wip: basic creates working properly

This commit is contained in:
Jonathan Kelley committed 2021-08-21 23:04:34 -04:00
1 parent 24572b63de
commit 1622f484b3
4 files changed
+237 -149

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+189 -133
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@@ -35,6 +35,19 @@
//! Other implementations either don't support fragments or use a "child + sibling" pattern to represent them. Our code is
//! vastly simpler and more performant when we can just create a placeholder element while the fragment has no children.
//!
//! ### Suspense
//! ------------
//! Dioxus implements suspense slightly differently than React. In React, each fiber is manually progressed until it runs
//! into a promise-like value. React will then work on the next "ready" fiber, checking back on the previous fiber once
//! it has finished its new work. In Dioxus, we use a similar approach, but try to completely render the tree before
//! switching sub-fibers. Instead, each future is submitted into a futures-queue and the node is manually loaded later on.
//!
//! We're able to use this approach because we use placeholder nodes - futures that aren't ready still get submitted to
//! DOM, but as a placeholder.
//!
//! Right now, the "suspense" queue is intertwined the hooks. In the future, we should allow any future to drive attributes
//! and contents, without the need for the "use_suspense" hook. For now, this is the quickest way to get suspense working.
//!
//! ## Subtree Memoization
//! -----------------------
//! We also employ "subtree memoization" which saves us from having to check trees which take no dynamic content. We can
@@ -121,6 +134,12 @@ pub enum DiffInstruction<'a> {
},
DiffChildren {
old: &'a [VNode<'a>],
new: &'a [VNode<'a>],
},
// diff two lists of equally sized children
DiffEqual {
progress: usize,
old: &'a [VNode<'a>],
new: &'a [VNode<'a>],
@@ -128,19 +147,29 @@ pub enum DiffInstruction<'a> {
Create {
node: &'a VNode<'a>,
and: MountType<'a>,
},
CreateChildren {
progress: usize,
children: &'a [VNode<'a>],
and: MountType<'a>,
},
// todo: merge this into the create instruction?
Append,
InsertAfter,
InsertBefore,
Replace {
with: usize,
Mount {
and: MountType<'a>,
},
PopScope,
}
#[derive(Debug, Clone, Copy)]
pub enum MountType<'a> {
Absorb,
Append,
Replace { old: &'a VNode<'a> },
InsertAfter { other_node: &'a VNode<'a> },
InsertBefore { other_node: &'a VNode<'a> },
}
impl<'bump> DiffMachine<'bump> {
@@ -178,63 +207,109 @@ impl<'bump> DiffMachine<'bump> {
///
/// This method implements a depth-first iterative tree traversal.
///
/// We do depth-first to maintain high cache locality (nodes were originally generated recursively) and because we
/// only need a stack (not a queue) of lists
/// We do depth-first to maintain high cache locality (nodes were originally generated recursively).
