mirror of
https://github.com/DioxusLabs/dioxus
synced 2024-12-21 10:03:13 +00:00
899 lines
31 KiB
Rust
899 lines
31 KiB
Rust
use crate::{innerlude::*, unsafe_utils::extend_vnode};
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use bumpalo::Bump;
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use futures_channel::mpsc::UnboundedSender;
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use fxhash::FxHashMap;
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use slab::Slab;
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use std::{
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any::{Any, TypeId},
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borrow::Borrow,
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cell::{Cell, RefCell},
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collections::HashMap,
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future::Future,
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pin::Pin,
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rc::Rc,
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};
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pub(crate) type FcSlot = *const ();
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pub(crate) struct Heuristic {
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hook_arena_size: usize,
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node_arena_size: usize,
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}
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// a slab-like arena with stable references even when new scopes are allocated
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// uses a bump arena as a backing
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//
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// has an internal heuristics engine to pre-allocate arenas to the right size
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pub(crate) struct ScopeArena {
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pub scope_gen: Cell<usize>,
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pub bump: Bump,
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pub scopes: RefCell<FxHashMap<ScopeId, *mut ScopeState>>,
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pub heuristics: RefCell<FxHashMap<FcSlot, Heuristic>>,
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pub free_scopes: RefCell<Vec<*mut ScopeState>>,
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pub nodes: RefCell<Slab<*const VNode<'static>>>,
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pub tasks: Rc<TaskQueue>,
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}
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impl ScopeArena {
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pub(crate) fn new(sender: UnboundedSender<SchedulerMsg>) -> Self {
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let bump = Bump::new();
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// allocate a container for the root element
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// this will *never* show up in the diffing process
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// todo: figure out why this is necessary. i forgot. whoops.
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let el = bump.alloc(VElement {
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tag: "root",
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namespace: None,
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key: None,
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id: Cell::new(Some(ElementId(0))),
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parent: Default::default(),
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listeners: &[],
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attributes: &[],
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children: &[],
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});
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let node = bump.alloc(VNode::Element(el));
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let mut nodes = Slab::new();
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let root_id = nodes.insert(unsafe { std::mem::transmute(node as *const _) });
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debug_assert_eq!(root_id, 0);
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Self {
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scope_gen: Cell::new(0),
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bump,
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scopes: RefCell::new(FxHashMap::default()),
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heuristics: RefCell::new(FxHashMap::default()),
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free_scopes: RefCell::new(Vec::new()),
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nodes: RefCell::new(nodes),
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tasks: TaskQueue::new(sender),
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}
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}
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/// Safety:
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/// - Obtaining a mutable refernece to any Scope is unsafe
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/// - Scopes use interior mutability when sharing data into components
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pub(crate) fn get_scope(&self, id: ScopeId) -> Option<&ScopeState> {
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unsafe { self.scopes.borrow().get(&id).map(|f| &**f) }
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}
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pub(crate) fn get_scope_raw(&self, id: ScopeId) -> Option<*mut ScopeState> {
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self.scopes.borrow().get(&id).copied()
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}
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pub(crate) fn new_with_key(
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&self,
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fc_ptr: *const (),
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vcomp: Box<dyn AnyProps>,
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parent_scope: Option<ScopeId>,
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container: ElementId,
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subtree: u32,
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) -> ScopeId {
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// Increment the ScopeId system. ScopeIDs are never reused
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let new_scope_id = ScopeId(self.scope_gen.get());
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self.scope_gen.set(self.scope_gen.get() + 1);
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// Get the height of the scope
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let height = parent_scope
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.map(|id| self.get_scope(id).map(|scope| scope.height))
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.flatten()
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.unwrap_or_default();
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let parent_scope = parent_scope.map(|f| self.get_scope_raw(f)).flatten();
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/*
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This scopearena aggressively reuse old scopes when possible.
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We try to minimize the new allocations for props/arenas.
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However, this will probably lead to some sort of fragmentation.
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I'm not exactly sure how to improve this today.
