Merge "Pass both IPv4 and IPv6 DNS servers as tethering DNS forwarders"
diff --git a/core/java/android/app/admin/DevicePolicyManager.java b/core/java/android/app/admin/DevicePolicyManager.java
index 937caf3..faed7a0 100644
--- a/core/java/android/app/admin/DevicePolicyManager.java
+++ b/core/java/android/app/admin/DevicePolicyManager.java
@@ -122,7 +122,10 @@
      * Provisioning adds a managed profile and sets the MDM as the profile owner who has full
      * control over the profile.
      *
-     * In version {@link android.os.Build.VERSION_CODES#LOLLIPOP}, this intent must contain the
+     * <p>It is possible to check if provisioning is allowed or not by querying the method
+     * {@link #isProvisioningAllowed(String)}.
+     *
+     * <p>In version {@link android.os.Build.VERSION_CODES#LOLLIPOP}, this intent must contain the
      * extra {@link #EXTRA_PROVISIONING_DEVICE_ADMIN_PACKAGE_NAME}.
      * As of {@link android.os.Build.VERSION_CODES#M}, it should contain the extra
      * {@link #EXTRA_PROVISIONING_DEVICE_ADMIN_COMPONENT_NAME} instead, although specifying only
@@ -157,9 +160,8 @@
      * been completed. Use {@link #isProvisioningAllowed(String)} to check if provisioning is
      * allowed.
      *
-     * This intent should contain the extra {@link #EXTRA_PROVISIONING_DEVICE_ADMIN_COMPONENT_NAME},
-     * although specifying only {@link #EXTRA_PROVISIONING_DEVICE_ADMIN_PACKAGE_NAME} is also
-     * supported.
+     * <p>This intent should contain the extra
+     * {@link #EXTRA_PROVISIONING_DEVICE_ADMIN_COMPONENT_NAME}.
      *
      * <p> If provisioning fails, the device returns to its previous state.
      *
@@ -185,10 +187,10 @@
      * employee or client.
      *
      * <p> An intent with this action can be sent only on an unprovisioned device.
-     * It is possible to check if the device is provisioned or not by looking at
-     * {@link android.provider.Settings.Global#DEVICE_PROVISIONED}
+     * It is possible to check if provisioning is allowed or not by querying the method
+     * {@link #isProvisioningAllowed(String)}.
      *
-     * The intent contains the following extras:
+     * <p>The intent contains the following extras:
      * <ul>
      * <li>{@link #EXTRA_PROVISIONING_DEVICE_ADMIN_COMPONENT_NAME}</li>
      * <li>{@link #EXTRA_PROVISIONING_SKIP_ENCRYPTION}, optional</li>
@@ -212,6 +214,53 @@
         = "android.app.action.PROVISION_MANAGED_DEVICE";
 
     /**
+     * Activity action: Starts the provisioning flow which sets up a managed device.
+     * Must be started with {@link android.app.Activity#startActivityForResult(Intent, int)}.
+     *
+     * <p>NOTE: This is only supported on split system user devices, and puts the device into a
+     * management state that is distinct from that reached by
+     * {@link #ACTION_PROVISION_MANAGED_DEVICE} - specifically the device owner runs on the system
+     * user, and only has control over device-wide policies, not individual users and their data.
+     * The primary benefit is that multiple non-system users are supported when provisioning using
+     * this form of device management.
+     *
+     * <p> During device owner provisioning a device admin app is set as the owner of the device.
+     * A device owner has full control over the device. The device owner can not be modified by the
+     * user.
+     *
+     * <p> A typical use case would be a device that is owned by a company, but used by either an
+     * employee or client.
+     *
+     * <p> An intent with this action can be sent only on an unprovisioned device.
+     * It is possible to check if provisioning is allowed or not by querying the method
+     * {@link #isProvisioningAllowed(String)}.
+     *
+     * <p>The intent contains the following extras:
+     * <ul>
+     * <li>{@link #EXTRA_PROVISIONING_DEVICE_ADMIN_COMPONENT_NAME}</li>
+     * <li>{@link #EXTRA_PROVISIONING_SKIP_ENCRYPTION}, optional</li>
+     * <li>{@link #EXTRA_PROVISIONING_LEAVE_ALL_SYSTEM_APPS_ENABLED}, optional</li>
+     * <li>{@link #EXTRA_PROVISIONING_ADMIN_EXTRAS_BUNDLE}, optional</li>
+     * </ul>
+     *
+     * <p> When device owner provisioning has completed, an intent of the type
+     * {@link DeviceAdminReceiver#ACTION_PROFILE_PROVISIONING_COMPLETE} is broadcast to the
+     * device owner.
+     *
+     * <p> If provisioning fails, the device is factory reset.
+     *
+     * <p>A result code of {@link android.app.Activity#RESULT_OK} implies that the synchronous part
+     * of the provisioning flow was successful, although this doesn't guarantee the full flow will
+     * succeed. Conversely a result code of {@link android.app.Activity#RESULT_CANCELED} implies
+     * that the user backed-out of provisioning, or some precondition for provisioning wasn't met.
+     *
+     * @hide
+     */
+    @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION)
+    public static final String ACTION_PROVISION_MANAGED_SHAREABLE_DEVICE
+        = "android.app.action.PROVISION_MANAGED_SHAREABLE_DEVICE";
+
+    /**
      * A {@link android.os.Parcelable} extra of type {@link android.os.PersistableBundle} that
      * allows a mobile device management application or NFC programmer application which starts
      * managed provisioning to pass data to the management application instance after provisioning.
diff --git a/packages/DocumentsUI/src/com/android/documentsui/Events.java b/packages/DocumentsUI/src/com/android/documentsui/Events.java
index 49dae3d..1b5b60de 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/Events.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/Events.java
@@ -117,6 +117,8 @@
         public MotionInputEvent(MotionEvent event, RecyclerView view) {
             mEvent = event;
             mView = view;
+
+            // Consider determining position lazily as an optimization.
             View child = mView.findChildViewUnder(mEvent.getX(), mEvent.getY());
             mPosition = (child != null)
                     ? mView.getChildAdapterPosition(child)
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/MultiSelectManager.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/MultiSelectManager.java
index 9eafcc3..65e1a28 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/MultiSelectManager.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/MultiSelectManager.java
@@ -41,10 +41,9 @@
 import android.view.MotionEvent;
 import android.view.View;
 
-import com.android.documentsui.Events;
-import com.android.documentsui.R;
 import com.android.documentsui.Events.InputEvent;
 import com.android.documentsui.Events.MotionInputEvent;
+import com.android.documentsui.R;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -88,9 +87,7 @@
      * @param mode Selection mode
      */
     public MultiSelectManager(final RecyclerView recyclerView, int mode) {
-        this(recyclerView.getAdapter(), mode);
-
-        mEnvironment = new RuntimeSelectionEnvironment(recyclerView);
+        this(recyclerView.getAdapter(), new RuntimeSelectionEnvironment(recyclerView), mode);
 
         if (mode == MODE_MULTIPLE) {
             mBandManager = new BandController();
@@ -137,16 +134,15 @@
 
     /**
      * Constructs a new instance with {@code adapter} and {@code helper}.
+     * @param runtimeSelectionEnvironment
      * @hide
      */
     @VisibleForTesting
-    MultiSelectManager(Adapter<?> adapter, int mode) {
-        checkNotNull(adapter, "'adapter' cannot be null.");
-
+    MultiSelectManager(Adapter<?> adapter, SelectionEnvironment environment, int mode) {
+        mAdapter = checkNotNull(adapter, "'adapter' cannot be null.");
+        mEnvironment = checkNotNull(environment, "'environment' cannot be null.");
         mSingleSelect = mode == MODE_SINGLE;
 
-        mAdapter = adapter;
-
         mAdapter.registerAdapterDataObserver(
                 new AdapterDataObserver() {
 
@@ -880,7 +876,7 @@
         void focusItem(int position);
     }
 
-    /** RvFacade implementation backed by good ol' RecyclerView. */
+    /** Recycler view facade implementation backed by good ol' RecyclerView. */
     private static final class RuntimeSelectionEnvironment implements SelectionEnvironment {
 
         private final RecyclerView mView;
@@ -1960,11 +1956,50 @@
             return false;
         }
 
-        int target = RecyclerView.NO_POSITION;
+        // Here we unpack information from the event and pass it to an more
+        // easily tested method....basically eliminating the need to synthesize
+        // events and views and so on in our tests.
+        int position = findTargetPosition(view, keyCode);
+        if (position == RecyclerView.NO_POSITION) {
+            // If there is no valid navigation target, don't handle the keypress.
+            return false;
+        }
+
+        return attemptChangePosition(position, event.isShiftPressed());
+    }
+
+    @VisibleForTesting
+    boolean attemptChangePosition(int targetPosition, boolean isShiftPressed) {
+        // Focus the new file.
+        mEnvironment.focusItem(targetPosition);
+
+        if (isShiftPressed) {
+            if (!hasSelection()) {
+                // If there is no selection, start a selection when the user presses shift-arrow.
+                toggleSelection(targetPosition);
+            } else if (!mSingleSelect) {
+                mRanger.snapSelection(targetPosition);
+                notifySelectionChanged();
+            } else {
+                // We're in single select and have an existing selection.
+                // Our best guess as to what the user would expect is to advance the selection.
+                clearSelection();
+                toggleSelection(targetPosition);
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Returns the adapter position that the key combo is targeted at.
+     */
+    private int findTargetPosition(View view, int keyCode) {
+        int position = RecyclerView.NO_POSITION;
         if (keyCode == KeyEvent.KEYCODE_MOVE_HOME) {
-            target = 0;
+            position = 0;
         } else if (keyCode == KeyEvent.KEYCODE_MOVE_END) {
-            target = mAdapter.getItemCount() - 1;
+            position = mAdapter.getItemCount() - 1;
         } else {
             // Find a navigation target based on the arrow key that the user pressed.  Ignore
             // navigation targets that aren't items in the recycler view.
@@ -1988,30 +2023,10 @@
                 // TargetView can be null, for example, if the user pressed <down> at the bottom of
                 // the list.
                 if (targetView != null) {
-                    target = mEnvironment.getAdapterPositionForChildView(targetView);
+                    position = mEnvironment.getAdapterPositionForChildView(targetView);
                 }
             }
         }
-
-        if (target == RecyclerView.NO_POSITION) {
-            // If there is no valid navigation target, don't handle the keypress.
-            return false;
-        }
-
-        // Focus the new file.
-        mEnvironment.focusItem(target);
-
-        if (event.isShiftPressed()) {
-            if (!hasSelection()) {
-                // If there is no selection, start a selection when the user presses shift-arrow.
-                toggleSelection(mEnvironment.getAdapterPositionForChildView(view));
-            }
-
-            mRanger.snapSelection(target);
-            notifySelectionChanged();
-        }
-
-        return true;
+        return position;
     }
-
 }
diff --git a/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/MultiSelectManagerTest.java b/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/MultiSelectManagerTest.java
index 24f5c9e..d1ce564 100644
--- a/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/MultiSelectManagerTest.java
+++ b/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/MultiSelectManagerTest.java
@@ -23,7 +23,6 @@
 import android.view.ViewGroup;
 
