Move DownloadManager to use JobScheduler.

JobScheduler is in a much better position to coordinate tasks across
the platform to optimize battery and RAM usage.  This change removes
a bunch of manual scheduling logic by representing each download as
a separate job with relevant scheduling constraints.  Requested
network types, retry backoff timing, and newly added charging and
idle constraints are plumbed through as job parameters.

When a job times out, we halt the download and schedule it to resume
later.  The majority of downloads should have ETag values to enable
resuming like this.

Remove local wakelocks, since the platform now acquires and blames
our jobs on the requesting app.

When an active download is pushing updates to the database, check for
both paused and cancelled state to quickly halt an ongoing download.

Shift DownloadNotifier to update directly based on a Cursor, since we
no longer have the overhead of fully-parsed DownloadInfo objects.

Unify a handful of worker threads into a single shared thread.

Remove legacy "large download" activity that was thrown in the face
of the user; the UX best-practice is to go through notification, and
update that dialog to let the user override and continue if under
the hard limit.

Bug: 28098882, 26571724
Change-Id: I33ebe59b3c2ea9c89ec526f70b1950c734abc4a7

1 files changed, 62 insertions, 48 deletions

diff --git a/src/com/android/providers/downloads/DownloadProvider.java b/src/com/android/providers/downloads/DownloadProvider.java
index 78b42949..00ed043d 100644
--- a/src/com/android/providers/downloads/DownloadProvider.java
+++ b/src/com/android/providers/downloads/DownloadProvider.java
@@ -16,9 +16,14 @@
 
 package com.android.providers.downloads;
 
+import static android.provider.BaseColumns._ID;
+import static android.provider.Downloads.Impl.COLUMN_MEDIAPROVIDER_URI;
+import static android.provider.Downloads.Impl._DATA;
+
 import android.app.AppOpsManager;
 import android.app.DownloadManager;
 import android.app.DownloadManager.Request;
+import android.app.job.JobScheduler;
 import android.content.ContentProvider;
 import android.content.ContentUris;
 import android.content.ContentValues;
@@ -35,8 +40,6 @@ import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.net.Uri;
 import android.os.Binder;
-import android.os.Handler;
-import android.os.HandlerThread;
 import android.os.ParcelFileDescriptor;
 import android.os.ParcelFileDescriptor.OnCloseListener;
 import android.os.Process;
@@ -47,9 +50,10 @@ import android.text.TextUtils;
 import android.text.format.DateUtils;
 import android.util.Log;
 
+import com.android.internal.util.IndentingPrintWriter;
+
 import libcore.io.IoUtils;
 
-import com.android.internal.util.IndentingPrintWriter;
 import com.google.android.collect.Maps;
 import com.google.common.annotations.VisibleForTesting;
 
@@ -73,7 +77,7 @@ public final class DownloadProvider extends ContentProvider {
     /** Database filename */
     private static final String DB_NAME = "downloads.db";
     /** Current database version */
-    private static final int DB_VERSION = 109;
+    private static final int DB_VERSION = 110;
     /** Name of table in the database */
     private static final String DB_TABLE = "downloads";
 
@@ -170,7 +174,8 @@ public final class DownloadProvider extends ContentProvider {
     private static final List<String> downloadManagerColumnsList =
             Arrays.asList(DownloadManager.UNDERLYING_COLUMNS);
 
-    private Handler mHandler;
+    @VisibleForTesting
+    SystemFacade mSystemFacade;
 
     /** The database that lies underneath this content provider */
     private SQLiteOpenHelper mOpenHelper = null;
@@ -179,9 +184,6 @@ public final class DownloadProvider extends ContentProvider {
     private int mSystemUid = -1;
     private int mDefContainerUid = -1;
 
-    @VisibleForTesting
-    SystemFacade mSystemFacade;
-
     /**
      * This class encapsulates a SQL where clause and its parameters.  It makes it possible for
      * shared methods (like {@link DownloadProvider#getWhereClause(Uri, String, String[], int)})
@@ -329,6 +331,11 @@ public final class DownloadProvider extends ContentProvider {
                             "BOOLEAN NOT NULL DEFAULT 0");
                     break;
 