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*/
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if let Some(old_scope) = self.free_scopes.borrow_mut().pop() {
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// reuse the old scope
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let scope = unsafe { &mut *old_scope };
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scope.props.get_mut().replace(vcomp);
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scope.parent_scope = parent_scope;
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scope.height = height;
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scope.subtree.set(subtree);
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scope.our_arena_idx = new_scope_id;
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scope.container = container;
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let any_item = self.scopes.borrow_mut().insert(new_scope_id, scope);
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debug_assert!(any_item.is_none());
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} else {
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// else create a new scope
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self.scopes.borrow_mut().insert(
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new_scope_id,
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self.bump.alloc(ScopeState::new(
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height,
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container,
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new_scope_id,
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parent_scope,
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vcomp,
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self.tasks.clone(),
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self.heuristics
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.borrow()
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.get(&fc_ptr)
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.map(|h| (h.node_arena_size, h.hook_arena_size))
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.unwrap_or_default(),
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)),
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);
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}
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new_scope_id
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}
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// Removes a scope and its descendents from the arena
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pub fn try_remove(&self, id: ScopeId) -> Option<()> {
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self.ensure_drop_safety(id);
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// Safety:
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// - ensure_drop_safety ensures that no references to this scope are in use
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// - this raw pointer is removed from the map
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let scope = unsafe { &mut *self.scopes.borrow_mut().remove(&id).unwrap() };
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scope.reset();
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self.free_scopes.borrow_mut().push(scope);
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Some(())
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}
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pub fn reserve_node<'a>(&self, node: &'a VNode<'a>) -> ElementId {
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let mut els = self.nodes.borrow_mut();
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let entry = els.vacant_entry();
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let key = entry.key();
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let id = ElementId(key);
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let node = unsafe { extend_vnode(node) };
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entry.insert(node as *const _);
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id
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}
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pub fn update_node<'a>(&self, node: &'a VNode<'a>, id: ElementId) {
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let node = unsafe { extend_vnode(node) };
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*self.nodes.borrow_mut().get_mut(id.0).unwrap() = node;
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}
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pub fn collect_garbage(&self, id: ElementId) {
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self.nodes.borrow_mut().remove(id.0);
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}
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/// This method cleans up any references to data held within our hook list. This prevents mutable aliasing from
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/// causing UB in our tree.
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///
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/// This works by cleaning up our references from the bottom of the tree to the top. The directed graph of components
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/// essentially forms a dependency tree that we can traverse from the bottom to the top. As we traverse, we remove
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/// any possible references to the data in the hook list.
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///
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/// References to hook data can only be stored in listeners and component props. During diffing, we make sure to log
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/// all listeners and borrowed props so we can clear them here.
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///
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/// This also makes sure that drop order is consistent and predictable. All resources that rely on being dropped will
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/// be dropped.
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pub(crate) fn ensure_drop_safety(&self, scope_id: ScopeId) {
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if let Some(scope) = self.get_scope(scope_id) {
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let mut items = scope.items.borrow_mut();
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// make sure we drop all borrowed props manually to guarantee that their drop implementation is called before we
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// run the hooks (which hold an &mut Reference)
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// recursively call ensure_drop_safety on all children
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items.borrowed_props.drain(..).for_each(|comp| {
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let scope_id = comp
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.scope
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.get()
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.expect("VComponents should be associated with a valid Scope");
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self.ensure_drop_safety(scope_id);
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drop(comp.props.take());
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});
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// Now that all the references are gone, we can safely drop our own references in our listeners.
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items
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.listeners
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.drain(..)
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.for_each(|listener| drop(listener.callback.callback.borrow_mut().take()));
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}
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}
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pub(crate) fn run_scope(&self, id: ScopeId) {
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// Cycle to the next frame and then reset it
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// This breaks any latent references, invalidating every pointer referencing into it.
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// Remove all the outdated listeners
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self.ensure_drop_safety(id);
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// todo: we *know* that this is aliased by the contents of the scope itself
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let scope = unsafe { &mut *self.get_scope_raw(id).expect("could not find scope") };
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// Safety:
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// - We dropped the listeners, so no more &mut T can be used while these are held
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// - All children nodes that rely on &mut T are replaced with a new reference
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scope.hook_idx.set(0);
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// book keeping to ensure safety around the borrowed data
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{
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// Safety:
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// - We've dropped all references to the wip bump frame with "ensure_drop_safety"
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unsafe { scope.reset_wip_frame() };
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let items = scope.items.borrow();
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// guarantee that we haven't screwed up - there should be no latent references anywhere
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debug_assert!(items.listeners.is_empty());
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debug_assert!(items.borrowed_props.is_empty());
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}
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// safety: this is definitely not dropped
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/*
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If the component returns None, then we fill in a placeholder node. This will wipe what was there.
