Debug option to disable sqlite WAL

app/src/main/java/eu/faircode/email/ActivitySetup.java

@@ -993,7 +993,8 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
                         if ("secure".equals(key) ||
                                 "shortcuts".equals(key) ||
                                 "language".equals(key) ||
-                                "query_threads".equals(key))
+                                "query_threads".equals(key) ||
+                                "wal".equals(key))
                             continue;
 
                         if (key != null && key.startsWith("widget."))

app/src/main/java/eu/faircode/email/ApplicationEx.java

@@ -196,6 +196,7 @@ public class ApplicationEx extends Application
             case "shortcuts": // misc
             case "language": // misc
             case "query_threads": // misc
+            case "wal": // misc
                 // Should be excluded for import
                 restart();
                 break;

app/src/main/java/eu/faircode/email/DB.java

@@ -266,14 +266,15 @@ public abstract class DB extends RoomDatabase {
 
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         int threads = prefs.getInt("query_threads", 4); // AndroidX default thread count: 4
-        Log.i("Query threads=" + threads);
+        boolean wal = prefs.getBoolean("wal", true);
+        Log.i("DB query threads=" + threads + " wal=" + wal);
         ExecutorService executor = Helper.getBackgroundExecutor(threads, "query");
 
         return Room
                 .databaseBuilder(context, DB.class, DB_NAME)
                 .openHelperFactory(new RequerySQLiteOpenHelperFactory())
                 .setQueryExecutor(executor)
-                .setJournalMode(JournalMode.WRITE_AHEAD_LOGGING) // using the latest sqlite
+                .setJournalMode(wal ? JournalMode.WRITE_AHEAD_LOGGING : JournalMode.TRUNCATE) // using the latest sqlite
                 .addCallback(new Callback() {
                     @Override
                     public void onOpen(@NonNull SupportSQLiteDatabase db) {

app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java

@@ -98,6 +98,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
     private SwitchCompat swExperiments;
     private TextView tvExperimentsHint;
     private SwitchCompat swQueries;
+    private SwitchCompat swWal;
     private SwitchCompat swCrashReports;
     private TextView tvUuid;
     private Button btnReset;
@@ -133,7 +134,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             "shortcuts", "fts",
             "classification", "class_min_probability", "class_min_difference",
             "language", "watchdog", "updates",
-            "experiments", "query_threads", "crash_reports", "cleanup_attachments",
+            "experiments", "wal", "query_threads", "crash_reports", "cleanup_attachments",
             "protocol", "debug", "perform_expunge", "auth_plain", "auth_login", "auth_ntlm", "auth_sasl"
     };
 
@@ -193,6 +194,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swExperiments = view.findViewById(R.id.swExperiments);
         tvExperimentsHint = view.findViewById(R.id.tvExperimentsHint);
         swQueries = view.findViewById(R.id.swQueries);
+        swWal = view.findViewById(R.id.swWal);
         swCrashReports = view.findViewById(R.id.swCrashReports);
         tvUuid = view.findViewById(R.id.tvUuid);
         btnReset = view.findViewById(R.id.btnReset);
@@ -404,6 +406,13 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             }
         });
 
+        swWal.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("wal", checked).commit(); // apply won't work here
+            }
+        });
+
         swCrashReports.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
@@ -852,6 +861,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
                         ? View.GONE : View.VISIBLE);
         swExperiments.setChecked(prefs.getBoolean("experiments", false));
         swQueries.setChecked(prefs.getInt("query_threads", 4) < 4);
+        swWal.setChecked(prefs.getBoolean("wal", true));
         swCrashReports.setChecked(prefs.getBoolean("crash_reports", false));
         tvUuid.setText(prefs.getString("uuid", null));
         swCleanupAttachments.setChecked(prefs.getBoolean("cleanup_attachments", false));

app/src/main/res/layout/fragment_options_misc.xml

@@ -338,6 +338,17 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/tvQueriesHint" />
 
+        <androidx.appcompat.widget.SwitchCompat
+            android:id="@+id/swWal"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="12dp"
+            android:text="@string/title_advanced_wal"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tvQueriesRemark"
+            app:switchPadding="12dp" />
+
         <androidx.appcompat.widget.SwitchCompat
             android:id="@+id/swCrashReports"
             android:layout_width="0dp"
@@ -346,7 +357,7 @@
             android:text="@string/title_advanced_crash_reports"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/tvQueriesRemark"
+            app:layout_constraintTop_toBottomOf="@id/swWal"
             app:switchPadding="12dp" />
 
         <eu.faircode.email.FixedTextView

app/src/main/res/values/strings.xml

@@ -531,6 +531,7 @@
     <string name="title_advanced_updates">Check for GitHub updates</string>
     <string name="title_advanced_experiments">Try experimental features</string>
     <string name="title_advanced_query_threads">Limit parallel database access</string>
+    <string name="title_advanced_wal">WAL (debug only)</string>
     <string name="title_advanced_crash_reports">Send error reports</string>
     <string name="title_advanced_protocol">Protocol logging</string>
     <string name="title_advanced_debug">Debug mode</string>