Merge "Extends MtpDatabase so that it can handle child documents." (3034538c) · Commits · e / os / android_frameworks_base

packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java

+106 −82

Original line number	Original line	Diff line number	Diff line
	@@ -84,8 +84,7 @@ class MtpDatabase {
	DocumentsContract.Document.COLUMN_DOCUMENT_ID + " = ?";		DocumentsContract.Document.COLUMN_DOCUMENT_ID + " = ?";
	private static final String SELECTION_ROOT_DOCUMENTS =		private static final String SELECTION_ROOT_DOCUMENTS =
	COLUMN_DEVICE_ID + " = ? AND " + COLUMN_PARENT_DOCUMENT_ID + " IS NULL";		COLUMN_DEVICE_ID + " = ? AND " + COLUMN_PARENT_DOCUMENT_ID + " IS NULL";
	private static final String SELECTION_ROOT_DOCUMENTS_WITH_STATE =		private static final String SELECTION_CHILD_DOCUMENTS = COLUMN_PARENT_DOCUMENT_ID + " = ?";
	SELECTION_ROOT_DOCUMENTS + " AND " + COLUMN_ROW_STATE + " = ?";

	static class ParentNotFoundException extends Exception {}		static class ParentNotFoundException extends Exception {}

	@@ -136,7 +135,7 @@ class MtpDatabase {
	}		}

	@VisibleForTesting		@VisibleForTesting
	Cursor queryChildDocuments(String[] columnNames) {		Cursor queryRootDocuments(String[] columnNames) {
	return database.query(		return database.query(
	TABLE_DOCUMENTS,		TABLE_DOCUMENTS,
	columnNames,		columnNames,
	@@ -159,84 +158,27 @@ class MtpDatabase {
	null);		null);
	}		}

	/**
	* Puts the roots into the database.
	* If the database found another unmapped document that shares the same name with the root,
	* 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 deviceId Device ID of roots.
	* @param resources Resources used to get localized root name.
	* @param roots Roots added to the database.
	*/
	@VisibleForTesting		@VisibleForTesting
	void putRootDocuments(int deviceId, Resources resources, MtpRoot[] roots) {		void putRootDocuments(int deviceId, Resources resources, MtpRoot[] roots) {
	database.beginTransaction();		final ContentValues[] valuesList = new ContentValues[roots.length];
	try {
	// Add roots to database.
	final ContentValues values = new ContentValues();
	for (int i = 0; i < roots.length; i++) {		for (int i = 0; i < roots.length; i++) {
	getRootDocumentValues(values, resources, roots[i]);		if (roots[i].mDeviceId != deviceId) {
	final String displayName =		throw new IllegalArgumentException();
	values.getAsString(DocumentsContract.Document.COLUMN_DISPLAY_NAME);
	final long numUnmapped = DatabaseUtils.queryNumEntries(
	database,
	TABLE_DOCUMENTS,
	SELECTION_ROOT_DOCUMENTS_WITH_STATE + " AND " +
	DocumentsContract.Document.COLUMN_DISPLAY_NAME + " = ?",
	strings(deviceId, ROW_STATE_UNMAPPED, displayName));
	if (numUnmapped != 0) {
	values.put(COLUMN_ROW_STATE, ROW_STATE_MAPPING);
	}		}
	database.insert(TABLE_DOCUMENTS, null, values);		valuesList[i] = new ContentValues();
	}		getRootDocumentValues(valuesList[i], resources, roots[i]);
	database.setTransactionSuccessful();
	} finally {
	database.endTransaction();
	}		}
			putDocuments(valuesList, SELECTION_ROOT_DOCUMENTS, Integer.toString(deviceId));
	}		}

