Fix ClassCastException in QuickstepModelDelegate

- Added a casting check as an immediate fix to b/173838775
- Added logging to help debug the corrupt state where an item of type other than FolderInfo is used as an other item's container.
- Added LoaderMemoryLogger for adding large logs that are only conditionally printed.

Bug: 173838775
Test: manually checked logs
Change-Id: I9491cb421b9fb807d5fb110b04ad069481de768f
diff --git a/quickstep/src/com/android/launcher3/model/QuickstepModelDelegate.java b/quickstep/src/com/android/launcher3/model/QuickstepModelDelegate.java
index e82c900..f9a0bb1 100644
--- a/quickstep/src/com/android/launcher3/model/QuickstepModelDelegate.java
+++ b/quickstep/src/com/android/launcher3/model/QuickstepModelDelegate.java
@@ -161,8 +161,7 @@
             }
             InstanceId instanceId = new InstanceIdSequence().newInstanceId();
             for (ItemInfo info : itemsIdMap) {
-                FolderInfo parent = info.container > 0
-                        ? (FolderInfo) itemsIdMap.get(info.container) : null;
+                FolderInfo parent = getContainer(info, itemsIdMap);
                 StatsLogCompatManager.writeSnapshot(info.buildProto(parent), instanceId);
             }
             additionalSnapshotEvents(instanceId);
@@ -199,8 +198,7 @@
                         }
 
                         for (ItemInfo info : itemsIdMap) {
-                            FolderInfo parent = info.container > 0
-                                    ? (FolderInfo) itemsIdMap.get(info.container) : null;
+                            FolderInfo parent = getContainer(info, itemsIdMap);
                             LauncherAtom.ItemInfo itemInfo = info.buildProto(parent);
                             Log.d(TAG, itemInfo.toString());
                             StatsEvent statsEvent = StatsLogCompatManager.buildStatsEvent(itemInfo,
@@ -222,6 +220,22 @@
         }
     }
 
+    private static FolderInfo getContainer(ItemInfo info, IntSparseArrayMap<ItemInfo> itemsIdMap) {
+        if (info.container > 0) {
+            ItemInfo containerInfo = itemsIdMap.get(info.container);
+
+            if (!(containerInfo instanceof FolderInfo)) {
+                Log.e(TAG, String.format(
+                        "Item info: %s found with invalid container: %s",
+                        info,
+                        containerInfo));
+            } else {
+                return (FolderInfo) containerInfo;
+            }
+        }
+        return null;
+    }
+
     @Override
     public void validateData() {
         super.validateData();
diff --git a/src/com/android/launcher3/model/BgDataModel.java b/src/com/android/launcher3/model/BgDataModel.java
index 13ad90e..d3351dc 100644
--- a/src/com/android/launcher3/model/BgDataModel.java
+++ b/src/com/android/launcher3/model/BgDataModel.java
@@ -31,6 +31,8 @@
 import android.util.ArraySet;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import com.android.launcher3.LauncherSettings;
 import com.android.launcher3.LauncherSettings.Favorites;
 import com.android.launcher3.Workspace;
@@ -215,6 +217,19 @@
     }
 
     public synchronized void addItem(Context context, ItemInfo item, boolean newItem) {
+        addItem(context, item, newItem, null);
+    }
+
+    public synchronized void addItem(
+            Context context, ItemInfo item, boolean newItem, @Nullable LoaderMemoryLogger logger) {
+        if (logger != null) {
+            logger.addLog(
+                    Log.DEBUG,
+                    TAG,
+                    String.format("Adding item to ID map: %s", item.toString()),
+                    /* stackTrace= */ null);
+        }
+
         itemsIdMap.put(item.id, item);
         switch (item.itemType) {
             case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
diff --git a/src/com/android/launcher3/model/LoaderCursor.java b/src/com/android/launcher3/model/LoaderCursor.java
index 47df538..08b38e8 100644
--- a/src/com/android/launcher3/model/LoaderCursor.java
+++ b/src/com/android/launcher3/model/LoaderCursor.java
@@ -383,18 +383,23 @@
         info.cellY = getInt(cellYIndex);
     }
 
