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, 122 insertions, 92 deletions

diff --git a/src/com/android/providers/downloads/DownloadNotifier.java b/src/com/android/providers/downloads/DownloadNotifier.java
index 5f961eb2..558393d6 100644
--- a/src/com/android/providers/downloads/DownloadNotifier.java
+++ b/src/com/android/providers/downloads/DownloadNotifier.java
@@ -20,6 +20,7 @@ import static android.app.DownloadManager.Request.VISIBILITY_VISIBLE;
 import static android.app.DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED;
 import static android.app.DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_ONLY_COMPLETION;
 import static android.provider.Downloads.Impl.STATUS_RUNNING;
+
 import static com.android.providers.downloads.Constants.TAG;
 
 import android.app.DownloadManager;
@@ -30,31 +31,27 @@ import android.content.ContentUris;
 import android.content.Context;
 import android.content.Intent;
 import android.content.res.Resources;
+import android.database.Cursor;
 import android.net.Uri;
 import android.os.SystemClock;
 import android.provider.Downloads;
 import android.service.notification.StatusBarNotification;
 import android.text.TextUtils;
 import android.text.format.DateUtils;
+import android.util.ArrayMap;
+import android.util.IntArray;
 import android.util.Log;
 import android.util.LongSparseLongArray;
 
 import com.android.internal.util.ArrayUtils;
 
-import com.google.common.collect.ArrayListMultimap;
-import com.google.common.collect.Maps;
-import com.google.common.collect.Multimap;
-
 import java.text.NumberFormat;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Iterator;
 
 import javax.annotation.concurrent.GuardedBy;
 
 /**
- * Update {@link NotificationManager} to reflect current {@link DownloadInfo}
- * states. Collapses similar downloads into a single notification, and builds
+ * Update {@link NotificationManager} to reflect current download states.
+ * Collapses similar downloads into a single notification, and builds
  * {@link PendingIntent} that launch towards {@link DownloadReceiver}.
  */
 public class DownloadNotifier {
@@ -70,20 +67,20 @@ public class DownloadNotifier {
      * Currently active notifications, mapped from clustering tag to timestamp
      * when first shown.
      *
-     * @see #buildNotificationTag(DownloadInfo)
+     * @see #buildNotificationTag(Cursor)
      */
     @GuardedBy("mActiveNotifs")
-    private final HashMap<String, Long> mActiveNotifs = Maps.newHashMap();
+    private final ArrayMap<String, Long> mActiveNotifs = new ArrayMap<>();
 
     /**
-     * Current speed of active downloads, mapped from {@link DownloadInfo#mId}
-     * to speed in bytes per second.
+     * Current speed of active downloads, mapped from download ID to speed in
+     * bytes per second.
      */
     @GuardedBy("mDownloadSpeed")
     private final LongSparseLongArray mDownloadSpeed = new LongSparseLongArray();
 
     /**
-     * Last time speed was reproted, mapped from {@link DownloadInfo#mId} to
+     * Last time speed was reproted, mapped from download ID to
      * {@link SystemClock#elapsedRealtime()}.
      */
     @GuardedBy("mDownloadSpeed")
@@ -123,48 +120,62 @@ public class DownloadNotifier {
         }
     }
 
-    /**
-     * Update {@link NotificationManager} to reflect the given set of
-     * {@link DownloadInfo}, adding, collapsing, and removing as needed.
-     */
-    public void updateWith(Collection<DownloadInfo> downloads) {
-        synchronized (mActiveNotifs) {
-            updateWithLocked(downloads);
-        }
+    private interface UpdateQuery {
+        final String[] PROJECTION = new String[] {
+                Downloads.Impl._ID,
+                Downloads.Impl.COLUMN_STATUS,
+                Downloads.Impl.COLUMN_VISIBILITY,
+                Downloads.Impl.COLUMN_NOTIFICATION_PACKAGE,
+                Downloads.Impl.COLUMN_CURRENT_BYTES,
+                Downloads.Impl.COLUMN_TOTAL_BYTES,
+                Downloads.Impl.COLUMN_DESTINATION,
+                Downloads.Impl.COLUMN_TITLE,
+                Downloads.Impl.COLUMN_DESCRIPTION,
+        };
+
+        final int _ID = 0;
+        final int STATUS = 1;
+        final int VISIBILITY = 2;
+        final int NOTIFICATION_PACKAGE = 3;
+        final int CURRENT_BYTES = 4;
+        final int TOTAL_BYTES = 5;
+        final int DESTINATION = 6;
+        final int TITLE = 7;
+        final int DESCRIPTION = 8;
     }
 
