1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.mtp;
18 
19 import static com.android.mtp.MtpDatabaseConstants.*;
20 
21 import android.annotation.Nullable;
22 import android.content.ContentValues;
23 import android.content.Context;
24 import android.content.res.Resources;
25 import android.database.Cursor;
26 import android.database.DatabaseUtils;
27 import android.database.MatrixCursor;
28 import android.database.MatrixCursor.RowBuilder;
29 import android.database.sqlite.SQLiteDatabase;
30 import android.database.sqlite.SQLiteOpenHelper;
31 import android.database.sqlite.SQLiteQueryBuilder;
32 import android.media.MediaFile;
33 import android.mtp.MtpConstants;
34 import android.mtp.MtpObjectInfo;
35 import android.net.Uri;
36 import android.provider.DocumentsContract;
37 import android.provider.DocumentsContract.Document;
38 import android.provider.DocumentsContract.Root;
39 
40 import com.android.internal.annotations.VisibleForTesting;
41 import com.android.internal.util.Preconditions;
42 
43 import java.io.FileNotFoundException;
44 import java.util.HashSet;
45 import java.util.Objects;
46 import java.util.Set;
47 
48 /**
49  * Database for MTP objects.
50  * The object handle which is identifier for object in MTP protocol is not stable over sessions.
51  * When we resume the process, we need to remap our document ID with MTP's object handle.
52  *
53  * If the remote MTP device is backed by typical file system, the file name
54  * is unique among files in a directory. However, MTP protocol itself does
55  * not guarantee the uniqueness of name so we cannot use fullpath as ID.
56  *
57  * Instead of fullpath, we use artificial ID generated by MtpDatabase itself. The database object
58  * remembers the map of document ID and object handle, and remaps new object handle with document ID
59  * by comparing the directory structure and object name.
60  *
61  * To start putting documents into the database, the client needs to call
62  * {@link Mapper#startAddingDocuments(String)} with the parent document ID. Also it
63  * needs to call {@link Mapper#stopAddingDocuments(String)} after putting all child
64  * documents to the database. (All explanations are same for root documents)
65  *
66  * database.getMapper().startAddingDocuments();
67  * database.getMapper().putChildDocuments();
68  * database.getMapper().stopAddingDocuments();
69  *
70  * To update the existing documents, the client code can repeat to call the three methods again.
71  * The newly added rows update corresponding existing rows that have same MTP identifier like
72  * objectHandle.
73  *
74  * The client can call putChildDocuments multiple times to add documents by chunk, but it needs to
75  * put all documents under the parent before calling stopAddingChildDocuments. Otherwise missing
76  * documents are regarded as deleted, and will be removed from the database.
77  *
78  * If the client calls clearMtpIdentifier(), it clears MTP identifier in the database. In this case,
79  * the database tries to find corresponding rows by using document's name instead of MTP identifier
80  * at the next update cycle.
81  *
82  * TODO: Improve performance by SQL optimization.
83  */
84 class MtpDatabase {
85     private final SQLiteDatabase mDatabase;
86     private final Mapper mMapper;
87 
getSQLiteDatabase()88     SQLiteDatabase getSQLiteDatabase() {
89         return mDatabase;
90     }
91 
MtpDatabase(Context context, int flags)92     MtpDatabase(Context context, int flags) {
93         final OpenHelper helper = new OpenHelper(context, flags);
94         mDatabase = helper.getWritableDatabase();
95         mMapper = new Mapper(this);
96     }
97 
close()98     void close() {
99         mDatabase.close();
100     }
101 
102     /**
103      * Returns operations for mapping.
104      * @return Mapping operations.
105      */
getMapper()106     Mapper getMapper() {
107         return mMapper;
108     }
109 
110     /**
111      * Queries roots information.
112      * @param columnNames Column names defined in {@link android.provider.DocumentsContract.Root}.
113      * @return Database cursor.