 import com.android.documentsui.TestInputEvent;
-import com.android.documentsui.dirlist.MultiSelectManager;
 import com.android.documentsui.dirlist.MultiSelectManager.Selection;
 
 import org.mockito.Mockito;
@@ -49,11 +48,13 @@
     private MultiSelectManager mManager;
     private TestAdapter mAdapter;
     private TestCallback mCallback;
+    private TestSelectionEnvironment mEnv;
 
     public void setUp() throws Exception {
         mAdapter = new TestAdapter(items);
         mCallback = new TestCallback();
-        mManager = new MultiSelectManager(mAdapter, MultiSelectManager.MODE_MULTIPLE);
+        mEnv = new TestSelectionEnvironment();
+        mManager = new MultiSelectManager(mAdapter, mEnv, MultiSelectManager.MODE_MULTIPLE);
         mManager.addCallback(mCallback);
     }
 
@@ -171,7 +172,7 @@
     }
 
     public void testSingleSelectMode() {
-        mManager = new MultiSelectManager(mAdapter, MultiSelectManager.MODE_SINGLE);
+        mManager = new MultiSelectManager(mAdapter, mEnv, MultiSelectManager.MODE_SINGLE);
         mManager.addCallback(mCallback);
         longPress(20);
         tap(13);
@@ -179,13 +180,21 @@
     }
 
     public void testSingleSelectMode_ShiftTap() {
-        mManager = new MultiSelectManager(mAdapter, MultiSelectManager.MODE_SINGLE);
+        mManager = new MultiSelectManager(mAdapter, mEnv, MultiSelectManager.MODE_SINGLE);
         mManager.addCallback(mCallback);
         longPress(13);
         shiftTap(20);
         assertSelection(20);
     }
 
+    public void testSingleSelectMode_ShiftDoesNotExtendSelection() {
+        mManager = new MultiSelectManager(mAdapter, mEnv, MultiSelectManager.MODE_SINGLE);
+        mManager.addCallback(mCallback);
+        longPress(20);
+        keyToPosition(22, true);
+        assertSelection(22);
+    }
+
     public void testProvisionalSelection() {
         Selection s = mManager.getSelection();
         assertSelection();
@@ -235,6 +244,10 @@
         mManager.onSingleTapUp(TestInputEvent.shiftClick(position));
     }
 
+    private void keyToPosition(int position, boolean shift) {
+        mManager.attemptChangePosition(position, shift);
+    }
+
     private void assertSelected(int... expected) {
         for (int i = 0; i < expected.length; i++) {
             Selection selection = mManager.getSelection();
@@ -290,11 +303,8 @@
 
     private static final class TestHolder extends RecyclerView.ViewHolder {
         // each data item is just a string in this case
-        public View view;
-        public String string;
         public TestHolder(View view) {
             super(view);
-            this.view = view;
         }
     }
 
diff --git a/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/TestSelectionEnvironment.java b/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/TestSelectionEnvironment.java
new file mode 100644
index 0000000..b4324a8
--- /dev/null
+++ b/packages/DocumentsUI/tests/src/com/android/documentsui/dirlist/TestSelectionEnvironment.java
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2015 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.documentsui.dirlist;
+
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.support.v7.widget.RecyclerView.OnScrollListener;
+import android.view.View;
+
+import com.android.documentsui.dirlist.MultiSelectManager.SelectionEnvironment;
+
+public class TestSelectionEnvironment implements SelectionEnvironment {
+
+    @Override
+    public void showBand(Rect rect) {
+    }
+
+    @Override
+    public void hideBand() {
+    }
+
+    @Override
+    public void addOnScrollListener(OnScrollListener listener) {
+    }
+
+    @Override
+    public void removeOnScrollListener(OnScrollListener listener) {
+    }
+
+    @Override
+    public void scrollBy(int dy) {
+    }
+
+    @Override
+    public int getHeight() {
+        return 0;
+    }
+
+    @Override
+    public void invalidateView() {
+    }
+
+    @Override
+    public void runAtNextFrame(Runnable r) {
+    }
+
+    @Override
+    public void removeCallback(Runnable r) {
+    }
+
+    @Override
+    public Point createAbsolutePoint(Point relativePoint) {
+        return null;
+    }
+
+    @Override
+    public Rect getAbsoluteRectForChildViewAt(int index) {
+        return null;
+    }
+
+    @Override
+    public int getAdapterPositionAt(int index) {
+        return 0;
+    }
+
+    @Override
+    public int getAdapterPositionForChildView(View view) {
+        return 0;
+    }
+
+    @Override
+    public int getColumnCount() {
+        return 0;
+    }
+
+    @Override
+    public int getRowCount() {
+        return 0;
+    }
+
+    @Override
+    public int getChildCount() {
+        return 0;
+    }
+
+    @Override
+    public int getVisibleChildCount() {
+        return 0;
+    }
+
+    @Override
+    public void focusItem(int position) {
+    }
+}
diff --git a/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java
index 0f31e2c..e3be534 100644
--- a/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java
+++ b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java
@@ -16,22 +16,20 @@
 
 package com.android.mtp;
 
+import static com.android.mtp.MtpDatabaseConstants.*;
+
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.res.Resources;
 import android.database.Cursor;
-import android.database.DatabaseUtils;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteOpenHelper;
-import android.database.sqlite.SQLiteQueryBuilder;
 import android.mtp.MtpObjectInfo;
 import android.provider.DocumentsContract.Document;
 import android.provider.DocumentsContract.Root;
-import android.util.Log;
 
 import com.android.internal.annotations.VisibleForTesting;
 
-import java.util.Objects;
+import java.util.HashMap;
+import java.util.Map;
 