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An alternate approach is to leave the Real Dom the same, but that can lead to safety issues and a lot more checks.
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Instead, we just treat the `None` as a shortcut to placeholder.
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If the developer wants to prevent a scope from updating, they should control its memoization instead.
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Also, the way we implement hooks allows us to cut rendering short before the next hook is recalled.
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I'm not sure if React lets you abort the component early, but we let you do that.
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*/
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let props = scope.props.borrow();
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let render = props.as_ref().unwrap();
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if let Some(node) = render.render(scope) {
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let frame = scope.wip_frame();
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let node = frame.bump.alloc(node);
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frame.node.set(unsafe { extend_vnode(node) });
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} else {
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let frame = scope.wip_frame();
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let node = frame
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.bump
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.alloc(VNode::Placeholder(frame.bump.alloc(VPlaceholder {
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id: Default::default(),
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})));
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frame.node.set(unsafe { extend_vnode(node) });
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}
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// make the "wip frame" contents the "finished frame"
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// any future dipping into completed nodes after "render" will go through "fin head"
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scope.cycle_frame();
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}
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pub fn call_listener_with_bubbling(&self, event: UserEvent, element: ElementId) {
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let nodes = self.nodes.borrow();
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let mut cur_el = Some(element);
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while let Some(id) = cur_el.take() {
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if let Some(el) = nodes.get(id.0) {
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let real_el = unsafe { &**el };
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if let VNode::Element(real_el) = real_el {
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for listener in real_el.listeners.borrow().iter() {
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if listener.event == event.name {
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let mut cb = listener.callback.callback.borrow_mut();
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if let Some(cb) = cb.as_mut() {
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// todo: arcs are pretty heavy to clone
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// we really want to convert arc to rc
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// unfortunately, the SchedulerMsg must be send/sync to be sent across threads
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// we could convert arc to rc internally or something
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(cb)(event.data.clone());
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}
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}
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}
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cur_el = real_el.parent.get();
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}
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}
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}
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}
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// The head of the bumpframe is the first linked NodeLink
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pub fn wip_head(&self, id: ScopeId) -> &VNode {
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let scope = self.get_scope(id).unwrap();
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let frame = scope.wip_frame();
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let node = unsafe { &*frame.node.get() };
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unsafe { extend_vnode(node) }
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}
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// The head of the bumpframe is the first linked NodeLink
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pub fn fin_head(&self, id: ScopeId) -> &VNode {
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let scope = self.get_scope(id).unwrap();
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let frame = scope.fin_frame();
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let node = unsafe { &*frame.node.get() };
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unsafe { extend_vnode(node) }
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}
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pub fn root_node(&self, id: ScopeId) -> &VNode {
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self.fin_head(id)
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}
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}
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/// Components in Dioxus use the "Context" object to interact with their lifecycle.
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///
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/// This lets components access props, schedule updates, integrate hooks, and expose shared state.
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///
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/// For the most part, the only method you should be using regularly is `render`.
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///
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/// ## Example
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///
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/// ```ignore
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/// #[derive(Props)]
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/// struct ExampleProps {
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/// name: String
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/// }
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///
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/// fn Example(cx: Scope<ExampleProps>) -> Element {
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/// cx.render(rsx!{ div {"Hello, {cx.props.name}"} })
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/// }
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/// ```
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pub struct Scope<'a, P = ()> {
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pub scope: &'a ScopeState,
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pub props: &'a P,
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}
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impl<P> Copy for Scope<'_, P> {}
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impl<P> Clone for Scope<'_, P> {
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fn clone(&self) -> Self {
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Self {
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scope: self.scope,
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props: self.props,
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}
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}
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}
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impl<'a, P> std::ops::Deref for Scope<'a, P> {
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// rust will auto deref again to the original 'a lifetime at the call site
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type Target = &'a ScopeState;
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fn deref(&self) -> &Self::Target {
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&self.scope
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}
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}
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/// A component's unique identifier.