	@VisibleForTesting		@VisibleForTesting
	void putDocument(int deviceId, MtpObjectInfo info) throws Exception {		void putChildDocuments(int deviceId, String parentId, MtpObjectInfo[] documents) {
	database.beginTransaction();		final ContentValues[] valuesList = new ContentValues[documents.length];
	try {		for (int i = 0; i < documents.length; i++) {
	final String mimeType = CursorHelper.formatTypeToMimeType(info.getFormat());		valuesList[i] = new ContentValues();
			getChildDocumentValues(valuesList[i], deviceId, parentId, documents[i]);
	int flag = 0;
	if (info.getProtectionStatus() == 0) {
	flag \|= DocumentsContract.Document.FLAG_SUPPORTS_DELETE \|
	DocumentsContract.Document.FLAG_SUPPORTS_WRITE;
	if (mimeType == DocumentsContract.Document.MIME_TYPE_DIR) {
	flag \|= DocumentsContract.Document.FLAG_DIR_SUPPORTS_CREATE;
	}
	}
	if (info.getThumbCompressedSize() > 0) {
	flag \|= DocumentsContract.Document.FLAG_SUPPORTS_THUMBNAIL;
	}

	final ContentValues values = new ContentValues();
	values.put(COLUMN_DEVICE_ID, deviceId);
	values.put(COLUMN_STORAGE_ID, info.getStorageId());
	values.put(COLUMN_OBJECT_HANDLE, info.getObjectHandle());
	// TODO: Specify correct document ID.
	values.putNull(COLUMN_PARENT_DOCUMENT_ID);
	values.put(COLUMN_ROW_STATE, ROW_STATE_MAPPED);
	values.put(Document.COLUMN_MIME_TYPE, mimeType);
	values.put(Document.COLUMN_DISPLAY_NAME, info.getName());
	values.putNull(Document.COLUMN_SUMMARY);
	values.put(
	Document.COLUMN_LAST_MODIFIED,
	info.getDateModified() != 0 ? info.getDateModified() : null);
	values.putNull(Document.COLUMN_ICON);
	values.put(Document.COLUMN_FLAGS, flag);
	values.put(Document.COLUMN_SIZE, info.getCompressedSize());
	if (database.insert(TABLE_DOCUMENTS, null, values) == -1) {
	throw new Exception("Failed to add document.");
	}

	database.setTransactionSuccessful();
	} finally {
	database.endTransaction();
	}		}
			putDocuments(valuesList, SELECTION_CHILD_DOCUMENTS, parentId);
	}		}

	/**		/**
	@@ -261,15 +203,59 @@ class MtpDatabase {
	}		}
	}		}

			@VisibleForTesting
			void resolveRootDocuments(int deviceId) {
			resolveDocuments(SELECTION_ROOT_DOCUMENTS, Integer.toString(deviceId));
			}

			@VisibleForTesting
			void resolveChildDocuments(String parentId) {
			resolveDocuments(SELECTION_CHILD_DOCUMENTS, parentId);
			}

			/**
			* 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.
			*/
			private void putDocuments(ContentValues[] valuesList, String selection, String arg) {
			database.beginTransaction();
			try {
			for (final ContentValues values : valuesList) {
			final String displayName =
			values.getAsString(DocumentsContract.Document.COLUMN_DISPLAY_NAME);
			final long numUnmapped = DatabaseUtils.queryNumEntries(
			database,
			TABLE_DOCUMENTS,
			selection + " AND " +
			COLUMN_ROW_STATE + " = ? AND " +
			DocumentsContract.Document.COLUMN_DISPLAY_NAME + " = ?",
			strings(arg, ROW_STATE_UNMAPPED, displayName));
			if (numUnmapped != 0) {
			values.put(COLUMN_ROW_STATE, ROW_STATE_MAPPING);
			}
			database.insert(TABLE_DOCUMENTS, null, values);
			}

			database.setTransactionSuccessful();
			} finally {
			database.endTransaction();
			}
			}