 /**
  * Database for MTP objects.
@@ -46,182 +44,76 @@
  * remembers the map of document ID and object handle, and remaps new object handle with document ID
  * by comparing the directory structure and object name.
  *
+ * To start putting documents into the database, the client needs to call
+ * {@link #startAddingChildDocuments(String)} with the parent document ID. Also it needs to call
+ * {@link #stopAddingChildDocuments(String)} after putting all child documents to the database.
+ * (All explanations are same for root documents)
+ *
+ * database.startAddingChildDocuments();
+ * database.putChildDocuments();
+ * database.stopAddingChildDocuments();
+ *
+ * To update the existing documents, the client code can repeat to call the three methods again.
+ * The newly added rows update corresponding existing rows that have same MTP identifier like
+ * objectHandle.
+ *
+ * The client can call putChildDocuments multiple times to add documents by chunk, but it needs to
+ * put all documents under the parent before calling stopAddingChildDocuments. Otherwise missing
+ * documents are regarded as deleted, and will be removed from the database.
+ *
+ * If the client calls clearMtpIdentifier(), it clears MTP identifier in the database. In this case,
+ * the database tries to find corresponding rows by using document's name instead of MTP identifier
+ * at the next update cycle.
+ *
  * TODO: Remove @VisibleForTesting annotation when we start to use this class.
  * TODO: Improve performance by SQL optimization.
  */
 @VisibleForTesting
 class MtpDatabase {
-    private static final int VERSION = 1;
-    private static final String NAME = "mtp";
-
-    /**
-     * Table representing documents including root documents.
-     */
-    private static final String TABLE_DOCUMENTS = "Documents";
-
-    /**
-     * Table containing additional information only available for root documents.
-     * The table uses same primary keys with corresponding documents.
-     */
-    private static final String TABLE_ROOT_EXTRA = "RootExtra";
-
-    /**
-     * View to join Documents and RootExtra tables to provide roots information.
-     */
-    private static final String VIEW_ROOTS = "Roots";
-
-    static final String COLUMN_DEVICE_ID = "device_id";
-    static final String COLUMN_STORAGE_ID = "storage_id";
-    static final String COLUMN_OBJECT_HANDLE = "object_handle";
-    static final String COLUMN_PARENT_DOCUMENT_ID = "parent_document_id";
-    static final String COLUMN_ROW_STATE = "row_state";
-
-    /**
-     * The state represents that the row has a valid object handle.
-     */
-    static final int ROW_STATE_MAPPED = 0;
-
-    /**
-     * The state represents that the object handle was cleared because the MTP session closed.
-     * External application can still fetch the unmapped documents. If the external application
-     * tries to open an unmapped document, the provider resolves the document with new object handle
-     * ahead.
-     */
-    static final int ROW_STATE_UNMAPPED = 1;
-
-    /**
-     * The state represents the raw has a valid object handle but it may be going to be merged into
-     * another unmapped row. After fetching all documents under the parent, the database tries to
-     * map the mapping document and the unmapped document in order to keep old document ID alive.
-     */
-    static final int ROW_STATE_MAPPING = 2;
-
-    private static final String SELECTION_DOCUMENT_ID = Document.COLUMN_DOCUMENT_ID + " = ?";
-    private static final String SELECTION_ROOT_ID = Root.COLUMN_ROOT_ID + " = ?";
-    private static final String SELECTION_ROOT_DOCUMENTS =
-            COLUMN_DEVICE_ID + " = ? AND " + COLUMN_PARENT_DOCUMENT_ID + " IS NULL";
-    private static final String SELECTION_CHILD_DOCUMENTS = COLUMN_PARENT_DOCUMENT_ID + " = ?";
-
-    static class ParentNotFoundException extends Exception {}
-
-    private static class OpenHelper extends SQLiteOpenHelper {
-        private static final String QUERY_CREATE_DOCUMENTS =
-                "CREATE TABLE " + TABLE_DOCUMENTS + " (" +
-                Document.COLUMN_DOCUMENT_ID +
-                    " INTEGER PRIMARY KEY AUTOINCREMENT," +
-                COLUMN_DEVICE_ID + " INTEGER NOT NULL," +
-                COLUMN_STORAGE_ID + " INTEGER," +
-                COLUMN_OBJECT_HANDLE + " INTEGER," +
-                COLUMN_PARENT_DOCUMENT_ID + " INTEGER," +
-                COLUMN_ROW_STATE + " INTEGER NOT NULL," +
-                Document.COLUMN_MIME_TYPE + " TEXT," +
-                Document.COLUMN_DISPLAY_NAME + " TEXT NOT NULL," +
-                Document.COLUMN_SUMMARY + " TEXT," +
-                Document.COLUMN_LAST_MODIFIED + " INTEGER," +
-                Document.COLUMN_ICON + " INTEGER," +
-                Document.COLUMN_FLAGS + " INTEGER NOT NULL," +
-                Document.COLUMN_SIZE + " INTEGER NOT NULL);";
-
-        private static final String QUERY_CREATE_ROOT_EXTRA =
-                "CREATE TABLE " + TABLE_ROOT_EXTRA + " (" +
-                Root.COLUMN_ROOT_ID + " INTEGER PRIMARY KEY," +
-                Root.COLUMN_FLAGS + " INTEGER NOT NULL," +
-                Root.COLUMN_AVAILABLE_BYTES + " INTEGER NOT NULL," +
-                Root.COLUMN_CAPACITY_BYTES + " INTEGER NOT NULL," +
-                Root.COLUMN_MIME_TYPES + " TEXT NOT NULL);";
-
-        /**
-         * Creates a view to join Documents table and RootExtra table on their primary keys to
-         * provide DocumentContract.Root equivalent information.
-         */
-        private static final String QUERY_CREATE_VIEW_ROOTS =
-                "CREATE VIEW " + VIEW_ROOTS + " AS SELECT " +
-                        TABLE_DOCUMENTS + "." + Document.COLUMN_DOCUMENT_ID + " AS " +
-                                Root.COLUMN_ROOT_ID + "," +
-                        TABLE_ROOT_EXTRA + "." + Root.COLUMN_FLAGS + "," +
-                        TABLE_DOCUMENTS + "." + Document.COLUMN_ICON + " AS " +
-                                Root.COLUMN_ICON + "," +
-                        TABLE_DOCUMENTS + "." + Document.COLUMN_DISPLAY_NAME + " AS " +
-                                Root.COLUMN_TITLE + "," +
-                        TABLE_DOCUMENTS + "." + Document.COLUMN_SUMMARY + " AS " +
-                                Root.COLUMN_SUMMARY + "," +
-                        TABLE_DOCUMENTS + "." + Document.COLUMN_DOCUMENT_ID + " AS " +
-                        Root.COLUMN_DOCUMENT_ID + "," +
-                        TABLE_ROOT_EXTRA + "." + Root.COLUMN_AVAILABLE_BYTES + "," +
-                        TABLE_ROOT_EXTRA + "." + Root.COLUMN_CAPACITY_BYTES + "," +
-                        TABLE_ROOT_EXTRA + "." + Root.COLUMN_MIME_TYPES + "," +
-                        TABLE_DOCUMENTS + "." + COLUMN_ROW_STATE +
-                " FROM " + TABLE_DOCUMENTS + " INNER JOIN " + TABLE_ROOT_EXTRA +
-                " ON " +
-                        COLUMN_PARENT_DOCUMENT_ID + " IS NULL AND " +
-                        TABLE_DOCUMENTS + "." + Document.COLUMN_DOCUMENT_ID +
-                        "=" +
-                        TABLE_ROOT_EXTRA + "." + Root.COLUMN_ROOT_ID;
-
-        public OpenHelper(Context context) {
-            super(context, NAME, null, VERSION);
-        }
-
-        @Override
-        public void onCreate(SQLiteDatabase db) {
-            db.execSQL(QUERY_CREATE_DOCUMENTS);
-            db.execSQL(QUERY_CREATE_ROOT_EXTRA);
-            db.execSQL(QUERY_CREATE_VIEW_ROOTS);
-        }
-
-        @Override
-        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
-            throw new UnsupportedOperationException();
-        }
-    }
-
-    private final SQLiteDatabase mDatabase;
+    private final MtpDatabaseInternal mDatabase;
+    private final Map<String, Integer> mMappingMode = new HashMap<>();
 
     @VisibleForTesting
     MtpDatabase(Context context) {
-        final OpenHelper helper = new OpenHelper(context);
-        mDatabase = helper.getWritableDatabase();
-    }
-
-    @VisibleForTesting
-    static void deleteDatabase(Context context) {
-        SQLiteDatabase.deleteDatabase(context.getDatabasePath(NAME));
+        mDatabase = new MtpDatabaseInternal(context);
     }
 
     @VisibleForTesting
     Cursor queryRoots(String[] columnNames) {
-        return mDatabase.query(
-                VIEW_ROOTS,
-                columnNames,
-                COLUMN_ROW_STATE + " IN (?, ?)",
-                strings(ROW_STATE_MAPPED, ROW_STATE_UNMAPPED),
-                null,
-                null,
-                null);
+        return mDatabase.queryRoots(columnNames);
     }
 
     @VisibleForTesting
     Cursor queryRootDocuments(String[] columnNames) {
-        return mDatabase.query(
-                TABLE_DOCUMENTS,
-                columnNames,
-                COLUMN_ROW_STATE + " IN (?, ?)",
-                strings(ROW_STATE_MAPPED, ROW_STATE_UNMAPPED),
-                null,
-                null,
-                null);
+        return mDatabase.queryRootDocuments(columnNames);
     }
 
     @VisibleForTesting
     Cursor queryChildDocuments(String[] columnNames, String parentDocumentId) {
-        return mDatabase.query(
-                TABLE_DOCUMENTS,
-                columnNames,
-                COLUMN_ROW_STATE + " IN (?, ?) AND " + COLUMN_PARENT_DOCUMENT_ID + " = ?",
-                strings(ROW_STATE_MAPPED, ROW_STATE_UNMAPPED, parentDocumentId),
-                null,
-                null,
-                null);
+        return mDatabase.queryChildDocuments(columnNames, parentDocumentId);
+    }
+
+    @VisibleForTesting
+    void startAddingRootDocuments(int deviceId) {
+        final String mappingStateKey = getRootDocumentsMappingStateKey(deviceId);
+        if (mMappingMode.containsKey(mappingStateKey)) {
+            throw new Error("Mapping for the root has already started.");
+        }
+        mMappingMode.put(
+                mappingStateKey,
+                mDatabase.startAddingDocuments(
+                        SELECTION_ROOT_DOCUMENTS, Integer.toString(deviceId)));
+    }
+
+    @VisibleForTesting
+    void startAddingChildDocuments(String parentDocumentId) {
+        final String mappingStateKey = getChildDocumentsMappingStateKey(parentDocumentId);
+        if (mMappingMode.containsKey(mappingStateKey)) {
+            throw new Error("Mapping for the root has already started.");
+        }
+        mMappingMode.put(
+                mappingStateKey,
+                mDatabase.startAddingDocuments(SELECTION_CHILD_DOCUMENTS, parentDocumentId));
     }
 
     @VisibleForTesting
@@ -236,20 +128,37 @@
                 valuesList[i] = new ContentValues();
                 getRootDocumentValues(valuesList[i], resources, roots[i]);
             }
-            final long[] documentIds =
-                    putDocuments(valuesList, SELECTION_ROOT_DOCUMENTS, Integer.toString(deviceId));
+            boolean heuristic;
+            String mapColumn;
+            switch (mMappingMode.get(getRootDocumentsMappingStateKey(deviceId))) {
+                case MAP_BY_MTP_IDENTIFIER:
+                    heuristic = false;
+                    mapColumn = COLUMN_STORAGE_ID;
+                    break;
+                case MAP_BY_NAME:
+                    heuristic = true;
+                    mapColumn = Document.COLUMN_DISPLAY_NAME;
+                    break;
+                default:
+                    throw new Error("Unexpected map mode.");
+            }
+            final long[] documentIds = mDatabase.putDocuments(
+                    valuesList,
+                    SELECTION_ROOT_DOCUMENTS,
+                    Integer.toString(deviceId),
+                    heuristic,
+                    mapColumn);
             final ContentValues values = new ContentValues();
             int i = 0;
             for (final MtpRoot root : roots) {
                 // Use the same value for the root ID and the corresponding document ID.
                 values.put(Root.COLUMN_ROOT_ID, documentIds[i++]);
-                values.put(Root.COLUMN_FLAGS,
-                        Root.FLAG_SUPPORTS_IS_CHILD |
-                        Root.FLAG_SUPPORTS_CREATE);
+                values.put(
+                        Root.COLUMN_FLAGS, Root.FLAG_SUPPORTS_IS_CHILD | Root.FLAG_SUPPORTS_CREATE);
                 values.put(Root.COLUMN_AVAILABLE_BYTES, root.mFreeSpace);
                 values.put(Root.COLUMN_CAPACITY_BYTES, root.mMaxCapacity);
                 values.put(Root.COLUMN_MIME_TYPES, "");
-                mDatabase.insert(TABLE_ROOT_EXTRA, null, values);
+                mDatabase.putRootExtra(values);
             }
             mDatabase.setTransactionSuccessful();
         } finally {
@@ -264,172 +173,72 @@
             valuesList[i] = new ContentValues();
             getChildDocumentValues(valuesList[i], deviceId, parentId, documents[i]);
         }
-        putDocuments(valuesList, SELECTION_CHILD_DOCUMENTS, parentId);
-    }
-
-    /**
-     * Clears MTP related identifier.
-     * It clears MTP's object handle and storage ID that are not stable over MTP sessions and mark
-     * the all documents as 'unmapped'. It also remove 'mapping' rows as mapping is cancelled now.
-     */
-    @VisibleForTesting
-    void clearMapping() {
-        mDatabase.beginTransaction();
-        try {
-            deleteDocumentsAndRoots(COLUMN_ROW_STATE + " = ?", strings(ROW_STATE_MAPPING));
-            final ContentValues values = new ContentValues();
-            values.putNull(COLUMN_OBJECT_HANDLE);
-            values.putNull(COLUMN_STORAGE_ID);
-            values.put(COLUMN_ROW_STATE, ROW_STATE_UNMAPPED);
-            mDatabase.update(TABLE_DOCUMENTS, values, null, null);
-            mDatabase.setTransactionSuccessful();
-        } finally {
-            mDatabase.endTransaction();
+        boolean heuristic;
+        String mapColumn;
+        switch (mMappingMode.get(getChildDocumentsMappingStateKey(parentId))) {
+            case MAP_BY_MTP_IDENTIFIER:
+                heuristic = false;
+                mapColumn = COLUMN_STORAGE_ID;
+                break;
+            case MAP_BY_NAME:
+                heuristic = true;
+                mapColumn = Document.COLUMN_DISPLAY_NAME;
+                break;
+            default:
+                throw new Error("Unexpected map mode.");
         }
+        mDatabase.putDocuments(
+                valuesList, SELECTION_CHILD_DOCUMENTS, parentId, heuristic, mapColumn);
     }
 
