Implement MTP device to host notifications when files are added and removed.

Now MTP events are sent to the host when objects are added and deleted
due to device-side changes (rather than MTP initiated).

Also clean up MTP database upgrade path, fixing bug 2841422
This change is incompatible with the state of master over the last couple weeks
but will not be a problem for upgrades from earlier releases.

BUG: 2841422

Change-Id: I138d252e9b2b01371711eb7db723a908dc97e75b
Signed-off-by: Mike Lockwood <lockwood@android.com>

4 files changed, 215 insertions, 69 deletions

diff --git a/Android.mk b/Android.mk
index 9ea335f7..fb8cb6e4 100644
--- a/Android.mk
+++ b/Android.mk
@@ -3,7 +3,8 @@ include $(CLEAR_VARS)
 
 LOCAL_MODULE_TAGS := optional
 
-LOCAL_SRC_FILES := $(call all-subdir-java-files)
+LOCAL_SRC_FILES := $(call all-subdir-java-files) \
+	src/com/android/providers/media/IMtpService.aidl
 
 LOCAL_JAVA_LIBRARIES := 
 
diff --git a/src/com/android/providers/media/IMtpService.aidl b/src/com/android/providers/media/IMtpService.aidl
new file mode 100644
index 00000000..e599f7bb
--- /dev/null
+++ b/src/com/android/providers/media/IMtpService.aidl
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2010 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.providers.media;
+
+interface IMtpService
+{
+    void sendObjectAdded(int objectHandle);
+    void sendObjectRemoved(int objectHandle);
+}
diff --git a/src/com/android/providers/media/MediaProvider.java b/src/com/android/providers/media/MediaProvider.java
index e766c625..0f459e73 100644
--- a/src/com/android/providers/media/MediaProvider.java
+++ b/src/com/android/providers/media/MediaProvider.java
@@ -42,6 +42,7 @@ import android.os.MemoryFile;
 import android.os.Message;
 import android.os.ParcelFileDescriptor;
 import android.os.Process;
+import android.os.RemoteException;
 import android.provider.BaseColumns;
 import android.provider.MediaStore;
 import android.provider.MediaStore.Audio;
@@ -166,12 +167,33 @@ public class MediaProvider extends ContentProvider {
         }
     };
 
+    // set to disable sending events when the operation originates from MTP
+    private boolean mDisableMtpObjectCallbacks;
+
+    private final SQLiteDatabase.CustomFunction mObjectRemovedCallback =
+                new SQLiteDatabase.CustomFunction() {
+        public void callback(String[] args) {
+            // do nothing if the operation originated from MTP
+            if (mDisableMtpObjectCallbacks) return;
+
+            Log.d(TAG, "object removed " + args[0]);
+            IMtpService mtpService = mMtpService;
+            if (mtpService != null) {
+                try {
+                    sendObjectRemoved(Integer.parseInt(args[0]));
+                } catch (NumberFormatException e) {
+                    Log.e(TAG, "NumberFormatException in mObjectRemovedCallback", e);
+                }
+            }
+        }
+    };
+
     /**
      * Wrapper class for a specific database (associated with one particular
      * external card, or with internal storage).  Can open the actual database
      * on demand, create and upgrade the schema, etc.
      */
-    private static final class DatabaseHelper extends SQLiteOpenHelper {
+    private final class DatabaseHelper extends SQLiteOpenHelper {
         final Context mContext;
         final boolean mInternal;  // True if this is the internal database
 
@@ -211,6 +233,8 @@ public class MediaProvider extends ContentProvider {
         public void onOpen(SQLiteDatabase db) {
             if (mInternal) return;  // The internal database is kept separately.
 