114      */
queryRoots(Resources resources, String[] columnNames)115     Cursor queryRoots(Resources resources, String[] columnNames) {
116         final String selection =
117                 COLUMN_ROW_STATE + " IN (?, ?) AND " + COLUMN_DOCUMENT_TYPE + " = ?";
118         final Cursor deviceCursor = mDatabase.query(
119                 TABLE_DOCUMENTS,
120                 strings(COLUMN_DEVICE_ID),
121                 selection,
122                 strings(ROW_STATE_VALID, ROW_STATE_INVALIDATED, DOCUMENT_TYPE_DEVICE),
123                 COLUMN_DEVICE_ID,
124                 null,
125                 null,
126                 null);
127 
128         try {
129             final SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
130             builder.setTables(JOIN_ROOTS);
131             builder.setProjectionMap(COLUMN_MAP_ROOTS);
132             final MatrixCursor result = new MatrixCursor(columnNames);
133             final ContentValues values = new ContentValues();
134 
135             while (deviceCursor.moveToNext()) {
136                 final int deviceId = deviceCursor.getInt(0);
137                 final Cursor storageCursor = builder.query(
138                         mDatabase,
139                         columnNames,
140                         selection + " AND " + COLUMN_DEVICE_ID + " = ?",
141                         strings(ROW_STATE_VALID,
142                                 ROW_STATE_INVALIDATED,
143                                 DOCUMENT_TYPE_STORAGE,
144                                 deviceId),
145                         null,
146                         null,
147                         null);
148                 try {
149                     values.clear();
150                     try (final Cursor deviceRoot = builder.query(
151                             mDatabase,
152                             columnNames,
153                             selection + " AND " + COLUMN_DEVICE_ID + " = ?",
154                             strings(ROW_STATE_VALID,
155                                     ROW_STATE_INVALIDATED,
156                                     DOCUMENT_TYPE_DEVICE,
157                                     deviceId),
158                             null,
159                             null,
160                             null)) {
161                         deviceRoot.moveToNext();
162                         DatabaseUtils.cursorRowToContentValues(deviceRoot, values);
163                     }
164 
165                     if (storageCursor.getCount() != 0) {
166                         long capacityBytes = 0;
167                         long availableBytes = 0;
168                         final int capacityIndex =
169                                 storageCursor.getColumnIndex(Root.COLUMN_CAPACITY_BYTES);
170                         final int availableIndex =
171                                 storageCursor.getColumnIndex(Root.COLUMN_AVAILABLE_BYTES);
172                         while (storageCursor.moveToNext()) {
173                             // If requested columnNames does not include COLUMN_XXX_BYTES, we
174                             // don't calculate corresponding values.
175                             if (capacityIndex != -1) {
176                                 capacityBytes += storageCursor.getLong(capacityIndex);
177                             }
178                             if (availableIndex != -1) {
179                                 availableBytes += storageCursor.getLong(availableIndex);
180                             }
181                         }
182                         values.put(Root.COLUMN_CAPACITY_BYTES, capacityBytes);
183                         values.put(Root.COLUMN_AVAILABLE_BYTES, availableBytes);
184                     } else {
185                         values.putNull(Root.COLUMN_CAPACITY_BYTES);
186                         values.putNull(Root.COLUMN_AVAILABLE_BYTES);
187                     }
188                     if (storageCursor.getCount() == 1 && values.containsKey(Root.COLUMN_TITLE)) {
189                         storageCursor.moveToFirst();
190                         // Add storage name to device name if we have only 1 storage.
191                         values.put(
192                                 Root.COLUMN_TITLE,
193                                 resources.getString(
194                                         R.string.root_name,
195                                         values.getAsString(Root.COLUMN_TITLE),
196                                         storageCursor.getString(
197                                                 storageCursor.getColumnIndex(Root.COLUMN_TITLE))));
198                     }
199                 } finally {
200                     storageCursor.close();
201                 }
202 
203                 final RowBuilder row = result.newRow();
204                 for (final String key : values.keySet()) {
205                     row.add(key, values.get(key));
206                 }
207             }
208 
209             return result;
210         } finally {
211             deviceCursor.close();
212         }
213     }
214 
215     /**
216      * Queries root documents information.
217      * @param columnNames Column names defined in
218      *     {@link android.provider.DocumentsContract.Document}.
219      * @return Database cursor.
220      */
221     @VisibleForTesting
queryRootDocuments(String[] columnNames)222     Cursor queryRootDocuments(String[] columnNames) {
223         return mDatabase.query(
224                 TABLE_DOCUMENTS,
225                 columnNames,
226                 COLUMN_ROW_STATE + " IN (?, ?) AND " + COLUMN_DOCUMENT_TYPE + " = ?",
227                 strings(ROW_STATE_VALID, ROW_STATE_INVALIDATED, DOCUMENT_TYPE_STORAGE),
228                 null,
229                 null,
230                 null);
231     }
232 
233     /**
234      * Queries documents information.
235      * @param columnNames Column names defined in
236      *     {@link android.provider.DocumentsContract.Document}.
237      * @return Database cursor.
238      */
queryChildDocuments(String[] columnNames, String parentDocumentId)239     Cursor queryChildDocuments(String[] columnNames, String parentDocumentId) {
240         return mDatabase.query(
241                 TABLE_DOCUMENTS,
242                 columnNames,
243                 COLUMN_ROW_STATE + " IN (?, ?) AND " + COLUMN_PARENT_DOCUMENT_ID + " = ?",
244                 strings(ROW_STATE_VALID, ROW_STATE_INVALIDATED, parentDocumentId),
245                 null,
246                 null,
247                 null);
248     }
249 
250     /**
251      * Returns document IDs of storages under the given device document.
252      *
253      * @param documentId Document ID that points a device.
254      * @return Storage document IDs.
