- struct filter_pred *preds;
- struct filter_pred *pred;
- enum move_type move = MOVE_DOWN;
- int done = 0;
- int err;
-
- preds = filter->preds;
- if (!preds)
- return -EINVAL;
- pred = root;
-
- do {
- switch (move) {
- case MOVE_DOWN:
- if (pred->index & FILTER_PRED_FOLD) {
- err = fold_pred(preds, pred);
- if (err)
- return err;
- /* Folded nodes are like leafs */
- } else if (pred->left != FILTER_PRED_INVALID) {
- pred = &preds[pred->left];
- continue;
- }
-
- /* A leaf at the root is just a leaf in the tree */
- if (pred == root)
- break;
- pred = get_pred_parent(pred, preds,
- pred->parent, &move);
- continue;
- case MOVE_UP_FROM_LEFT:
- pred = &preds[pred->right];
- move = MOVE_DOWN;
- continue;
- case MOVE_UP_FROM_RIGHT:
- if (pred == root)
- break;
- pred = get_pred_parent(pred, preds,
- pred->parent, &move);
- continue;
- }
- done = 1;
- } while (!done);
-
- return 0;
+ return walk_pred_tree(filter->preds, root, fold_pred_tree_cb,
+ filter->preds);