+            db.addCustomFunction("_OBJECT_REMOVED", 1, mObjectRemovedCallback);
+
             // touch the database file to show it is most recently used
             File file = new File(db.getPath());
             long now = System.currentTimeMillis();
@@ -271,8 +295,24 @@ public class MediaProvider extends ContentProvider {
         }
     }
 
+    private IMtpService mMtpService;
+
+    private final ServiceConnection mMtpServiceConnection = new ServiceConnection() {
+         public void onServiceConnected(ComponentName className, android.os.IBinder service) {
+            Log.d(TAG, "mMtpService connected");
+            mMtpService = IMtpService.Stub.asInterface(service);
+        }
+
+        public void onServiceDisconnected(ComponentName className) {
+            Log.d(TAG, "mMtpService disconnected");
+            mMtpService = null;
+        }
+    };
+
     @Override
     public boolean onCreate() {
+        final Context context = getContext();
+
         sArtistAlbumsMap.put(MediaStore.Audio.Albums._ID, "audio.album_id AS " +
                 MediaStore.Audio.Albums._ID);
         sArtistAlbumsMap.put(MediaStore.Audio.Albums.ALBUM, "album");
@@ -291,13 +331,13 @@ public class MediaProvider extends ContentProvider {
 
         mSearchColsBasic[SEARCH_COLUMN_BASIC_TEXT2] =
                 mSearchColsBasic[SEARCH_COLUMN_BASIC_TEXT2].replaceAll(
-                        "%1", getContext().getString(R.string.artist_label));
+                        "%1", context.getString(R.string.artist_label));
         mDatabases = new HashMap<String, DatabaseHelper>();
         attachVolume(INTERNAL_VOLUME);
 
         IntentFilter iFilter = new IntentFilter(Intent.ACTION_MEDIA_EJECT);
         iFilter.addDataScheme("file");
-        getContext().registerReceiver(mUnmountReceiver, iFilter);
+        context.registerReceiver(mUnmountReceiver, iFilter);
 
         // open external database if external storage is mounted
         String state = Environment.getExternalStorageState();
@@ -355,6 +395,8 @@ public class MediaProvider extends ContentProvider {
             }
         };
 
+        context.bindService(new Intent(context, MtpService.class),
+                mMtpServiceConnection, Context.BIND_AUTO_CREATE);
         return true;
     }
 
@@ -380,11 +422,14 @@ public class MediaProvider extends ContentProvider {
             throw new IllegalArgumentException();
         }
 
-        // Revisions 84-86 were a failed attempt at supporting the "album artist" id3 tag
+        // Revisions 84-86 were a failed attempt at supporting the "album artist" id3 tag.
+        // Revisions 91-93 were done while MTP support was being developed and were replaced
+        // by revision 94 in an incompatible way.
         // We can't downgrade from those revisions, so start over.
         // (the initial change to do this was wrong, so now we actually need to start over
         // if the database version is 84-89)
-        if (fromVersion < 63 || (fromVersion >= 84 && fromVersion <= 89)) {
+        if (fromVersion < 63 || (fromVersion >= 84 && fromVersion <= 89) ||
+                    (fromVersion >= 91 && fromVersion <= 93)) {
             fromVersion = 63;
             // Drop everything and start over.
             Log.i(TAG, "Upgrading media database from version " +
@@ -967,42 +1012,51 @@ public class MediaProvider extends ContentProvider {
                        "format INTEGER," +
                        "parent INTEGER," +
                        "date_modified INTEGER" +
+                       // ID of the media table for this object.
+                       // Possible values are IMAGES_MEDIA, AUDIO_MEDIA, and VIDEO_MEDIA
+                       // and AUDIO_PLAYLISTS.
+                       "media_table INTEGER" +
+                       // The row number of this object in the corresponding media table.
+                       "media_id INTEGER" +
                        ");");
-        }
-        if (fromVersion < 92) {
-            // Add columns for cross referencing to media tables
-            // media_table is the name of the table for the object,
-            // and media_id is the ID of the object in that table
-            db.execSQL("ALTER TABLE objects ADD COLUMN media_table INTEGER;");
-            db.execSQL("ALTER TABLE objects ADD COLUMN media_id INTEGER;");
-        }
-        if (fromVersion < 93) {
-            // cleans up objects table when an image file is deleted
-           db.execSQL("CREATE TRIGGER IF NOT EXISTS images_objects_cleanup DELETE ON images " +
-                    "BEGIN " +
-                        "DELETE FROM objects WHERE media_table = 1 AND media_id = old._id;" +
-                    "END");
-
-
-            // cleans up objects table when an audio file is deleted
-           db.execSQL("CREATE TRIGGER IF NOT EXISTS audio_objects_cleanup DELETE ON audio_meta " +
-                    "BEGIN " +
-                        "DELETE FROM objects WHERE media_table = 100 AND media_id = old._id;" +
-                    "END");
 