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///
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/// `ScopeId` is a `usize` that is unique across the entire VirtualDOM and across time. ScopeIDs will never be reused
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/// once a component has been unmounted.
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#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
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#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
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pub struct ScopeId(pub usize);
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/// A task's unique identifier.
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///
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/// `TaskId` is a `usize` that is unique across the entire VirtualDOM and across time. TaskIDs will never be reused
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/// once a Task has been completed.
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#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
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#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
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pub struct TaskId(pub usize);
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/// Every component in Dioxus is represented by a `ScopeState`.
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///
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/// Scopes contain the state for hooks, the component's props, and other lifecycle information.
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///
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/// Scopes are allocated in a generational arena. As components are mounted/unmounted, they will replace slots of dead components.
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/// The actual contents of the hooks, though, will be allocated with the standard allocator. These should not allocate as frequently.
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///
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/// We expose the `Scope` type so downstream users can traverse the Dioxus VirtualDOM for whatever
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/// use case they might have.
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pub struct ScopeState {
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pub(crate) parent_scope: Option<*mut ScopeState>,
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pub(crate) container: ElementId,
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pub(crate) our_arena_idx: ScopeId,
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pub(crate) height: u32,
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// todo: subtrees
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pub(crate) is_subtree_root: Cell<bool>,
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pub(crate) subtree: Cell<u32>,
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pub(crate) props: RefCell<Option<Box<dyn AnyProps>>>,
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// nodes, items
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pub(crate) frames: [BumpFrame; 2],
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pub(crate) generation: Cell<u32>,
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pub(crate) items: RefCell<SelfReferentialItems<'static>>,
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// hooks
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pub(crate) hook_arena: Bump,
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pub(crate) hook_vals: RefCell<Vec<*mut dyn Any>>,
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pub(crate) hook_idx: Cell<usize>,
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// shared state -> todo: move this out of scopestate
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pub(crate) shared_contexts: RefCell<HashMap<TypeId, Rc<dyn Any>>>,
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pub(crate) tasks: Rc<TaskQueue>,
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}
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pub struct SelfReferentialItems<'a> {
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pub(crate) listeners: Vec<&'a Listener<'a>>,
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pub(crate) borrowed_props: Vec<&'a VComponent<'a>>,
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}
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// Public methods exposed to libraries and components
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impl ScopeState {
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fn new(
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height: u32,
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container: ElementId,
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our_arena_idx: ScopeId,
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parent_scope: Option<*mut ScopeState>,
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vcomp: Box<dyn AnyProps>,
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tasks: Rc<TaskQueue>,
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(node_capacity, hook_capacity): (usize, usize),
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) -> Self {
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ScopeState {
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container,
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our_arena_idx,
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parent_scope,
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height,
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props: RefCell::new(Some(vcomp)),
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frames: [BumpFrame::new(node_capacity), BumpFrame::new(node_capacity)],
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// todo: subtrees
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subtree: Cell::new(0),
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is_subtree_root: Cell::new(false),
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generation: 0.into(),
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tasks,
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shared_contexts: Default::default(),
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items: RefCell::new(SelfReferentialItems {
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listeners: Default::default(),
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borrowed_props: Default::default(),
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}),
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hook_arena: Bump::new(),
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hook_vals: RefCell::new(Vec::with_capacity(hook_capacity)),
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hook_idx: Default::default(),
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}
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}
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/// Get the subtree ID that this scope belongs to.
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///
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/// Each component has its own subtree ID - the root subtree has an ID of 0. This ID is used by the renderer to route
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/// the mutations to the correct window/portal/subtree.
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///
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///
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/// # Example
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///
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/// ```rust, ignore
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/// let mut dom = VirtualDom::new(|cx| cx.render(rsx!{ div {} }));
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/// dom.rebuild();
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///
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/// let base = dom.base_scope();
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///
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/// assert_eq!(base.subtree(), 0);
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/// ```
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///
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/// todo: enable
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pub(crate) fn _subtree(&self) -> u32 {
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self.subtree.get()
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}
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|
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/// Create a new subtree with this scope as the root of the subtree.