pub async fn work(&mut self) -> Result<()> {
// todo: don't move the reused instructions around
// defer to individual functions so the compiler produces better code
// large functions tend to be difficult for the compiler to work with
while let Some(instruction) = self.instructions.last_mut() {
log::debug!("Handling diff instruction: {:?}", instruction);
// todo: call this less frequently, there is a bit of overhead involved
yield_now().await;
match instruction {
DiffInstruction::PopScope => {
self.instructions.pop();
self.scope_stack.pop();
}
DiffInstruction::DiffNode { old, new, .. } => {
let (old, new) = (*old, *new);
self.instructions.pop();
self.diff_node(old, new);
}
// this is slightly more complicated, we need to find a way to pause our LIS code
DiffInstruction::DiffChildren { progress, old, new } => {
todo!()
}
DiffInstruction::DiffEqual { progress, old, new } => {
debug_assert_eq!(old.len(), new.len());
DiffInstruction::Create { node, .. } => {
let node = *node;
self.instructions.pop();
self.create_node(node);
}
DiffInstruction::CreateChildren { progress, children } => {
if let Some(child) = children.get(*progress) {
if let (Some(old_child), Some(new_child)) =
(old.get(*progress), new.get(*progress))
{
*progress += 1;
self.create_node(child);
self.diff_node(old_child, new_child);
} else {
self.instructions.pop();
}
}
DiffInstruction::Append => {
let many = self.nodes_created_stack.pop().unwrap();
self.edit_append_children(many as u32);
// this is slightly more complicated, we need to find a way to pause our LIS code
DiffInstruction::DiffChildren { old, new } => {
let (old, new) = (*old, *new);
self.instructions.pop();
self.diff_children(old, new);
}
DiffInstruction::Replace { with } => {
let with = *with;
let many = self.nodes_created_stack.pop().unwrap();
self.edit_replace_with(with as u32, many as u32);
DiffInstruction::Create { node, and } => {
let (node, and) = (*node, *and);
self.instructions.pop();
self.nodes_created_stack.push(0);
self.instructions.push(DiffInstruction::Mount { and });
self.create_node(node);
}
DiffInstruction::InsertAfter => {
let n = self.nodes_created_stack.pop().unwrap();
self.edit_insert_after(n as u32);
self.instructions.pop();
DiffInstruction::CreateChildren {
progress,
children,
and,
} => {
let and = *and;
if *progress == 0 {
self.nodes_created_stack.push(0);
}
if let Some(child) = children.get(*progress) {
*progress += 1;
if *progress == children.len() {
self.instructions.pop();
self.instructions.push(DiffInstruction::Mount { and });
}
self.create_node(child);
} else if children.len() == 0 {
self.instructions.pop();
}
}
DiffInstruction::InsertBefore => {
let n = self.nodes_created_stack.pop().unwrap();
self.edit_insert_before(n as u32);
DiffInstruction::Mount { and } => {
let nodes_created = self.nodes_created_stack.pop().unwrap();
match and {
// add the nodes from this virtual list to the parent
// used by fragments and components
MountType::Absorb => {
*self.nodes_created_stack.last_mut().unwrap() += nodes_created;
}
MountType::Append => {
self.edit_append_children(nodes_created as u32);
}
MountType::Replace { old } => {
todo!()
// self.edit_replace_with(with as u32, many as u32);
}
MountType::InsertAfter { other_node } => {
self.edit_insert_after(nodes_created as u32);
}
MountType::InsertBefore { other_node } => {
self.edit_insert_before(nodes_created as u32);
}
}
self.instructions.pop();
}
};
@@ -292,7 +367,9 @@ impl<'bump> DiffMachine<'bump> {
let real_id = self.vdom.reserve_node();
self.edit_create_element(tag_name, *namespace, real_id);
*self.nodes_created_stack.last_mut().unwrap() += 1;
dom_id.set(Some(real_id));
let cur_scope = self.current_scope().unwrap();
@@ -307,19 +384,20 @@ impl<'bump> DiffMachine<'bump> {
self.edit_set_attribute(attr);
}
self.instructions.push(DiffInstruction::Append);
self.nodes_created_stack.push(0);
self.instructions.push(DiffInstruction::CreateChildren {
children,
progress: 0,
});
if children.len() > 0 {
self.instructions.push(DiffInstruction::CreateChildren {
children,
progress: 0,
and: MountType::Append,
});
}
}
fn create_fragment_node(&mut self, frag: &'bump VFragment<'bump>) {
self.instructions.push(DiffInstruction::CreateChildren {
children: frag.children,
progress: 0,
and: MountType::Absorb,
});
}
@@ -373,23 +451,18 @@ impl<'bump> DiffMachine<'bump> {
// Take the node that was just generated from running the component
let nextnode = new_component.frames.fin_head();
// // Push the new scope onto the stack
// self.scope_stack.push(new_idx);
// Push the new scope onto the stack
self.scope_stack.push(new_idx);
self.instructions.push(DiffInstruction::PopScope);
// // Run the creation algorithm with this scope on the stack
self.instructions
.push(DiffInstruction::Create { node: nextnode });
// Run the creation algorithm with this scope on the stack
// ?? I think we treat components as framgnets??