+            // Add cross reference from media table to MTP object table
+            // Object ID is the row number of this object in the "objects" table
+            db.execSQL("ALTER TABLE images ADD COLUMN object_id INTEGER;");
+            db.execSQL("ALTER TABLE audio_meta ADD COLUMN object_id INTEGER;");
+            db.execSQL("ALTER TABLE video ADD COLUMN object_id INTEGER;");
+            if (!internal) {
+                // audio_playlists does not exist in internal database
+                db.execSQL("ALTER TABLE audio_playlists ADD COLUMN object_id INTEGER;");
+    
+                // cleans up objects table when an image file is deleted
+                db.execSQL("CREATE TRIGGER IF NOT EXISTS images_objects_cleanup DELETE ON images " +
+                        "BEGIN " +
+                            "DELETE FROM objects WHERE _id = old.object_id;" +
+                            "SELECT _OBJECT_REMOVED(old.object_id);" +
+                        "END");
 
-            // cleans up objects table when a video file is deleted
-           db.execSQL("CREATE TRIGGER IF NOT EXISTS video_objects_cleanup DELETE ON video " +
-                    "BEGIN " +
-                        "DELETE FROM objects WHERE media_table = 200 AND media_id = old._id;" +
-                    "END");
+                // cleans up objects table when an audio file is deleted
+                db.execSQL("CREATE TRIGGER IF NOT EXISTS audio_objects_cleanup DELETE ON audio_meta " +
+                        "BEGIN " +
+                            "DELETE FROM objects WHERE _id = old.object_id;" +
+                            "SELECT _OBJECT_REMOVED(old.object_id);" +
+                        "END");
 
+                // cleans up objects table when a video file is deleted
+                db.execSQL("CREATE TRIGGER IF NOT EXISTS video_objects_cleanup DELETE ON video " +
+                        "BEGIN " +
+                            "DELETE FROM objects WHERE _id = old.object_id;" +
+                            "SELECT _OBJECT_REMOVED(old.object_id);" +
+                        "END");
 
-            // cleans up objects table when a playlist file is deleted
-           db.execSQL("CREATE TRIGGER IF NOT EXISTS playlists_objects_cleanup DELETE ON audio_playlists " +
-                    "BEGIN " +
-                        "DELETE FROM objects WHERE media_table = 110 AND media_id = old._id;" +
-                    "END");
+                // cleans up objects table when a playlist file is deleted
+                db.execSQL("CREATE TRIGGER IF NOT EXISTS playlists_objects_cleanup DELETE ON audio_playlists " +
+                        "BEGIN " +
+                            "DELETE FROM objects WHERE _id = old.object_id;" +
+                            "SELECT _OBJECT_REMOVED(old.object_id);" +
+                        "END");
+            }
         }
         sanityCheck(db, fromVersion);
     }
@@ -1668,6 +1722,28 @@ public class MediaProvider extends ContentProvider {
         return values;
     }
 