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///
|
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/// Each component has its own subtree ID - the root subtree has an ID of 0. This ID is used by the renderer to route
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/// the mutations to the correct window/portal/subtree.
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///
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/// This method
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///
|
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/// # Example
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///
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/// ```rust, ignore
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/// fn App(cx: Scope<()>) -> Element {
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/// rsx!(cx, div { "Subtree {id}"})
|
|
/// };
|
|
/// ```
|
|
///
|
|
/// todo: enable subtree
|
|
pub(crate) fn _create_subtree(&self) -> Option<u32> {
|
|
if self.is_subtree_root.get() {
|
|
None
|
|
} else {
|
|
todo!()
|
|
}
|
|
}
|
|
|
|
/// Get the height of this Scope - IE the number of scopes above it.
|
|
///
|
|
/// A Scope with a height of `0` is the root scope - there are no other scopes above it.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```rust, ignore
|
|
/// let mut dom = VirtualDom::new(|cx| cx.render(rsx!{ div {} }));
|
|
/// dom.rebuild();
|
|
///
|
|
/// let base = dom.base_scope();
|
|
///
|
|
/// assert_eq!(base.height(), 0);
|
|
/// ```
|
|
pub fn height(&self) -> u32 {
|
|
self.height
|
|
}
|
|
|
|
/// Get the Parent of this Scope within this Dioxus VirtualDOM.
|
|
///
|
|
/// This ID is not unique across Dioxus VirtualDOMs or across time. IDs will be reused when components are unmounted.
|
|
///
|
|
/// The base component will not have a parent, and will return `None`.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```rust, ignore
|
|
/// let mut dom = VirtualDom::new(|cx| cx.render(rsx!{ div {} }));
|
|
/// dom.rebuild();
|
|
///
|
|
/// let base = dom.base_scope();
|
|
///
|
|
/// assert_eq!(base.parent(), None);
|
|
/// ```
|
|
pub fn parent(&self) -> Option<ScopeId> {
|
|
// safety: the pointer to our parent is *always* valid thanks to the bump arena
|
|
self.parent_scope.map(|p| unsafe { &*p }.our_arena_idx)
|
|
}
|
|
|
|
/// Get the ID of this Scope within this Dioxus VirtualDOM.
|
|
///
|
|
/// This ID is not unique across Dioxus VirtualDOMs or across time. IDs will be reused when components are unmounted.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```rust, ignore
|
|
/// let mut dom = VirtualDom::new(|cx| cx.render(rsx!{ div {} }));
|
|
/// dom.rebuild();
|
|
/// let base = dom.base_scope();
|
|
///
|
|
/// assert_eq!(base.scope_id(), 0);
|
|
/// ```
|
|
pub fn scope_id(&self) -> ScopeId {
|
|
self.our_arena_idx
|
|
}
|
|
|
|
/// Create a subscription that schedules a future render for the reference component
|
|
///
|
|
/// ## Notice: you should prefer using prepare_update and get_scope_id
|
|
pub fn schedule_update(&self) -> Rc<dyn Fn() + 'static> {
|
|
let (chan, id) = (self.tasks.sender.clone(), self.scope_id());
|
|
Rc::new(move || {
|
|
let _ = chan.unbounded_send(SchedulerMsg::Immediate(id));
|
|
})
|
|
}
|
|
|
|
/// Schedule an update for any component given its ScopeId.
|
|
///
|
|
/// A component's ScopeId can be obtained from `use_hook` or the [`ScopeState::scope_id`] method.
|
|
///
|
|
/// This method should be used when you want to schedule an update for a component
|
|
pub fn schedule_update_any(&self) -> Rc<dyn Fn(ScopeId)> {
|
|
let chan = self.tasks.sender.clone();
|
|
Rc::new(move |id| {
|
|
let _ = chan.unbounded_send(SchedulerMsg::Immediate(id));
|
|
})
|
|
}
|
|
|
|
/// Get the [`ScopeId`] of a mounted component.
|
|
///
|
|
/// `ScopeId` is not unique for the lifetime of the VirtualDom - a ScopeId will be reused if a component is unmounted.
