Move ShadowNode::getAncestors to ShadowNodeFamily

Summary:
Changelog: [internal]

1. Moves `ShadowNode::getAncestors` to `ShadowNodeFamily`.
2. Exposes shadowNode's family through `ShadowNode::getFamily()`.

# Why?
This is a first step in order to merge `StateCoordinator` into `ShadowNodeFamily` and use it as target for state updates.

Reviewed By: shergin

Differential Revision: D19465188

fbshipit-source-id: b5a3625aa21c040301259de02beedbf97e11f20e

Author: sammy-SC

ReactCommon/fabric/components/root/RootShadowNode.cpp

@@ -47,10 +47,10 @@ RootShadowNode::Unshared RootShadowNode::clone(
 }
 
 RootShadowNode::Unshared RootShadowNode::clone(
-    ShadowNode const &shadowNode,
+    ShadowNodeFamily const &shadowNodeFamily,
     std::function<ShadowNode::Unshared(ShadowNode const &oldShadowNode)>
         callback) const {
-  auto ancestors = shadowNode.getAncestors(*this);
+  auto ancestors = shadowNodeFamily.getAncestors(*this);
 
   if (ancestors.size() == 0) {
     return RootShadowNode::Unshared{nullptr};
@@ -59,7 +59,6 @@ RootShadowNode::Unshared RootShadowNode::clone(
   auto &parent = ancestors.back();
   auto &oldShadowNode = parent.first.get().getChildren().at(parent.second);
 
-  assert(ShadowNode::sameFamily(shadowNode, *oldShadowNode));
   auto newShadowNode = callback(*oldShadowNode);
 
   auto childNode = newShadowNode;

ReactCommon/fabric/components/root/RootShadowNode.h

@@ -55,7 +55,7 @@ class RootShadowNode final
    * Returns `nullptr` if the operation cannot be performed successfully.
    */
   RootShadowNode::Unshared clone(
-      ShadowNode const &shadowNode,
+      ShadowNodeFamily const &shadowNodeFamily,
       std::function<ShadowNode::Unshared(ShadowNode const &oldShadowNode)>
           callback) const;
 

ReactCommon/fabric/core/componentdescriptor/ConcreteComponentDescriptor.h

@@ -17,7 +17,6 @@
 #include <react/core/ShadowNodeFragment.h>
 #include <react/core/State.h>
 #include <react/core/StateCoordinator.h>
-#include <react/core/StateUpdate.h>
 
 namespace facebook {
 namespace react {

ReactCommon/fabric/core/layout/LayoutableShadowNode.cpp

@@ -99,7 +99,7 @@ LayoutMetrics LayoutableShadowNode::getRelativeLayoutMetrics(
     return layoutMetrics;
   }
 
-  auto ancestors = shadowNode.getAncestors(ancestorShadowNode);
+  auto ancestors = shadowNode.getFamily().getAncestors(ancestorShadowNode);
 
   if (ancestors.size() == 0) {
     return EmptyLayoutMetrics;

ReactCommon/fabric/core/shadownode/ShadowNode.cpp

@@ -17,8 +17,6 @@
 namespace facebook {
 namespace react {
 
-using AncestorList = ShadowNode::AncestorList;
-
 SharedShadowNodeSharedList ShadowNode::emptySharedShadowNodeSharedList() {
   static const auto emptySharedShadowNodeSharedList =
       std::make_shared<SharedShadowNodeList>();
@@ -215,44 +213,8 @@ void ShadowNode::setMounted(bool mounted) const {
   family_->eventEmitter_->setEnabled(mounted);
 }
 
-AncestorList ShadowNode::getAncestors(
-    ShadowNode const &ancestorShadowNode) const {
-  auto families = better::small_vector<ShadowNodeFamily const *, 64>{};
-  auto ancestorFamily = ancestorShadowNode.family_.get();
-
-  auto family = family_.get();
-  while (family && family != ancestorFamily) {
-    families.push_back(family);
-    family = family->parent_.lock().get();
-  }
-
-  if (family != ancestorFamily) {
-    return {};
-  }
-
-  auto ancestors = AncestorList{};
-  auto parentNode = &ancestorShadowNode;
-  for (auto it = families.rbegin(); it != families.rend(); it++) {
-    auto childFamily = *it;
-    auto found = false;
-    auto childIndex = 0;
-    for (const auto &childNode : *parentNode->children_) {
-      if (childNode->family_.get() == childFamily) {
-        ancestors.push_back({*parentNode, childIndex});
-        parentNode = childNode.get();
-        found = true;
-        break;
-      }
-      childIndex++;
-    }
-
-    if (!found) {
-      ancestors.clear();
-      return ancestors;
-    }
-  }
-
-  return ancestors;
+ShadowNodeFamily const &ShadowNode::getFamily() const {
+  return *family_;
 }
 