255      * @throws FileNotFoundException The given document ID is not registered in database.
256      */
getStorageDocumentIds(String documentId)257     String[] getStorageDocumentIds(String documentId)
258             throws FileNotFoundException {
259         Preconditions.checkArgument(createIdentifier(documentId).mDocumentType ==
260                 DOCUMENT_TYPE_DEVICE);
261         // Check if the parent document is device that has single storage.
262         try (final Cursor cursor = mDatabase.query(
263                 TABLE_DOCUMENTS,
264                 strings(Document.COLUMN_DOCUMENT_ID),
265                 COLUMN_ROW_STATE + " IN (?, ?) AND " +
266                 COLUMN_PARENT_DOCUMENT_ID + " = ? AND " +
267                 COLUMN_DOCUMENT_TYPE + " = ?",
268                 strings(ROW_STATE_VALID,
269                         ROW_STATE_INVALIDATED,
270                         documentId,
271                         DOCUMENT_TYPE_STORAGE),
272                 null,
273                 null,
274                 null)) {
275             final String[] ids = new String[cursor.getCount()];
276             for (int i = 0; cursor.moveToNext(); i++) {
277                 ids[i] = cursor.getString(0);
278             }
279             return ids;
280         }
281     }
282 
283     /**
284      * Queries a single document.
285      * @param documentId
286      * @param projection
287      * @return Database cursor.
288      */
queryDocument(String documentId, String[] projection)289     Cursor queryDocument(String documentId, String[] projection) {
290         return mDatabase.query(
291                 TABLE_DOCUMENTS,
292                 projection,
293                 SELECTION_DOCUMENT_ID,
294                 strings(documentId),
295                 null,
296                 null,
297                 null,
298                 "1");
299     }
300 
getDocumentIdForDevice(int deviceId)301     @Nullable String getDocumentIdForDevice(int deviceId) {
302         final Cursor cursor = mDatabase.query(
303                 TABLE_DOCUMENTS,
304                 strings(Document.COLUMN_DOCUMENT_ID),
305                 COLUMN_DOCUMENT_TYPE + " = ? AND " + COLUMN_DEVICE_ID + " = ?",
306                 strings(DOCUMENT_TYPE_DEVICE, deviceId),
307                 null,
308                 null,
309                 null,
310                 "1");
311         try {
312             if (cursor.moveToNext()) {
313                 return cursor.getString(0);
314             } else {
315                 return null;
316             }
317         } finally {
318             cursor.close();
319         }
320     }
321 
322     /**
323      * Obtains parent identifier.
324      * @param documentId
325      * @return parent identifier.
326      * @throws FileNotFoundException
327      */
getParentIdentifier(String documentId)328     Identifier getParentIdentifier(String documentId) throws FileNotFoundException {
329         final Cursor cursor = mDatabase.query(
330                 TABLE_DOCUMENTS,
331                 strings(COLUMN_PARENT_DOCUMENT_ID),
332                 SELECTION_DOCUMENT_ID,
333                 strings(documentId),
334                 null,
335                 null,
336                 null,
337                 "1");
338         try {
339             if (cursor.moveToNext()) {
340                 return createIdentifier(cursor.getString(0));
341             } else {
342                 throw new FileNotFoundException("Cannot find a row having ID = " + documentId);
343             }
344         } finally {
345             cursor.close();
346         }
347     }
348 
getDeviceDocumentId(int deviceId)349     String getDeviceDocumentId(int deviceId) throws FileNotFoundException {
350         try (final Cursor cursor = mDatabase.query(
351                 TABLE_DOCUMENTS,
352                 strings(Document.COLUMN_DOCUMENT_ID),
353                 COLUMN_DEVICE_ID + " = ? AND " + COLUMN_DOCUMENT_TYPE + " = ? AND " +
354                 COLUMN_ROW_STATE + " != ?",
355                 strings(deviceId, DOCUMENT_TYPE_DEVICE, ROW_STATE_DISCONNECTED),
356                 null,
357                 null,
358                 null,
359                 "1")) {
360             if (cursor.getCount() > 0) {
361                 cursor.moveToNext();
362                 return cursor.getString(0);
363             } else {
364                 throw new FileNotFoundException("The device ID not found: " + deviceId);
365             }
366         }
367     }
368 
369     /**
370      * Adds new document under the parent.
371      * The method does not affect invalidated and pending documents because we know the document is
372      * newly added and never mapped with existing ones.
373      * @param parentDocumentId
374      * @param info
375      * @param size Object size. info#getCompressedSize() will be ignored because it does not contain
376      *     object size more than 4GB.
377      * @return Document ID of added document.