	/**		/**
	* Maps 'unmapped' document and 'mapping' document that don't have document but shares the same		* Maps 'unmapped' document and 'mapping' document that don't have document but shares the same
	* name.		* name.
	* If the database does not find corresponding 'mapping' document, it just removes 'unmapped'		* If the database does not find corresponding 'mapping' document, it just removes 'unmapped'
	* document from the database.		* document from the database.
	* @param deviceId Device ID of roots which the method tries to resolve.		* @param selection Query to select rows for resolving.
			* @param arg Argument for selection SQL.
	*/		*/
	@VisibleForTesting		private void resolveDocuments(String selection, String arg) {
	void resolveRootDocuments(int deviceId) {
	database.beginTransaction();		database.beginTransaction();
	try {		try {
	// Get 1-to-1 mapping of unmapped document and mapping document.		// Get 1-to-1 mapping of unmapped document and mapping document.
	@@ -290,8 +276,8 @@ class MtpDatabase {
	"group_concat(" + unmappedIdQuery + ")",		"group_concat(" + unmappedIdQuery + ")",
	"group_concat(" + mappingIdQuery + ")"		"group_concat(" + mappingIdQuery + ")"
	},		},
	SELECTION_ROOT_DOCUMENTS,		selection,
	strings(deviceId),		strings(arg),
	DocumentsContract.Document.COLUMN_DISPLAY_NAME,		DocumentsContract.Document.COLUMN_DISPLAY_NAME,
	"count(" + unmappedIdQuery + ") = 1 AND count(" + mappingIdQuery + ") = 1",		"count(" + unmappedIdQuery + ") = 1 AND count(" + mappingIdQuery + ") = 1",
	null);		null);
	@@ -335,8 +321,8 @@ class MtpDatabase {
	// Delete all unmapped rows that cannot be mapped.		// Delete all unmapped rows that cannot be mapped.
	database.delete(		database.delete(
	TABLE_DOCUMENTS,		TABLE_DOCUMENTS,
	SELECTION_ROOT_DOCUMENTS_WITH_STATE,		COLUMN_ROW_STATE + " = ? AND " + selection,
	strings(deviceId, ROW_STATE_UNMAPPED));		strings(ROW_STATE_UNMAPPED, arg));

	// The database cannot find old document ID for the mapping rows.		// 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		// Turn the all mapping rows into mapped state, which means the rows become to be
	@@ -346,8 +332,8 @@ class MtpDatabase {
	database.update(		database.update(
	TABLE_DOCUMENTS,		TABLE_DOCUMENTS,
	values,		values,
	SELECTION_ROOT_DOCUMENTS_WITH_STATE,		COLUMN_ROW_STATE + " = ? AND " + selection,
	strings(deviceId, ROW_STATE_MAPPING));		strings(ROW_STATE_MAPPING, arg));
	database.setTransactionSuccessful();		database.setTransactionSuccessful();
	} finally {		} finally {
	database.endTransaction();		database.endTransaction();
	@@ -378,6 +364,44 @@ class MtpDatabase {
	(int) Math.min(root.mMaxCapacity - root.mFreeSpace, Integer.MAX_VALUE));		(int) Math.min(root.mMaxCapacity - root.mFreeSpace, Integer.MAX_VALUE));
	}		}

			/**
			* Gets {@link ContentValues} for the given MTP object.
			* @param values {@link ContentValues} that receives values.
			* @param deviceId Device ID of the object.
			* @param parentId Parent document ID of the object.
			* @param info MTP object info.
			*/
			private void getChildDocumentValues(
			ContentValues values, int deviceId, String parentId, MtpObjectInfo info) {
			values.clear();
			final String mimeType = CursorHelper.formatTypeToMimeType(info.getFormat());
			int flag = 0;
			if (info.getProtectionStatus() == 0) {
			flag \|= DocumentsContract.Document.FLAG_SUPPORTS_DELETE \|
			DocumentsContract.Document.FLAG_SUPPORTS_WRITE;
			if (mimeType == DocumentsContract.Document.MIME_TYPE_DIR) {
			flag \|= DocumentsContract.Document.FLAG_DIR_SUPPORTS_CREATE;
			}
			}
			if (info.getThumbCompressedSize() > 0) {
			flag \|= DocumentsContract.Document.FLAG_SUPPORTS_THUMBNAIL;
			}
			values.put(COLUMN_DEVICE_ID, deviceId);
			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(Document.COLUMN_MIME_TYPE, mimeType);
			values.put(Document.COLUMN_DISPLAY_NAME, info.getName());
			values.putNull(Document.COLUMN_SUMMARY);
			values.put(
			Document.COLUMN_LAST_MODIFIED,
			info.getDateModified() != 0 ? info.getDateModified() : null);
			values.putNull(Document.COLUMN_ICON);
			values.put(Document.COLUMN_FLAGS, flag);
			values.put(Document.COLUMN_SIZE, info.getCompressedSize());
			}

