refactor(ivy): replace LView.child with TView.childIndex lookup (#24211)

PR Close #24211

packages/core/src/render3/di.ts

@@ -590,7 +590,7 @@ export function getOrCreateContainerRef(di: LInjector): viewEngine_ViewContainer
     lContainerNode.tNode = hostTNode.dynamicContainerNode;
     vcRefHost.dynamicLContainerNode = lContainerNode;
 
-    addToViewTree(vcRefHost.view, lContainer);
+    addToViewTree(vcRefHost.view, hostTNode.index as number, lContainer);
 
     di.viewContainerRef = new ViewContainerRef(lContainerNode);
   }

packages/core/src/render3/instructions.ts

@@ -17,7 +17,7 @@ import {CurrentMatchesList, LView, LViewFlags, LifecycleStage, RootContext, TDat
 
 import {AttributeMarker, TAttributes, LContainerNode, LElementNode, LNode, TNodeType, TNodeFlags, LProjectionNode, LTextNode, LViewNode, TNode, TContainerNode, InitialInputData, InitialInputs, PropertyAliases, PropertyAliasValue, TElementNode,} from './interfaces/node';
 import {assertNodeType} from './node_assert';
-import {appendChild, insertView, appendProjectedNode, removeView, canInsertNativeNode, createTextNode, getNextLNode, getChildLNode, getParentLNode} from './node_manipulation';
+import {appendChild, insertView, appendProjectedNode, removeView, canInsertNativeNode, createTextNode, getNextLNode, getChildLNode, getParentLNode, getLViewChild} from './node_manipulation';
 import {isNodeMatchingSelectorList, matchingSelectorIndex} from './node_selector_matcher';
 import {ComponentDef, ComponentTemplate, DirectiveDef, DirectiveDefList, DirectiveDefListOrFactory, PipeDefList, PipeDefListOrFactory, RenderFlags} from './interfaces/definition';
 import {RElement, RText, Renderer3, RendererFactory3, ProceduralRenderer3, RendererStyleFlags3, isProceduralRenderer} from './interfaces/renderer';
@@ -314,7 +314,6 @@ export function createLView<T>(
     tView: tView,
     cleanup: null,
     renderer: renderer,
-    child: null,
     tail: null,
     next: null,
     bindingStartIndex: -1,
@@ -802,6 +801,7 @@ export function createTView(
   return {
     node: null !,
     data: [],
+    childIndex: -1,  // Children set in addToViewTree(), if any
     directives: null,
     firstTemplatePass: true,
     initHooks: null,
@@ -1329,11 +1329,12 @@ function addComponentLogic<T>(index: number, instance: T, def: ComponentDef<T>):
   // Only component views should be added to the view tree directly. Embedded views are
   // accessed through their containers because they may be removed / re-added later.
   const hostView = addToViewTree(
-      currentView, createLView(
-                       -1, rendererFactory.createRenderer(
-                               previousOrParentNode.native as RElement, def.rendererType),
-                       tView, null, null, def.onPush ? LViewFlags.Dirty : LViewFlags.CheckAlways,
-                       getCurrentSanitizer()));
+      currentView, previousOrParentNode.tNode.index as number,
+      createLView(
+          -1,
+          rendererFactory.createRenderer(previousOrParentNode.native as RElement, def.rendererType),
+          tView, null, null, def.onPush ? LViewFlags.Dirty : LViewFlags.CheckAlways,
+          getCurrentSanitizer()));
 
   // We need to set the host node/data here because when the component LNode was created,
   // we didn't yet know it was a component (just an element).
@@ -1512,7 +1513,7 @@ export function container(
 
   // Containers are added to the current view tree instead of their embedded views
   // because views can be removed and re-inserted.
-  addToViewTree(currentView, node.data);
+  addToViewTree(currentView, index, node.data);
   createDirectivesAndLocals(localRefs);
 
   isParent = false;
@@ -1574,7 +1575,7 @@ export function containerRefreshEnd(): void {
 }
 
 function refreshDynamicChildren() {
-  for (let current = currentView.child; current !== null; current = current.next) {
+  for (let current = getLViewChild(currentView); current !== null; current = current.next) {
     // Note: current can be a LView or a LContainer, but here we are only interested in LContainer.
     // The distinction is made because nextIndex and views do not exist on LView.
     if (isLContainer(current)) {
@@ -1921,11 +1922,18 @@ function findComponentHost(lView: LView): LElementNode {
  * and call onDestroy callbacks.
  *
  * @param currentView The view where LView or LContainer should be added
+ * @param hostIndex Index of the view's host node in data[]
  * @param state The LView or LContainer to add to the view tree
  * @returns The state passed in
  */
-export function addToViewTree<T extends LView|LContainer>(currentView: LView, state: T): T {
-  currentView.tail ? (currentView.tail.next = state) : (currentView.child = state);
+export function addToViewTree<T extends LView|LContainer>(
+    currentView: LView, hostIndex: number, state: T): T {
+  // TODO(kara): move next and tail properties off of LView
+  if (currentView.tail) {
+    currentView.tail.next = state;
+  } else if (firstTemplatePass) {
+    currentView.tView.childIndex = hostIndex;
+  }
   currentView.tail = state;
   return state;
 }

packages/core/src/render3/interfaces/view.ts

@@ -112,17 +112,6 @@ export interface LView {
    */
   lifecycleStage: LifecycleStage;
 
-  /**
-   * The first LView or LContainer beneath this LView in the hierarchy.
-   *
-   * Necessary to store this so views can traverse through their nested views
-   * to remove listeners and call onDestroy callbacks.
-   *
-   * For embedded views, we store the LContainer rather than the first ViewState
-   * to avoid managing splicing when views are added/removed.
-   */
-  child: LView|LContainer|null;
-
   /**
    * The last LView or LContainer beneath this LView in the hierarchy.
    *
@@ -222,8 +211,8 @@ export const enum LViewFlags {
 /** Interface necessary to work with view tree traversal */
 export interface LViewOrLContainer {
   next: LView|LContainer|null;
-  child?: LView|LContainer|null;
   views?: LViewNode[];
+  tView?: TView;
   parent: LView|null;
 }
 
@@ -251,6 +240,18 @@ export interface TView {
   /** Static data equivalent of LView.data[]. Contains TNodes. */
   data: TData;
 
+  /**
+   * Index of the host node of the first LView or LContainer beneath this LView in
+   * the hierarchy.
+   *
+   * Necessary to store this so views can traverse through their nested views
+   * to remove listeners and call onDestroy callbacks.
+   *
+   * For embedded views, we store the index of an LContainer's host rather than the first
+   * LView to avoid managing splicing when views are added/removed.
+   */
+  childIndex: number;
+
   /**
    * Selector matches for a node are temporarily cached on the TView so the
    * DI system can eagerly instantiate directives on the same node if they are

packages/core/src/render3/node_manipulation.ts

@@ -261,19 +261,19 @@ export function addRemoveViewFromContainer(
  *  @param rootView The view to destroy
  */
 export function destroyViewTree(rootView: LView): void {
-  // A view to cleanup doesn't have children so we should not try to descend down the view tree.
-  if (!rootView.child) {
+  // If the view has no children, we can clean it up and return early.
+  if (rootView.tView.childIndex === -1) {
     return cleanUpView(rootView);
   }
-  let viewOrContainer: LViewOrLContainer|null = rootView.child;
+  let viewOrContainer: LViewOrLContainer|null = getLViewChild(rootView);
 
   while (viewOrContainer) {
     let next: LViewOrLContainer|null = null;
 
     if (viewOrContainer.views && viewOrContainer.views.length) {
       next = viewOrContainer.views[0].data;
-    } else if (viewOrContainer.child) {
-      next = viewOrContainer.child;
+    } else if (viewOrContainer.tView && viewOrContainer.tView.childIndex > -1) {
+      next = getLViewChild(viewOrContainer as LView);
     } else if (viewOrContainer.next) {
       // Only move to the side and clean if operating below rootView -
       // otherwise we would start cleaning up sibling views of the rootView.
@@ -383,6 +383,15 @@ export function removeView(container: LContainerNode, removeIndex: number): LVie
   return viewNode;
 }
 
+/** Gets the child of the given LView */
+export function getLViewChild(view: LView): LView|LContainer|null {
+  if (view.tView.childIndex === -1) return null;
+
+  const hostNode: LElementNode|LContainerNode = view.data[view.tView.childIndex];
+
+  return hostNode.data ? hostNode.data : (hostNode.dynamicLContainerNode as LContainerNode).data;
+}
+
 /**
  * Determines which LViewOrLContainer to jump to when traversing back up the
  * tree in destroyViewTree.

packages/core/test/bundling/hello_world/bundle.golden_symbols.json

@@ -107,6 +107,9 @@
   {
     "name": "getDirectiveInstance"
   },
+  {
+    "name": "getLViewChild"
+  },
   {
     "name": "getOrCreateTView"
   },

packages/core/test/bundling/todo/bundle.golden_symbols.json

@@ -389,6 +389,9 @@
   {
     "name": "getDirectiveInstance"
   },
+  {
+    "name": "getLViewChild"
+  },
   {
     "name": "getNextLNode"
   },