Auto force on repeated manual sync

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

@@ -68,7 +68,7 @@ import io.requery.android.database.sqlite.SQLiteDatabase;
 // https://developer.android.com/topic/libraries/architecture/room.html
 
 @Database(
-        version = 216,
+        version = 217,
         entities = {
                 EntityIdentity.class,
                 EntityAccount.class,
@@ -2201,6 +2201,12 @@ public abstract class DB extends RoomDatabase {
                         Log.i("DB migration from version " + startVersion + " to " + endVersion);
                         db.execSQL("ALTER TABLE `message` ADD COLUMN `infrastructure` TEXT");
                     }
+                }).addMigrations(new Migration(216, 217) {
+                    @Override
+                    public void migrate(@NonNull SupportSQLiteDatabase db) {
+                        Log.i("DB migration from version " + startVersion + " to " + endVersion);
+                        db.execSQL("ALTER TABLE `folder` ADD COLUMN `last_sync_foreground` INTEGER");
+                    }
                 }).addMigrations(new Migration(998, 999) {
                     @Override
                     public void migrate(@NonNull SupportSQLiteDatabase db) {

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

@@ -350,6 +350,9 @@ public interface DaoFolder {
     @Query("UPDATE folder SET last_sync = :last_sync WHERE id = :id AND NOT (last_sync IS :last_sync)")
     int setFolderLastSync(long id, long last_sync);
 
+    @Query("UPDATE folder SET last_sync_foreground = :last_sync_foreground WHERE id = :id AND NOT (last_sync_foreground IS :last_sync_foreground)")
+    int setFolderLastSyncForeground(long id, long last_sync_foreground);
+
     @Query("UPDATE folder SET last_sync_count = :last_sync_count WHERE id = :id AND NOT (last_sync_count IS :last_sync_count)")
     int setFolderLastSyncCount(long id, Integer last_sync_count);
 

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

@@ -139,6 +139,7 @@ public class EntityFolder extends EntityOrder implements Serializable {
     public Boolean inferiors = true;
     public String error;
     public Long last_sync;
+    public Long last_sync_foreground;
     public Integer last_sync_count; // POP3
 
     static final String INBOX = "Inbox";

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

@@ -103,6 +103,7 @@ public class EntityOperation {
     static final String EXPUNGE = "expunge";
 
     private static final int MAX_FETCH = 100; // operations
+    private static final long FORCE_WITHIN = 30 * 1000; // milliseconds
 
     static void queue(Context context, EntityMessage message, String name, Object... values) {
         DB db = DB.getInstance(context);
@@ -494,6 +495,16 @@ public class EntityOperation {
         if (folder == null)
             return;
 
+        if (foreground) {
+            long now = new Date().getTime();
+            if (folder.last_sync_foreground != null &&
+                    now - folder.last_sync_foreground < FORCE_WITHIN) {
+                Log.i(folder.name + " Auto force");
+                force = true;
+            }
+            db.folder().setFolderLastSyncForeground(folder.id, now);
+        }
+
         if (force)
             db.operation().deleteOperation(fid, SYNC);
 
@@ -508,7 +519,7 @@ public class EntityOperation {
             operation.created = new Date().getTime();
             operation.id = db.operation().insertOperation(operation);
 
-            Log.i("Queued sync folder=" + folder);
+            Log.i("Queued sync folder=" + folder + " force=" + force);
         }
 
         if (foreground && folder.sync_state == null) // Show spinner