dioxus/packages/core/src/diff.rs
2022-11-15 18:32:48 -08:00

667 lines
25 KiB
Rust

use std::any::Any;
use crate::factory::RenderReturn;
use crate::innerlude::Mutations;
use crate::virtual_dom::VirtualDom;
use crate::{Attribute, AttributeValue, TemplateNode};
use crate::any_props::VComponentProps;
use crate::mutations::Mutation;
use crate::nodes::{DynamicNode, Template, TemplateId};
use crate::scopes::Scope;
use crate::{
any_props::AnyProps,
arena::ElementId,
bump_frame::BumpFrame,
nodes::VNode,
scopes::{ScopeId, ScopeState},
};
use fxhash::{FxHashMap, FxHashSet};
use slab::Slab;
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct DirtyScope {
pub height: u32,
pub id: ScopeId,
}
impl PartialOrd for DirtyScope {
fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
Some(self.height.cmp(&other.height))
}
}
impl Ord for DirtyScope {
fn cmp(&self, other: &Self) -> std::cmp::Ordering {
self.height.cmp(&other.height)
}
}
impl<'b> VirtualDom {
pub fn diff_scope(&mut self, mutations: &mut Mutations<'b>, scope: ScopeId) {
let scope_state = &mut self.scopes[scope.0];
let cur_arena = scope_state.current_frame();
let prev_arena = scope_state.previous_frame();
// relax the borrow checker
let cur_arena: &BumpFrame = unsafe { std::mem::transmute(cur_arena) };
let prev_arena: &BumpFrame = unsafe { std::mem::transmute(prev_arena) };
// Make sure the nodes arent null (they've been set properly)
assert_ne!(
cur_arena.node.get(),
std::ptr::null_mut(),
"Call rebuild before diffing"
);
assert_ne!(
prev_arena.node.get(),
std::ptr::null_mut(),
"Call rebuild before diffing"
);
self.scope_stack.push(scope);
let left = unsafe { prev_arena.load_node() };
let right = unsafe { cur_arena.load_node() };
self.diff_maybe_node(mutations, left, right);
self.scope_stack.pop();
}
fn diff_maybe_node(
&mut self,
m: &mut Mutations<'b>,
left: &'b RenderReturn<'b>,
right: &'b RenderReturn<'b>,
) {
use RenderReturn::{Async, Sync};
match (left, right) {
// diff
(Sync(Some(l)), Sync(Some(r))) => self.diff_node(m, l, r),
// remove old with placeholder
(Sync(Some(l)), Sync(None)) | (Sync(Some(l)), Async(_)) => {
//
let id = self.next_element(l); // todo!
m.push(Mutation::CreatePlaceholder { id });
self.drop_template(m, l, true);
}
// remove placeholder with nodes
(Sync(None), Sync(Some(_))) => {}
(Async(_), Sync(Some(v))) => {}
// nothing...
(Async(_), Async(_))
| (Sync(None), Sync(None))
| (Sync(None), Async(_))
| (Async(_), Sync(None)) => {}
}
}
pub fn diff_node(
&mut self,
muts: &mut Mutations<'b>,
left_template: &'b VNode<'b>,
right_template: &'b VNode<'b>,
) {
if left_template.template.id != right_template.template.id {
// do a light diff of the roots nodes.
