WIP: still a bit stumped on DFS vs BFS

This commit is contained in:
Jonathan Kelley 2021-03-05 15:02:36 -05:00
parent 89f2290692
commit 3740f81383
6 changed files with 205 additions and 291 deletions

View file

@ -1,34 +1,19 @@
//! An example that shows how to:
//! create a scope,
//! render a component,
//! change some data
//! render it again
//! consume the diffs and write that to a renderer
use dioxus_core::prelude::*;
fn main() -> Result<(), ()> {
let p1 = Props { name: "bob".into() };
let _vdom = VirtualDom::new_with_props(Example, p1);
// vdom.progress()?;
let mut vdom = VirtualDom::new_with_props(Example, p1);
vdom.update_props(|p: &mut Props| {});
Ok(())
}
#[derive(Debug)]
#[derive(Debug, PartialEq)]
struct Props {
name: String,
}
// impl Properties for Props {
// fn call(&self, ptr: *const ()) {}
// // fn new() -> Self {
// // todo!()
// // }
// }
static Example: FC<Props> = |ctx, _props| {
ctx.render(html! {
<div>

View file

@ -32,10 +32,14 @@
//!
//! More info on how to improve this diffing algorithm:
//! - https://hacks.mozilla.org/2019/03/fast-bump-allocated-virtual-doms-with-rust-and-wasm/
use crate::innerlude::*;
use crate::{
innerlude::*,
scope::{create_scoped, Scoped},
};
use bumpalo::Bump;
use fxhash::{FxHashMap, FxHashSet};
use std::cmp::Ordering;
use generational_arena::Arena;
use std::{cell::RefCell, cmp::Ordering, collections::VecDeque, rc::Rc};
/// The DiffState is a cursor internal to the VirtualDOM's diffing algorithm that allows persistence of state while
/// diffing trees of components. This means we can "re-enter" a subtree of a component by queuing a "NeedToDiff" event.
@ -49,20 +53,23 @@ use std::cmp::Ordering;
/// The order of these re-entrances is stored in the DiffState itself. The DiffState comes pre-loaded with a set of components
/// that were modified by the eventtrigger. This prevents doubly evaluating components if they wereboth updated via
/// subscriptions and props changes.
pub struct DiffMachine<'a> {
pub struct DiffMachine<'a, 'b> {
pub change_list: EditMachine<'a>,
immediate_queue: Vec<ScopeIdx>,
diffed: FxHashSet<ScopeIdx>,
need_to_diff: FxHashSet<ScopeIdx>,
pub vdom: &'b VirtualDom,
pub cur_idx: ScopeIdx,
pub diffed: FxHashSet<ScopeIdx>,
pub need_to_diff: FxHashSet<ScopeIdx>,
}
impl<'a> DiffMachine<'a> {
pub fn new(bump: &'a Bump) -> Self {
impl<'a, 'b> DiffMachine<'a, 'b> {
pub fn new(vdom: &'b VirtualDom, bump: &'a Bump, idx: ScopeIdx) -> Self {
Self {
cur_idx: idx,
change_list: EditMachine::new(bump),
immediate_queue: Vec::new(),
diffed: FxHashSet::default(),
need_to_diff: FxHashSet::default(),
vdom,
}
}
@ -71,6 +78,7 @@ impl<'a> DiffMachine<'a> {
}
pub fn diff_node(&mut self, old: &VNode<'a>, new: &VNode<'a>) {
// pub fn diff_node(&mut self, old: &VNode<'a>, new: &VNode<'a>) {
/*
For each valid case, we "commit traversal", meaning we save this current position in the tree.
Then, we diff and queue an edit event (via chagelist). s single trees - when components show up, we save that traversal and then re-enter later.
@ -120,7 +128,45 @@ impl<'a> DiffMachine<'a> {
todo!("Usage of component VNode not currently supported");
}
(_, VNode::Component(_)) | (VNode::Component(_), _) => {
(_, VNode::Component(new)) => {
// let VComponent {
// props,
// props_type,
// comp,
// caller,
// assigned_scope,
// ..
// } = *new;
// make the component
// let idx = unsafe {
// // let vdom = &mut *self.vdom;
// vdom.insert_with(|f| {
// todo!()
// //
// // create_scoped(caller, props, myidx, parent)
// })
// };
// we have no stable reference to work from
// push the lifecycle event onto the queue
// self.lifecycle_events
// .borrow_mut()
// .push_back(LifecycleEvent {
// event_type: LifecycleType::Mount {
// props: new.props,
// to: self.cur_idx,
// },
// });
// we need to associaote this new component with a scope...
// self.change_list.save_known_root(id)
self.change_list.commit_traversal();
// push the current
}
(VNode::Component(old), _) => {
todo!("Usage of component VNode not currently supported");
}
@ -137,7 +183,8 @@ impl<'a> DiffMachine<'a> {
// [... node]
//
// The change list stack is left unchanged.
fn diff_listeners(&mut self, old: &[Listener<'a>], new: &[Listener<'a>]) {
fn diff_listeners(&mut self, old: &[Listener<'_>], new: &[Listener<'_>]) {
// fn diff_listeners(&mut self, old: &[Listener<'a>], new: &[Listener<'a>]) {
if !old.is_empty() || !new.is_empty() {
self.change_list.commit_traversal();
}