+    private void sendObjectAdded(long objectHandle) {
+        IMtpService mtpService = mMtpService;
+        if (mtpService != null) {
+            try {
+                mtpService.sendObjectAdded((int)objectHandle);
+            } catch (RemoteException e) {
+                Log.e(TAG, "RemoteException in sendObjectAdded", e);
+            }
+        }
+    }
+
+    private void sendObjectRemoved(long objectHandle) {
+        IMtpService mtpService = mMtpService;
+        if (mtpService != null) {
+            try {
+                mtpService.sendObjectRemoved((int)objectHandle);
+            } catch (RemoteException e) {
+                Log.e(TAG, "RemoteException in sendObjectRemoved", e);
+            }
+        }
+    }
+
     @Override
     public int bulkInsert(Uri uri, ContentValues values[]) {
         int match = URI_MATCHER.match(uri);
@@ -1768,7 +1844,9 @@ public class MediaProvider extends ContentProvider {
                     values.put(ObjectColumns.FORMAT, Mtp.Object.FORMAT_ASSOCIATION);
                     values.put(ObjectColumns.DATA, parentPath);
                     values.put(ObjectColumns.PARENT, getParent(db, parentPath));
-                    return db.insert("objects", ObjectColumns.DATE_MODIFIED, values);
+                    long parent = db.insert("objects", ObjectColumns.DATE_MODIFIED, values);
+                    sendObjectAdded(parent);
+                    return parent;
                 } else {
                     c.moveToFirst();
                     return c.getLong(0);
@@ -1781,12 +1859,12 @@ public class MediaProvider extends ContentProvider {
         }
     }
 
-    private void insertObject(SQLiteDatabase db, long objectHandle, ContentValues initialValues,
+    private long insertObject(SQLiteDatabase db, long objectHandle, ContentValues initialValues,
             int tableId, long rowId) {
         String path = initialValues.getAsString(MediaStore.MediaColumns.DATA);
         if (path == null) {
             Log.e(TAG, "_data missing in insertObject");
-            return;
+            return 0;
         }
 
         ContentValues values = new ContentValues();
@@ -1826,12 +1904,13 @@ public class MediaProvider extends ContentProvider {
             }
 
             objectHandle = db.insert("objects", ObjectColumns.DATE_MODIFIED, values);
-            Log.v(TAG, "insertObject: values=" + values + " returned: " + objectHandle);
+            if (LOCAL_LOGV) Log.v(TAG, "insertObject: values=" + values + " returned: " + objectHandle);
         } else {
             // only need to update MEDIA_TABLE and MEDIA_ID
             db.update("objects", values, ObjectColumns._ID + "=?",
                     new String[] { Long.toString(objectHandle) });
         }
+        return objectHandle;
     }
 
     private int deleteObject(SQLiteDatabase db, String volume, String table,
@@ -1879,8 +1958,9 @@ public class MediaProvider extends ContentProvider {
     private Uri insertInternal(Uri uri, int match, ContentValues initialValues) {
         long rowId;
         int objectHandle = 0;
+        String mediaTable = null;
 
-        Log.v(TAG, "insertInternal: "+uri+", initValues="+initialValues);
+        if (LOCAL_LOGV) Log.v(TAG, "insertInternal: "+uri+", initValues="+initialValues);
         // handle MEDIA_SCANNER before calling getDatabaseForUri()
         if (match == MEDIA_SCANNER) {
             mMediaScannerVolume = initialValues.getAsString(MediaStore.MEDIA_SCANNER_VOLUME);
@@ -1898,10 +1978,11 @@ public class MediaProvider extends ContentProvider {
         if (initialValues == null) {
             initialValues = new ContentValues();
         } else {
-            Integer i = initialValues.getAsInteger(MediaStore.MediaColumns.MTP_OBJECT_HANDLE);
+            Integer i = initialValues.getAsInteger(
+                    MediaStore.MediaColumns.MEDIA_SCANNER_NEW_OBJECT_ID);
             if (i != null) {
                 objectHandle = i.intValue();
-                initialValues.remove(MediaStore.MediaColumns.MTP_OBJECT_HANDLE);
+                initialValues.remove(MediaStore.MediaColumns.MEDIA_SCANNER_NEW_OBJECT_ID);
             }
         }
 