 #pragma mark - DebugStringConvertible

ReactCommon/fabric/core/shadownode/ShadowNode.h

@@ -28,7 +28,6 @@ static constexpr const int kShadowNodeChildrenSmallVectorSize = 8;
 
 class ComponentDescriptor;
 struct ShadowNodeFragment;
-
 class ShadowNode;
 
 using SharedShadowNode = std::shared_ptr<const ShadowNode>;
@@ -127,6 +126,8 @@ class ShadowNode : public virtual Sealable,
 
   void sealRecursive() const;
 
+  ShadowNodeFamily const &getFamily() const;
+
 #pragma mark - Mutating Methods
 
   void appendChild(ShadowNode::Shared const &child);
@@ -142,17 +143,6 @@ class ShadowNode : public virtual Sealable,
    */
   void setMounted(bool mounted) const;
 
-  /*
-   * Returns a list of all ancestors of the node relative to the given ancestor.
-   * The list starts from the given ancestor node and ends with the parent node
-   * of `this` node. The elements of the list have a reference to some parent
-   * node and an index of the child of the parent node.
-   * Returns an empty array if there is no ancestor-descendant relationship.
-   * Can be called from any thread.
-   * The theoretical complexity of the algorithm is `O(ln(n))`. Use it wisely.
-   */
-  AncestorList getAncestors(ShadowNode const &ancestorShadowNode) const;
-
 #pragma mark - DebugStringConvertible
 
 #if RN_DEBUG_STRING_CONVERTIBLE
@@ -175,6 +165,7 @@ class ShadowNode : public virtual Sealable,
   State::Shared state_;
 
  private:
+  friend ShadowNodeFamily;
   /*
    * Clones the list of children (and creates a new `shared_ptr` to it) if
    * `childrenAreShared_` flag is `true`.

ReactCommon/fabric/core/shadownode/ShadowNodeFamily.cpp

@@ -6,12 +6,15 @@
  */
 
 #include "ShadowNodeFamily.h"
+#include "ShadowNode.h"
 
 #include <react/core/ComponentDescriptor.h>
 
 namespace facebook {
 namespace react {
 
+using AncestorList = ShadowNode::AncestorList;
+
 ShadowNodeFamily::ShadowNodeFamily(
     ShadowNodeFamilyFragment const &fragment,
     ComponentDescriptor const &componentDescriptor)
@@ -40,5 +43,45 @@ ComponentName ShadowNodeFamily::getComponentName() const {
   return componentName_;
 }
 
+AncestorList ShadowNodeFamily::getAncestors(
+    ShadowNode const &ancestorShadowNode) const {
+  auto families = better::small_vector<ShadowNodeFamily const *, 64>{};
+  auto ancestorFamily = ancestorShadowNode.family_.get();
+
+  auto family = this;
+  while (family && family != ancestorFamily) {
+    families.push_back(family);
+    family = family->parent_.lock().get();
+  }
+
+  if (family != ancestorFamily) {
+    return {};
+  }
+
+  auto ancestors = AncestorList{};
+  auto parentNode = &ancestorShadowNode;
+  for (auto it = families.rbegin(); it != families.rend(); it++) {
+    auto childFamily = *it;
+    auto found = false;
+    auto childIndex = 0;
+    for (const auto &childNode : *parentNode->children_) {
+      if (childNode->family_.get() == childFamily) {
+        ancestors.push_back({*parentNode, childIndex});
+        parentNode = childNode.get();
+        found = true;
+        break;
+      }
+      childIndex++;
+    }
+
+    if (!found) {
+      ancestors.clear();
+      return ancestors;
+    }
+  }
+
+  return ancestors;
+}
+
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/core/shadownode/ShadowNodeFamily.h

@@ -17,6 +17,7 @@ namespace facebook {
 namespace react {
 
 class ComponentDescriptor;
+class ShadowNode;
 
 /*
  * Represents all things that shadow nodes from the same family have in common.
@@ -27,6 +28,12 @@ class ShadowNodeFamily {
   using Shared = std::shared_ptr<ShadowNodeFamily const>;
   using Weak = std::weak_ptr<ShadowNodeFamily const>;
 
+  using AncestorList = better::small_vector<
+      std::pair<
+          std::reference_wrapper<ShadowNode const> /* parentNode */,
+          int /* childIndex */>,
+      64>;
+
   ShadowNodeFamily(
       ShadowNodeFamilyFragment const &fragment,
       ComponentDescriptor const &componentDescriptor);
@@ -44,6 +51,17 @@ class ShadowNodeFamily {
   ComponentHandle getComponentHandle() const;
   ComponentName getComponentName() const;
 