	/**		/**
	* Converts values into string array.		* Converts values into string array.
	* @param args Values converted into string array.		* @param args Values converted into string array.

packages/MtpDocumentsProvider/tests/src/com/android/mtp/MtpDatabaseTest.java

+181 −24

Original line number	Original line	Diff line number	Diff line
	@@ -46,7 +46,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	MtpDatabase.deleteDatabase(getContext());		MtpDatabase.deleteDatabase(getContext());
	}		}

	public void testPutRootDocument() throws Exception {		public void testPutRootDocuments() throws Exception {
	final MtpDatabase database = new MtpDatabase(getContext());		final MtpDatabase database = new MtpDatabase(getContext());
	database.putRootDocuments(0, resources, new MtpRoot[] {		database.putRootDocuments(0, resources, new MtpRoot[] {
	new MtpRoot(0, 1, "Device", "Storage", 1000, 2000, ""),		new MtpRoot(0, 1, "Device", "Storage", 1000, 2000, ""),
	@@ -54,7 +54,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	new MtpRoot(0, 3, "Device", "/@#%&<>Storage", 1000, 2000,"")		new MtpRoot(0, 3, "Device", "/@#%&<>Storage", 1000, 2000,"")
	});		});

	final Cursor cursor = database.queryChildDocuments(COLUMN_NAMES);		final Cursor cursor = database.queryRootDocuments(COLUMN_NAMES);
	assertEquals(3, cursor.getCount());		assertEquals(3, cursor.getCount());

	cursor.moveToNext();		cursor.moveToNext();
	@@ -81,25 +81,34 @@ public class MtpDatabaseTest extends AndroidTestCase {
	cursor.close();		cursor.close();
	}		}

	public void testPutDocument() throws Exception {		private MtpObjectInfo createDocument(int objectHandle, String name, int format, int size) {
	final MtpDatabase database = new MtpDatabase(getContext());
	final MtpObjectInfo.Builder builder = new MtpObjectInfo.Builder();		final MtpObjectInfo.Builder builder = new MtpObjectInfo.Builder();
	builder.setObjectHandle(100);		builder.setObjectHandle(objectHandle);
	builder.setName("test.txt");		builder.setName(name);
	builder.setStorageId(5);		builder.setFormat(format);
	builder.setFormat(MtpConstants.FORMAT_TEXT);		builder.setCompressedSize(size);
	builder.setCompressedSize(1000);		return builder.build();
	database.putDocument(0, builder.build());		}

	final Cursor cursor = database.queryChildDocuments(COLUMN_NAMES);		public void testPutChildDocuments() throws Exception {
	assertEquals(1, cursor.getCount());		final MtpDatabase database = new MtpDatabase(getContext());

			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),
			createDocument(102, "music.mp3", MtpConstants.FORMAT_MP3, 3 * 1024 * 1024)
			});

			final Cursor cursor = database.queryChildDocuments(COLUMN_NAMES, "parentId");
			assertEquals(3, cursor.getCount());

