bound artwork seeds and size the now-playing prefetch

app/src/main/kotlin/com/subtracks/data/db/ArtworkSeedDao.kt

@@ -12,4 +12,16 @@ interface ArtworkSeedDao {
 
     @Upsert
     suspend fun upsert(seed: ArtworkSeed)
+
+    @Query("UPDATE artwork_seeds SET lastUsed = :lastUsed WHERE cacheKey = :cacheKey")
+    suspend fun touch(
+        cacheKey: String,
+        lastUsed: Long,
+    )
+
+    @Query(
+        "DELETE FROM artwork_seeds WHERE cacheKey NOT IN " +
+            "(SELECT cacheKey FROM artwork_seeds ORDER BY lastUsed DESC LIMIT :keep)",
+    )
+    suspend fun prune(keep: Int)
 }

app/src/main/kotlin/com/subtracks/data/db/Migrations.kt

@@ -112,6 +112,21 @@ val MIGRATION_11_12 =
         }
     }
 
+val MIGRATION_12_13 =
+    object : Migration(12, 13) {
+        override suspend fun migrate(connection: SQLiteConnection) {
+            connection.execSQL("DROP TABLE IF EXISTS `artwork_seeds`")
+            connection.execSQL(
+                "CREATE TABLE IF NOT EXISTS `artwork_seeds` (`cacheKey` TEXT NOT NULL, " +
+                    "`primary` INTEGER NOT NULL, `secondary` INTEGER, `nameBusy` INTEGER, " +
+                    "`sourceId` INTEGER NOT NULL, `lastUsed` INTEGER NOT NULL DEFAULT 0, " +
+                    "PRIMARY KEY(`cacheKey`), " +
+                    "FOREIGN KEY(`sourceId`) REFERENCES `sources`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )",
+            )
+            connection.execSQL("CREATE INDEX IF NOT EXISTS `index_artwork_seeds_sourceId` ON `artwork_seeds` (`sourceId`)")
+        }
+    }
+
 val MIGRATIONS: Array<Migration> =
     arrayOf(
         MIGRATION_1_2,
@@ -125,4 +140,5 @@ val MIGRATIONS: Array<Migration> =
         MIGRATION_9_10,
         MIGRATION_10_11,
         MIGRATION_11_12,
+        MIGRATION_12_13,
     )

app/src/main/kotlin/com/subtracks/data/db/SubtracksDatabase.kt

@@ -32,7 +32,7 @@ import com.subtracks.data.model.SubsonicSource
         ShuffleOrder::class,
         ArtworkSeed::class,
     ],
-    version = 12,
+    version = 13,
     exportSchema = true,
 )
 @ColumnTypeConverters(QueueKindConverter::class)

app/src/main/kotlin/com/subtracks/data/model/Models.kt

@@ -237,12 +237,25 @@ data class ShuffleOrder(
     val flatPosition: Long,
 )
 
-@Entity(tableName = "artwork_seeds")
+@Entity(
+    tableName = "artwork_seeds",
+    foreignKeys = [
+        ForeignKey(
+            entity = Source::class,
+            parentColumns = ["id"],
+            childColumns = ["sourceId"],
+            onDelete = ForeignKey.CASCADE,
+        ),
+    ],
+    indices = [Index("sourceId")],
+)
 data class ArtworkSeed(
     @PrimaryKey val cacheKey: String,
     val primary: Int,
     val secondary: Int?,
     val nameBusy: Boolean? = null,
+    val sourceId: Long = 0,
+    @ColumnInfo(defaultValue = "0") val lastUsed: Long = 0,
 )
 
 class QueueKindConverter {

app/src/main/kotlin/com/subtracks/data/repo/ArtworkSeedRepository.kt

@@ -3,6 +3,8 @@ package com.subtracks.data.repo
 import com.subtracks.data.db.SubtracksDatabase
 import com.subtracks.data.model.ArtworkSeed
 
+private const val MAX_STORED_SEEDS = 1024
+
 interface ArtworkSeedStore {
     suspend fun seed(cacheKey: String): ArtworkSeed?
 
@@ -11,10 +13,19 @@ interface ArtworkSeedStore {
 
 class ArtworkSeedRepository(
     private val db: SubtracksDatabase,
+    private val maxStoredSeeds: Int = MAX_STORED_SEEDS,
 ) : ArtworkSeedStore {
-    override suspend fun seed(cacheKey: String): ArtworkSeed? = db.artworkSeedDao().seed(cacheKey)
+    override suspend fun seed(cacheKey: String): ArtworkSeed? {
+        val dao = db.artworkSeedDao()
+        val row = dao.seed(cacheKey) ?: return null
+        dao.touch(cacheKey, System.currentTimeMillis())
+        return row
+    }
 
     override suspend fun save(seed: ArtworkSeed) {
-        db.artworkSeedDao().upsert(seed)
+        val sourceId = seed.cacheKey.substringBefore(':').toLongOrNull() ?: return
+        val dao = db.artworkSeedDao()
+        dao.upsert(seed.copy(sourceId = sourceId, lastUsed = System.currentTimeMillis()))
+        dao.prune(maxStoredSeeds)
     }
 }

app/src/main/kotlin/com/subtracks/playback/PlaybackController.kt

@@ -580,11 +580,10 @@ class PlaybackController(
         thumbnail: Boolean = false,
     ): CoverArtRef? = sourceRepository.coverArt(item?.coverArtId, thumbnail)
 