378      */
putNewDocument( int deviceId, String parentDocumentId, int[] operationsSupported, MtpObjectInfo info, long size)379     String putNewDocument(
380             int deviceId, String parentDocumentId, int[] operationsSupported, MtpObjectInfo info,
381             long size) {
382         final ContentValues values = new ContentValues();
383         getObjectDocumentValues(
384                 values, deviceId, parentDocumentId, operationsSupported, info, size);
385         mDatabase.beginTransaction();
386         try {
387             final long id = mDatabase.insert(TABLE_DOCUMENTS, null, values);
388             mDatabase.setTransactionSuccessful();
389             return Long.toString(id);
390         } finally {
391             mDatabase.endTransaction();
392         }
393     }
394 
395     /**
396      * Deletes document and its children.
397      * @param documentId
398      */
deleteDocument(String documentId)399     void deleteDocument(String documentId) {
400         deleteDocumentsAndRootsRecursively(SELECTION_DOCUMENT_ID, strings(documentId));
401     }
402 
403     /**
404      * Gets identifier from document ID.
405      * @param documentId Document ID.
406      * @return Identifier.
407      * @throws FileNotFoundException
408      */
createIdentifier(String documentId)409     Identifier createIdentifier(String documentId) throws FileNotFoundException {
410         // Currently documentId is old format.
411         final Cursor cursor = mDatabase.query(
412                 TABLE_DOCUMENTS,
413                 strings(COLUMN_DEVICE_ID,
414                         COLUMN_STORAGE_ID,
415                         COLUMN_OBJECT_HANDLE,
416                         COLUMN_DOCUMENT_TYPE),
417                 SELECTION_DOCUMENT_ID + " AND " + COLUMN_ROW_STATE + " IN (?, ?)",
418                 strings(documentId, ROW_STATE_VALID, ROW_STATE_INVALIDATED),
419                 null,
420                 null,
421                 null,
422                 "1");
423         try {
424             if (cursor.getCount() == 0) {
425                 throw new FileNotFoundException("ID \"" + documentId + "\" is not found.");
426             } else {
427                 cursor.moveToNext();
428                 return new Identifier(
429                         cursor.getInt(0),
430                         cursor.getInt(1),
431                         cursor.getInt(2),
432                         documentId,
433                         cursor.getInt(3));
434             }
435         } finally {
436             cursor.close();
437         }
438     }
439 
440     /**
441      * Deletes a document, and its root information if the document is a root document.
442      * @param selection Query to select documents.
443      * @param args Arguments for selection.
444      * @return Whether the method deletes rows.
445      */
deleteDocumentsAndRootsRecursively(String selection, String[] args)446     boolean deleteDocumentsAndRootsRecursively(String selection, String[] args) {
447         mDatabase.beginTransaction();
448         try {
449             boolean changed = false;
450             final Cursor cursor = mDatabase.query(
451                     TABLE_DOCUMENTS,
452                     strings(Document.COLUMN_DOCUMENT_ID),
453                     selection,
454                     args,
455                     null,
456                     null,
457                     null);
458             try {
459                 while (cursor.moveToNext()) {
460                     if (deleteDocumentsAndRootsRecursively(
461                             COLUMN_PARENT_DOCUMENT_ID + " = ?",
462                             strings(cursor.getString(0)))) {
463                         changed = true;
464                     }
465                 }
466             } finally {
467                 cursor.close();
468             }
469             if (deleteDocumentsAndRoots(selection, args)) {
470                 changed = true;
471             }
472             mDatabase.setTransactionSuccessful();
473             return changed;
474         } finally {
475             mDatabase.endTransaction();
476         }
477     }
478 
479     /**
480      * Marks the documents and their child as disconnected documents.
481      * @param selection
482      * @param args
483      * @return True if at least one row is updated.
484      */
disconnectDocumentsRecursively(String selection, String[] args)485     boolean disconnectDocumentsRecursively(String selection, String[] args) {
486         mDatabase.beginTransaction();
487         try {
488             boolean changed = false;
489             try (final Cursor cursor = mDatabase.query(
490                     TABLE_DOCUMENTS,
491                     strings(Document.COLUMN_DOCUMENT_ID),
492                     selection,
493                     args,
494                     null,
495                     null,
496                     null)) {
497                 while (cursor.moveToNext()) {
498                     if (disconnectDocumentsRecursively(
499                             COLUMN_PARENT_DOCUMENT_ID + " = ?",
500                             strings(cursor.getString(0)))) {
501                         changed = true;
502                     }
503                 }
504             }
505             if (disconnectDocuments(selection, args)) {
506                 changed = true;
507             }
508             mDatabase.setTransactionSuccessful();
509             return changed;
510         } finally {
511             mDatabase.endTransaction();
512         }
513     }
514 
deleteDocumentsAndRoots(String selection, String[] args)515     boolean deleteDocumentsAndRoots(String selection, String[] args) {
516         mDatabase.beginTransaction();
517         try {
518             int deleted = 0;
519             deleted += mDatabase.delete(
520                     TABLE_ROOT_EXTRA,
521                     Root.COLUMN_ROOT_ID + " IN (" + SQLiteQueryBuilder.buildQueryString(
522                             false,
523                             TABLE_DOCUMENTS,
524                             new String[] { Document.COLUMN_DOCUMENT_ID },
525                             selection,
526                             null,
527                             null,
528                             null,
529                             null) + ")",
530                     args);
531             deleted += mDatabase.delete(TABLE_DOCUMENTS, selection, args);
532             mDatabase.setTransactionSuccessful();
533             // TODO Remove mappingState.