View file

@ -296,11 +296,13 @@ mod vtext {
/// Virtual Components for custom user-defined components
/// Only supports the functional syntax
mod vcomponent {
use crate::innerlude::{Context, FC};
use std::{any::TypeId, marker::PhantomData};
use crate::innerlude::{Context, ScopeIdx, FC};
use std::{any::TypeId, cell::RefCell, marker::PhantomData, rc::Rc};
use super::DomTree;
pub type StableScopeAddres = Rc<RefCell<Option<ScopeIdx>>>;
#[derive(Debug)]
pub struct VComponent<'src> {
_p: PhantomData<&'src ()>,
@ -308,6 +310,11 @@ mod vcomponent {
pub(crate) props_type: TypeId,
pub(crate) comp: *const (),
pub(crate) caller: Caller,
// once a component gets mounted, its parent gets a stable address.
// this way we can carry the scope index from between renders
// genius, really!
pub assigned_scope: StableScopeAddres,
}
pub struct Caller(Box<dyn Fn(Context) -> DomTree>);
@ -323,10 +330,10 @@ mod vcomponent {
// - perform comparisons when diffing (memoization)
// -
pub fn new<P>(comp: FC<P>, props: P) -> Self {
let caller = move |ctx: Context| {
let t = comp(ctx, &props);
t
};
// let caller = move |ctx: Context| {
// let t = comp(ctx, &props);
// t
// };
// let _caller = comp as *const ();
// let _props = Box::new(props);

View file

@ -126,6 +126,7 @@ pub struct EditMachine<'src> {
pub traversal: Traversal,
next_temporary: u32,
forcing_new_listeners: bool,
pub emitter: EditList<'src>,
}
@ -214,10 +215,6 @@ impl<'a> EditMachine<'a> {
debug_assert!(self.traversal_is_committed());
debug_assert!(start < end);
let temp_base = self.next_temporary;
// debug!(
// "emit: save_children_to_temporaries({}, {}, {})",
// temp_base, start, end
// );
self.next_temporary = temp_base + (end - start) as u32;
self.emitter.push(Edit::SaveChildrenToTemporaries {
temp: temp_base,
@ -367,6 +364,11 @@ impl<'a> EditMachine<'a> {
// debug!("emit: remove_event_listener({:?})", event);
}
pub fn save_known_root(&mut self, id: ScopeIdx) {
log::debug!("emit: save_known_root({:?})", id);
self.emitter.push(Edit::MakeKnown { node: id })
}
// pub fn save_template(&mut self, id: CacheId) {
// debug_assert!(self.traversal_is_committed());
// debug_assert!(!self.has_template(id));