return;
}
for (_idx, (left_attr, right_attr)) in left_template
.dynamic_attrs
.iter()
.zip(right_template.dynamic_attrs.iter())
.enumerate()
{
debug_assert!(left_attr.name == right_attr.name);
debug_assert!(left_attr.value == right_attr.value);
// Move over the ID from the old to the new
right_attr
.mounted_element
.set(left_attr.mounted_element.get());
if left_attr.value != right_attr.value {
let value = "todo!()";
muts.push(Mutation::SetAttribute {
id: left_attr.mounted_element.get(),
name: left_attr.name,
value,
});
}
}
for (idx, (left_node, right_node)) in left_template
.dynamic_nodes
.iter()
.zip(right_template.dynamic_nodes.iter())
.enumerate()
{
#[rustfmt::skip]
match (left_node, right_node) {
(DynamicNode::Component { props: lprops, .. }, DynamicNode::Component { static_props: is_static , props: rprops, .. }) => {
let left_props = unsafe { &mut *lprops.get()};
let right_props = unsafe { &mut *rprops.get()};
// Ensure these two props are of the same component type
match left_props.as_ptr() == right_props.as_ptr() {
true => {
//
if *is_static {
let props_are_same = unsafe { left_props.memoize(right_props) };
if props_are_same{
//
} else {
//
}
} else {
}
},
false => todo!(),
}
//
},
// Make sure to drop the component properly
(DynamicNode::Component { .. }, right) => {
// remove all the component roots except for the first
// replace the first with the new node
let m = self.create_dynamic_node(muts, right_template, right, idx);
todo!()
},
(DynamicNode::Text { id: lid, value: lvalue, .. }, DynamicNode::Text { id: rid, value: rvalue, .. }) => {
rid.set(lid.get());
if lvalue != rvalue {
muts.push(Mutation::SetText {
id: lid.get(),
value: rvalue,
});
}
},
(DynamicNode::Text { id: lid, .. }, right) => {
let m = self.create_dynamic_node(muts, right_template, right, idx);
muts.push(Mutation::ReplaceWith { id: lid.get(), m });
}
(DynamicNode::Placeholder(_), DynamicNode::Placeholder(_)) => todo!(),
(DynamicNode::Placeholder(_), _) => todo!(),
(DynamicNode::Fragment { nodes: lnodes, ..}, DynamicNode::Fragment { nodes: rnodes, ..}) => {
// match (old, new) {
// ([], []) => rp.set(lp.get()),
// ([], _) => {
// //
// todo!()
// },
// (_, []) => {
// todo!()
// },
// _ => {
// let new_is_keyed = new[0].key.is_some();
// let old_is_keyed = old[0].key.is_some();
// debug_assert!(
// new.iter().all(|n| n.key.is_some() == new_is_keyed),
// "all siblings must be keyed or all siblings must be non-keyed"
// );
// debug_assert!(
// old.iter().all(|o| o.key.is_some() == old_is_keyed),
// "all siblings must be keyed or all siblings must be non-keyed"
// );
// if new_is_keyed && old_is_keyed {
// self.diff_keyed_children(muts, old, new);
// } else {
// self.diff_non_keyed_children(muts, old, new);
// }
// }
// }
},
// Make sure to drop all the fragment children properly
(DynamicNode::Fragment { .. }, right) => todo!(),
};
}
}
// Diff children that are not keyed.
//
// The parent must be on the top of the change list stack when entering this
// function:
//
// [... parent]
//
// the change list stack is in the same state when this function returns.
fn diff_non_keyed_children(
&mut self,
muts: &mut Mutations<'b>,
old: &'b [VNode<'b>],
new: &'b [VNode<'b>],
) {
use std::cmp::Ordering;
// Handled these cases in `diff_children` before calling this function.
debug_assert!(!new.is_empty());
debug_assert!(!old.is_empty());
match old.len().cmp(&new.len()) {
Ordering::Greater => self.remove_nodes(muts, &old[new.len()..]),
Ordering::Less => todo!(),
// Ordering::Less => self.create_and_insert_after(&new[old.len()..], old.last().unwrap()),
Ordering::Equal => {}
}
for (new, old) in new.iter().zip(old.iter()) {
self.diff_node(muts, old, new);
}
}
// Diffing "keyed" children.
//
// With keyed children, we care about whether we delete, move, or create nodes
// versus mutate existing nodes in place. Presumably there is some sort of CSS
// transition animation that makes the virtual DOM diffing algorithm
// observable. By specifying keys for nodes, we know which virtual DOM nodes
// must reuse (or not reuse) the same physical DOM nodes.