534             return deleted != 0;
535         } finally {
536             mDatabase.endTransaction();
537         }
538     }
539 
disconnectDocuments(String selection, String[] args)540     boolean disconnectDocuments(String selection, String[] args) {
541         mDatabase.beginTransaction();
542         try {
543             final ContentValues values = new ContentValues();
544             values.put(COLUMN_ROW_STATE, ROW_STATE_DISCONNECTED);
545             values.putNull(COLUMN_DEVICE_ID);
546             values.putNull(COLUMN_STORAGE_ID);
547             values.putNull(COLUMN_OBJECT_HANDLE);
548             final boolean updated = mDatabase.update(TABLE_DOCUMENTS, values, selection, args) != 0;
549             mDatabase.setTransactionSuccessful();
550             return updated;
551         } finally {
552             mDatabase.endTransaction();
553         }
554     }
555 
getRowState(String documentId)556     int getRowState(String documentId) throws FileNotFoundException {
557         try (final Cursor cursor = mDatabase.query(
558                 TABLE_DOCUMENTS,
559                 strings(COLUMN_ROW_STATE),
560                 SELECTION_DOCUMENT_ID,
561                 strings(documentId),
562                 null,
563                 null,
564                 null)) {
565             if (cursor.getCount() == 0) {
566                 throw new FileNotFoundException();
567             }
568             cursor.moveToNext();
569             return cursor.getInt(0);
570         }
571     }
572 
writeRowSnapshot(String documentId, ContentValues values)573     void writeRowSnapshot(String documentId, ContentValues values) throws FileNotFoundException {
574         try (final Cursor cursor = mDatabase.query(
575                 JOIN_ROOTS,
576                 strings("*"),
577                 SELECTION_DOCUMENT_ID,
578                 strings(documentId),
579                 null,
580                 null,
581                 null,
582                 "1")) {
583             if (cursor.getCount() == 0) {
584                 throw new FileNotFoundException();
585             }
586             cursor.moveToNext();
587             values.clear();
588             DatabaseUtils.cursorRowToContentValues(cursor, values);
589         }
590     }
591 
updateObject(String documentId, int deviceId, String parentId, int[] operationsSupported, MtpObjectInfo info, Long size)592     void updateObject(String documentId, int deviceId, String parentId, int[] operationsSupported,
593                       MtpObjectInfo info, Long size) {
594         final ContentValues values = new ContentValues();
595         getObjectDocumentValues(values, deviceId, parentId, operationsSupported, info, size);
596 
597         mDatabase.beginTransaction();
598         try {
599             mDatabase.update(
600                     TABLE_DOCUMENTS,
601                     values,
602                     Document.COLUMN_DOCUMENT_ID + " = ?",
603                     strings(documentId));
604             mDatabase.setTransactionSuccessful();
605         } finally {
606             mDatabase.endTransaction();
607         }
608     }
609 
610     /**
611      * Obtains a document that has already mapped but has unmapped children.
612      * @param deviceId Device to find documents.
613      * @return Identifier of found document or null.
614      */
getUnmappedDocumentsParent(int deviceId)615     @Nullable Identifier getUnmappedDocumentsParent(int deviceId) {
616         final String fromClosure =
617                 TABLE_DOCUMENTS + " AS child INNER JOIN " +
618                 TABLE_DOCUMENTS + " AS parent ON " +
619                 "child." + COLUMN_PARENT_DOCUMENT_ID + " = " +
620                 "parent." + Document.COLUMN_DOCUMENT_ID;
621         final String whereClosure =
622                 "parent." + COLUMN_DEVICE_ID + " = ? AND " +
623                 "parent." + COLUMN_ROW_STATE + " IN (?, ?) AND " +
624                 "parent." + COLUMN_DOCUMENT_TYPE + " != ? AND " +
625                 "child." + COLUMN_ROW_STATE + " = ?";
626         try (final Cursor cursor = mDatabase.query(
627                 fromClosure,
628                 strings("parent." + COLUMN_DEVICE_ID,
629                         "parent." + COLUMN_STORAGE_ID,
630                         "parent." + COLUMN_OBJECT_HANDLE,
631                         "parent." + Document.COLUMN_DOCUMENT_ID,
632                         "parent." + COLUMN_DOCUMENT_TYPE),
633                 whereClosure,
634                 strings(deviceId, ROW_STATE_VALID, ROW_STATE_INVALIDATED, DOCUMENT_TYPE_DEVICE,
635                         ROW_STATE_DISCONNECTED),
636                 null,
637                 null,
638                 null,
639                 "1")) {
640             if (cursor.getCount() == 0) {
641                 return null;
642             }
643             cursor.moveToNext();
644             return new Identifier(
645                     cursor.getInt(0),
646                     cursor.getInt(1),
647                     cursor.getInt(2),
648                     cursor.getString(3),
649                     cursor.getInt(4));
650         }
651     }
652 
653     /**
654      * Removes metadata except for data used by outgoingPersistedUriPermissions.