     @VisibleForTesting
-    void resolveRootDocuments(int deviceId) {
-        resolveDocuments(SELECTION_ROOT_DOCUMENTS, Integer.toString(deviceId));
+    void clearMapping() {
+        mDatabase.clearMapping();
+        mMappingMode.clear();
     }
 
     @VisibleForTesting
-    void resolveChildDocuments(String parentId) {
-        resolveDocuments(SELECTION_CHILD_DOCUMENTS, parentId);
+    void stopAddingRootDocuments(int deviceId) {
+        final String mappingModeKey = getRootDocumentsMappingStateKey(deviceId);
+        switch (mMappingMode.get(mappingModeKey)) {
+            case MAP_BY_MTP_IDENTIFIER:
+                mDatabase.stopAddingDocuments(
+                        SELECTION_ROOT_DOCUMENTS,
+                        Integer.toString(deviceId),
+                        COLUMN_STORAGE_ID);
+                break;
+            case MAP_BY_NAME:
+                mDatabase.stopAddingDocuments(
+                        SELECTION_ROOT_DOCUMENTS,
+                        Integer.toString(deviceId),
+                        Document.COLUMN_DISPLAY_NAME);
+                break;
+            default:
+                throw new Error("Unexpected mapping state.");
+        }
+        mMappingMode.remove(mappingModeKey);
     }
 
-    /**
-     * Puts the documents into the database.
-     * If the database found another unmapped document that shares the same name and parent,
-     * the document may be merged into the unmapped document. In that case, the database marks the
-     * root as 'mapping' and wait for {@link #resolveRootDocuments(int)} is invoked.
-     * @param valuesList Values that are stored in the database.
-     * @param selection SQL where closure to select rows that shares the same parent.
-     * @param arg Argument for selection SQL.
-     * @return List of Document ID inserted to the table.
-     */
-    private long[] putDocuments(ContentValues[] valuesList, String selection, String arg) {
-        mDatabase.beginTransaction();
-        try {
-            final long[] documentIds = new long[valuesList.length];
-            int i = 0;
-            for (final ContentValues values : valuesList) {
-                final String displayName =
-                        values.getAsString(Document.COLUMN_DISPLAY_NAME);
-                final long numUnmapped = DatabaseUtils.queryNumEntries(
-                        mDatabase,
-                        TABLE_DOCUMENTS,
-                        selection + " AND " +
-                        COLUMN_ROW_STATE + " = ? AND " +
-                        Document.COLUMN_DISPLAY_NAME + " = ?",
-                        strings(arg, ROW_STATE_UNMAPPED, displayName));
-                if (numUnmapped != 0) {
-                    values.put(COLUMN_ROW_STATE, ROW_STATE_MAPPING);
-                }
-                // Document ID is a primary integer key of the table. So the returned row IDs should
-                // be same with the document ID.
-                documentIds[i++] = mDatabase.insert(TABLE_DOCUMENTS, null, values);
-            }
-
-            mDatabase.setTransactionSuccessful();
-            return documentIds;
-        } finally {
-            mDatabase.endTransaction();
+    @VisibleForTesting
+    void stopAddingChildDocuments(String parentId) {
+        final String mappingModeKey = getChildDocumentsMappingStateKey(parentId);
+        switch (mMappingMode.get(mappingModeKey)) {
+            case MAP_BY_MTP_IDENTIFIER:
+                mDatabase.stopAddingDocuments(
+                        SELECTION_CHILD_DOCUMENTS,
+                        parentId,
+                        COLUMN_OBJECT_HANDLE);
+                break;
+            case MAP_BY_NAME:
+                mDatabase.stopAddingDocuments(
+                        SELECTION_CHILD_DOCUMENTS,
+                        parentId,
+                        Document.COLUMN_DISPLAY_NAME);
+                break;
+            default:
+                throw new Error("Unexpected mapping state.");
         }
-    }
-
-    /**
-     * Maps 'unmapped' document and 'mapping' document that don't have document but shares the same
-     * name.
-     * If the database does not find corresponding 'mapping' document, it just removes 'unmapped'
-     * document from the database.
-     * @param selection Query to select rows for resolving.
-     * @param arg Argument for selection SQL.
-     */
-    private void resolveDocuments(String selection, String arg) {
-        mDatabase.beginTransaction();
-        try {
-            // Get 1-to-1 mapping of unmapped document and mapping document.
-            final String unmappedIdQuery = createStateFilter(
-                    ROW_STATE_UNMAPPED, Document.COLUMN_DOCUMENT_ID);
-            final String mappingIdQuery = createStateFilter(
-                    ROW_STATE_MAPPING, Document.COLUMN_DOCUMENT_ID);
-            // SQL should be like:
-            // SELECT group_concat(CASE WHEN raw_state = 1 THEN document_id ELSE NULL END),
-            //        group_concat(CASE WHEN raw_state = 2 THEN document_id ELSE NULL END)
-            // WHERE device_id = ? AND parent_document_id IS NULL
-            // GROUP BY display_name
-            // HAVING count(CASE WHEN raw_state = 1 THEN document_id ELSE NULL END) = 1 AND
-            //        count(CASE WHEN raw_state = 2 THEN document_id ELSE NULL END) = 1
-            final Cursor mergingCursor = mDatabase.query(
-                    TABLE_DOCUMENTS,
-                    new String[] {
-                            "group_concat(" + unmappedIdQuery + ")",
-                            "group_concat(" + mappingIdQuery + ")"
-                    },
-                    selection,
-                    strings(arg),
-                    Document.COLUMN_DISPLAY_NAME,
-                    "count(" + unmappedIdQuery + ") = 1 AND count(" + mappingIdQuery + ") = 1",
-                    null);
-
-            final ContentValues values = new ContentValues();
-            while (mergingCursor.moveToNext()) {
-                final String unmappedId = mergingCursor.getString(0);
-                final String mappingId = mergingCursor.getString(1);
-
-                // Obtain the new values including the latest object handle from mapping row.
-                getFirstRow(
-                        TABLE_DOCUMENTS,
-                        SELECTION_DOCUMENT_ID,
-                        new String[] { mappingId },
-                        values);
-                values.remove(Document.COLUMN_DOCUMENT_ID);
-                values.put(COLUMN_ROW_STATE, ROW_STATE_MAPPED);
-                mDatabase.update(
-                        TABLE_DOCUMENTS,
-                        values,
-                        SELECTION_DOCUMENT_ID,
-                        new String[] { unmappedId });
-
-                getFirstRow(
-                        TABLE_ROOT_EXTRA,
-                        SELECTION_ROOT_ID,
-                        new String[] { mappingId },
-                        values);
-                if (values.size() > 0) {
-                    values.remove(Root.COLUMN_ROOT_ID);
-                    mDatabase.update(
-                            TABLE_ROOT_EXTRA,
-                            values,
-                            SELECTION_ROOT_ID,
-                            new String[] { unmappedId });
-                }
-
-                // Delete 'mapping' row.
-                deleteDocumentsAndRoots(SELECTION_DOCUMENT_ID, new String[] { mappingId });
-            }
-            mergingCursor.close();
-
-            // Delete all unmapped rows that cannot be mapped.
-            deleteDocumentsAndRoots(
-                    COLUMN_ROW_STATE + " = ? AND " + selection,
-                    strings(ROW_STATE_UNMAPPED, arg));
-
-            // The database cannot find old document ID for the mapping rows.
-            // Turn the all mapping rows into mapped state, which means the rows become to be
-            // valid with new document ID.
-            values.clear();
-            values.put(COLUMN_ROW_STATE, ROW_STATE_MAPPED);
-            mDatabase.update(
-                    TABLE_DOCUMENTS,
-                    values,
-                    COLUMN_ROW_STATE + " = ? AND " + selection,
-                    strings(ROW_STATE_MAPPING, arg));
-            mDatabase.setTransactionSuccessful();
-        } finally {
-            mDatabase.endTransaction();
-        }
+        mMappingMode.remove(mappingModeKey);
     }
 