//
// This is loosely based on Inferno's keyed patching implementation. However, we
// have to modify the algorithm since we are compiling the diff down into change
// list instructions that will be executed later, rather than applying the
// changes to the DOM directly as we compare virtual DOMs.
//
// https://github.com/infernojs/inferno/blob/36fd96/packages/inferno/src/DOM/patching.ts#L530-L739
//
// The stack is empty upon entry.
fn diff_keyed_children(
&mut self,
muts: &mut Mutations<'b>,
old: &'b [VNode<'b>],
new: &'b [VNode<'b>],
) {
// if cfg!(debug_assertions) {
// let mut keys = fxhash::FxHashSet::default();
// let mut assert_unique_keys = |children: &'b [VNode<'b>]| {
// keys.clear();
// for child in children {
// let key = child.key;
// debug_assert!(
// key.is_some(),
// "if any sibling is keyed, all siblings must be keyed"
// );
// keys.insert(key);
// }
// debug_assert_eq!(
// children.len(),
// keys.len(),
// "keyed siblings must each have a unique key"
// );
// };
// assert_unique_keys(old);
// assert_unique_keys(new);
// }
// // First up, we diff all the nodes with the same key at the beginning of the
// // children.
// //
// // `shared_prefix_count` is the count of how many nodes at the start of
// // `new` and `old` share the same keys.
// let (left_offset, right_offset) = match self.diff_keyed_ends(muts, old, new) {
// Some(count) => count,
// None => return,
// };
// // Ok, we now hopefully have a smaller range of children in the middle
// // within which to re-order nodes with the same keys, remove old nodes with
// // now-unused keys, and create new nodes with fresh keys.
// let old_middle = &old[left_offset..(old.len() - right_offset)];
// let new_middle = &new[left_offset..(new.len() - right_offset)];
// debug_assert!(
// !((old_middle.len() == new_middle.len()) && old_middle.is_empty()),
// "keyed children must have the same number of children"
// );
// if new_middle.is_empty() {
// // remove the old elements
// self.remove_nodes(muts, old_middle);
// } else if old_middle.is_empty() {
// // there were no old elements, so just create the new elements
// // we need to find the right "foothold" though - we shouldn't use the "append" at all
// if left_offset == 0 {
// // insert at the beginning of the old list
// let foothold = &old[old.len() - right_offset];
// self.create_and_insert_before(new_middle, foothold);
// } else if right_offset == 0 {
// // insert at the end the old list
// let foothold = old.last().unwrap();
// self.create_and_insert_after(new_middle, foothold);
// } else {
// // inserting in the middle
// let foothold = &old[left_offset - 1];
// self.create_and_insert_after(new_middle, foothold);
// }
// } else {
// self.diff_keyed_middle(muts, old_middle, new_middle);
// }
}
// /// Diff both ends of the children that share keys.
// ///
// /// Returns a left offset and right offset of that indicates a smaller section to pass onto the middle diffing.
// ///
// /// If there is no offset, then this function returns None and the diffing is complete.
// fn diff_keyed_ends(
// &mut self,
// muts: &mut Renderer<'b>,
// old: &'b [VNode<'b>],
// new: &'b [VNode<'b>],
// ) -> Option<(usize, usize)> {
// let mut left_offset = 0;
// for (old, new) in old.iter().zip(new.iter()) {
// // abort early if we finally run into nodes with different keys
// if old.key != new.key {
// break;
// }
// self.diff_node(muts, old, new);
// left_offset += 1;
// }
// // If that was all of the old children, then create and append the remaining
// // new children and we're finished.
// if left_offset == old.len() {
// self.create_and_insert_after(&new[left_offset..], old.last().unwrap());
// return None;
// }
// // And if that was all of the new children, then remove all of the remaining
// // old children and we're finished.