	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 1, cursor.getInt(0));		assertEquals("documentId", 1, cursor.getInt(0));
	assertEquals("deviceId", 0, cursor.getInt(1));		assertEquals("deviceId", 0, cursor.getInt(1));
	assertEquals("storageId", 5, cursor.getInt(2));		assertEquals("storageId", 0, cursor.getInt(2));
	assertEquals("objectHandle", 100, cursor.getInt(3));		assertEquals("objectHandle", 100, cursor.getInt(3));
	assertEquals("mimeType", "text/plain", cursor.getString(4));		assertEquals("mimeType", "text/plain", cursor.getString(4));
	assertEquals("displayName", "test.txt", cursor.getString(5));		assertEquals("displayName", "note.txt", cursor.getString(5));
	assertTrue("summary", cursor.isNull(6));		assertTrue("summary", cursor.isNull(6));
	assertTrue("lastModified", cursor.isNull(7));		assertTrue("lastModified", cursor.isNull(7));
	assertTrue("icon", cursor.isNull(8));		assertTrue("icon", cursor.isNull(8));
	@@ -108,7 +117,43 @@ public class MtpDatabaseTest extends AndroidTestCase {
	DocumentsContract.Document.FLAG_SUPPORTS_DELETE \|		DocumentsContract.Document.FLAG_SUPPORTS_DELETE \|
	DocumentsContract.Document.FLAG_SUPPORTS_WRITE,		DocumentsContract.Document.FLAG_SUPPORTS_WRITE,
	cursor.getInt(9));		cursor.getInt(9));
	assertEquals("size", 1000, cursor.getInt(10));		assertEquals("size", 1024, cursor.getInt(10));

			cursor.moveToNext();
			assertEquals("documentId", 2, cursor.getInt(0));
			assertEquals("deviceId", 0, cursor.getInt(1));
			assertEquals("storageId", 0, cursor.getInt(2));
			assertEquals("objectHandle", 101, cursor.getInt(3));
			assertEquals("mimeType", "image/jpeg", cursor.getString(4));
			assertEquals("displayName", "image.jpg", cursor.getString(5));
			assertTrue("summary", cursor.isNull(6));
			assertTrue("lastModified", cursor.isNull(7));
			assertTrue("icon", cursor.isNull(8));
			assertEquals(
			"flag",
			DocumentsContract.Document.FLAG_SUPPORTS_DELETE \|
			DocumentsContract.Document.FLAG_SUPPORTS_WRITE,
			cursor.getInt(9));
			assertEquals("size", 2 * 1024 * 1024, cursor.getInt(10));

			cursor.moveToNext();
			assertEquals("documentId", 3, cursor.getInt(0));
			assertEquals("deviceId", 0, cursor.getInt(1));
			assertEquals("storageId", 0, cursor.getInt(2));
			assertEquals("objectHandle", 102, cursor.getInt(3));
			assertEquals("mimeType", "audio/mpeg", cursor.getString(4));
			assertEquals("displayName", "music.mp3", cursor.getString(5));
			assertTrue("summary", cursor.isNull(6));
			assertTrue("lastModified", cursor.isNull(7));
			assertTrue("icon", cursor.isNull(8));
			assertEquals(
			"flag",
			DocumentsContract.Document.FLAG_SUPPORTS_DELETE \|
			DocumentsContract.Document.FLAG_SUPPORTS_WRITE,
			cursor.getInt(9));
			assertEquals("size", 3 * 1024 * 1024, cursor.getInt(10));

			cursor.close();
	}		}

	public void testRestoreIdForRootDocuments() throws Exception {		public void testRestoreIdForRootDocuments() throws Exception {
	@@ -124,7 +169,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	});		});

	{		{
	final Cursor cursor = database.queryChildDocuments(columns);		final Cursor cursor = database.queryRootDocuments(columns);
	assertEquals(2, cursor.getCount());		assertEquals(2, cursor.getCount());
	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 1, cursor.getInt(0));		assertEquals("documentId", 1, cursor.getInt(0));
	@@ -140,7 +185,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	database.clearMapping();		database.clearMapping();