     /**
@@ -445,7 +254,7 @@
         values.put(COLUMN_STORAGE_ID, root.mStorageId);
         values.putNull(COLUMN_OBJECT_HANDLE);
         values.putNull(COLUMN_PARENT_DOCUMENT_ID);
-        values.put(COLUMN_ROW_STATE, ROW_STATE_MAPPED);
+        values.put(COLUMN_ROW_STATE, ROW_STATE_VALID);
         values.put(Document.COLUMN_MIME_TYPE, Document.MIME_TYPE_DIR);
         values.put(Document.COLUMN_DISPLAY_NAME, root.getRootName(resources));
         values.putNull(Document.COLUMN_SUMMARY);
@@ -482,7 +291,7 @@
         values.put(COLUMN_STORAGE_ID, info.getStorageId());
         values.put(COLUMN_OBJECT_HANDLE, info.getObjectHandle());
         values.put(COLUMN_PARENT_DOCUMENT_ID, parentId);
-        values.put(COLUMN_ROW_STATE, ROW_STATE_MAPPED);
+        values.put(COLUMN_ROW_STATE, ROW_STATE_VALID);
         values.put(Document.COLUMN_MIME_TYPE, mimeType);
         values.put(Document.COLUMN_DISPLAY_NAME, info.getName());
         values.putNull(Document.COLUMN_SUMMARY);
@@ -494,73 +303,11 @@
         values.put(Document.COLUMN_SIZE, info.getCompressedSize());
     }
 
-    /**
-     * Obtains values of the first row for the query.
-     * @param values ContentValues that the values are stored to.
-     * @param table Target table.
-     * @param selection Query to select rows.
-     * @param args Argument for query.
-     */
-    private void getFirstRow(String table, String selection, String[] args, ContentValues values) {
-        values.clear();
-        final Cursor cursor = mDatabase.query(table, null, selection, args, null, null, null, "1");
-        if (cursor.getCount() == 0) {
-            return;
-        }
-        cursor.moveToNext();
-        DatabaseUtils.cursorRowToContentValues(cursor, values);
-        cursor.close();
+    private String getRootDocumentsMappingStateKey(int deviceId) {
+        return "RootDocuments/" + deviceId;
     }
 