// if left_offset == new.len() {
// self.remove_nodes(muts, &old[left_offset..]);
// return None;
// }
// // if the shared prefix is less than either length, then we need to walk backwards
// let mut right_offset = 0;
// for (old, new) in old.iter().rev().zip(new.iter().rev()) {
// // abort early if we finally run into nodes with different keys
// if old.key != new.key {
// break;
// }
// self.diff_node(muts, old, new);
// right_offset += 1;
// }
// Some((left_offset, right_offset))
// }
// // The most-general, expensive code path for keyed children diffing.
// //
// // We find the longest subsequence within `old` of children that are relatively
// // ordered the same way in `new` (via finding a longest-increasing-subsequence
// // of the old child's index within `new`). The children that are elements of
// // this subsequence will remain in place, minimizing the number of DOM moves we
// // will have to do.
// //
// // Upon entry to this function, the change list stack must be empty.
// //
// // This function will load the appropriate nodes onto the stack and do diffing in place.
// //
// // Upon exit from this function, it will be restored to that same self.
// #[allow(clippy::too_many_lines)]
// fn diff_keyed_middle(
// &mut self,
// muts: &mut Renderer<'b>,
// old: &'b [VNode<'b>],
// new: &'b [VNode<'b>],
// ) {
// /*
// 1. Map the old keys into a numerical ordering based on indices.
// 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(|i| i.key), old.first().map(|i| i.key));
// debug_assert_ne!(new.last().map(|i| i.key), old.last().map(|i| i.key));
// // 1. Map the old keys into a numerical ordering based on indices.
// // 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 old_key_to_old_index = old
// .iter()
// .enumerate()
// .map(|(i, o)| (o.key.unwrap(), i))
// .collect::<FxHashMap<_, _>>();
// let mut shared_keys = FxHashSet::default();
// // 3. Map each new key to the old key, carrying over the old index.
// let new_index_to_old_index = new
// .iter()
// .map(|node| {
// let key = node.key.unwrap();
// if let Some(&index) = old_key_to_old_index.get(&key) {
// shared_keys.insert(key);
// index
// } else {
// u32::MAX as usize
// }
// })
// .collect::<Vec<_>>();
// // 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.
// if shared_keys.is_empty() {
// if let Some(first_old) = old.get(0) {
// self.remove_nodes(muts, &old[1..]);
// let nodes_created = self.create_children(new);
// self.replace_inner(first_old, nodes_created);
// } else {
// // I think this is wrong - why are we appending?
// // only valid of the if there are no trailing elements
// self.create_and_append_children(new);
// }
// return;
// }
// // remove any old children that are not shared
// // todo: make this an iterator
// for child in old {
// let key = child.key.unwrap();
// if !shared_keys.contains(&key) {
// todo!("remove node");
// // self.remove_nodes(muts, [child]);
// }
// }
// // 4. Compute the LIS of this list
// let mut lis_sequence = Vec::default();
// lis_sequence.reserve(new_index_to_old_index.len());
// let mut predecessors = vec![0; new_index_to_old_index.len()];
// let mut starts = vec![0; new_index_to_old_index.len()];
// longest_increasing_subsequence::lis_with(
// &new_index_to_old_index,
// &mut lis_sequence,
// |a, b| a < b,
// &mut predecessors,
// &mut starts,
// );
// // the lis comes out backwards, I think. can't quite tell.
