From 4cbc32a98b88fd6d18d6263151eac23d54e65d54 Mon Sep 17 00:00:00 2001
From: Liu Ye Dong <yed.liu@gmail.com>
Date: Wed, 20 Jun 2018 03:51:31 +0800
Subject: [PATCH] Reduce memory (#433)

* Make EpoxyModelGroup.Holder static

* Clear oldStateList and oldStateMap to release old models

* Make EpoxyModelGroup.Holder static

* Make EpoxyModelGroup.Holder static
---
 .../java/com/airbnb/epoxy/DiffHelper.java     |  7 +++++++
 .../com/airbnb/epoxy/EpoxyModelGroup.java     | 20 ++++++++++++++++---
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/epoxy-adapter/src/main/java/com/airbnb/epoxy/DiffHelper.java b/epoxy-adapter/src/main/java/com/airbnb/epoxy/DiffHelper.java
index 286daae801..865d448573 100755
--- a/epoxy-adapter/src/main/java/com/airbnb/epoxy/DiffHelper.java
+++ b/epoxy-adapter/src/main/java/com/airbnb/epoxy/DiffHelper.java
@@ -189,9 +189,16 @@ private UpdateOpHelper buildDiff(UpdateOpHelper updateOpHelper) {
     collectMoves(updateOpHelper);
     collectChanges(updateOpHelper);
 
+    resetOldState();
+
     return updateOpHelper;
   }
 
+  private void resetOldState() {
+    oldStateList.clear();
+    oldStateMap.clear();
+  }
+
   private void prepareStateForDiff() {
     // We use a list of the models as well as a map by their id,
     // so we can easily find them by both position and id
diff --git a/epoxy-adapter/src/main/java/com/airbnb/epoxy/EpoxyModelGroup.java b/epoxy-adapter/src/main/java/com/airbnb/epoxy/EpoxyModelGroup.java
index 774abe20d3..1d77079633 100644
--- a/epoxy-adapter/src/main/java/com/airbnb/epoxy/EpoxyModelGroup.java
+++ b/epoxy-adapter/src/main/java/com/airbnb/epoxy/EpoxyModelGroup.java
@@ -301,14 +301,22 @@ protected boolean useViewStubLayoutParams(EpoxyModel<?> model, int modelPosition
 
   @Override
   protected final Holder createNewHolder() {
-    return new Holder();
+    return new Holder(this);
   }
 
-  public class Holder extends EpoxyHolder {
+  public static class Holder extends EpoxyHolder {
+    // Hold it for `bindView`, clear it after `bindView` be called
+    private EpoxyModelGroup modelGroup;
+    private List<? extends EpoxyModel<?>> models;
     private List<View> views;
     private List<EpoxyHolder> holders;
     private ViewGroup rootView;
 
+    public Holder(@NonNull EpoxyModelGroup modelGroup) {
+      this.modelGroup = modelGroup;
+      this.models = modelGroup.models;
+    }
+
     /**
      * Get the root view group (aka
      * {@link android.support.v7.widget.RecyclerView.ViewHolder#itemView}.
@@ -337,7 +345,8 @@ protected void bindView(View itemView) {
         EpoxyModel model = models.get(i);
         View view;
         if (useViewStubs) {
-          view = replaceNextViewStub(childContainer, model, useViewStubLayoutParams(model, i));
+          view = replaceNextViewStub(childContainer, model,
+              modelGroup.useViewStubLayoutParams(model, i));
         } else {
           view = createAndAddView(childContainer, model);
         }
@@ -352,6 +361,11 @@ protected void bindView(View itemView) {
 
         views.add(view);
       }
+
+      // Clear the reference, because of `EpoxyController.buildModels`
+      // will build new modelGroup instance during every call.
+      modelGroup = null;
+      models = null;
     }
 
     /**