655      */
cleanDatabase(Uri[] outgoingPersistedUris)656     void cleanDatabase(Uri[] outgoingPersistedUris) {
657         mDatabase.beginTransaction();
658         try {
659             final Set<String> ids = new HashSet<>();
660             for (final Uri uri : outgoingPersistedUris) {
661                 String documentId = DocumentsContract.getDocumentId(uri);
662                 while (documentId != null) {
663                     if (ids.contains(documentId)) {
664                         break;
665                     }
666                     ids.add(documentId);
667                     try (final Cursor cursor = mDatabase.query(
668                             TABLE_DOCUMENTS,
669                             strings(COLUMN_PARENT_DOCUMENT_ID),
670                             SELECTION_DOCUMENT_ID,
671                             strings(documentId),
672                             null,
673                             null,
674                             null)) {
675                         documentId = cursor.moveToNext() ? cursor.getString(0) : null;
676                     }
677                 }
678             }
679             deleteDocumentsAndRoots(
680                     Document.COLUMN_DOCUMENT_ID + " NOT IN " + getIdList(ids), null);
681             mDatabase.setTransactionSuccessful();
682         } finally {
683             mDatabase.endTransaction();
684         }
685     }
686 
getLastBootCount()687     int getLastBootCount() {
688         try (final Cursor cursor = mDatabase.query(
689                 TABLE_LAST_BOOT_COUNT, strings(COLUMN_VALUE), null, null, null, null, null)) {
690             if (cursor.moveToNext()) {
691                 return cursor.getInt(0);
692             } else {
693                 return 0;
694             }
695         }
696     }
697 
setLastBootCount(int value)698     void setLastBootCount(int value) {
699         Preconditions.checkArgumentNonnegative(value, "Boot count must not be negative.");
700         mDatabase.beginTransaction();
701         try {
702             final ContentValues values = new ContentValues();
703             values.put(COLUMN_VALUE, value);
704             mDatabase.delete(TABLE_LAST_BOOT_COUNT, null, null);
705             mDatabase.insert(TABLE_LAST_BOOT_COUNT, null, values);
706             mDatabase.setTransactionSuccessful();
707         } finally {
708             mDatabase.endTransaction();
709         }
710     }
711 
712     private static class OpenHelper extends SQLiteOpenHelper {
OpenHelper(Context context, int flags)713         public OpenHelper(Context context, int flags) {
714             super(context,
715                   flags == FLAG_DATABASE_IN_MEMORY ? null : DATABASE_NAME,
716                   null,
717                   DATABASE_VERSION);
718         }
719 
720         @Override
onCreate(SQLiteDatabase db)721         public void onCreate(SQLiteDatabase db) {
722             db.execSQL(QUERY_CREATE_DOCUMENTS);
723             db.execSQL(QUERY_CREATE_ROOT_EXTRA);
724             db.execSQL(QUERY_CREATE_LAST_BOOT_COUNT);
725         }
726 
727         @Override
onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)728         public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
729             db.execSQL("DROP TABLE IF EXISTS " + TABLE_DOCUMENTS);
730             db.execSQL("DROP TABLE IF EXISTS " + TABLE_ROOT_EXTRA);
731             db.execSQL("DROP TABLE IF EXISTS " + TABLE_LAST_BOOT_COUNT);
732             onCreate(db);
733         }
734     }
735 
736     @VisibleForTesting
deleteDatabase(Context context)737     static void deleteDatabase(Context context) {
738         context.deleteDatabase(DATABASE_NAME);
739     }
740 
getDeviceDocumentValues( ContentValues values, ContentValues extraValues, MtpDeviceRecord device)741     static void getDeviceDocumentValues(
742             ContentValues values,
743             ContentValues extraValues,
744             MtpDeviceRecord device) {
745         values.clear();
746         values.put(COLUMN_DEVICE_ID, device.deviceId);
747         values.putNull(COLUMN_STORAGE_ID);
748         values.putNull(COLUMN_OBJECT_HANDLE);
749         values.putNull(COLUMN_PARENT_DOCUMENT_ID);
750         values.put(COLUMN_ROW_STATE, ROW_STATE_VALID);
751         values.put(COLUMN_DOCUMENT_TYPE, DOCUMENT_TYPE_DEVICE);
752         values.put(COLUMN_MAPPING_KEY, device.deviceKey);
753         values.put(Document.COLUMN_MIME_TYPE, Document.MIME_TYPE_DIR);
754         values.put(Document.COLUMN_DISPLAY_NAME, device.name);
755         values.putNull(Document.COLUMN_SUMMARY);
756         values.putNull(Document.COLUMN_LAST_MODIFIED);
757         values.put(Document.COLUMN_ICON, R.drawable.ic_root_mtp);
758         values.put(Document.COLUMN_FLAGS, getDocumentFlags(
759                 device.operationsSupported,
760                 Document.MIME_TYPE_DIR,
761                 0,
762                 MtpConstants.PROTECTION_STATUS_NONE,
763                 DOCUMENT_TYPE_DEVICE));
764         values.putNull(Document.COLUMN_SIZE);
765 
766         extraValues.clear();
767         extraValues.put(Root.COLUMN_FLAGS, getRootFlags(device.operationsSupported));
768         extraValues.putNull(Root.COLUMN_AVAILABLE_BYTES);
769         extraValues.putNull(Root.COLUMN_CAPACITY_BYTES);
770         extraValues.put(Root.COLUMN_MIME_TYPES, "");
771     }
772 
773     /**
774      * Gets {@link ContentValues} for the given root.
