Refactor db export with resourceDSL

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

@@ -38,7 +38,6 @@ import com.hippo.ehviewer.download.DownloadManager
 import com.hippo.ehviewer.util.sendTo
 
 object EhDB {
-    private const val CUR_DB_VER = 4
     private val db = ehDatabase
 
     // Fix state
@@ -366,12 +365,15 @@ object EhDB {
         for (item in list) to.insert(item)
     }
 
-    @Synchronized
-    fun exportDB(context: Context, uri: Uri): Boolean {
+    suspend fun exportDB(context: Context, uri: Uri) {
         val ehExportName = "eh.export.db"
-        runCatching {
+        resource {
             context.deleteDatabase(ehExportName)
-            val newDb = databaseBuilder(context, EhDatabase::class.java, ehExportName).build()
+            databaseBuilder(context, EhDatabase::class.java, ehExportName).build()
+        } release {
+            it.close()
+            context.deleteDatabase(ehExportName)
+        } use { newDb ->
             copyDao(db.downloadsDao(), newDb.downloadsDao())
             copyDao(db.downloadLabelDao(), newDb.downloadLabelDao())
             copyDao(db.downloadDirnameDao(), newDb.downloadDirnameDao())
@@ -386,11 +388,7 @@ object EhDB {
                     fromFd sendTo toFd
                 }
             }
-            return true
-        }.onFailure {
-            it.printStackTrace()
         }
-        return false
     }
 
     suspend fun importDB(context: Context, uri: Uri) {

app/src/main/java/com/hippo/ehviewer/ui/fragment/AdvancedFragment.kt

@@ -30,7 +30,6 @@ import androidx.preference.Preference
 import com.hippo.ehviewer.AppConfig
 import com.hippo.ehviewer.BuildConfig
 import com.hippo.ehviewer.EhDB
-import com.hippo.ehviewer.GetText
 import com.hippo.ehviewer.R
 import com.hippo.ehviewer.client.EhEngine
 import com.hippo.ehviewer.client.data.FavListUrlBuilder
@@ -75,20 +74,18 @@ class AdvancedFragment : BasePreferenceFragment() {
                     .setView(R.layout.preference_dialog_task)
                     .show()
                 lifecycleScope.launchIO {
-                    val success = EhDB.exportDB(requireActivity(), uri)
+                    val e = runSuspendCatching {
+                        EhDB.exportDB(requireActivity(), uri)
+                    }.exceptionOrNull()?.run {
+                        printStackTrace()
+                        getString(R.string.settings_advanced_export_data_failed)
+                    }
                     withUIContext {
                         if (alertDialog.isShowing) {
                             alertDialog.dismiss()
                         }
                         showTip(
-                            if (success) {
-                                GetText.getString(
-                                    R.string.settings_advanced_export_data_to,
-                                    uri.toString(),
-                                )
-                            } else {
-                                GetText.getString(R.string.settings_advanced_export_data_failed)
-                            },
+                            e ?: getString(R.string.settings_advanced_export_data_to, uri.toString()),
                             BaseScene.LENGTH_SHORT,
                         )
                     }