From cc3d45d2e9cc701604d27714103cbee49171bcfa Mon Sep 17 00:00:00 2001
From: David Vacca <dvacca@fb.com>
Date: Mon, 19 Mar 2018 18:21:43 -0700
Subject: [PATCH] Add logging to debug Fabric diffing algorithm

Reviewed By: achen1

Differential Revision: D7319185

fbshipit-source-id: fe47c21db5e1415aebe806f0d74b1f65f667a397
---
 .../facebook/react/fabric/FabricReconciler.java  | 16 +++++++++++++++-
 .../facebook/react/fabric/FabricUIManager.java   | 13 ++++++++++++-
 .../facebook/react/uimanager/ViewAtIndex.java    |  5 +++++
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricReconciler.java b/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricReconciler.java
index a4666759c..d60cfdaed 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricReconciler.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricReconciler.java
@@ -7,10 +7,12 @@
 
 package com.facebook.react.fabric;
 
+import android.util.Log;
 import com.facebook.react.common.ArrayUtils;
 import com.facebook.react.uimanager.ReactShadowNode;
 import com.facebook.react.uimanager.UIViewOperationQueue;
 import com.facebook.react.uimanager.ViewAtIndex;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedList;
@@ -20,6 +22,9 @@ import javax.annotation.Nullable;
 
 public class FabricReconciler {
 
+  private static final String TAG = FabricReconciler.class.getSimpleName();
+  private static final boolean DEBUG = true;
+
   private UIViewOperationQueue uiViewOperationQueue;
 
   public FabricReconciler(UIViewOperationQueue uiViewOperationQueue) {
@@ -101,8 +106,17 @@ public class FabricReconciler {
       }
     }
 
+    int[] tagsToDeleteArray = ArrayUtils.copyListToArray(tagsToDelete);
+    if (DEBUG) {
+      Log.d(
+        TAG,
+        "manageChildren.enqueueManageChildren parent: " + parent.getReactTag() +
+          "\n\tIndices2Remove: " + Arrays.toString(indicesToRemove) +
+          "\n\tViews2Add: " + Arrays.toString(viewsToAdd) +
+          "\n\tTags2Delete: " + Arrays.toString(tagsToDeleteArray));
+    }
     uiViewOperationQueue.enqueueManageChildren(
-      parent.getReactTag(), indicesToRemove, viewsToAdd, ArrayUtils.copyListToArray(tagsToDelete));
+      parent.getReactTag(), indicesToRemove, viewsToAdd, tagsToDeleteArray);
   }
 
 }
diff --git a/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java b/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java
index 4820e8496..8fd0dd706 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java
@@ -42,7 +42,8 @@ import javax.annotation.Nullable;
 @SuppressWarnings("unused") // used from JNI
 public class FabricUIManager implements UIManager {
 
-  private static final String TAG = FabricUIManager.class.toString();
+  private static final String TAG = FabricUIManager.class.getSimpleName();
+  private static final boolean DEBUG = true;
   private final RootShadowNodeRegistry mRootShadowNodeRegistry = new RootShadowNodeRegistry();
   private final ReactApplicationContext mReactApplicationContext;
   private final ViewManagerRegistry mViewManagerRegistry;
@@ -225,9 +226,19 @@ public class FabricUIManager implements UIManager {
 
       rootNode = calculateDiffingAndCreateNewRootNode(rootNode, childList);
 
+      if (DEBUG) {
+        Log.d(TAG, "ReactShadowNodeHierarchy after diffing: " + rootNode.getHierarchyInfo());
+      }
+
       notifyOnBeforeLayoutRecursive(rootNode);
       rootNode.calculateLayout();
 
+      if (DEBUG) {
+        Log.d(
+          TAG,
+          "ReactShadowNodeHierarchy after calculate Layout: " + rootNode.getHierarchyInfo());
+      }
+
       applyUpdatesRecursive(rootNode, 0, 0);
       mUIViewOperationQueue.dispatchViewUpdates(
         mCurrentBatch++, System.currentTimeMillis(), System.currentTimeMillis());
diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewAtIndex.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewAtIndex.java
index 6000e0554..ef2a914d3 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewAtIndex.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewAtIndex.java
@@ -28,4 +28,9 @@ public class ViewAtIndex {
     mTag = tag;
     mIndex = index;
   }
+
+  @Override
+  public String toString() {
+    return "[" + mIndex + ", " + mTag + "]";
+  }
 }