775      * @param values {@link ContentValues} that receives values.
776      * @param extraValues {@link ContentValues} that receives extra values for roots.
777      * @param parentDocumentId Parent document ID.
778      * @param operationsSupported Array of Operation code supported by the device.
779      * @param root Root to be converted {@link ContentValues}.
780      */
getStorageDocumentValues( ContentValues values, ContentValues extraValues, String parentDocumentId, int[] operationsSupported, MtpRoot root)781     static void getStorageDocumentValues(
782             ContentValues values,
783             ContentValues extraValues,
784             String parentDocumentId,
785             int[] operationsSupported,
786             MtpRoot root) {
787         values.clear();
788         values.put(COLUMN_DEVICE_ID, root.mDeviceId);
789         values.put(COLUMN_STORAGE_ID, root.mStorageId);
790         values.putNull(COLUMN_OBJECT_HANDLE);
791         values.put(COLUMN_PARENT_DOCUMENT_ID, parentDocumentId);
792         values.put(COLUMN_ROW_STATE, ROW_STATE_VALID);
793         values.put(COLUMN_DOCUMENT_TYPE, DOCUMENT_TYPE_STORAGE);
794         values.put(Document.COLUMN_MIME_TYPE, Document.MIME_TYPE_DIR);
795         values.put(Document.COLUMN_DISPLAY_NAME, root.mDescription);
796         values.putNull(Document.COLUMN_SUMMARY);
797         values.putNull(Document.COLUMN_LAST_MODIFIED);
798         values.put(Document.COLUMN_ICON, R.drawable.ic_root_mtp);
799         values.put(Document.COLUMN_FLAGS, getDocumentFlags(
800                 operationsSupported,
801                 Document.MIME_TYPE_DIR,
802                 0,
803                 MtpConstants.PROTECTION_STATUS_NONE,
804                 DOCUMENT_TYPE_STORAGE));
805         values.put(Document.COLUMN_SIZE, root.mMaxCapacity - root.mFreeSpace);
806 
807         extraValues.put(Root.COLUMN_FLAGS, getRootFlags(operationsSupported));
808         extraValues.put(Root.COLUMN_AVAILABLE_BYTES, root.mFreeSpace);
809         extraValues.put(Root.COLUMN_CAPACITY_BYTES, root.mMaxCapacity);
810         extraValues.put(Root.COLUMN_MIME_TYPES, "");
811     }
812 
813     /**
814      * Gets {@link ContentValues} for the given MTP object.
815      * @param values {@link ContentValues} that receives values.
816      * @param deviceId Device ID of the object.
817      * @param parentId Parent document ID of the object.
818      * @param info MTP object info. getCompressedSize will be ignored.
819      * @param size 64-bit size of documents. Negative value is regarded as unknown size.