View file

@ -12,11 +12,14 @@ use std::{
};
pub trait Properties: PartialEq {}
impl Properties for () {}
// just for now
impl<T: PartialEq> Properties for T {}
pub trait Scoped {
fn run(&mut self);
fn compare_props(&self, new: &dyn std::any::Any) -> bool;
fn call_listener(&mut self, trigger: EventTrigger);
fn new_frame<'bump>(&'bump self) -> &'bump VNode<'bump>;
fn old_frame<'bump>(&'bump self) -> &'bump VNode<'bump>;
}
@ -46,6 +49,7 @@ pub struct Scope<P: Properties> {
// These hooks are actually references into the hook arena
// These two could be combined with "OwningRef" to remove unsafe usage
// or we could dedicate a tiny bump arena just for them
// could also use ourborous
pub hooks: RefCell<Vec<*mut Hook>>,
pub hook_arena: typed_arena::Arena<Hook>,
@ -95,8 +99,51 @@ pub fn create_scoped<P: Properties + 'static>(
}
impl<P: Properties + 'static> Scoped for Scope<P> {
fn run(&mut self) {
self.run()
/// Create a new context and run the component with references from the Virtual Dom
/// This function downcasts the function pointer based on the stored props_type
///
/// Props is ?Sized because we borrow the props and don't need to know the size. P (sized) is used as a marker (unsized)
fn run<'bump>(&'bump mut self) {
let frame = {
let frame = self.frames.next();
frame.bump.reset();
frame
};
let node_slot = std::rc::Rc::new(RefCell::new(None));
let ctx: Context<'bump> = Context {
arena: &self.hook_arena,
hooks: &self.hooks,
bump: &frame.bump,
idx: 0.into(),
_p: PhantomData {},
final_nodes: node_slot.clone(),
scope: self.myidx,
listeners: &self.listeners,
};
// Note that the actual modification of the vnode head element occurs during this call
// let _: DomTree = caller(ctx, props);
let _: DomTree = (self.caller)(ctx, &self.props);
/*
SAFETY ALERT
DO NOT USE THIS VNODE WITHOUT THE APPOPRIATE ACCESSORS.
KEEPING THIS STATIC REFERENCE CAN LEAD TO UB.
Some things to note:
- The VNode itself is bound to the lifetime, but it itself is owned by scope.
- The VNode has a private API and can only be used from accessors.
- Public API cannot drop or destructure VNode
*/
frame.head_node = node_slot
.deref()
.borrow_mut()
.take()
.expect("Viewing did not happen");
}
fn compare_props(&self, new: &Any) -> bool {
@ -145,103 +192,10 @@ impl<P: Properties + 'static> Scoped for Scope<P> {
}
}
impl<P: Properties> Scope<P> {
/// Create a new context and run the component with references from the Virtual Dom
/// This function downcasts the function pointer based on the stored props_type
///
/// Props is ?Sized because we borrow the props and don't need to know the size. P (sized) is used as a marker (unsized)
pub fn run<'bump>(&'bump mut self) {
// pub fn run<'bump, PLocked: Sized + 'static>(&'bump mut self) {
let frame = {
let frame = self.frames.next();
frame.bump.reset();
frame
};
let node_slot = std::rc::Rc::new(RefCell::new(None));
let ctx: Context<'bump> = Context {
arena: &self.hook_arena,
hooks: &self.hooks,
bump: &frame.bump,
idx: 0.into(),
_p: PhantomData {},
final_nodes: node_slot.clone(),
scope: self.myidx,
listeners: &self.listeners,
};
// unsafe {
/*
SAFETY ALERT
This particular usage of transmute is outlined in its docs https://doc.rust-lang.org/std/mem/fn.transmute.html
We hide the generic bound on the function item by casting it to raw pointer. When the function is actually called,
we transmute the function back using the props as reference.
we could do a better check to make sure that the TypeID is correct before casting
--
This is safe because we check that the generic type matches before casting.
*/
// we use plocked to be able to remove the borrowed lifetime
// these lifetimes could be very broken, so we need to dynamically manage them
// let caller = std::mem::transmute::<*const (), FC<PLocked>>(self.caller);
// let props = self.props.downcast_ref::<PLocked>().unwrap();
let caller = self.caller;
let props = &self.props;
// Note that the actual modification of the vnode head element occurs during this call
let _: DomTree = caller(ctx, props);
/*
SAFETY ALERT
DO NOT USE THIS VNODE WITHOUT THE APPOPRIATE ACCESSORS.
KEEPING THIS STATIC REFERENCE CAN LEAD TO UB.
Some things to note:
- The VNode itself is bound to the lifetime, but it itself is owned by scope.
- The VNode has a private API and can only be used from accessors.
- Public API cannot drop or destructure VNode
*/
// the nodes we care about have been unsafely extended to a static lifetime in context
frame.head_node = node_slot
.deref()
.borrow_mut()
.take()
.expect("Viewing did not happen");
// }
}
}
fn retrieve_listeners(node: &VNode<'static>, listeners: &mut Vec<&Listener>) {
if let VNode::Element(el) = *node {
for listener in el.listeners {
// let g = listener as *const Listener;
listeners.push(listener);
}
for child in el.children {
retrieve_listeners(child, listeners);
}
}
}
// ==========================
// Active-frame related code
// ==========================
// impl<P: Properties> Scope<P> {
// /// Accessor to get the root node and its children (safely)\
// /// Scope is self-referntial, so we are forced to use the 'static lifetime to cheat
// pub fn new_frame<'bump>(&'bump self) -> &'bump VNode<'bump> {
// self.frames.current_head_node()
// }
// pub fn old_frame<'bump>(&'bump self) -> &'bump VNode<'bump> {
// self.frames.prev_head_node()
// }
// }
// todo, do better with the active frame stuff
// somehow build this vnode with a lifetime tied to self
// This root node has "static" lifetime, but it's really not static.