-    /**
-     * Deletes a document, and its root information if the document is a root document.
-     * @param selection Query to select documents.
-     * @param args Arguments for selection.
-     */
-    private void deleteDocumentsAndRoots(String selection, String[] args) {
-        mDatabase.beginTransaction();
-        try {
-            mDatabase.delete(
-                    TABLE_ROOT_EXTRA,
-                    Root.COLUMN_ROOT_ID + " IN (" + SQLiteQueryBuilder.buildQueryString(
-                            false,
-                            TABLE_DOCUMENTS,
-                            new String[] { Document.COLUMN_DOCUMENT_ID },
-                            selection,
-                            null,
-                            null,
-                            null,
-                            null) + ")",
-                    args);
-            mDatabase.delete(TABLE_DOCUMENTS, selection, args);
-            mDatabase.setTransactionSuccessful();
-        } finally {
-            mDatabase.endTransaction();
-        }
-    }
-
-    /**
-     * Converts values into string array.
-     * @param args Values converted into string array.
-     * @return String array.
-     */
-    private static String[] strings(Object... args) {
-        final String[] results = new String[args.length];
-        for (int i = 0; i < args.length; i++) {
-            results[i] = Objects.toString(args[i]);
-        }
-        return results;
-    }
-
-    /**
-     * Gets SQL expression that represents the given value or NULL depends on the row state.
-     * @param state Expected row state.
-     * @param a SQL value.
-     * @return Expression that represents a if the row state is expected one, and represents NULL
-     *     otherwise.
-     */
-    private static String createStateFilter(int state, String a) {
-        return "CASE WHEN " + COLUMN_ROW_STATE + " = " + Integer.toString(state) +
-                " THEN " + a + " ELSE NULL END";
+    private String getChildDocumentsMappingStateKey(String parentDocumentId) {
+        return "ChildDocuments/" + parentDocumentId;
     }
 }
diff --git a/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabaseConstants.java b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabaseConstants.java
new file mode 100644
index 0000000..5fb16ec
--- /dev/null
+++ b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabaseConstants.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2015 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.mtp;
+
+import android.provider.DocumentsContract.Document;
+import android.provider.DocumentsContract.Root;
+
+/**
+ * Class containing MtpDatabase constants.
+ */
+class MtpDatabaseConstants {
+    static final int DATABASE_VERSION = 1;
+    static final String DATABASE_NAME = null;
+
+    /**
+     * Table representing documents including root documents.
+     */
+    static final String TABLE_DOCUMENTS = "Documents";
+
+    /**
+     * Table containing additional information only available for root documents.
+     * The table uses same primary keys with corresponding documents.
+     */
+    static final String TABLE_ROOT_EXTRA = "RootExtra";
+
+    /**
+     * View to join Documents and RootExtra tables to provide roots information.
+     */
+    static final String VIEW_ROOTS = "Roots";
+
+    static final String COLUMN_DEVICE_ID = "device_id";
+    static final String COLUMN_STORAGE_ID = "storage_id";
+    static final String COLUMN_OBJECT_HANDLE = "object_handle";
+    static final String COLUMN_PARENT_DOCUMENT_ID = "parent_document_id";
+    static final String COLUMN_ROW_STATE = "row_state";
+
+    /**
+     * The state represents that the row has a valid object handle.
+     */
+    static final int ROW_STATE_VALID = 0;
+
+    /**
+     * The state represents that the rows added at the previous cycle and need to be updated with
+     * fresh values.
+     * The row may not have valid object handle. External application can still fetch the documents.
+     * If the external application tries to fetch object handle, the provider resolves pending
+     * documents with invalidated documents ahead.
+     */
+    static final int ROW_STATE_INVALIDATED = 1;
+
+    /**
+     * The state represents the raw has a valid object handle but it may be going to be mapped with
+     * another rows invalidated. After fetching all documents under the parent, the database tries
+     * to map the pending documents and the invalidated documents in order to keep old document ID
+     * alive.
+     */
+    static final int ROW_STATE_PENDING = 2;
+
+    /**
+     * Mapping mode that uses MTP identifier to find corresponding rows.
+     */
+    static final int MAP_BY_MTP_IDENTIFIER = 0;
+
+    /**
+     * Mapping mode that uses name to find corresponding rows.
+     */
+    static final int MAP_BY_NAME = 1;
+
+    static final String SELECTION_DOCUMENT_ID = Document.COLUMN_DOCUMENT_ID + " = ?";
+    static final String SELECTION_ROOT_ID = Root.COLUMN_ROOT_ID + " = ?";
+    static final String SELECTION_ROOT_DOCUMENTS =
+            COLUMN_DEVICE_ID + " = ? AND " + COLUMN_PARENT_DOCUMENT_ID + " IS NULL";
+    static final String SELECTION_CHILD_DOCUMENTS = COLUMN_PARENT_DOCUMENT_ID + " = ?";
+
+    static final String QUERY_CREATE_DOCUMENTS =
+            "CREATE TABLE " + TABLE_DOCUMENTS + " (" +
+            Document.COLUMN_DOCUMENT_ID +
+                " INTEGER PRIMARY KEY AUTOINCREMENT," +
+            COLUMN_DEVICE_ID + " INTEGER NOT NULL," +
+            COLUMN_STORAGE_ID + " INTEGER," +
+            COLUMN_OBJECT_HANDLE + " INTEGER," +
+            COLUMN_PARENT_DOCUMENT_ID + " INTEGER," +
+            COLUMN_ROW_STATE + " INTEGER NOT NULL," +
+            Document.COLUMN_MIME_TYPE + " TEXT," +
+            Document.COLUMN_DISPLAY_NAME + " TEXT NOT NULL," +
+            Document.COLUMN_SUMMARY + " TEXT," +
+            Document.COLUMN_LAST_MODIFIED + " INTEGER," +
+            Document.COLUMN_ICON + " INTEGER," +
+            Document.COLUMN_FLAGS + " INTEGER NOT NULL," +
+            Document.COLUMN_SIZE + " INTEGER NOT NULL);";
+
+    static final String QUERY_CREATE_ROOT_EXTRA =
+            "CREATE TABLE " + TABLE_ROOT_EXTRA + " (" +
+            Root.COLUMN_ROOT_ID + " INTEGER PRIMARY KEY," +
+            Root.COLUMN_FLAGS + " INTEGER NOT NULL," +
+            Root.COLUMN_AVAILABLE_BYTES + " INTEGER NOT NULL," +
+            Root.COLUMN_CAPACITY_BYTES + " INTEGER NOT NULL," +
+            Root.COLUMN_MIME_TYPES + " TEXT NOT NULL);";
+
+    /**
+     * Creates a view to join Documents table and RootExtra table on their primary keys to
+     * provide DocumentContract.Root equivalent information.
+     */
+    static final String QUERY_CREATE_VIEW_ROOTS =
+            "CREATE VIEW " + VIEW_ROOTS + " AS SELECT " +
+                    TABLE_DOCUMENTS + "." + Document.COLUMN_DOCUMENT_ID + " AS " +
+                            Root.COLUMN_ROOT_ID + "," +
+                    TABLE_ROOT_EXTRA + "." + Root.COLUMN_FLAGS + "," +
+                    TABLE_DOCUMENTS + "." + Document.COLUMN_ICON + " AS " +
+                            Root.COLUMN_ICON + "," +
+                    TABLE_DOCUMENTS + "." + Document.COLUMN_DISPLAY_NAME + " AS " +
+                            Root.COLUMN_TITLE + "," +
+                    TABLE_DOCUMENTS + "." + Document.COLUMN_SUMMARY + " AS " +
+                            Root.COLUMN_SUMMARY + "," +
+                    TABLE_DOCUMENTS + "." + Document.COLUMN_DOCUMENT_ID + " AS " +
+                    Root.COLUMN_DOCUMENT_ID + "," +
+                    TABLE_ROOT_EXTRA + "." + Root.COLUMN_AVAILABLE_BYTES + "," +
+                    TABLE_ROOT_EXTRA + "." + Root.COLUMN_CAPACITY_BYTES + "," +
+                    TABLE_ROOT_EXTRA + "." + Root.COLUMN_MIME_TYPES + "," +
+                    TABLE_DOCUMENTS + "." + COLUMN_ROW_STATE +
+            " FROM " + TABLE_DOCUMENTS + " INNER JOIN " + TABLE_ROOT_EXTRA +
+            " ON " +
+                    COLUMN_PARENT_DOCUMENT_ID + " IS NULL AND " +
+                    TABLE_DOCUMENTS + "." + Document.COLUMN_DOCUMENT_ID +
+                    "=" +
+                    TABLE_ROOT_EXTRA + "." + Root.COLUMN_ROOT_ID;
+}
diff --git a/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabaseInternal.java b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabaseInternal.java
new file mode 100644
index 0000000..730012d
--- /dev/null
+++ b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabaseInternal.java
@@ -0,0 +1,391 @@
+/*
+ * Copyright (C) 2015 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.mtp;
+
+import static com.android.mtp.MtpDatabaseConstants.*;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.database.sqlite.SQLiteQueryBuilder;
+import android.provider.DocumentsContract.Document;
+import android.provider.DocumentsContract.Root;
+
+import java.util.Objects;
+
+/**
+ * Class that provides operations processing SQLite database directly.
+ */
+class MtpDatabaseInternal {
+    private static class OpenHelper extends SQLiteOpenHelper {
+        public OpenHelper(Context context) {
+            super(context, DATABASE_NAME, null, DATABASE_VERSION);
+        }
+
+        @Override
+        public void onCreate(SQLiteDatabase db) {
+            db.execSQL(QUERY_CREATE_DOCUMENTS);
+            db.execSQL(QUERY_CREATE_ROOT_EXTRA);
+            db.execSQL(QUERY_CREATE_VIEW_ROOTS);
+        }
+
+        @Override
+        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+            throw new UnsupportedOperationException();
+        }
+    }
+
+    private final SQLiteDatabase mDatabase;
+
+    MtpDatabaseInternal(Context context) {
+        final OpenHelper helper = new OpenHelper(context);
+        mDatabase = helper.getWritableDatabase();
+    }
+
+    Cursor queryRoots(String[] columnNames) {
+        return mDatabase.query(
+                VIEW_ROOTS,
+                columnNames,
+                COLUMN_ROW_STATE + " IN (?, ?)",
+                strings(ROW_STATE_VALID, ROW_STATE_INVALIDATED),
+                null,
+                null,
+                null);
+    }
+
+    Cursor queryRootDocuments(String[] columnNames) {
+        return mDatabase.query(
+                TABLE_DOCUMENTS,
+                columnNames,
+                COLUMN_ROW_STATE + " IN (?, ?)",
+                strings(ROW_STATE_VALID, ROW_STATE_INVALIDATED),
+                null,
+                null,
+                null);
+    }
+
+    Cursor queryChildDocuments(String[] columnNames, String parentDocumentId) {
+        return mDatabase.query(
+                TABLE_DOCUMENTS,
+                columnNames,
+                COLUMN_ROW_STATE + " IN (?, ?) AND " + COLUMN_PARENT_DOCUMENT_ID + " = ?",
+                strings(ROW_STATE_VALID, ROW_STATE_INVALIDATED, parentDocumentId),
+                null,
+                null,
+                null);
+    }
+
+    /**
+     * Starts adding new documents.
+     * The methods decides mapping mode depends on if all documents under the given parent have MTP
+     * identifier or not. If all the documents have MTP identifier, it uses the identifier to find
+     * a corresponding existing row. Otherwise it does heuristic.
+     *
+     * @param selection Query matches valid documents.
+     * @param arg Argument for selection.
+     * @return Mapping mode.
+     */
+    int startAddingDocuments(String selection, String arg) {
+        mDatabase.beginTransaction();
+        try {
+            // Delete all pending rows.
+            deleteDocumentsAndRoots(
+                    selection + " AND " + COLUMN_ROW_STATE + "=?", strings(arg, ROW_STATE_PENDING));
+
+            // Set all documents as invalidated.
+            final ContentValues values = new ContentValues();
+            values.put(COLUMN_ROW_STATE, ROW_STATE_INVALIDATED);
+            mDatabase.update(TABLE_DOCUMENTS, values, selection, new String[] { arg });
+
+            // If we have rows that does not have MTP identifier, do heuristic mapping by name.
+            final boolean useNameForResolving = DatabaseUtils.queryNumEntries(
+                    mDatabase,
+                    TABLE_DOCUMENTS,
+                    selection + " AND " + COLUMN_STORAGE_ID + " IS NULL",
+                    new String[] { arg }) > 0;
+            mDatabase.setTransactionSuccessful();
+            return useNameForResolving ? MAP_BY_NAME : MAP_BY_MTP_IDENTIFIER;
+        } finally {
+            mDatabase.endTransaction();
+        }
+    }
+
+    /**
+     * Puts the documents into the database.
+     * If the mapping mode is not heuristic, it just adds the rows to the database or updates the
+     * existing rows with the new values. If the mapping mode is heuristic, it adds some new rows as
+     * 'pending' state when that rows may be corresponding to existing 'invalidated' rows. Then
+     * {@link #stopAddingDocuments(String, String, String)} turns the pending rows into 'valid'
+     * rows.
+     *
+     * @param valuesList Values that are stored in the database.
+     * @param selection SQL where closure to select rows that shares the same parent.
+     * @param arg Argument for selection SQL.
+     * @param heuristic Whether the mapping mode is heuristic.
+     * @return List of Document ID inserted to the table.
+     */
+    long[] putDocuments(
+            ContentValues[] valuesList,
+            String selection,
+            String arg,
+            boolean heuristic,
+            String mappingKey) {
+        mDatabase.beginTransaction();
+        try {
+            final long[] documentIds = new long[valuesList.length];
+            int i = 0;
+            for (final ContentValues values : valuesList) {
+                final Cursor candidateCursor = mDatabase.query(
+                        TABLE_DOCUMENTS,
+                        strings(Document.COLUMN_DOCUMENT_ID),
+                        selection + " AND " +
+                        COLUMN_ROW_STATE + "=? AND " +
+                        mappingKey + "=?",
+                        strings(arg, ROW_STATE_INVALIDATED, values.getAsString(mappingKey)),
+                        null,
+                        null,
+                        null,
+                        "1");
+                final long rowId;
+                if (candidateCursor.getCount() == 0) {
+                    rowId = mDatabase.insert(TABLE_DOCUMENTS, null, values);
+                } else if (!heuristic) {
+                    candidateCursor.moveToNext();
+                    final String documentId = candidateCursor.getString(0);
+                    rowId = mDatabase.update(
+                            TABLE_DOCUMENTS, values, SELECTION_DOCUMENT_ID, strings(documentId));
+                } else {
+                    values.put(COLUMN_ROW_STATE, ROW_STATE_PENDING);
+                    rowId = mDatabase.insert(TABLE_DOCUMENTS, null, values);
+                }
+                // Document ID is a primary integer key of the table. So the returned row
+                // IDs should be same with the document ID.
+                documentIds[i++] = rowId;
+                candidateCursor.close();
+            }
+
+            mDatabase.setTransactionSuccessful();
+            return documentIds;
+        } finally {
+            mDatabase.endTransaction();
+        }
+    }
+
+    void putRootExtra(ContentValues values) {
+        mDatabase.replace(TABLE_ROOT_EXTRA, null, values);
+    }
+
+    /**
+     * Maps 'pending' document and 'invalidated' document that shares the same column of groupKey.
+     * If the database does not find corresponding 'invalidated' document, it just removes
+     * 'invalidated' document from the database.
+     * @param selection Query to select rows for resolving.
+     * @param arg Argument for selection SQL.
+     * @param groupKey Column name used to find corresponding rows.
+     */
+    void stopAddingDocuments(String selection, String arg, String groupKey) {
+        mDatabase.beginTransaction();
+        try {
+            // Get 1-to-1 mapping of invalidated document and pending document.
+            final String invalidatedIdQuery = createStateFilter(
+                    ROW_STATE_INVALIDATED, Document.COLUMN_DOCUMENT_ID);
+            final String pendingIdQuery = createStateFilter(
+                    ROW_STATE_PENDING, Document.COLUMN_DOCUMENT_ID);
+            // SQL should be like:
+            // SELECT group_concat(CASE WHEN raw_state = 1 THEN document_id ELSE NULL END),
+            //        group_concat(CASE WHEN raw_state = 2 THEN document_id ELSE NULL END)
+            // WHERE device_id = ? AND parent_document_id IS NULL
+            // GROUP BY display_name
+            // HAVING count(CASE WHEN raw_state = 1 THEN document_id ELSE NULL END) = 1 AND
+            //        count(CASE WHEN raw_state = 2 THEN document_id ELSE NULL END) = 1
+            final Cursor mergingCursor = mDatabase.query(
+                    TABLE_DOCUMENTS,
+                    new String[] {
+                            "group_concat(" + invalidatedIdQuery + ")",
+                            "group_concat(" + pendingIdQuery + ")"
+                    },
+                    selection,
+                    strings(arg),
+                    groupKey,
+                    "count(" + invalidatedIdQuery + ") = 1 AND count(" + pendingIdQuery + ") = 1",
+                    null);
+
+            final ContentValues values = new ContentValues();
+            while (mergingCursor.moveToNext()) {
+                final String invalidatedId = mergingCursor.getString(0);
+                final String pendingId = mergingCursor.getString(1);
+
+                // Obtain the new values including the latest object handle from mapping row.
+                getFirstRow(
+                        TABLE_DOCUMENTS,
+                        SELECTION_DOCUMENT_ID,
+                        new String[] { pendingId },
+                        values);
+                values.remove(Document.COLUMN_DOCUMENT_ID);
+                values.put(COLUMN_ROW_STATE, ROW_STATE_VALID);
+                mDatabase.update(
+                        TABLE_DOCUMENTS,
+                        values,
+                        SELECTION_DOCUMENT_ID,
+                        new String[] { invalidatedId });
+
+                getFirstRow(
+                        TABLE_ROOT_EXTRA,
+                        SELECTION_ROOT_ID,
+                        new String[] { pendingId },
+                        values);
+                if (values.size() > 0) {
+                    values.remove(Root.COLUMN_ROOT_ID);
+                    mDatabase.update(
+                            TABLE_ROOT_EXTRA,
+                            values,
+                            SELECTION_ROOT_ID,
+                            new String[] { invalidatedId });
+                }
+
+                // Delete 'pending' row.
+                deleteDocumentsAndRoots(SELECTION_DOCUMENT_ID, new String[] { pendingId });
+            }
+            mergingCursor.close();
+
+            // Delete all invalidated rows that cannot be mapped.
+            deleteDocumentsAndRoots(
+                    COLUMN_ROW_STATE + " = ? AND " + selection,
+                    strings(ROW_STATE_INVALIDATED, arg));
+
+            // The database cannot find old document ID for the pending rows.
+            // Turn the all pending rows into valid state, which means the rows become to be
+            // valid with new document ID.
+            values.clear();
+            values.put(COLUMN_ROW_STATE, ROW_STATE_VALID);
+            mDatabase.update(
+                    TABLE_DOCUMENTS,
+                    values,
+                    COLUMN_ROW_STATE + " = ? AND " + selection,
+                    strings(ROW_STATE_PENDING, arg));
+            mDatabase.setTransactionSuccessful();
+        } finally {
+            mDatabase.endTransaction();
+        }
+    }
+
+    /**
+     * Clears MTP related identifier.
+     * It clears MTP's object handle and storage ID that are not stable over MTP sessions and mark
+     * the all documents as 'invalidated'. It also remove 'pending' rows as adding is cancelled
+     * now.
+     */
+    void clearMapping() {
+        mDatabase.beginTransaction();
+        try {
+            deleteDocumentsAndRoots(COLUMN_ROW_STATE + " = ?", strings(ROW_STATE_PENDING));
+            final ContentValues values = new ContentValues();
+            values.putNull(COLUMN_OBJECT_HANDLE);
+            values.putNull(COLUMN_STORAGE_ID);
+            values.put(COLUMN_ROW_STATE, ROW_STATE_INVALIDATED);
+            mDatabase.update(TABLE_DOCUMENTS, values, null, null);
+            mDatabase.setTransactionSuccessful();
+        } finally {
+            mDatabase.endTransaction();
+        }
+    }
+
+    void beginTransaction() {
+        mDatabase.beginTransaction();
+    }
+
+    void setTransactionSuccessful() {
+        mDatabase.setTransactionSuccessful();
+    }
+
+    void endTransaction() {
+        mDatabase.endTransaction();
+    }
+
+    /**
+     * Deletes a document, and its root information if the document is a root document.
+     * @param selection Query to select documents.
+     * @param args Arguments for selection.
+     */
+    private void deleteDocumentsAndRoots(String selection, String[] args) {
+        mDatabase.beginTransaction();
+        try {
+            mDatabase.delete(
+                    TABLE_ROOT_EXTRA,
+                    Root.COLUMN_ROOT_ID + " IN (" + SQLiteQueryBuilder.buildQueryString(
+                            false,
+                            TABLE_DOCUMENTS,
+                            new String[] { Document.COLUMN_DOCUMENT_ID },
+                            selection,
+                            null,
+                            null,
+                            null,
+                            null) + ")",
+                    args);
+            mDatabase.delete(TABLE_DOCUMENTS, selection, args);
+            mDatabase.setTransactionSuccessful();
+        } finally {
+            mDatabase.endTransaction();
+        }
+    }
+
+    /**
+     * Obtains values of the first row for the query.
+     * @param values ContentValues that the values are stored to.
+     * @param table Target table.
+     * @param selection Query to select rows.
+     * @param args Argument for query.
+     */
+    private void getFirstRow(String table, String selection, String[] args, ContentValues values) {
+        values.clear();
+        final Cursor cursor = mDatabase.query(table, null, selection, args, null, null, null, "1");
+        if (cursor.getCount() == 0) {
+            return;
+        }
+        cursor.moveToNext();
+        DatabaseUtils.cursorRowToContentValues(cursor, values);
+        cursor.close();
+    }
+
+    /**
+     * Gets SQL expression that represents the given value or NULL depends on the row state.
+     * @param state Expected row state.
+     * @param a SQL value.
+     * @return Expression that represents a if the row state is expected one, and represents NULL
+     *     otherwise.
+     */
+    private static String createStateFilter(int state, String a) {
+        return "CASE WHEN " + COLUMN_ROW_STATE + " = " + Integer.toString(state) +
+                " THEN " + a + " ELSE NULL END";
+    }
+
+    /**
+     * Converts values into string array.
+     * @param args Values converted into string array.
+     * @return String array.
+     */
+    private static String[] strings(Object... args) {
+        final String[] results = new String[args.length];
+        for (int i = 0; i < args.length; i++) {
+            results[i] = Objects.toString(args[i]);
+        }
+        return results;
+    }
+}
diff --git a/packages/MtpDocumentsProvider/tests/src/com/android/mtp/MtpDatabaseTest.java b/packages/MtpDocumentsProvider/tests/src/com/android/mtp/MtpDatabaseTest.java
index 3878ba6..05345e1 100644
--- a/packages/MtpDocumentsProvider/tests/src/com/android/mtp/MtpDatabaseTest.java
+++ b/packages/MtpDocumentsProvider/tests/src/com/android/mtp/MtpDatabaseTest.java
@@ -28,9 +28,9 @@
 public class MtpDatabaseTest extends AndroidTestCase {
     private final String[] COLUMN_NAMES = new String[] {
         DocumentsContract.Document.COLUMN_DOCUMENT_ID,
-        MtpDatabase.COLUMN_DEVICE_ID,
-        MtpDatabase.COLUMN_STORAGE_ID,
-        MtpDatabase.COLUMN_OBJECT_HANDLE,
+        MtpDatabaseConstants.COLUMN_DEVICE_ID,
+        MtpDatabaseConstants.COLUMN_STORAGE_ID,
+        MtpDatabaseConstants.COLUMN_OBJECT_HANDLE,
         DocumentsContract.Document.COLUMN_MIME_TYPE,
         DocumentsContract.Document.COLUMN_DISPLAY_NAME,
         DocumentsContract.Document.COLUMN_SUMMARY,
@@ -42,13 +42,9 @@
 