self.instructions.push(DiffInstruction::Create {
node: nextnode,
and: MountType::Absorb,
});
// let meta = self.create_vnode(nextnode);
// // pop the scope off the stack
// self.scope_stack.pop();
// if meta.added_to_stack == 0 {
// panic!("Components should *always* generate nodes - even if they fail");
// }
// // Finally, insert this scope as a seen node.
// Finally, insert this scope as a seen node.
self.seen_scopes.insert(new_idx);
}
@@ -641,20 +714,24 @@ impl<'bump> DiffMachine<'bump> {
// If old no anchors are provided, then it's assumed that we can freely append to the parent.
//
// Remember, non-empty lists does not mean that there are real elements, just that there are virtual elements.
//
// Frament nodes cannot generate empty children lists, so we can assume that when a list is empty, it belongs only
// to an element, and appending makes sense.
fn diff_children(&mut self, old: &'bump [VNode<'bump>], new: &'bump [VNode<'bump>]) {
const IS_EMPTY: bool = true;
const IS_NOT_EMPTY: bool = false;
// Remember, fragments can never be empty (they always have a single child)
match (old.is_empty(), new.is_empty()) {
(IS_EMPTY, IS_EMPTY) => {}
// Completely adding new nodes, removing any placeholder if it exists
(IS_EMPTY, IS_NOT_EMPTY) => {
todo!();
// let meta = todo!();
// let meta = self.create_children(new);
// let meta = self.create_children(new);
// self.edit_append_children(meta.added_to_stack);
self.instructions.push(DiffInstruction::CreateChildren {
children: new,
progress: 0,
and: MountType::Append,
});
}
// Completely removing old nodes and putting an anchor in its place
@@ -678,14 +755,11 @@ impl<'bump> DiffMachine<'bump> {
// Replace the anchor with whatever new nodes are coming down the pipe
(VNode::Anchor(anchor), _) => {
self.edit_push_root(anchor.dom_id.get().unwrap());
let mut added = 0;
for el in new {
todo!();
// let meta = self.create_vnode(el);
// added += meta.added_to_stack;
}
self.edit_replace_with(1, added);
self.instructions.push(DiffInstruction::CreateChildren {
children: new,
progress: 0,
and: MountType::Replace { old: first_old },
});
}
// Replace whatever nodes are sitting there with the anchor
@@ -888,53 +962,60 @@ impl<'bump> DiffMachine<'bump> {
shared_suffix_count: usize,
old_shared_suffix_start: usize,
) {
/*
1. Map the old keys into a numerical ordering based on indicies.
2. Create a map of old key to its index
3. Map each new key to the old key, carrying over the old index.
- IE if we have ABCD becomes BACD, our sequence would be 1,0,2,3
- if we have ABCD to ABDE, our sequence would be 0,1,3,MAX because E doesn't exist
now, we should have a list of integers that indicates where in the old list the new items map to.
4. Compute the LIS of this list
- this indicates the longest list of new children that won't need to be moved.
5. Identify which nodes need to be removed
6. Identify which nodes will need to be diffed
7. Going along each item in the new list, create it and insert it before the next closest item in the LIS.
- if the item already existed, just move it to the right place.
8. Finally, generate instructions to remove any old children.
9. Generate instructions to finally diff children that are the same between both
*/
// 0. Debug sanity checks
// Should have already diffed the shared-key prefixes and suffixes.
debug_assert_ne!(new.first().map(|n| n.key()), old.first().map(|o| o.key()));
debug_assert_ne!(new.last().map(|n| n.key()), old.last().map(|o| o.key()));
// // The algorithm below relies upon using `u32::MAX` as a sentinel
// // value, so if we have that many new nodes, it won't work. This
// // check is a bit academic (hence only enabled in debug), since
// // wasm32 doesn't have enough address space to hold that many nodes
// // in memory.