	{		{
	final Cursor cursor = database.queryChildDocuments(columns);		final Cursor cursor = database.queryRootDocuments(columns);
	assertEquals(2, cursor.getCount());		assertEquals(2, cursor.getCount());
	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 1, cursor.getInt(0));		assertEquals("documentId", 1, cursor.getInt(0));
	@@ -159,7 +204,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	});		});

	{		{
	final Cursor cursor = database.queryChildDocuments(columns);		final Cursor cursor = database.queryRootDocuments(columns);
	assertEquals(3, cursor.getCount());		assertEquals(3, cursor.getCount());
	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 1, cursor.getInt(0));		assertEquals("documentId", 1, cursor.getInt(0));
	@@ -179,7 +224,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	database.resolveRootDocuments(0);		database.resolveRootDocuments(0);

	{		{
	final Cursor cursor = database.queryChildDocuments(columns);		final Cursor cursor = database.queryRootDocuments(columns);
	assertEquals(2, cursor.getCount());		assertEquals(2, cursor.getCount());
	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 1, cursor.getInt(0));		assertEquals("documentId", 1, cursor.getInt(0));
	@@ -193,6 +238,78 @@ public class MtpDatabaseTest extends AndroidTestCase {
	}		}
	}		}

			public void testRestoreIdForChildDocuments() throws Exception {
			final MtpDatabase database = new MtpDatabase(getContext());
			final String[] columns = new String[] {
			DocumentsContract.Document.COLUMN_DOCUMENT_ID,
			MtpDatabase.COLUMN_OBJECT_HANDLE,
			DocumentsContract.Document.COLUMN_DISPLAY_NAME
			};
			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),
			createDocument(102, "music.mp3", MtpConstants.FORMAT_MP3, 3 * 1024 * 1024)
			});
			database.clearMapping();

			{
			final Cursor cursor = database.queryChildDocuments(columns, "parentId");
			assertEquals(3, cursor.getCount());

			cursor.moveToNext();
			assertEquals("documentId", 1, cursor.getInt(0));
			assertTrue("objectHandle", cursor.isNull(1));
			assertEquals("name", "note.txt", cursor.getString(2));

			cursor.moveToNext();
			assertEquals("documentId", 2, cursor.getInt(0));
			assertTrue("objectHandle", cursor.isNull(1));
			assertEquals("name", "image.jpg", cursor.getString(2));

			cursor.moveToNext();
			assertEquals("documentId", 3, cursor.getInt(0));
			assertTrue("objectHandle", cursor.isNull(1));
			assertEquals("name", "music.mp3", cursor.getString(2));

			cursor.close();
			}

			database.putChildDocuments(0, "parentId", new MtpObjectInfo[] {
			createDocument(200, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
			createDocument(203, "video.mp4", MtpConstants.FORMAT_MP4_CONTAINER, 1024),
			});

			{
			final Cursor cursor = database.queryChildDocuments(columns, "parentId");
			assertEquals(4, cursor.getCount());

			cursor.moveToPosition(3);
			assertEquals("documentId", 5, cursor.getInt(0));
			assertEquals("objectHandle", 203, cursor.getInt(1));
			assertEquals("name", "video.mp4", cursor.getString(2));

			cursor.close();
			}

			database.resolveChildDocuments("parentId");

			{
			final Cursor cursor = database.queryChildDocuments(columns, "parentId");
			assertEquals(2, cursor.getCount());

			cursor.moveToNext();
			assertEquals("documentId", 1, cursor.getInt(0));
			assertEquals("objectHandle", 200, cursor.getInt(1));
			assertEquals("name", "note.txt", cursor.getString(2));

			cursor.moveToNext();
			assertEquals("documentId", 5, cursor.getInt(0));
			assertEquals("objectHandle", 203, cursor.getInt(1));
			assertEquals("name", "video.mp4", cursor.getString(2));
			cursor.close();
			}
			}

	public void testRestoreIdForDifferentDevices() throws Exception {		public void testRestoreIdForDifferentDevices() throws Exception {
	final MtpDatabase database = new MtpDatabase(getContext());		final MtpDatabase database = new MtpDatabase(getContext());
	final String[] columns = new String[] {		final String[] columns = new String[] {
	@@ -208,7 +325,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	});		});