     private final TestResources resources = new TestResources();
 
-    @Override
-    public void tearDown() {
-        MtpDatabase.deleteDatabase(getContext());
-    }
-
     public void testPutRootDocuments() throws Exception {
         final MtpDatabase database = new MtpDatabase(getContext());
+        database.startAddingRootDocuments(0);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 1, "Device", "Storage", 1000, 2000, ""),
                 new MtpRoot(0, 2, "Device", "Storage", 2000, 4000, ""),
@@ -141,7 +137,7 @@
 
     public void testPutChildDocuments() throws Exception {
         final MtpDatabase database = new MtpDatabase(getContext());
-
+        database.startAddingChildDocuments("parentId");
         database.putChildDocuments(0, "parentId", new MtpObjectInfo[] {
                 createDocument(100, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
                 createDocument(101, "image.jpg", MtpConstants.FORMAT_EXIF_JPEG, 2 * 1024 * 1024),
@@ -209,13 +205,14 @@
         final MtpDatabase database = new MtpDatabase(getContext());
         final String[] columns = new String[] {
                 DocumentsContract.Document.COLUMN_DOCUMENT_ID,
-                MtpDatabase.COLUMN_STORAGE_ID,
+                MtpDatabaseConstants.COLUMN_STORAGE_ID,
                 DocumentsContract.Document.COLUMN_DISPLAY_NAME
         };
         final String[] rootColumns = new String[] {
                 Root.COLUMN_ROOT_ID,
                 Root.COLUMN_AVAILABLE_BYTES
         };
+        database.startAddingRootDocuments(0);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 100, "Device", "Storage A", 1000, 0, ""),
                 new MtpRoot(0, 101, "Device", "Storage B", 1001, 0, "")
@@ -275,6 +272,7 @@
             cursor.close();
         }
 
+        database.startAddingRootDocuments(0);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 200, "Device", "Storage A", 2000, 0, ""),
                 new MtpRoot(0, 202, "Device", "Storage C", 2002, 0, "")
@@ -313,7 +311,7 @@
             cursor.close();
         }
 
-        database.resolveRootDocuments(0);
+        database.stopAddingRootDocuments(0);
 
         {
             final Cursor cursor = database.queryRootDocuments(columns);
@@ -346,9 +344,10 @@
         final MtpDatabase database = new MtpDatabase(getContext());
         final String[] columns = new String[] {
                 DocumentsContract.Document.COLUMN_DOCUMENT_ID,
-                MtpDatabase.COLUMN_OBJECT_HANDLE,
+                MtpDatabaseConstants.COLUMN_OBJECT_HANDLE,
                 DocumentsContract.Document.COLUMN_DISPLAY_NAME
         };
+        database.startAddingChildDocuments("parentId");
         database.putChildDocuments(0, "parentId", new MtpObjectInfo[] {
                 createDocument(100, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
                 createDocument(101, "image.jpg", MtpConstants.FORMAT_EXIF_JPEG, 2 * 1024 * 1024),
@@ -378,6 +377,7 @@
             cursor.close();
         }
 
+        database.startAddingChildDocuments("parentId");
         database.putChildDocuments(0, "parentId", new MtpObjectInfo[] {
                 createDocument(200, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
                 createDocument(203, "video.mp4", MtpConstants.FORMAT_MP4_CONTAINER, 1024),
@@ -395,7 +395,7 @@
             cursor.close();
         }
 
-        database.resolveChildDocuments("parentId");
+        database.stopAddingChildDocuments("parentId");
 