// debug_assert!(new.len() < u32::MAX as usize);
// Map from each `old` node's key to its index within `old`.
// 1. Map the old keys into a numerical ordering based on indicies.
// 2. Create a map of old key to its index
// IE if the keys were A B C, then we would have (A, 1) (B, 2) (C, 3).
let mut old_key_to_old_index = old
let old_key_to_old_index = old
.iter()
.enumerate()
.map(|(i, o)| (o.key().unwrap(), i))
.collect::<FxHashMap<_, _>>();
// The set of shared keys between `new` and `old`.
let mut shared_keys = FxHashSet::default();
// let mut to_remove = FxHashSet::default();
let mut to_add = FxHashSet::default();
// Map from each index in `new` to the index of the node in `old` that
// has the same key.
let mut new_index_to_old_index = new
// 3. Map each new key to the old key, carrying over the old index.
let new_index_to_old_index = new
.iter()
.map(|n| {
let key = n.key().unwrap();
match old_key_to_old_index.get(&key) {
Some(&index) => {
shared_keys.insert(key);
index
}
None => {
//
to_add.insert(key);
u32::MAX as usize
}
if let Some(&index) = old_key_to_old_index.get(&key) {
shared_keys.insert(key);
index
} else {
to_add.insert(key);
u32::MAX as usize
}
})
.collect::<Vec<_>>();
dbg!(&shared_keys);
dbg!(&to_add);
// If none of the old keys are reused by the new children, then we
// remove all the remaining old children and create the new children
// afresh.
@@ -943,23 +1024,7 @@ impl<'bump> DiffMachine<'bump> {
return;
}
// // Remove any old children whose keys were not reused in the new
// // children. Remove from the end first so that we don't mess up indices.
// for old_child in old.iter().rev() {
// if !shared_keys.contains(&old_child.key()) {
// self.remove_child(old_child);
// }
// }
// let old_keyds = old.iter().map(|f| f.key()).collect::<Vec<_>>();
// let new_keyds = new.iter().map(|f| f.key()).collect::<Vec<_>>();
// dbg!(old_keyds);
// dbg!(new_keyds);
// // If there aren't any more new children, then we are done!
// if new.is_empty() {
// return;
// }
// 4. Compute the LIS of this list
// The longest increasing subsequence within `new_index_to_old_index`. This
// is the longest sequence on DOM nodes in `old` that are relatively ordered
@@ -981,16 +1046,11 @@ impl<'bump> DiffMachine<'bump> {
&mut starts,
);
dbg!(&new_index_is_in_lis);
// use the old nodes to navigate the new nodes
let mut lis_in_order = new_index_is_in_lis.into_iter().collect::<Vec<_>>();
lis_in_order.sort_unstable();
dbg!(&lis_in_order);
// we walk front to back, creating the head node
// diff the shared, in-place nodes first
// this makes sure we can rely on their first/last nodes being correct later on
for id in &lis_in_order {
@@ -1016,9 +1076,9 @@ impl<'bump> DiffMachine<'bump> {
let new_anchor = &new[*lis_id];
root = Some(new_anchor);
let anchor_el = self.find_first_element(new_anchor);
self.edit_push_root(anchor_el.direct_id());
// let mut pushed = false;
// let anchor_el = self.find_first_element(new_anchor);
// self.edit_push_root(anchor_el.direct_id());
// // let mut pushed = false;
'inner: loop {
let (next_id, next_new) = new_iter.next().unwrap();
@@ -1044,12 +1104,12 @@ impl<'bump> DiffMachine<'bump> {
self.edit_insert_before(1);
}
} else {
eprintln!("key is not contained {:?}", key);
// new node needs to be created
// insert it before the current milestone
todo!();
// let meta = self.create_vnode(next_new);
// self.edit_insert_before(meta.added_to_stack);
self.instructions.push(DiffInstruction::Create {
node: next_new,
and: MountType::InsertBefore {
other_node: new_anchor,
},
});
}
}
}
@@ -1129,11 +1189,7 @@ impl<'bump> DiffMachine<'bump> {
// [... parent]
//
// the change list stack is in the same state when this function returns.
