we
|
|
// run the hooks (which hold an &mut Reference)
|
|
// recursively call ensure_drop_safety on all children
|
|
items.borrowed_props.drain(..).for_each(|comp| {
|
|
let scope_id = comp
|
|
.associated_scope
|
|
.get()
|
|
.expect("VComponents should be associated with a valid Scope");
|
|
|
|
self.ensure_drop_safety(&scope_id);
|
|
|
|
let mut drop_props = comp.drop_props.borrow_mut().take().unwrap();
|
|
drop_props();
|
|
});
|
|
|
|
// Now that all the references are gone, we can safely drop our own references in our listeners.
|
|
items
|
|
.listeners
|
|
.drain(..)
|
|
.for_each(|listener| drop(listener.callback.borrow_mut().take()));
|
|
}
|
|
|
|
pub(crate) fn run_scope(&self, id: &ScopeId) -> bool {
|
|
let scope = unsafe {
|
|
&mut *self
|
|
.get_scope_mut(id)
|
|
.expect("The base scope should never be moved")
|
|
};
|
|
|
|
// Cycle to the next frame and then reset it
|
|
// This breaks any latent references, invalidating every pointer referencing into it.
|
|
// Remove all the outdated listeners
|
|
self.ensure_drop_safety(id);
|
|
|
|
// Safety:
|
|
// - We dropped the listeners, so no more &mut T can be used while these are held
|
|
// - All children nodes that rely on &mut T are replaced with a new reference
|
|
unsafe { scope.hooks.reset() };
|
|
|
|
// Safety:
|
|
// - We've dropped all references to the wip bump frame with "ensure_drop_safety"
|
|
unsafe { scope.reset_wip_frame() };
|
|
|
|
{
|
|
let mut items = scope.items.borrow_mut();
|
|
|
|
// just forget about our suspended nodes while we're at it
|
|
items.suspended_nodes.clear();
|
|
items.tasks.clear();
|
|
items.pending_effects.clear();
|
|
|
|
// guarantee that we haven't screwed up - there should be no latent references anywhere
|
|
debug_assert!(items.listeners.is_empty());
|
|
debug_assert!(items.borrowed_props.is_empty());
|
|
debug_assert!(items.suspended_nodes.is_empty());
|
|
debug_assert!(items.tasks.is_empty());
|
|
debug_assert!(items.pending_effects.is_empty());
|
|
|
|
// Todo: see if we can add stronger guarantees around internal bookkeeping and failed component renders.
|
|
scope.wip_frame().nodes.borrow_mut().clear();
|
|
}
|
|
|
|
let render: &dyn Fn(&Scope) -> Element = unsafe { &*scope.caller };
|
|
|
|
if let Some(link) = render(scope) {
|
|
// right now, it's a panic to render a nodelink from another scope
|
|
// todo: enable this. it should (reasonably) work even if it doesnt make much sense
|
|
assert_eq!(link.scope_id.get(), Some(*id));
|
|
|
|
// nodelinks are not assigned when called and must be done so through the create/diff phase
|
|
// however, we need to link this one up since it will never be used in diffing
|
|
scope.wip_frame().assign_nodelink(&link);
|
|
debug_assert_eq!(scope.wip_frame().nodes.borrow().len(), 1);
|
|
|
|
if !scope.items.borrow().tasks.is_empty() {
|
|
// self.
|
|
}
|
|
|
|
// make the "wip frame" contents the "finished frame"
|
|
// any future dipping into completed nodes after "render" will go through "fin head"
|
|
scope.cycle_frame();
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
// The head of the bumpframe is the first linked NodeLink
|
|
pub fn wip_head(&self, id: &ScopeId) -> &VNode {
|
|
let scope = self.get_scope(id).unwrap();
|
|
let wip_frame = scope.wip_frame();
|
|
let nodes = wip_frame.nodes.borrow();
|
|
let node: &VNode = unsafe { &**nodes.get(0).unwrap() };
|
|
unsafe { std::mem::transmute::<&VNode, &VNode>(node) }
|
|
}
|
|
|
|
// The head of the bumpframe is the first linked NodeLink
|
|
pub fn fin_head(&self, id: &ScopeId) -> &VNode {
|
|
let scope = self.get_scope(id).unwrap();
|
|
let wip_frame = scope.fin_frame();
|
|
let nodes = wip_frame.nodes.borrow();
|
|
let node: &VNode = unsafe { &**nodes.get(0).unwrap() };
|
|
unsafe { std::mem::transmute::<&VNode, &VNode>(node) }
|
|
}
|
|
|
|
pub fn root_node(&self, id: &ScopeId) -> &VNode {
|
|
self.fin_head(id)
|
|
}
|
|
}
|