+  /*
+   * Returns a list of all ancestors of the node relative to the given ancestor.
+   * The list starts from the given ancestor node and ends with the parent node
+   * of `this` node. The elements of the list have a reference to some parent
+   * node and an index of the child of the parent node.
+   * Returns an empty array if there is no ancestor-descendant relationship.
+   * Can be called from any thread.
+   * The theoretical complexity of the algorithm is `O(ln(n))`. Use it wisely.
+   */
+  AncestorList getAncestors(ShadowNode const &ancestorShadowNode) const;
+
  private:
   friend ShadowNode;
 

ReactCommon/fabric/core/state/State.cpp

@@ -12,7 +12,6 @@
 #include <react/core/ShadowNodeFragment.h>
 #include <react/core/State.h>
 #include <react/core/StateTarget.h>
-#include <react/core/StateUpdate.h>
 
 #ifdef ANDROID
 #include <folly/dynamic.h>

ReactCommon/fabric/core/tests/ShadowNodeFamilyTest.cpp

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <exception>
+
+#include <gtest/gtest.h>
+#include "TestComponent.h"
+
+using namespace facebook::react;
+
+TEST(ShadowNodeFamilyTest, sealObjectCorrectly) {
+  /*
+   * The structure:
+   * <A>
+   *  <AA>
+   *    <AAA/>
+   *  </AA>
+   * </A>
+   */
+  SurfaceId surfaceId = 1;
+  auto eventDispatcher = std::shared_ptr<EventDispatcher const>();
+  auto componentDescriptor = TestComponentDescriptor({eventDispatcher});
+  auto props = std::make_shared<const TestProps>();
+
+  auto familyAAA = std::make_shared<ShadowNodeFamily>(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 12,
+          /* .surfaceId = */ surfaceId,
+          /* .eventEmitter = */ nullptr,
+      },
+      componentDescriptor);
+
+  auto nodeAAA = std::make_shared<TestShadowNode>(
+      ShadowNodeFragment{
+          /* .props = */ props,
+          /* .children = */ ShadowNode::emptySharedShadowNodeSharedList(),
+      },
+      familyAAA,
+      ShadowNodeTraits{});
+
+  auto nodeAAChildren =
+      std::make_shared<SharedShadowNodeList>(SharedShadowNodeList{nodeAAA});
+  auto familyAA = std::make_shared<ShadowNodeFamily>(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 11,
+          /* .surfaceId = */ surfaceId,
+          /* .eventEmitter = */ nullptr,
+      },
+      componentDescriptor);
+  auto nodeAA = std::make_shared<TestShadowNode>(
+      ShadowNodeFragment{
+          /* .props = */ props,
+          /* .children = */ nodeAAChildren,
+      },
+      familyAA,
+      ShadowNodeTraits{});
+
+  auto nodeAChildren =
+      std::make_shared<SharedShadowNodeList>(SharedShadowNodeList{nodeAA});
+
+  auto familyA = std::make_shared<ShadowNodeFamily>(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 17,
+          /* .surfaceId = */ surfaceId,
+          /* .eventEmitter = */ nullptr,
+      },
+      componentDescriptor);
+  auto nodeA = std::make_shared<TestShadowNode>(
+      ShadowNodeFragment{
+          /* .props = */ props,
+          /* .children = */ nodeAChildren,
+      },
+      familyA,
+      ShadowNodeTraits{});
+
+  auto familyZ = std::make_shared<ShadowNodeFamily>(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 18,
+          /* .surfaceId = */ surfaceId,
+          /* .eventEmitter = */ nullptr,
+      },
+      componentDescriptor);
+  auto nodeZ = std::make_shared<TestShadowNode>(
+      ShadowNodeFragment{
+          /* .props = */ props,
+          /* .children = */ ShadowNode::emptySharedShadowNodeSharedList(),
+      },
+      familyZ,
+      ShadowNodeTraits{});
+
+  // Negative case:
+  auto ancestors1 = nodeZ->getFamily().getAncestors(*nodeA);
+  EXPECT_EQ(ancestors1.size(), 0);
+
+  // Positive case:
+  auto ancestors2 = nodeAAA->getFamily().getAncestors(*nodeA);
+  EXPECT_EQ(ancestors2.size(), 2);
+  EXPECT_EQ(&ancestors2[0].first.get(), nodeA.get());
+  EXPECT_EQ(&ancestors2[1].first.get(), nodeAA.get());
+}