View file

@ -1,7 +1,10 @@
// use crate::{changelist::EditList, nodes::VNode};
use crate::scope::{create_scoped, Scoped};
use crate::{innerlude::*, scope::Properties};
use crate::{
patch::Edit,
scope::{create_scoped, Scoped},
};
use bumpalo::Bump;
use generational_arena::Arena;
use std::{
@ -25,19 +28,31 @@ pub struct VirtualDom {
/// like a generational typemap bump arena
/// -> IE a cache line for each P type with soem heuristics on optimizing layout
pub(crate) components: Arena<Box<dyn Scoped>>,
// pub(crate) components: Rc<RefCell<Arena<Box<dyn Scoped>>>>,
/// The index of the root component.
/// Will not be ready if the dom is fresh
base_scope: ScopeIdx,
event_queue: RefCell<VecDeque<LifecycleEvent>>,
// todo: encapsulate more state into this so we can better reuse it
diff_bump: Bump,
pub(crate) base_scope: ScopeIdx,
// Type of the original props. This is done so VirtualDom does not need to be generic.
#[doc(hidden)]
_root_prop_type: std::any::TypeId,
// ======================
// DIFF RELATED ITEMs
// ======================
// // todo: encapsulate more state into this so we can better reuse it
pub(crate) diff_bump: Bump,
// // be very very very very very careful
// pub change_list: EditMachine<'static>,
// // vdom: &'a VirtualDom,
// vdom: *mut Arena<Box<dyn Scoped>>,
// // vdom: Rc<RefCell<Arena<Box<dyn Scoped>>>>,
// pub cur_idx: ScopeIdx,
// // todo
// // do an indexmap sorted by height
// dirty_nodes: fxhash::FxHashSet<ScopeIdx>,
}
impl VirtualDom {
@ -57,51 +72,53 @@ impl VirtualDom {
pub fn new_with_props<P: Properties + 'static>(root: FC<P>, root_props: P) -> Self {
let mut components = Arena::new();
let event_queue = RefCell::new(VecDeque::new());
// Create a reference to the component in the arena
// Note: we are essentially running the "Mount" lifecycle event manually while the vdom doesnt yet exist
// This puts the dom in a usable state on creation, rather than being potentially invalid
let base_scope = components.insert_with(|id| create_scoped(root, root_props, id, None));
// evaluate the component, pushing any updates its generates into the lifecycle queue
// todo!
let _root_prop_type = TypeId::of::<P>();
let diff_bump = Bump::new();
Self {
components,
base_scope,
event_queue,
diff_bump,
_root_prop_type,
}
todo!()
// Self {
// // components: RefCell::new(components),
// components: components,
// // components: Rc::new(RefCell::new(components)),
// base_scope,
// // event_queue: RefCell::new(VecDeque::new()),
// diff_bump: Bump::new(),
// _root_prop_type: TypeId::of::<P>(),
// }
}
/// Performs a *full* rebuild of the virtual dom, returning every edit required to generate the actual dom.
///
///
pub fn rebuild(&mut self) -> Result<EditList<'_>> {
// pub fn rebuild<'s>(&'s mut self) -> Result<> {
// pub fn rebuild<'s>(&'s mut self) -> Result<std::cell::Ref<'_, Arena<Box<dyn Scoped>>>> {
pub fn rebuild<'s>(&'s mut self) -> Result<EditList<'s>> {
// Reset and then build a new diff machine
// The previous edit list cannot be around while &mut is held
// Make sure variance doesnt break this
self.diff_bump.reset();
let mut diff_machine = DiffMachine::new(&self.diff_bump);
// this is still a WIP
// we'll need to re-fecth all the scopes that were changed and build the diff machine
// fetch the component again
let component = self
.components
self.components
.get_mut(self.base_scope)
.expect("Root should always exist");
.expect("Root should always exist")
.run();
component.run();
let b = Bump::new();
diff_machine.diff_node(component.old_frame(), component.new_frame());
let mut diff_machine = DiffMachine::new(self, &b, self.base_scope);
// let mut diff_machine = DiffMachine::new(self, &self.diff_bump, self.base_scope);
Ok(diff_machine.consume())
todo!()
// let component = self.components.get(self.base_scope).unwrap();
// diff_machine.diff_node(component.old_frame(), component.new_frame());
// let edits = diff_machine.consume();
// self.diff_bump = b;
// Ok(edits)
}
/// This method is the most sophisticated way of updating the virtual dom after an external event has been triggered.
@ -129,23 +146,32 @@ impl VirtualDom {
///
/// ```