820      */
getObjectDocumentValues( ContentValues values, int deviceId, String parentId, int[] operationsSupported, MtpObjectInfo info, long size)821     static void getObjectDocumentValues(
822             ContentValues values, int deviceId, String parentId,
823             int[] operationsSupported, MtpObjectInfo info, long size) {
824         values.clear();
825         final String mimeType = getMimeType(info);
826         values.put(COLUMN_DEVICE_ID, deviceId);
827         values.put(COLUMN_STORAGE_ID, info.getStorageId());
828         values.put(COLUMN_OBJECT_HANDLE, info.getObjectHandle());
829         values.put(COLUMN_PARENT_DOCUMENT_ID, parentId);
830         values.put(COLUMN_ROW_STATE, ROW_STATE_VALID);
831         values.put(COLUMN_DOCUMENT_TYPE, DOCUMENT_TYPE_OBJECT);
832         values.put(Document.COLUMN_MIME_TYPE, mimeType);
833         values.put(Document.COLUMN_DISPLAY_NAME, info.getName());
834         values.putNull(Document.COLUMN_SUMMARY);
835         values.put(
836                 Document.COLUMN_LAST_MODIFIED,
837                 info.getDateModified() != 0 ? info.getDateModified() : null);
838         values.putNull(Document.COLUMN_ICON);
839         values.put(Document.COLUMN_FLAGS, getDocumentFlags(
840                 operationsSupported, mimeType, info.getThumbCompressedSizeLong(),
841                 info.getProtectionStatus(), DOCUMENT_TYPE_OBJECT));
842         if (size >= 0) {
843             values.put(Document.COLUMN_SIZE, size);
844         } else {
845             values.putNull(Document.COLUMN_SIZE);
846         }
847     }
848 
getMimeType(MtpObjectInfo info)849     private static String getMimeType(MtpObjectInfo info) {
850         if (info.getFormat() == MtpConstants.FORMAT_ASSOCIATION) {
851             return DocumentsContract.Document.MIME_TYPE_DIR;
852         }
853 
854         final String formatCodeMimeType = MediaFile.getMimeTypeForFormatCode(info.getFormat());
855         final String mediaFileMimeType = MediaFile.getMimeTypeForFile(info.getName());
856 
857         // Format code can be mapped with multiple mime types, e.g. FORMAT_MPEG is mapped with
858         // audio/mp4 and video/mp4.
859         // As file extension contains more information than format code, returns mime type obtained
860         // from file extension if it is consistent with format code.
861         if (mediaFileMimeType != null &&
862                 MediaFile.getFormatCode("", mediaFileMimeType) == info.getFormat()) {
863             return mediaFileMimeType;
864         }
865         if (formatCodeMimeType != null) {
866             return formatCodeMimeType;
867         }
868         if (mediaFileMimeType != null) {
869             return mediaFileMimeType;
870         }
871         // We don't know the file type.
872         return "application/octet-stream";
873     }
874 
getRootFlags(int[] operationsSupported)875     private static int getRootFlags(int[] operationsSupported) {
876         int rootFlag = Root.FLAG_SUPPORTS_IS_CHILD;
877         if (MtpDeviceRecord.isWritingSupported(operationsSupported)) {
878             rootFlag |= Root.FLAG_SUPPORTS_CREATE;
879         }
880         return rootFlag;
881     }
882 
getDocumentFlags( @ullable int[] operationsSupported, String mimeType, long thumbnailSize, int protectionState, @DocumentType int documentType)883     private static int getDocumentFlags(
884             @Nullable int[] operationsSupported, String mimeType, long thumbnailSize,
885             int protectionState, @DocumentType int documentType) {
886         int flag = 0;
887         if (!mimeType.equals(Document.MIME_TYPE_DIR) &&
888                 MtpDeviceRecord.isWritingSupported(operationsSupported) &&
889                 protectionState == MtpConstants.PROTECTION_STATUS_NONE) {
890             flag |= Document.FLAG_SUPPORTS_WRITE;
891         }
892         if (MtpDeviceRecord.isSupported(
893                 operationsSupported, MtpConstants.OPERATION_DELETE_OBJECT) &&
894                 (protectionState == MtpConstants.PROTECTION_STATUS_NONE ||
895                  protectionState == MtpConstants.PROTECTION_STATUS_NON_TRANSFERABLE_DATA) &&
896                 documentType == DOCUMENT_TYPE_OBJECT) {
897             flag |= Document.FLAG_SUPPORTS_DELETE;
898         }
899         if (mimeType.equals(Document.MIME_TYPE_DIR) &&
900                 MtpDeviceRecord.isWritingSupported(operationsSupported) &&
901                 protectionState == MtpConstants.PROTECTION_STATUS_NONE) {
902             flag |= Document.FLAG_DIR_SUPPORTS_CREATE;
903         }
904         if (thumbnailSize > 0) {
905             flag |= Document.FLAG_SUPPORTS_THUMBNAIL;
906         }
907         return flag;
908     }
909 
strings(Object... args)910     static String[] strings(Object... args) {
911         final String[] results = new String[args.length];
912         for (int i = 0; i < args.length; i++) {
913             results[i] = Objects.toString(args[i]);
914         }
915         return results;
916     }
917 
getIdList(Set<String> ids)918     private static String getIdList(Set<String> ids) {
919         String result = "(";
920         for (final String id : ids) {
921             if (result.length() > 1) {
922                 result += ",";
923             }
924             result += id;
925         }
926         result += ")";
927         return result;
928     }
929 }
930