-    suspend fun upcomingCoverArt(thumbnail: Boolean = false): CoverArtRef? {
+    suspend fun upcomingItem(): QueueItem? {
         val snap = snapshot ?: return null
         val position = currentPosition() ?: return null
-        val next = queueRepository.itemAt(snap, position + 1) ?: return null
-        return sourceRepository.coverArt(next.toQueueItem().coverArtId, thumbnail)
+        return queueRepository.itemAt(snap, position + 1)?.toQueueItem()
     }
 
     private fun play(

app/src/main/kotlin/com/subtracks/ui/playback/NowPlayingScreen.kt

@@ -98,8 +98,10 @@ fun NowPlayingRoute(
     }
     LaunchedEffect(state.item?.id, state.hasNext) {
         if (!state.hasNext) return@LaunchedEffect
-        controller.upcomingCoverArt(thumbnail = true)?.let { ArtworkSeedCache.prefetch(context, it) }
-        controller.upcomingCoverArt()?.let { prefetchImage(context, it) }
+        controller.upcomingItem()?.let { next ->
+            controller.coverArt(next, thumbnail = true)?.let { ArtworkSeedCache.prefetch(context, it) }
+            controller.coverArt(next)?.let { prefetchImage(context, it) }
+        }
     }
     NowPlayingScreen(
         state = state,
@@ -120,18 +122,26 @@ fun NowPlayingRoute(
     )
 }
 
-private fun prefetchImage(
+internal fun prefetchImage(
     context: Context,
     ref: CoverArtRef,
 ) {
-    SingletonImageLoader.get(context).enqueue(
-        ImageRequest
-            .Builder(context)
-            .data(ref.url)
-            .memoryCacheKey(ref.cacheKey)
-            .diskCacheKey(ref.cacheKey)
-            .build(),
-    )
+    SingletonImageLoader.get(context).enqueue(prefetchImageRequest(context, ref))
+}
+
+internal fun prefetchImageRequest(
+    context: Context,
+    ref: CoverArtRef,
+): ImageRequest {
+    val metrics = context.resources.displayMetrics
+    val maxDimension = maxOf(metrics.widthPixels, metrics.heightPixels)
+    return ImageRequest
+        .Builder(context)
+        .data(ref.url)
+        .memoryCacheKey(ref.cacheKey)
+        .diskCacheKey(ref.cacheKey)
+        .size(maxDimension)
+        .build()
 }
 
 @OptIn(ExperimentalMaterial3Api::class)