-    private static boolean isClusterDeleted(Collection<DownloadInfo> cluster) {
-        boolean wasDeleted = true;
-        for (DownloadInfo info : cluster) {
-            wasDeleted = wasDeleted && info.mDeleted;
+    public void update() {
+        try (Cursor cursor = mContext.getContentResolver().query(
+                Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, UpdateQuery.PROJECTION,
+                Downloads.Impl.COLUMN_DELETED + " == '0'", null, null)) {
+            synchronized (mActiveNotifs) {
+                updateWithLocked(cursor);
+            }
         }
-        return wasDeleted;
     }
 
-    private void updateWithLocked(Collection<DownloadInfo> downloads) {
+    private void updateWithLocked(Cursor cursor) {
         final Resources res = mContext.getResources();
 
         // Cluster downloads together
-        final Multimap<String, DownloadInfo> clustered = ArrayListMultimap.create();
-        for (DownloadInfo info : downloads) {
-            final String tag = buildNotificationTag(info);
+        final ArrayMap<String, IntArray> clustered = new ArrayMap<>();
+        while (cursor.moveToNext()) {
+            final String tag = buildNotificationTag(cursor);
             if (tag != null) {
-                clustered.put(tag, info);
+                IntArray cluster = clustered.get(tag);
+                if (cluster == null) {
+                    cluster = new IntArray();
+                    clustered.put(tag, cluster);
+                }
+                cluster.add(cursor.getPosition());
             }
         }
 
         // Build notification for each cluster
-        Iterator<String> it = clustered.keySet().iterator();
-        while (it.hasNext()) {
-            final String tag = it.next();
+        for (int i = 0; i < clustered.size(); i++) {
+            final String tag = clustered.keyAt(i);
+            final IntArray cluster = clustered.valueAt(i);
             final int type = getNotificationTagType(tag);
-            final Collection<DownloadInfo> cluster = clustered.get(tag);
-
-            // If each of the downloads was canceled, don't show notification for the cluster
-            if (isClusterDeleted(cluster)) {
-                it.remove();
-                continue;
-            }
 
             final Notification.Builder builder = new Notification.Builder(mContext);
             builder.setColor(res.getColor(
@@ -191,7 +202,7 @@ public class DownloadNotifier {
 
             // Build action intents
             if (type == TYPE_ACTIVE || type == TYPE_WAITING) {
-                long[] downloadIds = getDownloadIds(cluster);
+                final long[] downloadIds = getDownloadIds(cursor, cluster);
 
                 // build a synthetic uri for intent identification purposes
                 final Uri uri = new Uri.Builder().scheme("active-dl").appendPath(tag).build();
@@ -217,16 +228,20 @@ public class DownloadNotifier {
                             0, cancelIntent, PendingIntent.FLAG_UPDATE_CURRENT));
 
             } else if (type == TYPE_COMPLETE) {
-                final DownloadInfo info = cluster.iterator().next();
+                cursor.moveToPosition(cluster.get(0));
+                final long id = cursor.getLong(UpdateQuery._ID);
+                final int status = cursor.getInt(UpdateQuery.STATUS);
+                final int destination = cursor.getInt(UpdateQuery.DESTINATION);
+
                 final Uri uri = ContentUris.withAppendedId(
-                        Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, info.mId);
+                        Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, id);
                 builder.setAutoCancel(true);
 
                 final String action;
-                if (Downloads.Impl.isStatusError(info.mStatus)) {
+                if (Downloads.Impl.isStatusError(status)) {
                     action = Constants.ACTION_LIST;
                 } else {
-                    if (info.mDestination != Downloads.Impl.DESTINATION_SYSTEMCACHE_PARTITION) {
+                    if (destination != Downloads.Impl.DESTINATION_SYSTEMCACHE_PARTITION) {
                         action = Constants.ACTION_OPEN;
                     } else {
                         action = Constants.ACTION_LIST;
@@ -235,7 +250,7 @@ public class DownloadNotifier {
 
                 final Intent intent = new Intent(action, uri, mContext, DownloadReceiver.class);
                 intent.putExtra(DownloadManager.EXTRA_NOTIFICATION_CLICK_DOWNLOAD_IDS,
-                        getDownloadIds(cluster));
+                        getDownloadIds(cursor, cluster));
                 builder.setContentIntent(PendingIntent.getBroadcast(mContext,
                         0, intent, PendingIntent.FLAG_UPDATE_CURRENT));
 