+                case 110:
+                    addColumn(db, DB_TABLE, Downloads.Impl.COLUMN_FLAGS,
+                            "INTEGER NOT NULL DEFAULT 0");
+                    break;
+
                 default:
                     throw new IllegalStateException("Don't know how to upgrade to " + version);
             }
@@ -442,11 +449,6 @@ public final class DownloadProvider extends ContentProvider {
             mSystemFacade = new RealSystemFacade(getContext());
         }
 
-        HandlerThread handlerThread =
-                new HandlerThread("DownloadProvider handler", Process.THREAD_PRIORITY_BACKGROUND);
-        handlerThread.start();
-        mHandler = new Handler(handlerThread.getLooper());
-
         mOpenHelper = new DatabaseHelper(getContext());
         // Initialize the system uid
         mSystemUid = Process.SYSTEM_UID;
@@ -462,10 +464,6 @@ public final class DownloadProvider extends ContentProvider {
         if (appInfo != null) {
             mDefContainerUid = appInfo.uid;
         }
-        // start the DownloadService class. don't wait for the 1st download to be issued.
-        // saves us by getting some initialization code in DownloadService out of the way.
-        Context context = getContext();
-        context.startService(new Intent(context, DownloadService.class));
         return true;
     }
 
@@ -669,6 +667,7 @@ public final class DownloadProvider extends ContentProvider {
             copyInteger(Downloads.Impl.COLUMN_ALLOWED_NETWORK_TYPES, values, filteredValues);
             copyBoolean(Downloads.Impl.COLUMN_ALLOW_ROAMING, values, filteredValues);
             copyBoolean(Downloads.Impl.COLUMN_ALLOW_METERED, values, filteredValues);
+            copyInteger(Downloads.Impl.COLUMN_FLAGS, values, filteredValues);
         }
 
         if (Constants.LOGVV) {
@@ -689,9 +688,12 @@ public final class DownloadProvider extends ContentProvider {
         insertRequestHeaders(db, rowID, values);
         notifyContentChanged(uri, match);
 
-        // Always start service to handle notifications and/or scanning
-        final Context context = getContext();
-        context.startService(new Intent(context, DownloadService.class));
+        final long token = Binder.clearCallingIdentity();
+        try {
+            Helpers.scheduleJob(getContext(), rowID);
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
 
         return ContentUris.withAppendedId(Downloads.Impl.CONTENT_URI, rowID);
     }
@@ -806,6 +808,7 @@ public final class DownloadProvider extends ContentProvider {
         values.remove(Downloads.Impl.COLUMN_ALLOWED_NETWORK_TYPES);
         values.remove(Downloads.Impl.COLUMN_ALLOW_ROAMING);
         values.remove(Downloads.Impl.COLUMN_ALLOW_METERED);
+        values.remove(Downloads.Impl.COLUMN_FLAGS);
         values.remove(Downloads.Impl.COLUMN_IS_VISIBLE_IN_DOWNLOADS_UI);
         values.remove(Downloads.Impl.COLUMN_MEDIA_SCANNED);
         values.remove(Downloads.Impl.COLUMN_ALLOW_WRITE);
@@ -1053,14 +1056,7 @@ public final class DownloadProvider extends ContentProvider {
         SQLiteDatabase db = mOpenHelper.getWritableDatabase();
 
         int count;
-        boolean startService = false;
-
-        if (values.containsKey(Downloads.Impl.COLUMN_DELETED)) {
-            if (values.getAsInteger(Downloads.Impl.COLUMN_DELETED) == 1) {
-                // some rows are to be 'deleted'. need to start DownloadService.
-                startService = true;
-            }
-        }
+        boolean updateSchedule = false;
 
         ContentValues filteredValues;
         if (Binder.getCallingPid() != Process.myPid()) {
@@ -1070,7 +1066,7 @@ public final class DownloadProvider extends ContentProvider {
             Integer i = values.getAsInteger(Downloads.Impl.COLUMN_CONTROL);
             if (i != null) {
                 filteredValues.put(Downloads.Impl.COLUMN_CONTROL, i);
-                startService = true;
+                updateSchedule = true;
             }
 
             copyInteger(Downloads.Impl.COLUMN_CONTROL, values, filteredValues);
@@ -1099,7 +1095,7 @@ public final class DownloadProvider extends ContentProvider {
             boolean isUserBypassingSizeLimit =
                 values.containsKey(Downloads.Impl.COLUMN_BYPASS_RECOMMENDED_SIZE_LIMIT);
             if (isRestart || isUserBypassingSizeLimit) {
-                startService = true;
+                updateSchedule = true;
             }
         }
 
