Rewrite purgeToVisibleLimit

k9mail/src/main/java/com/fsck/k9/mailstore/LocalFolder.java

@@ -398,23 +398,46 @@ public class LocalFolder extends Folder<LocalMessage> {
         return visibleLimit;
     }
 
-    public void purgeToVisibleLimit(MessageRemovalListener listener) throws MessagingException {
+    public void purgeToVisibleLimit(final MessageRemovalListener listener) throws MessagingException {
-        //don't purge messages while a Search is active since it might throw away search results
+        // don't purge messages while a Search is active since it might throw away search results
-        if (!Search.isActive()) {
+        if (Search.isActive()) {
-            if (visibleLimit == 0) {
+            return;
-                return ;
-            }
-            open(OPEN_MODE_RW);
-            List<? extends Message> messages = getMessages(null, false);
-            for (int i = visibleLimit; i < messages.size(); i++) {
-                if (listener != null) {
-                    listener.messageRemoved(messages.get(i));
-                }
-                messages.get(i).destroy();
-            }
         }
-    }
 
+        if (visibleLimit == 0) {
+            return;
+        }
+
+        open(OPEN_MODE_RW);
+
+        localStore.getDatabase().execute(false, new DbCallback<Void>() {
+            @Override
+            public Void doDbWork(final SQLiteDatabase db) {
+                Cursor cursor = db.rawQuery("SELECT uid " +
+                                "FROM messages " +
+                                "WHERE empty = 0 AND deleted = 0 AND folder_id = ? ORDER BY date DESC " +
+                                " LIMIT -1 OFFSET ?",
+                        new String[] { Long.toString(getDatabaseId()), Integer.toString(visibleLimit) });
+
+                try {
+                    while (cursor.moveToNext()) {
+                        String uid = cursor.getString(0);
+                        LocalMessage localMessage = getMessage(uid);
+
+                        if (listener != null) {
+                            listener.messageRemoved(localMessage);
+                        }
+                        destroyMessage(localMessage);
+                    }
+                } catch (Exception e) {
+                    Timber.d(e, "Got an exception");
+                } finally {
+                    Utility.closeQuietly(cursor);
+                }
+                return null;
+            }
+        });
+    }
 
     public void setVisibleLimit(final int visibleLimit) throws MessagingException {
         updateMoreMessagesOnVisibleLimitChange(visibleLimit, this.visibleLimit);