@@ -252,11 +267,17 @@ public class DownloadNotifier {
                 long total = 0;
                 long speed = 0;
                 synchronized (mDownloadSpeed) {
-                    for (DownloadInfo info : cluster) {
-                        if (info.mTotalBytes != -1) {
-                            current += info.mCurrentBytes;
-                            total += info.mTotalBytes;
-                            speed += mDownloadSpeed.get(info.mId);
+                    for (int j = 0; j < cluster.size(); j++) {
+                        cursor.moveToPosition(cluster.get(j));
+
+                        final long id = cursor.getLong(UpdateQuery._ID);
+                        final long currentBytes = cursor.getLong(UpdateQuery.CURRENT_BYTES);
+                        final long totalBytes = cursor.getLong(UpdateQuery.TOTAL_BYTES);
+
+                        if (totalBytes != -1) {
+                            current += currentBytes;
+                            total += totalBytes;
+                            speed += mDownloadSpeed.get(id);
                         }
                     }
                 }
@@ -281,13 +302,13 @@ public class DownloadNotifier {
             // Build titles and description
             final Notification notif;
             if (cluster.size() == 1) {
-                final DownloadInfo info = cluster.iterator().next();
-
-                builder.setContentTitle(getDownloadTitle(res, info));
+                cursor.moveToPosition(cluster.get(0));
+                builder.setContentTitle(getDownloadTitle(res, cursor));
 
                 if (type == TYPE_ACTIVE) {
-                    if (!TextUtils.isEmpty(info.mDescription)) {
-                        builder.setContentText(info.mDescription);
+                    final String description = cursor.getString(UpdateQuery.DESCRIPTION);
+                    if (!TextUtils.isEmpty(description)) {
+                        builder.setContentText(description);
                     } else {
                         builder.setContentText(remainingText);
                     }
@@ -298,9 +319,10 @@ public class DownloadNotifier {
                             res.getString(R.string.notification_need_wifi_for_size));
 
                 } else if (type == TYPE_COMPLETE) {
-                    if (Downloads.Impl.isStatusError(info.mStatus)) {
+                    final int status = cursor.getInt(UpdateQuery.STATUS);
+                    if (Downloads.Impl.isStatusError(status)) {
                         builder.setContentText(res.getText(R.string.notification_download_failed));
-                    } else if (Downloads.Impl.isStatusSuccess(info.mStatus)) {
+                    } else if (Downloads.Impl.isStatusSuccess(status)) {
                         builder.setContentText(
                                 res.getText(R.string.notification_download_complete));
                     }
@@ -311,8 +333,9 @@ public class DownloadNotifier {
             } else {
                 final Notification.InboxStyle inboxStyle = new Notification.InboxStyle(builder);
 
-                for (DownloadInfo info : cluster) {
-                    inboxStyle.addLine(getDownloadTitle(res, info));
+                for (int j = 0; j < cluster.size(); j++) {
+                    cursor.moveToPosition(cluster.get(j));
+                    inboxStyle.addLine(getDownloadTitle(res, cursor));
                 }
 
                 if (type == TYPE_ACTIVE) {
@@ -338,29 +361,31 @@ public class DownloadNotifier {
         }
 
         // Remove stale tags that weren't renewed
-        it = mActiveNotifs.keySet().iterator();
-        while (it.hasNext()) {
-            final String tag = it.next();
-            if (!clustered.containsKey(tag)) {
+        for (int i = 0; i < mActiveNotifs.size();) {
+            final String tag = mActiveNotifs.keyAt(i);
+            if (clustered.containsKey(tag)) {
+                i++;
+            } else {
                 mNotifManager.cancel(tag, 0);
-                it.remove();
+                mActiveNotifs.removeAt(i);
             }
         }
     }
 