|
|
pub fn needs_update(&self) {
|
|
self.needs_update_any(self.scope_id())
|
|
}
|
|
|
|
/// Get the [`ScopeId`] of a mounted component.
|
|
///
|
|
/// `ScopeId` is not unique for the lifetime of the VirtualDom - a ScopeId will be reused if a component is unmounted.
|
|
pub fn needs_update_any(&self, id: ScopeId) {
|
|
let _ = self
|
|
.tasks
|
|
.sender
|
|
.unbounded_send(SchedulerMsg::Immediate(id));
|
|
}
|
|
|
|
/// Get the Root Node of this scope
|
|
pub fn root_node(&self) -> &VNode {
|
|
let node = unsafe { &*self.fin_frame().node.get() };
|
|
unsafe { std::mem::transmute(node) }
|
|
}
|
|
|
|
/// This method enables the ability to expose state to children further down the VirtualDOM Tree.
|
|
///
|
|
/// This is a "fundamental" operation and should only be called during initialization of a hook.
|
|
///
|
|
/// For a hook that provides the same functionality, use `use_provide_context` and `use_consume_context` instead.
|
|
///
|
|
/// When the component is dropped, so is the context. Be aware of this behavior when consuming
|
|
/// the context via Rc/Weak.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```rust, ignore
|
|
/// struct SharedState(&'static str);
|
|
///
|
|
/// static App: Component = |cx| {
|
|
/// cx.use_hook(|_| cx.provide_context(SharedState("world")), |_| {}, |_| {});
|
|
/// rsx!(cx, Child {})
|
|
/// }
|
|
///
|
|
/// static Child: Component = |cx| {
|
|
/// let state = cx.consume_state::<SharedState>();
|
|
/// rsx!(cx, div { "hello {state.0}" })
|
|
/// }
|
|
/// ```
|
|
pub fn provide_context<T: 'static>(&self, value: T) {
|
|
self.shared_contexts
|
|
.borrow_mut()
|
|
.insert(TypeId::of::<T>(), Rc::new(value))
|
|
.map(|f| f.downcast::<T>().ok())
|
|
.flatten();
|
|
}
|
|
|
|
/// Try to retrieve a SharedState with type T from the any parent Scope.
|
|
pub fn consume_context<T: 'static>(&self) -> Option<Rc<T>> {
|
|
if let Some(shared) = self.shared_contexts.borrow().get(&TypeId::of::<T>()) {
|
|
Some(shared.clone().downcast::<T>().unwrap())
|
|
} else {
|
|
let mut search_parent = self.parent_scope;
|
|
|
|
while let Some(parent_ptr) = search_parent {
|
|
// safety: all parent pointers are valid thanks to the bump arena
|
|
let parent = unsafe { &*parent_ptr };
|
|
if let Some(shared) = parent.shared_contexts.borrow().get(&TypeId::of::<T>()) {
|
|
return Some(shared.clone().downcast::<T>().unwrap());
|
|
}
|
|
search_parent = parent.parent_scope;
|
|
}
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Pushes the future onto the poll queue to be polled after the component renders.
|
|
///
|
|
/// The future is forcibly dropped if the component is not ready by the next render
|
|
pub fn push_future(&self, fut: impl Future<Output = ()> + 'static) -> TaskId {
|
|
// wake up the scheduler if it is sleeping
|
|
self.tasks
|
|
.sender
|
|
.unbounded_send(SchedulerMsg::NewTask(self.our_arena_idx))
|
|
.unwrap();
|
|
|
|
self.tasks.push_fut(fut)
|
|
}
|
|
|
|
// todo: attach some state to the future to know if we should poll it
|
|
pub fn remove_future(&self, id: TaskId) {
|
|
self.tasks.remove_fut(id);
|
|
}
|
|
|
|
/// Take a lazy VNode structure and actually build it with the context of the VDom's efficient VNode allocator.
|
|
///
|
|
/// This function consumes the context and absorb the lifetime, so these VNodes *must* be returned.