// lis_sequence.sort_unstable();
// // if a new node gets u32 max and is at the end, then it might be part of our LIS (because u32 max is a valid LIS)
// if lis_sequence.last().map(|f| new_index_to_old_index[*f]) == Some(u32::MAX as usize) {
// lis_sequence.pop();
// }
// for idx in &lis_sequence {
// self.diff_node(muts, &old[new_index_to_old_index[*idx]], &new[*idx]);
// }
// let mut nodes_created = 0;
// // add mount instruction for the first items not covered by the lis
// let last = *lis_sequence.last().unwrap();
// if last < (new.len() - 1) {
// for (idx, new_node) in new[(last + 1)..].iter().enumerate() {
// let new_idx = idx + last + 1;
// let old_index = new_index_to_old_index[new_idx];
// if old_index == u32::MAX as usize {
// nodes_created += self.create(muts, new_node);
// } else {
// self.diff_node(muts, &old[old_index], new_node);
// nodes_created += self.push_all_real_nodes(new_node);
// }
// }
// self.mutations.insert_after(
// self.find_last_element(&new[last]).unwrap(),
// nodes_created as u32,
// );
// nodes_created = 0;
// }
// // for each spacing, generate a mount instruction
// let mut lis_iter = lis_sequence.iter().rev();
// let mut last = *lis_iter.next().unwrap();
// for next in lis_iter {
// if last - next > 1 {
// for (idx, new_node) in new[(next + 1)..last].iter().enumerate() {
// let new_idx = idx + next + 1;
// let old_index = new_index_to_old_index[new_idx];
// if old_index == u32::MAX as usize {
// nodes_created += self.create(muts, new_node);
// } else {
// self.diff_node(muts, &old[old_index], new_node);
// nodes_created += self.push_all_real_nodes(new_node);
// }
// }
// self.mutations.insert_before(
// self.find_first_element(&new[last]).unwrap(),
// nodes_created as u32,
// );
// nodes_created = 0;
// }
// last = *next;
// }
// // add mount instruction for the last items not covered by the lis
// let first_lis = *lis_sequence.first().unwrap();
// if first_lis > 0 {
// for (idx, new_node) in new[..first_lis].iter().enumerate() {
// let old_index = new_index_to_old_index[idx];
// if old_index == u32::MAX as usize {
// nodes_created += self.create_node(new_node);
// } else {
// self.diff_node(muts, &old[old_index], new_node);
// nodes_created += self.push_all_real_nodes(new_node);
// }
// }
// self.mutations.insert_before(
// self.find_first_element(&new[first_lis]).unwrap(),
// nodes_created as u32,
// );
// }
// }
/// Remove these nodes from the dom
/// Wont generate mutations for the inner nodes
fn remove_nodes(&mut self, muts: &mut Mutations<'b>, nodes: &'b [VNode<'b>]) {
//
}
}
// /// Lightly diff the two templates and apply their edits to the dom
// fn light_diff_template_roots(
// &'a mut self,
// mutations: &mut Vec<Mutation<'a>>,
// left: &VNode,
// right: &VNode,
// ) {
// match right.template.roots.len().cmp(&left.template.roots.len()) {
// std::cmp::Ordering::Less => {
// // remove the old nodes at the end
// }
// std::cmp::Ordering::Greater => {
// // add the extra nodes.
// }
// std::cmp::Ordering::Equal => {}
// }
// for (left_node, right_node) in left.template.roots.iter().zip(right.template.roots.iter()) {
// if let (TemplateNode::Dynamic(lidx), TemplateNode::Dynamic(ridx)) =
// (left_node, right_node)
// {
// let left_node = &left.dynamic_nodes[*lidx];
// let right_node = &right.dynamic_nodes[*ridx];
// // match (left_node, right_node) {
// // (
// // DynamicNode::Component {
// // name,
// // can_memoize,
// // props,
// // },
// // DynamicNode::Component {
// // name,
// // can_memoize,
// // props,
// // },
// // ) => todo!(),
// // (
// // DynamicNode::Component {
// // name,
// // can_memoize,
// // props,
// // },
// // DynamicNode::Fragment { children },
// // ) => todo!(),
// // (
// // DynamicNode::Fragment { children },
// // DynamicNode::Component {
// // name,
// // can_memoize,
// // props,
// // },
// // ) => todo!(),
// // _ => {}
// // }
// }
// }
// }