	{		{
	final Cursor cursor = database.queryChildDocuments(columns);		final Cursor cursor = database.queryRootDocuments(columns);
	assertEquals(2, cursor.getCount());		assertEquals(2, cursor.getCount());
	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 1, cursor.getInt(0));		assertEquals("documentId", 1, cursor.getInt(0));
	@@ -231,8 +348,9 @@ public class MtpDatabaseTest extends AndroidTestCase {
	});		});
	database.resolveRootDocuments(0);		database.resolveRootDocuments(0);
	database.resolveRootDocuments(1);		database.resolveRootDocuments(1);

	{		{
	final Cursor cursor = database.queryChildDocuments(columns);		final Cursor cursor = database.queryRootDocuments(columns);
	assertEquals(2, cursor.getCount());		assertEquals(2, cursor.getCount());
	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 1, cursor.getInt(0));		assertEquals("documentId", 1, cursor.getInt(0));
	@@ -246,6 +364,45 @@ public class MtpDatabaseTest extends AndroidTestCase {
	}		}
	}		}

			public void testRestoreIdForDifferentParents() throws Exception {
			final MtpDatabase database = new MtpDatabase(getContext());
			final String[] columns = new String[] {
			DocumentsContract.Document.COLUMN_DOCUMENT_ID,
			MtpDatabase.COLUMN_OBJECT_HANDLE
			};
			database.putChildDocuments(0, "parentId1", new MtpObjectInfo[] {
			createDocument(100, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
			});
			database.putChildDocuments(0, "parentId2", new MtpObjectInfo[] {
			createDocument(101, "note.txt", MtpConstants.FORMAT_TEXT, 1024),
			});
			database.clearMapping();
			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");

			{
			final Cursor cursor = database.queryChildDocuments(columns, "parentId1");
			assertEquals(1, cursor.getCount());
			cursor.moveToNext();
			assertEquals("documentId", 1, cursor.getInt(0));
			assertEquals("objectHandle", 200, cursor.getInt(1));
			cursor.close();
			}
			{
			final Cursor cursor = database.queryChildDocuments(columns, "parentId2");
			assertEquals(1, cursor.getCount());
			cursor.moveToNext();
			assertEquals("documentId", 2, cursor.getInt(0));
			assertTrue("objectHandle", cursor.isNull(1));
			cursor.close();
			}
			}

	public void testClearMtpIdentifierBeforeResolveRootDocuments() {		public void testClearMtpIdentifierBeforeResolveRootDocuments() {
	final MtpDatabase database = new MtpDatabase(getContext());		final MtpDatabase database = new MtpDatabase(getContext());
	final String[] columns = new String[] {		final String[] columns = new String[] {
	@@ -266,7 +423,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	});		});
	database.resolveRootDocuments(0);		database.resolveRootDocuments(0);
	{		{
	final Cursor cursor = database.queryChildDocuments(columns);		final Cursor cursor = database.queryRootDocuments(columns);
	assertEquals(1, cursor.getCount());		assertEquals(1, cursor.getCount());
	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 1, cursor.getInt(0));		assertEquals("documentId", 1, cursor.getInt(0));
	@@ -293,7 +450,7 @@ public class MtpDatabaseTest extends AndroidTestCase {
	});		});
	database.resolveRootDocuments(0);		database.resolveRootDocuments(0);
	{		{
	final Cursor cursor = database.queryChildDocuments(columns);		final Cursor cursor = database.queryRootDocuments(columns);
	assertEquals(2, cursor.getCount());		assertEquals(2, cursor.getCount());
	cursor.moveToNext();		cursor.moveToNext();
	assertEquals("documentId", 2, cursor.getInt(0));		assertEquals("documentId", 2, cursor.getInt(0));