|
|
///
|
|
/// ## Example
|
|
///
|
|
/// ```ignore
|
|
/// fn Component(cx: Scope<Props>) -> Element {
|
|
/// // Lazy assemble the VNode tree
|
|
/// let lazy_nodes = rsx!("hello world");
|
|
///
|
|
/// // Actually build the tree and allocate it
|
|
/// cx.render(lazy_tree)
|
|
/// }
|
|
///```
|
|
pub fn render<'src>(&'src self, rsx: LazyNodes<'src, '_>) -> Option<VNode<'src>> {
|
|
let fac = NodeFactory {
|
|
bump: &self.wip_frame().bump,
|
|
};
|
|
Some(rsx.call(fac))
|
|
}
|
|
|
|
/// Store a value between renders
|
|
///
|
|
/// This is *the* foundational hook for all other hooks.
|
|
///
|
|
/// - Initializer: closure used to create the initial hook state
|
|
/// - Runner: closure used to output a value every time the hook is used
|
|
///
|
|
/// To "cleanup" the hook, implement `Drop` on the stored hook value. Whenever the component is dropped, the hook
|
|
/// will be dropped as well.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```ignore
|
|
/// // use_ref is the simplest way of storing a value between renders
|
|
/// fn use_ref<T: 'static>(initial_value: impl FnOnce() -> T) -> &RefCell<T> {
|
|
/// use_hook(
|
|
/// || Rc::new(RefCell::new(initial_value())),
|
|
/// |state| state,
|
|
/// )
|
|
/// }
|
|
/// ```
|
|
pub fn use_hook<'src, State: 'static, Output: 'src>(
|
|
&'src self,
|
|
initializer: impl FnOnce(usize) -> State,
|
|
runner: impl FnOnce(&'src mut State) -> Output,
|
|
) -> Output {
|
|
let mut vals = self.hook_vals.borrow_mut();
|
|
|
|
let hook_len = vals.len();
|
|
let cur_idx = self.hook_idx.get();
|
|
|
|
if cur_idx >= hook_len {
|
|
vals.push(self.hook_arena.alloc(initializer(hook_len)));
|
|
}
|
|
|
|
let state = vals
|
|
.get(cur_idx)
|
|
.and_then(|inn| {
|
|
self.hook_idx.set(cur_idx + 1);
|
|
let raw_box = unsafe { &mut **inn };
|
|
raw_box.downcast_mut::<State>()
|
|
})
|
|
.expect(
|
|
r###"
|
|
Unable to retrieve the hook that was initialized at this index.
|
|
Consult the `rules of hooks` to understand how to use hooks properly.
|
|
|
|
You likely used the hook in a conditional. Hooks rely on consistent ordering between renders.
|
|
Functions prefixed with "use" should never be called conditionally.
|
|
"###,
|
|
);
|
|
|
|
runner(state)
|
|
}
|
|
|
|
/// The "work in progress frame" represents the frame that is currently being worked on.
|
|
pub(crate) fn wip_frame(&self) -> &BumpFrame {
|
|
match self.generation.get() & 1 == 0 {
|
|
true => &self.frames[0],
|
|
false => &self.frames[1],
|
|
}
|
|
}
|
|
|
|
/// Mutable access to the "work in progress frame" - used to clear it
|
|
pub(crate) fn wip_frame_mut(&mut self) -> &mut BumpFrame {
|
|
match self.generation.get() & 1 == 0 {
|
|
true => &mut self.frames[0],
|
|
false => &mut self.frames[1],
|
|
}
|
|
}
|
|
|
|
/// Access to the frame where finalized nodes existed
|
|
pub(crate) fn fin_frame(&self) -> &BumpFrame {
|
|
match self.generation.get() & 1 == 1 {
|
|
true => &self.frames[0],
|
|
false => &self.frames[1],
|
|
}
|
|
}
|
|
|
|
/// Reset this component's frame
|
|
///
|
|
/// # Safety:
|
|
///
|
|
/// This method breaks every reference of VNodes in the current frame.
|
|
///
|
|
/// Calling reset itself is not usually a big deal, but we consider it important
|
|
/// due to the complex safety guarantees we need to uphold.
