Improve performance across screens (#4071)

* Keep screens loaded while they're hidden and rebuild the library faster

* Count chapters in SQL for the migration list

* Show the extension list sooner and check trust against loaded stores

* Cancel the previous tracker search when searching again

* Write reader progress less often and keep its work off the main thread

* Stop rebuilding the settings search index on every key

* Watch updates for widgets only while one is placed

The query re-ran on every chapter or manga write even with no widget on
the home screen.

* Observe download pages and limit how often their progress updates

* Throttle the library update notification and write fetch data together

data/src/main/java/tachiyomi/data/QueryExtension.kt

@@ -6,17 +6,18 @@ import app.cash.sqldelight.coroutines.mapToList
 import app.cash.sqldelight.coroutines.mapToOne
 import app.cash.sqldelight.coroutines.mapToOneOrNull
 import kotlinx.coroutines.flow.Flow
+import tachiyomi.core.common.util.lang.pausedWhileUnsubscribed
 import kotlin.coroutines.CoroutineContext
 import kotlin.coroutines.EmptyCoroutineContext
 
 fun <T : Any> Query<T>.subscribeToList(
     context: CoroutineContext = EmptyCoroutineContext,
-): Flow<List<T>> = asFlow().mapToList(context)
+): Flow<List<T>> = asFlow().pausedWhileUnsubscribed().mapToList(context)
 
 fun <T : Any> Query<T>.subscribeToOne(
     context: CoroutineContext = EmptyCoroutineContext,
-): Flow<T> = asFlow().mapToOne(context)
+): Flow<T> = asFlow().pausedWhileUnsubscribed().mapToOne(context)
 
 fun <T : Any> Query<T>.subscribeToOneOrNull(
     context: CoroutineContext = EmptyCoroutineContext,
-): Flow<T?> = asFlow().mapToOneOrNull(context)
+): Flow<T?> = asFlow().pausedWhileUnsubscribed().mapToOneOrNull(context)

data/src/main/java/tachiyomi/data/chapter/ChapterRepositoryImpl.kt

@@ -14,6 +14,7 @@ import tachiyomi.data.Database
 import tachiyomi.data.subscribeToList
 import tachiyomi.domain.chapter.model.Chapter
 import tachiyomi.domain.chapter.model.ChapterRemoteUpdate
+import tachiyomi.domain.chapter.model.ChapterSummary
 import tachiyomi.domain.chapter.model.ChapterUpdate
 import tachiyomi.domain.chapter.repository.ChapterRepository
 import kotlin.time.Instant
@@ -112,6 +113,14 @@ class ChapterRepositoryImpl(
             .awaitAsList()
     }
 
+    override suspend fun getChapterSummaryByMangaId(mangaId: Long): ChapterSummary {
+        return database.chapterQueries
+            .getChapterSummaryByMangaId(mangaId) { total, latestChapterNumber ->
+                ChapterSummary(chapterCount = total, latestChapterNumber = latestChapterNumber)
+            }
+            .awaitAsOne()
+    }
+
     override suspend fun getScanlatorsByMangaId(mangaId: Long): List<String> {
         return database.chapterQueries
             .getScanlatorsByMangaId(mangaId) { it.orEmpty() }

data/src/main/sqldelight/tachiyomi/data/chapter.sq

@@ -48,6 +48,11 @@ AND (
     OR ES.scanlator IS NULL
 );
 
+getChapterSummaryByMangaId:
+SELECT count(*) AS total, max(remote_chapter_number) AS latestChapterNumber
+FROM chapter
+WHERE manga_id = :mangaId;
+
 getScanlatorsByMangaId:
 SELECT DISTINCT remote_scanlator
 FROM chapter