@@ -1916,7 +1997,8 @@ public class MediaProvider extends ContentProvider {
                 }
                 computeBucketValues(data, values);
                 computeTakenTime(values);
-                rowId = db.insert("images", "name", values);
+                mediaTable = "images";
+                rowId = db.insert(mediaTable, "name", values);
 
                 if (rowId > 0) {
                     newUri = ContentUris.withAppendedId(
@@ -2013,7 +2095,8 @@ public class MediaProvider extends ContentProvider {
                 computeDisplayName(values.getAsString("_data"), values);
                 values.put(MediaStore.MediaColumns.DATE_ADDED, System.currentTimeMillis() / 1000);
 
-                rowId = db.insert("audio_meta", "duration", values);
+                mediaTable = "audio_meta";
+                rowId = db.insert(mediaTable, "duration", values);
                 if (rowId > 0) {
                     newUri = ContentUris.withAppendedId(Audio.Media.getContentUri(uri.getPathSegments().get(0)), rowId);
                 }
@@ -2065,7 +2148,8 @@ public class MediaProvider extends ContentProvider {
             case AUDIO_PLAYLISTS: {
                 ContentValues values = new ContentValues(initialValues);
                 values.put(MediaStore.Audio.Playlists.DATE_ADDED, System.currentTimeMillis() / 1000);
-                rowId = db.insert("audio_playlists", "name", initialValues);
+                mediaTable = "audio_playlists";
+                rowId = db.insert(mediaTable, "name", initialValues);
                 if (rowId > 0) {
                     newUri = ContentUris.withAppendedId(Audio.Playlists.getContentUri(uri.getPathSegments().get(0)), rowId);
                 }
@@ -2091,7 +2175,8 @@ public class MediaProvider extends ContentProvider {
                 computeBucketValues(data, values);
                 values.put(MediaStore.MediaColumns.DATE_ADDED, System.currentTimeMillis() / 1000);
                 computeTakenTime(values);
-                rowId = db.insert("video", "artist", values);
+                mediaTable = "video";
+                rowId = db.insert(mediaTable, "artist", values);
                 if (rowId > 0) {
                     newUri = ContentUris.withAppendedId(Video.Media.getContentUri(
                             uri.getPathSegments().get(0)), rowId);
@@ -2121,8 +2206,8 @@ public class MediaProvider extends ContentProvider {
                 return attachVolume(initialValues.getAsString("name"));
 
             case MTP_OBJECTS: {
-                 rowId = db.insert("objects", ObjectColumns.DATE_MODIFIED, initialValues);
-                if (rowId > 0) {
+                    rowId = db.insert("objects", ObjectColumns.DATE_MODIFIED, initialValues);
+                 if (rowId > 0) {
                     newUri = MtpObjects.getContentUri(uri.getPathSegments().get(0), rowId);
                 }
                 break;
@@ -2132,12 +2217,16 @@ public class MediaProvider extends ContentProvider {
                 throw new UnsupportedOperationException("Invalid URI " + uri);
         }
 
-        if (rowId > 0 &&
-                (match == IMAGES_MEDIA ||
-                match == AUDIO_MEDIA ||
-                match == VIDEO_MEDIA ||
-                match == AUDIO_PLAYLISTS)) {
-            insertObject(db, objectHandle, initialValues, match, rowId);
+        if (rowId > 0 && mediaTable != null) {
+            long objectId = insertObject(db, objectHandle, initialValues, match, rowId);
+
+            // Set object_id in the media table
+            ContentValues values = new ContentValues();
+            values.put(MediaColumns.MTP_OBJECT_ID, objectId);
+            db.update(mediaTable, values, MediaColumns._ID + "=?",
+                    new String[] { Long.toString(rowId) });
+
+            sendObjectAdded(objectId);
         }
 