|
|
pub(crate) unsafe fn reset_wip_frame(&mut self) {
|
|
self.wip_frame_mut().bump.reset();
|
|
}
|
|
|
|
/// Cycle to the next generation
|
|
pub(crate) fn cycle_frame(&self) {
|
|
self.generation.set(self.generation.get() + 1);
|
|
}
|
|
|
|
// todo: disable bookkeeping on drop (unncessary)
|
|
pub(crate) fn reset(&mut self) {
|
|
// first: book keaping
|
|
self.hook_idx.set(0);
|
|
self.parent_scope = None;
|
|
self.generation.set(0);
|
|
self.is_subtree_root.set(false);
|
|
self.subtree.set(0);
|
|
|
|
// next: shared context data
|
|
self.shared_contexts.get_mut().clear();
|
|
|
|
// next: reset the node data
|
|
let SelfReferentialItems {
|
|
borrowed_props,
|
|
listeners,
|
|
} = self.items.get_mut();
|
|
borrowed_props.clear();
|
|
listeners.clear();
|
|
self.frames[0].reset();
|
|
self.frames[1].reset();
|
|
|
|
// Finally, free up the hook values
|
|
self.hook_arena.reset();
|
|
self.hook_vals.get_mut().drain(..).for_each(|state| {
|
|
let as_mut = unsafe { &mut *state };
|
|
let boxed = unsafe { bumpalo::boxed::Box::from_raw(as_mut) };
|
|
drop(boxed);
|
|
});
|
|
}
|
|
}
|
|
|
|
pub(crate) struct BumpFrame {
|
|
pub bump: Bump,
|
|
pub node: Cell<*const VNode<'static>>,
|
|
}
|
|
impl BumpFrame {
|
|
pub(crate) fn new(capacity: usize) -> Self {
|
|
let bump = Bump::with_capacity(capacity);
|
|
|
|
let node = &*bump.alloc(VText {
|
|
text: "placeholdertext",
|
|
id: Default::default(),
|
|
is_static: false,
|
|
});
|
|
let node = bump.alloc(VNode::Text(unsafe { std::mem::transmute(node) }));
|
|
let nodes = Cell::new(node as *const _);
|
|
Self { bump, node: nodes }
|
|
}
|
|
|
|
pub(crate) fn reset(&mut self) {
|
|
self.bump.reset();
|
|
let node = self.bump.alloc(VText {
|
|
text: "placeholdertext",
|
|
id: Default::default(),
|
|
is_static: false,
|
|
});
|
|
let node = self
|
|
.bump
|
|
.alloc(VNode::Text(unsafe { std::mem::transmute(node) }));
|
|
self.node.set(node as *const _);
|
|
}
|
|
}
|
|
|
|
pub(crate) struct TaskQueue {
|
|
pub(crate) tasks: RefCell<FxHashMap<TaskId, InnerTask>>,
|
|
gen: Cell<usize>,
|
|
sender: UnboundedSender<SchedulerMsg>,
|
|
}
|
|
pub(crate) type InnerTask = Pin<Box<dyn Future<Output = ()>>>;
|
|
impl TaskQueue {
|
|
fn new(sender: UnboundedSender<SchedulerMsg>) -> Rc<Self> {
|
|
Rc::new(Self {
|
|
tasks: RefCell::new(FxHashMap::default()),
|
|
gen: Cell::new(0),
|
|
sender,
|
|
})
|
|
}
|
|
fn push_fut(&self, task: impl Future<Output = ()> + 'static) -> TaskId {
|
|
let pinned = Box::pin(task);
|
|
let id = self.gen.get();
|
|
self.gen.set(id + 1);
|
|
let tid = TaskId(id);
|
|
|
|
self.tasks.borrow_mut().insert(tid, pinned);
|
|
tid
|
|
}
|
|
fn remove_fut(&self, id: TaskId) {
|
|
if let Ok(mut tasks) = self.tasks.try_borrow_mut() {
|
|
let _ = tasks.remove(&id);
|
|
} else {
|
|
// todo: it should be okay to remote a fut while the queue is being polled
|
|
// However, it's not currently possible to do that.
|
|
log::debug!("Unable to remove task from task queue. This is probably a bug.");
|
|
}
|
|
}
|
|
pub(crate) fn has_tasks(&self) -> bool {
|
|
!self.tasks.borrow().is_empty()
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn sizeof() {
|
|
dbg!(std::mem::size_of::<ScopeState>());
|
|
}
|