async fn diff_non_keyed_children(
&mut self,
old: &'bump [VNode<'bump>],
new: &'bump [VNode<'bump>],
) {
fn diff_non_keyed_children(&mut self, old: &'bump [VNode<'bump>], new: &'bump [VNode<'bump>]) {
// Handled these cases in `diff_children` before calling this function.
//
debug_assert!(!new.is_empty());
+3 -4
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@@ -163,9 +163,9 @@ impl VirtualDom {
// // We run the component. If it succeeds, then we can diff it and add the changes to the dom.
if cur_component.run_scope().is_ok() {
diff_machine.nodes_created_stack.push(0);
diff_machine.instructions.push(DiffInstruction::Create {
node: cur_component.frames.fin_head(),
and: MountType::Append,
});
} else {
// todo: should this be a hard error?
@@ -178,6 +178,7 @@ impl VirtualDom {
Ok(diff_machine.mutations)
}
/// Rebuild the dom
pub async fn rebuild_async<'s>(&'s mut self) -> Result<Mutations<'s>> {
let mut diff_machine = DiffMachine::new(Mutations::new(), self.base_scope, &self.shared);
@@ -189,13 +190,11 @@ impl VirtualDom {
// // We run the component. If it succeeds, then we can diff it and add the changes to the dom.
if cur_component.run_scope().is_ok() {
diff_machine.nodes_created_stack.push(0);
diff_machine.instructions.push(DiffInstruction::Create {
node: cur_component.frames.fin_head(),
and: MountType::Append,
});
diff_machine.work().await.unwrap();
let many = diff_machine.nodes_created_stack.pop().unwrap() as u32;
diff_machine.edit_append_children(many);
} else {
// todo: should this be a hard error?
log::warn!(
+45 -10
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@@ -60,7 +60,7 @@ async fn test_iterative_create() {
async fn test_iterative_create_list() {
static App: FC<()> = |cx| {
cx.render(rsx! {
{(0..10).map(|f| rsx!{ div {
{(0..3).map(|f| rsx!{ div {
"hello"
}})}
})
@@ -73,12 +73,47 @@ async fn test_iterative_create_list() {
dbg!(mutations);
}
// #[async_std::test]
// async fn websys_loop() {
// ///loop {
// /// let deadline = request_idle_callback().await;
// /// let edits = dom.work(deadline);
// /// request_animation_frame().await;
// /// apply(edits);
// ///}
// }
#[async_std::test]
async fn test_iterative_create_simple() {
static App: FC<()> = |cx| {
cx.render(rsx! {
div {}
div {}
div {}
div {}
})
};
test_logging::set_up_logging();
let mut dom = VirtualDom::new(App);
let mutations = dom.rebuild_async().await.unwrap();
dbg!(mutations);
}
#[async_std::test]
async fn test_iterative_create_components() {
static App: FC<()> = |cx| {
cx.render(rsx! {
Child { "abc1" }
Child { "abc2" }
Child { "abc3" }
})
};
static Child: FC<()> = |cx| {
cx.render(rsx! {
h1 {}
div {
{cx.children()}
}
p {}
})
};
test_logging::set_up_logging();
let mut dom = VirtualDom::new(App);
let mutations = dom.rebuild_async().await.unwrap();
dbg!(mutations);
}
-2
View File
@@ -44,6 +44,4 @@ pub fn set_up_logging() {
.chain(std::io::stdout())
.apply()
.unwrap();
debug!("finished setting up logging! yay!");
}