Small database efficiency tweaks (#7058)

- When checking whether there is a subscription, there is no need to create feed objects (plus counters etc). Just the number of episodes is enough.
- Downloads section only needs to load the items it actually displays.
- No need to load FeedMedia, just to load FeedItem including the same FeedMedia afterwards.
- No need to convert columns to Strings and back to Longs.
- No need to join favorites when we are only interested in the list of IDs anyway.

2 files changed, 6 insertions, 11 deletions

diff --git a/app/src/main/java/de/danoeh/antennapod/ui/screen/home/HomeFragment.java b/app/src/main/java/de/danoeh/antennapod/ui/screen/home/HomeFragment.java
index bcbc2675a..0ed96a70c 100644
--- a/app/src/main/java/de/danoeh/antennapod/ui/screen/home/HomeFragment.java
+++ b/app/src/main/java/de/danoeh/antennapod/ui/screen/home/HomeFragment.java
@@ -19,6 +19,7 @@ import androidx.core.content.ContextCompat;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentContainerView;
 
+import de.danoeh.antennapod.model.feed.FeedItemFilter;
 import de.danoeh.antennapod.net.download.serviceinterface.FeedUpdateManager;
 import de.danoeh.antennapod.ui.echo.EchoConfig;
 import de.danoeh.antennapod.ui.screen.home.sections.AllowNotificationsSection;
@@ -44,7 +45,6 @@ import de.danoeh.antennapod.databinding.HomeFragmentBinding;
 import de.danoeh.antennapod.event.FeedListUpdateEvent;
 import de.danoeh.antennapod.event.FeedUpdateRunningEvent;
 import de.danoeh.antennapod.ui.screen.SearchFragment;
-import de.danoeh.antennapod.storage.preferences.UserPreferences;
 import de.danoeh.antennapod.ui.view.LiftOnScrollListener;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
@@ -193,14 +193,12 @@ public class HomeFragment extends Fragment implements Toolbar.OnMenuItemClickLis
         if (disposable != null) {
             disposable.dispose();
         }
-        disposable = Observable.fromCallable(() ->
-                        DBReader.getNavDrawerData(UserPreferences.getSubscriptionsFilter(),
-                                UserPreferences.getFeedOrder(), UserPreferences.getFeedCounterSetting()).items.size())
+        disposable = Observable.fromCallable(() -> DBReader.getTotalEpisodeCount(FeedItemFilter.unfiltered()))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(numSubscriptions -> {
-                    viewBinding.welcomeContainer.setVisibility(numSubscriptions == 0 ? View.VISIBLE : View.GONE);
-                    viewBinding.homeContainer.setVisibility(numSubscriptions == 0 ? View.GONE : View.VISIBLE);
+                .subscribe(numEpisodes -> {
+                    viewBinding.welcomeContainer.setVisibility(numEpisodes == 0 ? View.VISIBLE : View.GONE);
+                    viewBinding.homeContainer.setVisibility(numEpisodes == 0 ? View.GONE : View.VISIBLE);
                 }, error -> Log.e(TAG, Log.getStackTraceString(error)));
     }
 
diff --git a/app/src/main/java/de/danoeh/antennapod/ui/screen/home/sections/DownloadsSection.java b/app/src/main/java/de/danoeh/antennapod/ui/screen/home/sections/DownloadsSection.java
index 4dc34a80e..cc3288e2f 100644
--- a/app/src/main/java/de/danoeh/antennapod/ui/screen/home/sections/DownloadsSection.java
+++ b/app/src/main/java/de/danoeh/antennapod/ui/screen/home/sections/DownloadsSection.java
@@ -124,14 +124,11 @@ public class DownloadsSection extends HomeSection {
             disposable.dispose();
         }
         SortOrder sortOrder = UserPreferences.getDownloadsSortedOrder();
-        disposable = Observable.fromCallable(() -> DBReader.getEpisodes(0, Integer.MAX_VALUE,
+        disposable = Observable.fromCallable(() -> DBReader.getEpisodes(0, NUM_EPISODES,
                         new FeedItemFilter(FeedItemFilter.DOWNLOADED), sortOrder))
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(downloads -> {
-                    if (downloads.size() > NUM_EPISODES) {
-                        downloads = downloads.subList(0, NUM_EPISODES);
-                    }
                     items = downloads;
                     adapter.setDummyViews(0);
                     adapter.updateItems(items);