app/src/test/kotlin/com/subtracks/data/db/ArtworkSeedDaoTest.kt

@@ -0,0 +1,103 @@
+package com.subtracks.data.db
+
+import android.content.Context
+import androidx.room3.Room
+import androidx.sqlite.driver.bundled.BundledSQLiteDriver
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.subtracks.data.model.ArtworkSeed
+import com.subtracks.data.model.Source
+import com.subtracks.data.repo.ArtworkSeedRepository
+import kotlinx.coroutines.test.runTest
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class ArtworkSeedDaoTest {
+    private lateinit var db: SubtracksDatabase
+
+    @Before
+    fun setUp() {
+        val context = ApplicationProvider.getApplicationContext<Context>()
+        db =
+            Room
+                .inMemoryDatabaseBuilder(context, SubtracksDatabase::class.java)
+                .setDriver(BundledSQLiteDriver())
+                .build()
+    }
+
+    @After
+    fun tearDown() {
+        db.close()
+    }
+
+    @Test
+    fun deletingASourceCascadesToItsSeeds() =
+        runTest {
+            val sourceId = source()
+            val dao = db.artworkSeedDao()
+            dao.upsert(ArtworkSeed(cacheKey = "$sourceId:cover:false", sourceId = sourceId, primary = 1, secondary = null))
+
+            db.sourcesDao().deleteSource(sourceId)
+
+            assertNull(dao.seed("$sourceId:cover:false"))
+        }
+
+    @Test
+    fun pruningKeepsTheMostRecentlyUsedSeeds() =
+        runTest {
+            val sourceId = source()
+            val dao = db.artworkSeedDao()
+            (1..5).forEach { index ->
+                dao.upsert(
+                    ArtworkSeed(
+                        cacheKey = "$sourceId:cover$index:false",
+                        sourceId = sourceId,
+                        primary = index,
+                        secondary = null,
+                        lastUsed = index.toLong(),
+                    ),
+                )
+            }
+
+            dao.prune(keep = 2)
+
+            val remaining = (1..5).mapNotNull { dao.seed("$sourceId:cover$it:false")?.cacheKey }.toSet()
+            assertEquals(setOf("$sourceId:cover5:false", "$sourceId:cover4:false"), remaining)
+        }
+
+    @Test
+    fun savingDerivesTheSourceFromTheCacheKey() =
+        runTest {
+            val sourceId = source()
+            val repository = ArtworkSeedRepository(db)
+
+            repository.save("$sourceId:cover:true", 10 to 20)
+
+            val row = db.artworkSeedDao().seed("$sourceId:cover:true")
+            assertEquals(sourceId, row?.sourceId)
+            assertEquals(10, row?.primary)
+            assertEquals(20, row?.secondary)
+        }
+
+    @Test
+    fun savingBeyondTheCapPrunesTheOldestSeeds() =
+        runTest {
+            val sourceId = source()
+            val repository = ArtworkSeedRepository(db, maxStoredSeeds = 2)
+
+            repository.save("$sourceId:cover1:false", 1 to null)
+            repository.save("$sourceId:cover2:false", 2 to null)
+            repository.save("$sourceId:cover3:false", 3 to null)
+
+            val stored = (1..3).count { db.artworkSeedDao().seed("$sourceId:cover$it:false") != null }
+            assertEquals(2, stored)
+        }
+
+    private suspend fun source(): Long =
+        db.sourcesDao().insertSource(Source(name = "Navidrome", address = "http://localhost", isActive = true, createdAt = 0))
+}

app/src/test/kotlin/com/subtracks/playback/PlaybackControllerTest.kt

@@ -6,6 +6,7 @@ import androidx.sqlite.driver.bundled.BundledSQLiteDriver
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import com.subtracks.data.db.SubtracksDatabase
+import com.subtracks.data.model.Album
 import com.subtracks.data.model.QueueEntry
 import com.subtracks.data.model.QueueKind
 import com.subtracks.data.model.Song
@@ -74,6 +75,39 @@ class PlaybackControllerTest {
         assertEquals(listOf("prepare", "play"), handle.operations.takeLast(2))
     }
 
+    @Test
+    fun upcomingItemIsTheNextQueueItemWithItsCoverArt() {
+        seedAlbum(3, sourceId = 1)
+        runBlocking {
+            db.libraryDao().upsertAlbums(
+                listOf(
+                    Album(
+                        sourceId = 1,
+                        id = "al1",
+                        artistId = "ar1",
+                        name = "Album",
+                        albumArtist = "Artist",
+                        created = 0,
+                        coverArt = "cover-al1",
+                        genre = null,
+                        year = null,
+                        starred = null,
+                        songCount = 3,
+                        frequentRank = null,
+                        recentRank = null,
+                    ),
+                ),
+            )
+        }
+        controller.playAlbum(1, "al1", 0)
+        await {
+            controller.state.value.item
+                ?.id == "s1"
+        }
+
+        assertEquals("cover-al1", runBlocking { controller.upcomingItem()?.coverArtId })
+    }
+
     @Test
     fun playingTheSongsListQueuesTheWholeLibrary() {
         seedAlbum(60, sourceId = 1)

app/src/test/kotlin/com/subtracks/ui/playback/NowPlayingArtworkTest.kt

@@ -0,0 +1,39 @@
+package com.subtracks.ui.playback
+
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import coil3.SingletonImageLoader
+import coil3.annotation.DelicateCoilApi
+import coil3.size.Dimension
+import com.subtracks.data.model.CoverArtRef
+import kotlinx.coroutines.runBlocking
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@OptIn(DelicateCoilApi::class)
+@RunWith(AndroidJUnit4::class)
+class NowPlayingArtworkTest {
+    @After
+    fun resetImageLoader() {
+        SingletonImageLoader.reset()
+    }
+
+    @Test
+    fun prefetchingTheNextOriginalIsBoundedToTheScreen() =
+        runBlocking {
+            val context = ApplicationProvider.getApplicationContext<Context>()
+            val ref = CoverArtRef(url = "http://example.test/art", cacheKey = "1:art:false")
+
+            val request = prefetchImageRequest(context, ref)
+            val resolved = request.sizeResolver.size()
+            val width = (resolved.width as Dimension.Pixels).px
+
+            val metrics = context.resources.displayMetrics
+            assertEquals(maxOf(metrics.widthPixels, metrics.heightPixels), width)
+            assertEquals(ref.cacheKey, request.memoryCacheKey)
+            assertEquals(ref.cacheKey, request.diskCacheKey)
+        }
+}