+    public void checkAndAddItem(ItemInfo info, BgDataModel dataModel) {
+        checkAndAddItem(info, dataModel, null);
+    }
+
     /**
      * Adds the {@param info} to {@param dataModel} if it does not overlap with any other item,
      * otherwise marks it for deletion.
      */
-    public void checkAndAddItem(ItemInfo info, BgDataModel dataModel) {
+    public void checkAndAddItem(
+            ItemInfo info, BgDataModel dataModel, LoaderMemoryLogger logger) {
         if (info.itemType == LauncherSettings.Favorites.ITEM_TYPE_DEEP_SHORTCUT) {
             // Ensure that it is a valid intent. An exception here will
             // cause the item loading to get skipped
             ShortcutKey.fromItemInfo(info);
         }
         if (checkItemPlacement(info)) {
-            dataModel.addItem(mContext, info, false);
+            dataModel.addItem(mContext, info, false, logger);
         } else {
             markDeleted("Item position overlap");
         }
diff --git a/src/com/android/launcher3/model/LoaderMemoryLogger.java b/src/com/android/launcher3/model/LoaderMemoryLogger.java
new file mode 100644
index 0000000..f48efcb
--- /dev/null
+++ b/src/com/android/launcher3/model/LoaderMemoryLogger.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.model;
+
+import android.util.Log;
+
+import androidx.annotation.Nullable;
+
+import java.util.ArrayList;
+
+/**
+ * Helper logger that collects logs while {@code LoaderTask#run} executes and prints them all iff
+ * an exception is caught in {@code LoaderTask#run}.
+ */
+public class LoaderMemoryLogger {
+
+    private static final String TAG = "LoaderMemoryLogger";
+
+    private final ArrayList<LogEntry> mLogEntries = new ArrayList<>();
+
+    protected LoaderMemoryLogger() {}
+
+    protected void addLog(int logLevel, String tag, String log) {
+        addLog(logLevel, tag, log, null);
+    }
+
+    protected void addLog(
+            int logLevel, String tag, String log, Exception stackTrace) {
+        switch (logLevel) {
+            case Log.ASSERT:
+            case Log.ERROR:
+            case Log.DEBUG:
+            case Log.INFO:
+            case Log.VERBOSE:
+            case Log.WARN:
+                mLogEntries.add(new LogEntry(logLevel, tag, log, stackTrace));
+                break;
+            default:
+                throw new IllegalArgumentException("Invalid log level provided: " + logLevel);
+
+        }
+    }
+
+    protected void clearLogs() {
+        mLogEntries.clear();
+    }
+
+    protected void printLogs() {
+        for (LogEntry logEntry : mLogEntries) {
+            String tag = String.format("%s: %s", TAG, logEntry.mLogTag);
+            String logString = logEntry.mStackStrace == null
+                    ? logEntry.mLogString
+                    : String.format(
+                            "%s\n%s",
+                            logEntry.mLogString,
+                            Log.getStackTraceString(logEntry.mStackStrace));
+
+            Log.println(logEntry.mLogLevel, tag, logString);
+        }
+        clearLogs();
+    }
+
+    private static class LogEntry {
+
+        protected final int mLogLevel;
+        protected final String mLogTag;
+        protected final String mLogString;
+        @Nullable protected final Exception mStackStrace;
+
+        protected LogEntry(
+                int logLevel, String logTag, String logString, @Nullable Exception stackStrace) {
+            mLogLevel = logLevel;
+            mLogTag = logTag;
+            mLogString = logString;
+            mStackStrace = stackStrace;
+        }
+    }
+}
diff --git a/src/com/android/launcher3/model/LoaderTask.java b/src/com/android/launcher3/model/LoaderTask.java
index a4f6f7a..2a0f9a6 100644
--- a/src/com/android/launcher3/model/LoaderTask.java
+++ b/src/com/android/launcher3/model/LoaderTask.java
@@ -52,6 +52,8 @@
 import android.util.LongSparseArray;
 import android.util.TimingLogger;
 
+import androidx.annotation.Nullable;
+
 import com.android.launcher3.DeviceProfile;
 import com.android.launcher3.InvariantDeviceProfile;
 import com.android.launcher3.LauncherAppState;
@@ -197,11 +199,12 @@
 
         Object traceToken = TraceHelper.INSTANCE.beginSection(TAG);
         TimingLogger logger = new TimingLogger(TAG, "run");
+        LoaderMemoryLogger memoryLogger = new LoaderMemoryLogger();
         try (LauncherModel.LoaderTransaction transaction = mApp.getModel().beginLoader(this)) {
             List<ShortcutInfo> allShortcuts = new ArrayList<>();
             Trace.beginSection("LoadWorkspace");
             try {
-                loadWorkspace(allShortcuts);
+                loadWorkspace(allShortcuts, memoryLogger);
             } finally {
                 Trace.endSection();
             }
@@ -311,9 +314,13 @@
 
             mModelDelegate.modelLoadComplete();
             transaction.commit();
+            memoryLogger.clearLogs();
         } catch (CancellationException e) {
             // Loader stopped, ignore
             logASplit(logger, "Cancelled");
+        } catch (Exception e) {
+            memoryLogger.printLogs();
+            throw e;
         } finally {
             logger.dumpToLog();
         }
@@ -325,13 +332,21 @@
         this.notify();
     }
 
-    private void loadWorkspace(List<ShortcutInfo> allDeepShortcuts) {
+    private void loadWorkspace(List<ShortcutInfo> allDeepShortcuts, LoaderMemoryLogger logger) {
         loadWorkspace(allDeepShortcuts, LauncherSettings.Favorites.CONTENT_URI,
-                null /* selection */);
+                null /* selection */, logger);
     }
 
-    protected void loadWorkspace(List<ShortcutInfo> allDeepShortcuts, Uri contentUri,
-            String selection) {
+    protected void loadWorkspace(
+            List<ShortcutInfo> allDeepShortcuts, Uri contentUri, String selection) {
+        loadWorkspace(allDeepShortcuts, contentUri, selection, null);
+    }
+
+    protected void loadWorkspace(
+            List<ShortcutInfo> allDeepShortcuts,
+            Uri contentUri,
+            String selection,
+            @Nullable LoaderMemoryLogger logger) {
         final Context context = mApp.getContext();
         final ContentResolver contentResolver = context.getContentResolver();
         final PackageManagerHelper pmHelper = new PackageManagerHelper(context);
@@ -635,7 +650,7 @@
                                         }
                                 }
 
-                                c.checkAndAddItem(info, mBgDataModel);
+                                c.checkAndAddItem(info, mBgDataModel, logger);
                             } else {
                                 throw new RuntimeException("Unexpected null WorkspaceItemInfo");
                             }
@@ -654,7 +669,7 @@
                             // no special handling required for restored folders
                             c.markRestored();
 
-                            c.checkAndAddItem(folderInfo, mBgDataModel);
+                            c.checkAndAddItem(folderInfo, mBgDataModel, logger);
                             break;
 
                         case LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET: