Performance improvements for library filters

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadManager.java

@@ -378,17 +378,21 @@ public class DownloadManager {
         savePageList(download.source, download.manga, download.chapter, download.pages);
     }
 
-    // Get the absolute path to the chapter directory
-    public File getAbsoluteChapterDirectory(Source source, Manga manga, Chapter chapter) {
+    public File getAbsoluteMangaDirectory(Source source, Manga manga) {
         String chapterRelativePath = source.getName() +
                 File.separator +
-                manga.title.replaceAll("[^\\sa-zA-Z0-9.-]", "_") +
-                File.separator +
-                chapter.name.replaceAll("[^\\sa-zA-Z0-9.-]", "_");
+                manga.title.replaceAll("[^\\sa-zA-Z0-9.-]", "_");
 
         return new File(preferences.getDownloadsDirectory(), chapterRelativePath);
     }
 
+    // Get the absolute path to the chapter directory
+    public File getAbsoluteChapterDirectory(Source source, Manga manga, Chapter chapter) {
+        String chapterRelativePath = chapter.name.replaceAll("[^\\sa-zA-Z0-9.-]", "_");
+
+        return new File(getAbsoluteMangaDirectory(source, manga), chapterRelativePath);
+    }
+
     // Shortcut for the method above
     private File getAbsoluteChapterDirectory(Download download) {
         return getAbsoluteChapterDirectory(download.source, download.manga, download.chapter);

app/src/main/java/eu/kanade/tachiyomi/data/preference/PreferencesHelper.kt

@@ -11,6 +11,10 @@ import eu.kanade.tachiyomi.data.source.base.Source
 import java.io.File
 import java.io.IOException
 
+fun <T> Preference<T>.getOrDefault(): T {
+    return get() ?: defaultValue()!!
+}
+
 class PreferencesHelper(private val context: Context) {
 
     private val prefs = PreferenceManager.getDefaultSharedPreferences(context)

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryPresenter.kt

@@ -5,11 +5,11 @@ import android.util.Pair
 import eu.kanade.tachiyomi.data.cache.CoverCache
 import eu.kanade.tachiyomi.data.database.DatabaseHelper
 import eu.kanade.tachiyomi.data.database.models.Category
-import eu.kanade.tachiyomi.data.database.models.Chapter
 import eu.kanade.tachiyomi.data.database.models.Manga
 import eu.kanade.tachiyomi.data.database.models.MangaCategory
 import eu.kanade.tachiyomi.data.download.DownloadManager
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
+import eu.kanade.tachiyomi.data.preference.getOrDefault
 import eu.kanade.tachiyomi.data.source.SourceManager
 import eu.kanade.tachiyomi.event.LibraryMangasEvent
 import eu.kanade.tachiyomi.ui.base.presenter.BasePresenter
@@ -62,6 +62,11 @@ class LibraryPresenter : BasePresenter<LibraryFragment>() {
      */
     @Inject lateinit var sourceManager: SourceManager
 
+    /**
+     * Download manager.
+     */
+    @Inject lateinit var downloadManager: DownloadManager
+
     companion object {
         /**
          * Id of the restartable that listens for library updates.
@@ -153,55 +158,40 @@ class LibraryPresenter : BasePresenter<LibraryFragment>() {
      * @return filter status
      */
     fun filterLibrary(manga: Manga): Boolean {
+        val prefFilterDownloaded = preferences.filterDownloaded().getOrDefault()
+        val prefFilterUnread = preferences.filterUnread().getOrDefault()
+
         // Check if filter option is selected
-        if (preferences.filterDownloaded().get() as Boolean || preferences.filterUnread().get() as Boolean) {
+        if (prefFilterDownloaded || prefFilterUnread) {
 
             // Does it have downloaded chapters.
             var hasDownloaded = false
 
             // Does it have unread chapters.
-            var hasUnread = false
-
-            // Get chapters from database.
-            val chapters = getChapters(manga)
-
-            if (preferences.filterDownloaded().get() as Boolean) {
-                // Get download manager.
-                val downloadManager = DownloadManager(context, sourceManager, preferences)
-                // Loop through chapters and check if library has downloaded manga
-                chapters?.forEach { chapter ->
-                    if (downloadManager.isChapterDownloaded(sourceManager.get(manga.source), manga, chapter)) {
-                        hasDownloaded = true
-                    }
-                }
-            }
-            if (preferences.filterUnread().get() as Boolean) {
-                // Loop through chapters and check if library has unread manga
-                chapters?.forEach { chapter ->
-                    if (!chapter.read) {
-                        hasUnread = true
+            val hasUnread = manga.unread > 0
+
+            if (prefFilterDownloaded) {
+                val mangaDir = downloadManager.getAbsoluteMangaDirectory(sourceManager.get(manga.source), manga)
+
+                if (mangaDir.exists()) {
+                    for (file in mangaDir.listFiles()) {
+                        if (file.isDirectory && file.listFiles().isNotEmpty()) {
+                            hasDownloaded = true
+                            break
+                        }
                     }
                 }
             }
 
             // Return correct filter status
-            if (preferences.filterDownloaded().get() as Boolean && preferences.filterUnread().get() as Boolean) {
+            if (prefFilterDownloaded && prefFilterUnread) {
                 return (hasDownloaded && hasUnread)
             } else {
                 return (hasDownloaded || hasUnread)
             }
-        } else
+        } else {
             return true
-    }
-
-    /**
-     * Returns list of chapters belonging to manga
-     *
-     * @param manga manga from library
-     * @return list of chapters belonging to manga
-     */
-    fun getChapters(manga: Manga): MutableList<Chapter>? {
-        return db.getChapters(manga).executeAsBlocking()
+        }
     }
 
     /**