         {
             final Cursor cursor = database.queryChildDocuments(columns, "parentId");
@@ -418,13 +418,15 @@
         final MtpDatabase database = new MtpDatabase(getContext());
         final String[] columns = new String[] {
                 DocumentsContract.Document.COLUMN_DOCUMENT_ID,
-                MtpDatabase.COLUMN_STORAGE_ID,
+                MtpDatabaseConstants.COLUMN_STORAGE_ID,
                 DocumentsContract.Document.COLUMN_DISPLAY_NAME
         };
         final String[] rootColumns = new String[] {
                 Root.COLUMN_ROOT_ID,
                 Root.COLUMN_AVAILABLE_BYTES
         };
+        database.startAddingRootDocuments(0);
+        database.startAddingRootDocuments(1);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 100, "Device", "Storage", 0, 0, "")
         });
@@ -460,14 +462,16 @@
 
         database.clearMapping();
 
+        database.startAddingRootDocuments(0);
+        database.startAddingRootDocuments(1);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 200, "Device", "Storage", 2000, 0, "")
         });
         database.putRootDocuments(1, resources, new MtpRoot[] {
                 new MtpRoot(1, 300, "Device", "Storage", 3000, 0, "")
         });
-        database.resolveRootDocuments(0);
-        database.resolveRootDocuments(1);
+        database.stopAddingRootDocuments(0);
+        database.stopAddingRootDocuments(1);
 
         {
             final Cursor cursor = database.queryRootDocuments(columns);
@@ -500,8 +504,11 @@
         final MtpDatabase database = new MtpDatabase(getContext());
         final String[] columns = new String[] {
                 DocumentsContract.Document.COLUMN_DOCUMENT_ID,
-                MtpDatabase.COLUMN_OBJECT_HANDLE
+                MtpDatabaseConstants.COLUMN_OBJECT_HANDLE
         };
+
+        database.startAddingChildDocuments("parentId1");
+        database.startAddingChildDocuments("parentId2");
         database.putChildDocuments(0, "parentId1", new MtpObjectInfo[] {
                 createDocument(100, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
         });
@@ -509,13 +516,16 @@
                 createDocument(101, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
         });
         database.clearMapping();
+
+        database.startAddingChildDocuments("parentId1");
+        database.startAddingChildDocuments("parentId2");
         database.putChildDocuments(0, "parentId1", new MtpObjectInfo[] {
                 createDocument(200, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
         });
         database.putChildDocuments(0, "parentId2", new MtpObjectInfo[] {
                 createDocument(201, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
         });
-        database.resolveChildDocuments("parentId1");
+        database.stopAddingChildDocuments("parentId1");
 
         {
             final Cursor cursor = database.queryChildDocuments(columns, "parentId1");
@@ -539,25 +549,32 @@
         final MtpDatabase database = new MtpDatabase(getContext());
         final String[] columns = new String[] {
                 DocumentsContract.Document.COLUMN_DOCUMENT_ID,
-                MtpDatabase.COLUMN_STORAGE_ID,
+                MtpDatabaseConstants.COLUMN_STORAGE_ID,
                 DocumentsContract.Document.COLUMN_DISPLAY_NAME
         };
         final String[] rootColumns = new String[] {
                 Root.COLUMN_ROOT_ID,
                 Root.COLUMN_AVAILABLE_BYTES
         };
+
+        database.startAddingRootDocuments(0);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 100, "Device", "Storage", 0, 0, ""),
         });
         database.clearMapping();
+
+        database.startAddingRootDocuments(0);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 200, "Device", "Storage", 2000, 0, ""),
         });
         database.clearMapping();
+
+        database.startAddingRootDocuments(0);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 300, "Device", "Storage", 3000, 0, ""),
         });
-        database.resolveRootDocuments(0);
+        database.stopAddingRootDocuments(0);
+
         {
             final Cursor cursor = database.queryRootDocuments(columns);
             assertEquals(1, cursor.getCount());
@@ -581,22 +598,27 @@
         final MtpDatabase database = new MtpDatabase(getContext());
         final String[] columns = new String[] {
                 DocumentsContract.Document.COLUMN_DOCUMENT_ID,
-                MtpDatabase.COLUMN_STORAGE_ID,
+                MtpDatabaseConstants.COLUMN_STORAGE_ID,
                 DocumentsContract.Document.COLUMN_DISPLAY_NAME
         };
         final String[] rootColumns = new String[] {
                 Root.COLUMN_ROOT_ID,
                 Root.COLUMN_AVAILABLE_BYTES
         };
+
+        database.startAddingRootDocuments(0);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 100, "Device", "Storage", 0, 0, ""),
         });
         database.clearMapping();
+
+        database.startAddingRootDocuments(0);
         database.putRootDocuments(0, resources, new MtpRoot[] {
                 new MtpRoot(0, 200, "Device", "Storage", 2000, 0, ""),
                 new MtpRoot(0, 201, "Device", "Storage", 2001, 0, ""),
         });
-        database.resolveRootDocuments(0);
+        database.stopAddingRootDocuments(0);
+
         {
             final Cursor cursor = database.queryRootDocuments(columns);
             assertEquals(2, cursor.getCount());
@@ -622,4 +644,71 @@
             cursor.close();
         }
     }
+
+    public void testReplaceExistingRoots() {
+        // The client code should be able to replace exisitng rows with new information.
+        final MtpDatabase database = new MtpDatabase(getContext());
+        // Add one.
+        database.startAddingRootDocuments(0);
+        database.putRootDocuments(0, resources, new MtpRoot[] {
+                new MtpRoot(0, 100, "Device", "Storage A", 0, 0, ""),
+        });
+        database.stopAddingRootDocuments(0);
+        // Replace it.
+        database.startAddingRootDocuments(0);
+        database.putRootDocuments(0, resources, new MtpRoot[] {
+                new MtpRoot(0, 100, "Device", "Storage B", 1000, 1000, ""),
+        });
+        database.stopAddingRootDocuments(0);
+        {
+            final String[] columns = new String[] {
+                    DocumentsContract.Document.COLUMN_DOCUMENT_ID,
+                    MtpDatabaseConstants.COLUMN_STORAGE_ID,
+                    DocumentsContract.Document.COLUMN_DISPLAY_NAME
+            };
+            final Cursor cursor = database.queryRootDocuments(columns);
+            assertEquals(1, cursor.getCount());
+            cursor.moveToNext();
+            assertEquals("documentId", 1, cursor.getInt(0));
+            assertEquals("storageId", 100, cursor.getInt(1));
+            assertEquals("name", "Device Storage B", cursor.getString(2));
+            cursor.close();
+        }
+        {
+            final String[] columns = new String[] {
+                    Root.COLUMN_ROOT_ID,
+                    Root.COLUMN_AVAILABLE_BYTES
+            };
+            final Cursor cursor = database.queryRoots(columns);
+            assertEquals(1, cursor.getCount());
+            cursor.moveToNext();
+            assertEquals("rootId", 1, cursor.getInt(0));
+            assertEquals("availableBytes", 1000, cursor.getInt(1));
+            cursor.close();
+        }
+    }
+
+    public void _testFailToReplaceExisitingUnmappedRoots() {
+        // The client code should not be able to replace rows before resolving 'unmapped' rows.
+        final MtpDatabase database = new MtpDatabase(getContext());
+        // Add one.
+        database.startAddingRootDocuments(0);
+        database.putRootDocuments(0, resources, new MtpRoot[] {
+                new MtpRoot(0, 100, "Device", "Storage A", 0, 0, ""),
+        });
+        database.clearMapping();
+        // Add one.
+        database.putRootDocuments(0, resources, new MtpRoot[] {
+                new MtpRoot(0, 100, "Device", "Storage B", 1000, 1000, ""),
+        });
+        // Add one more before resolving unmapped documents.
+        try {
+            database.putRootDocuments(0, resources, new MtpRoot[] {
+                    new MtpRoot(0, 100, "Device", "Storage B", 1000, 1000, ""),
+            });
+            fail();
+        } catch (Throwable e) {
+            assertTrue(e instanceof Error);
+        }
+    }
 }
diff --git a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
index d55fa4a..c611503 100644
--- a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
+++ b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
@@ -6728,26 +6728,40 @@
             }
             return true;
         } else if (DevicePolicyManager.ACTION_PROVISION_MANAGED_DEVICE.equals(action)) {
-            if (getProfileOwner(callingUserId) != null) {
-                return false;
-            }
-            if (mInjector.settingsGlobalGetInt(Settings.Global.DEVICE_PROVISIONED, 0) != 0) {
-                return false;
-            }
-            if (callingUserId != UserHandle.USER_SYSTEM) {
-                // Device owner provisioning can only be initiated from system user.
-                return false;
-            }
-            return true;
+            return isDeviceOwnerProvisioningAllowed(callingUserId);
         } else if (DevicePolicyManager.ACTION_PROVISION_MANAGED_USER.equals(action)) {
+            if (!UserManager.isSplitSystemUser()) {
+                // ACTION_PROVISION_MANAGED_USER only supported on split-user systems.
+                return false;
+            }
             if (hasUserSetupCompleted(callingUserId)) {
                 return false;
             }
             return true;
+        } else if (DevicePolicyManager.ACTION_PROVISION_MANAGED_SHAREABLE_DEVICE.equals(action)) {
+            if (!UserManager.isSplitSystemUser()) {
+                // ACTION_PROVISION_MANAGED_SHAREABLE_DEVICE only supported on split-user systems.
+                return false;
+            }
+            return isDeviceOwnerProvisioningAllowed(callingUserId);
         }
         throw new IllegalArgumentException("Unknown provisioning action " + action);
     }
 
+    private boolean isDeviceOwnerProvisioningAllowed(int callingUserId) {
+        if (getProfileOwner(callingUserId) != null) {
+            return false;
+        }
+        if (mInjector.settingsGlobalGetInt(Settings.Global.DEVICE_PROVISIONED, 0) != 0) {
+            return false;
+        }
+        if (callingUserId != UserHandle.USER_SYSTEM) {
+            // Device owner provisioning can only be initiated from system user.
+            return false;
+        }
+        return true;
+    }
+
     /**
      * Returns the target sdk version number that the given packageName was built for
      * in the given user.