@@ -1109,12 +1105,27 @@ public final class DownloadProvider extends ContentProvider {
             case MY_DOWNLOADS_ID:
             case ALL_DOWNLOADS:
             case ALL_DOWNLOADS_ID:
-                SqlSelection selection = getWhereClause(uri, where, whereArgs, match);
-                if (filteredValues.size() > 0) {
-                    count = db.update(DB_TABLE, filteredValues, selection.getSelection(),
-                            selection.getParameters());
-                } else {
+                if (filteredValues.size() == 0) {
                     count = 0;
+                    break;
+                }
+
+                final SqlSelection selection = getWhereClause(uri, where, whereArgs, match);
+                count = db.update(DB_TABLE, filteredValues, selection.getSelection(),
+                        selection.getParameters());
+                if (updateSchedule) {
+                    final long token = Binder.clearCallingIdentity();
+                    try {
+                        try (Cursor cursor = db.query(DB_TABLE, new String[] { _ID },
+                                selection.getSelection(), selection.getParameters(),
+                                null, null, null)) {
+                            while (cursor.moveToNext()) {
+                                Helpers.scheduleJob(getContext(), cursor.getInt(0));
+                            }
+                        }
+                    } finally {
+                        Binder.restoreCallingIdentity(token);
+                    }
                 }
                 break;
 
@@ -1124,10 +1135,6 @@ public final class DownloadProvider extends ContentProvider {
         }
 
         notifyContentChanged(uri, match);
-        if (startService) {
-            Context context = getContext();
-            context.startService(new Intent(context, DownloadService.class));
-        }
         return count;
     }
 
@@ -1176,7 +1183,8 @@ public final class DownloadProvider extends ContentProvider {
             Helpers.validateSelection(where, sAppReadableColumnsSet);
         }
 
-        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+        final JobScheduler scheduler = getContext().getSystemService(JobScheduler.class);
+        final SQLiteDatabase db = mOpenHelper.getWritableDatabase();
         int count;
         int match = sURIMatcher.match(uri);
         switch (match) {
@@ -1184,15 +1192,16 @@ public final class DownloadProvider extends ContentProvider {
             case MY_DOWNLOADS_ID:
             case ALL_DOWNLOADS:
             case ALL_DOWNLOADS_ID:
-                SqlSelection selection = getWhereClause(uri, where, whereArgs, match);
+                final SqlSelection selection = getWhereClause(uri, where, whereArgs, match);
                 deleteRequestHeaders(db, selection.getSelection(), selection.getParameters());
 
-                final Cursor cursor = db.query(DB_TABLE, new String[] {
-                        Downloads.Impl._ID, Downloads.Impl._DATA
-                }, selection.getSelection(), selection.getParameters(), null, null, null);
-                try {
+                try (Cursor cursor = db.query(DB_TABLE, new String[] {
+                        _ID, _DATA, COLUMN_MEDIAPROVIDER_URI
+                }, selection.getSelection(), selection.getParameters(), null, null, null)) {
                     while (cursor.moveToNext()) {
                         final long id = cursor.getLong(0);
+                        scheduler.cancel((int) id);
+
                         DownloadStorageProvider.onDownloadProviderDelete(getContext(), id);
 
                         final String path = cursor.getString(1);
@@ -1207,9 +1216,13 @@ public final class DownloadProvider extends ContentProvider {
                             } catch (IOException ignored) {
                             }
                         }
+
+                        final String mediaUri = cursor.getString(2);
+                        if (!TextUtils.isEmpty(mediaUri)) {
+                            getContext().getContentResolver().delete(Uri.parse(mediaUri), null,
+                                    null);
+                        }
                     }
-                } finally {
-                    IoUtils.closeQuietly(cursor);
                 }
 
                 count = db.delete(DB_TABLE, selection.getSelection(), selection.getParameters());
@@ -1287,7 +1300,8 @@ public final class DownloadProvider extends ContentProvider {
         } else {
             try {
                 // When finished writing, update size and timestamp
-                return ParcelFileDescriptor.open(file, pfdMode, mHandler, new OnCloseListener() {
+                return ParcelFileDescriptor.open(file, pfdMode, Helpers.getAsyncHandler(),
+                        new OnCloseListener() {
                     @Override
                     public void onClose(IOException e) {
                         final ContentValues values = new ContentValues();