pub fn progress_with_event(&mut self, event: EventTrigger) -> Result<EditList<'_>> {
let component = self
.components
.get_mut(event.component_id)
.expect("Component should exist if an event was triggered");
// self.components
// .borrow_mut()
// .get_mut(event.component_id)
// .map(|f| {
// f.call_listener(event);
// f
// })
// .map(|f| f.run())
// .expect("Borrowing should not fail");
component.call_listener(event);
// component.call_listener(event);
// .expect("Component should exist if an event was triggered");
// Reset and then build a new diff machine
// The previous edit list cannot be around while &mut is held
// Make sure variance doesnt break this
self.diff_bump.reset();
let mut diff_machine = DiffMachine::new(&self.diff_bump);
// self.diff_bump.reset();
// let mut diff_machine = DiffMachine::new(&mut self, event.component_id);
// let mut diff_machine =
// DiffMachine::new(&self.diff_bump, &mut self.components, event.component_id);
component.run();
diff_machine.diff_node(component.old_frame(), component.new_frame());
// component.run();
// diff_machine.diff_node(component.old_frame(), component.new_frame());
Ok(diff_machine.consume())
todo!()
// Ok(diff_machine.consume())
// Err(crate::error::Error::NoEvent)
// Mark dirty components. Descend from the highest node until all dirty nodes are updated.
// let mut affected_components = Vec::new();
@ -159,115 +185,8 @@ impl VirtualDom {
// todo!()
}
/// Using mutable access to the Virtual Dom, progress a given lifecycle event
fn process_lifecycle(&mut self, LifecycleEvent { event_type }: LifecycleEvent) -> Result<()> {
match event_type {
// Component needs to be mounted to the virtual dom
LifecycleType::Mount {
to: _,
under: _,
props: _,
} => {}
// The parent for this component generated new props and the component needs update
LifecycleType::PropsChanged {
props: _,
component: _,
} => {}
// Component was messaged via the internal subscription service
LifecycleType::Callback { component: _ } => {}
}
Ok(())
}
/// Pop the top event of the internal lifecycle event queu
pub fn pop_event(&self) -> Option<LifecycleEvent> {
self.event_queue.borrow_mut().pop_front()
}
/// With access to the virtual dom, schedule an update to the Root component's props.
/// This generates the appropriate Lifecycle even. It's up to the renderer to actually feed this lifecycle event
/// back into the event system to get an edit list.
/// todo
/// change this to accept a modification closure, so the user gets 0-cost access to the props item.
/// Good for cases where the props is changed remotely (or something similar) and building a whole new props item would
/// be wasteful
pub fn update_props<P: 'static>(
&mut self,
updater: impl FnOnce(&mut P),
) -> Result<LifecycleEvent> {
todo!()
// // pub fn update_props<P: 'static>(&mut self, new_props: P) -> Result<LifecycleEvent> {
// // Ensure the props match
// if TypeId::of::<P>() != self._root_prop_type {
// return Err(Error::WrongProps);
// }
// Ok(LifecycleEvent {
// event_type: LifecycleType::PropsChanged {
// props: Box::new(new_props),
// component: self.base_scope,
// },
// })
}
}
pub struct LifecycleEvent {
pub event_type: LifecycleType,
}
pub enum LifecycleType {
// Component needs to be mounted, but its scope doesn't exist yet
Mount {
to: ScopeIdx,
under: usize,
props: Box<dyn std::any::Any>,
},
// Parent was evalauted causing new props to generate
PropsChanged {
props: Box<dyn std::any::Any>,
component: ScopeIdx,
},
// Hook for the subscription API
Callback {
component: ScopeIdx,
},
}
impl LifecycleEvent {
fn index(&self) -> Option<ScopeIdx> {
match &self.event_type {
LifecycleType::Mount {
to: _,
under: _,
props: _,
} => None,
LifecycleType::PropsChanged { component, .. }
| LifecycleType::Callback { component } => Some(component.clone()),
}
}
}
mod tests {
use super::*;
#[test]
fn start_dom() {
let mut dom = VirtualDom::new(|ctx, props| {
todo!()
// ctx.render(|ctx| {
// use crate::builder::*;
// let bump = ctx.bump();
// div(bump).child(text("hello, world")).finish()
// })
});
let edits = dom.rebuild().unwrap();
println!("{:#?}", edits);
}
}
// struct LockedEdits<'src> {
// edits:
// }