Nonnullize and Immutablize DownloadDirname, upgrade db

app/src/main/java/com/hippo/ehviewer/EhDB.kt

@@ -79,12 +79,11 @@ object EhDB {
     }
 
     @Synchronized
-    fun putDownloadDirname(gid: Long, dirname: String?) {
+    fun putDownloadDirname(gid: Long, dirname: String) {
         val dao = db.downloadDirnameDao()
         var raw = dao.load(gid)
         if (raw != null) {
-            raw.dirname = dirname
-            dao.update(raw)
+            dao.update(raw.copy(dirname = dirname))
         } else {
             raw = DownloadDirname(gid, dirname)
             dao.insert(raw)

app/src/main/java/com/hippo/ehviewer/dao/DownloadDirname.kt

@@ -8,8 +8,8 @@ import androidx.room.PrimaryKey
 data class DownloadDirname(
     @PrimaryKey
     @ColumnInfo(name = "GID")
-    var gid: Long = 0,
+    val gid: Long,
 
     @ColumnInfo(name = "DIRNAME")
-    var dirname: String? = null,
+    val dirname: String,
 )

app/src/main/java/com/hippo/ehviewer/dao/EhDatabase.kt

@@ -30,8 +30,14 @@ val EHDB_MIGRATION_4_5 = object : Migration(4, 5) {
 
 @Database(
     entities = [BookmarkInfo::class, DownloadInfo::class, DownloadLabel::class, DownloadDirname::class, Filter::class, HistoryInfo::class, LocalFavoriteInfo::class, QuickSearch::class],
-    version = 5,
+    version = 6,
     exportSchema = true,
+    autoMigrations = [
+        AutoMigration(
+            from = 5,
+            to = 6,
+        ),
+    ],
 )
 abstract class EhDatabase : RoomDatabase() {
     abstract fun bookmarksBao(): BookmarksDao

app/src/main/java/com/hippo/ehviewer/preference/RestoreDownloadPreference.kt

@@ -53,7 +53,7 @@ class RestoreDownloadPreference @JvmOverloads constructor(
         return runCatching {
             val spiderInfo = readCompatFromUniFile(siFile) ?: return null
             val gid = spiderInfo.gid
-            val dirname = file.name
+            val dirname = file.name ?: return null
             if (mManager.containDownloadInfo(gid)) {
                 // Restore download dir to avoid redownload
                 val dbdirname = EhDB.getDownloadDirname(gid)
@@ -63,10 +63,9 @@ class RestoreDownloadPreference @JvmOverloads constructor(
                 }
                 return null
             }
-            RestoreItem().also {
+            RestoreItem(dirname).also {
                 it.gid = spiderInfo.gid
                 it.token = spiderInfo.token
-                it.dirname = file.name
             }
         }.onFailure {
             it.printStackTrace()
@@ -85,9 +84,9 @@ class RestoreDownloadPreference @JvmOverloads constructor(
         }
     }
 
-    private class RestoreItem : BaseGalleryInfo() {
-        var dirname: String? = null
-    }
+    private class RestoreItem(
+        val dirname: String,
+    ) : BaseGalleryInfo()
 
     override fun launchJob() {
         if (singletonJob?.isActive == true) {