-    private static CharSequence getDownloadTitle(Resources res, DownloadInfo info) {
-        if (!TextUtils.isEmpty(info.mTitle)) {
-            return info.mTitle;
+    private static CharSequence getDownloadTitle(Resources res, Cursor cursor) {
+        final String title = cursor.getString(UpdateQuery.TITLE);
+        if (!TextUtils.isEmpty(title)) {
+            return title;
         } else {
             return res.getString(R.string.download_unknown_title);
         }
     }
 
-    private long[] getDownloadIds(Collection<DownloadInfo> infos) {
-        final long[] ids = new long[infos.size()];
-        int i = 0;
-        for (DownloadInfo info : infos) {
-            ids[i++] = info.mId;
+    private long[] getDownloadIds(Cursor cursor, IntArray cluster) {
+        final long[] ids = new long[cluster.size()];
+        for (int i = 0; i < cluster.size(); i++) {
+            cursor.moveToPosition(cluster.get(i));
+            ids[i] = cursor.getLong(UpdateQuery._ID);
         }
         return ids;
     }
@@ -377,17 +402,22 @@ public class DownloadNotifier {
     }
 
     /**
-     * Build tag used for collapsing several {@link DownloadInfo} into a single
+     * Build tag used for collapsing several downloads into a single
      * {@link Notification}.
      */
-    private static String buildNotificationTag(DownloadInfo info) {
-        if (info.mStatus == Downloads.Impl.STATUS_QUEUED_FOR_WIFI) {
-            return TYPE_WAITING + ":" + info.mPackage;
-        } else if (isActiveAndVisible(info)) {
-            return TYPE_ACTIVE + ":" + info.mPackage;
-        } else if (isCompleteAndVisible(info)) {
+    private static String buildNotificationTag(Cursor cursor) {
+        final long id = cursor.getLong(UpdateQuery._ID);
+        final int status = cursor.getInt(UpdateQuery.STATUS);
+        final int visibility = cursor.getInt(UpdateQuery.VISIBILITY);
+        final String notifPackage = cursor.getString(UpdateQuery.NOTIFICATION_PACKAGE);
+
+        if (status == Downloads.Impl.STATUS_QUEUED_FOR_WIFI) {
+            return TYPE_WAITING + ":" + notifPackage;
+        } else if (isActiveAndVisible(status, visibility)) {
+            return TYPE_ACTIVE + ":" + notifPackage;
+        } else if (isCompleteAndVisible(status, visibility)) {
             // Complete downloads always have unique notifs
-            return TYPE_COMPLETE + ":" + info.mId;
+            return TYPE_COMPLETE + ":" + id;
         } else {
             return null;
         }
@@ -395,21 +425,21 @@ public class DownloadNotifier {
 
     /**
      * Return the cluster type of the given tag, as created by
-     * {@link #buildNotificationTag(DownloadInfo)}.
+     * {@link #buildNotificationTag(Cursor)}.
      */
     private static int getNotificationTagType(String tag) {
         return Integer.parseInt(tag.substring(0, tag.indexOf(':')));
     }
 
-    private static boolean isActiveAndVisible(DownloadInfo download) {
-        return download.mStatus == STATUS_RUNNING &&
-                (download.mVisibility == VISIBILITY_VISIBLE
-                || download.mVisibility == VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
+    private static boolean isActiveAndVisible(int status, int visibility) {
+        return status == STATUS_RUNNING &&
+                (visibility == VISIBILITY_VISIBLE
+                || visibility == VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
     }
 
-    private static boolean isCompleteAndVisible(DownloadInfo download) {
-        return Downloads.Impl.isStatusCompleted(download.mStatus) &&
-                (download.mVisibility == VISIBILITY_VISIBLE_NOTIFY_COMPLETED
-                || download.mVisibility == VISIBILITY_VISIBLE_NOTIFY_ONLY_COMPLETION);
+    private static boolean isCompleteAndVisible(int status, int visibility) {
+        return Downloads.Impl.isStatusCompleted(status) &&
+                (visibility == VISIBILITY_VISIBLE_NOTIFY_COMPLETED
+                || visibility == VISIBILITY_VISIBLE_NOTIFY_ONLY_COMPLETION);
     }
 }