         return newUri;
@@ -2409,10 +2498,16 @@ public class MediaProvider extends ContentProvider {
                         throw new UnsupportedOperationException(
                                 "Deleting multiple objects via MTP not supported");
                     case MTP_OBJECTS_ID:
-                        // return here to avoid calling notifyChange()
-                        return deleteObject(db, uri.getPathSegments().get(0),
-                                sGetTableAndWhereParam.table,
-                                sGetTableAndWhereParam.where, whereArgs);
+                        try {
+                            // don't send objectRemoved event since this originated from MTP
+                            mDisableMtpObjectCallbacks = true;
+                            // return here to avoid calling notifyChange()
+                            return deleteObject(db, uri.getPathSegments().get(0),
+                                    sGetTableAndWhereParam.table,
+                                    sGetTableAndWhereParam.where, whereArgs);
+                        } finally {
+                            mDisableMtpObjectCallbacks = false;
+                        }
                     default:
                         count = db.delete(sGetTableAndWhereParam.table,
                                 sGetTableAndWhereParam.where, whereArgs);
@@ -3283,7 +3378,7 @@ public class MediaProvider extends ContentProvider {
 
     private static String TAG = "MediaProvider";
     private static final boolean LOCAL_LOGV = false;
-    private static final int DATABASE_VERSION = 93;
+    private static final int DATABASE_VERSION = 94;
     private static final String INTERNAL_DATABASE_NAME = "internal.db";
 
     // maximum number of cached external databases to keep
diff --git a/src/com/android/providers/media/MtpService.java b/src/com/android/providers/media/MtpService.java
index 1d088974..7250c03d 100644
--- a/src/com/android/providers/media/MtpService.java
+++ b/src/com/android/providers/media/MtpService.java
@@ -17,6 +17,7 @@
 package com.android.providers.media;
 
 import android.app.Service;
+import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.Intent;
@@ -36,21 +37,24 @@ public class MtpService extends Service
     @Override
     public void onStart(Intent intent, int startId)
     {
-         Log.d(TAG, "onStart");
+         Log.d(TAG, "onStart intent " + intent + " startId " + startId);
+         ContentResolver resolver = getContentResolver();
 
         // make sure external media database is open
         try {
             ContentValues values = new ContentValues();
             values.put("name", MediaProvider.EXTERNAL_VOLUME);
-            getContentResolver().insert(Uri.parse("content://media/"), values);
+            resolver.insert(Uri.parse("content://media/"), values);
         } catch (IllegalArgumentException ex) {
             Log.w(TAG, "failed to open media database");
         }
 
         MtpDatabase database = new MtpDatabase(this, MediaProvider.EXTERNAL_VOLUME);
         String storagePath = Environment.getExternalStorageDirectory().getPath();
-        mServer = new MtpServer(database, storagePath);
-        mServer.start();
+        synchronized (mBinder) {
+            mServer = new MtpServer(database, storagePath);
+            mServer.start();
+        }
     }
 
     @Override
@@ -58,15 +62,38 @@ public class MtpService extends Service
     {
         Log.d(TAG, "onDestroy");
 
-        mServer.stop();
-        mServer = null;
+        synchronized (mBinder) {
+            mServer.stop();
+            mServer = null;
+        }
     }
 
+    private final IMtpService.Stub mBinder =
+            new IMtpService.Stub() {
+        public void sendObjectAdded(int objectHandle) {
+            synchronized (this) {
+                Log.d(TAG, "sendObjectAdded " + objectHandle);
+                if (mServer != null) {
+                    mServer.sendObjectAdded(objectHandle);
+                }
+            }
+        }
+
+        public void sendObjectRemoved(int objectHandle) {
+            synchronized (this) {
+                Log.d(TAG, "sendObjectRemoved " + objectHandle);
+                if (mServer != null) {
+                    mServer.sendObjectRemoved(objectHandle);
+                }
+            }
+        }
+    };
+
     @Override
     public IBinder onBind(Intent intent)
     {
-        return null;
+        Log.d(TAG, "onBind");
+        return mBinder;
     }
-
 }