# Re: \[PATCH v2 4/8\] merge-ort: introduce wrappers for alternate tree traversal

- From: Derrick Stolee \<hidden\>
- Date: 2021-03-09 23:07:25 
- List: git
- Page: https://ratatoskr.run/git/2021/03/7879168
- Thread: https://ratatoskr.run/git/2021/02/7877825/t.md

```text
On 3/8/2021 7:09 PM, Elijah Newren via GitGitGadget wrote:
> From: Elijah Newren <redacted>
> 
> Add traverse_trees_wrapper() and traverse_trees_wrapper_callback()
> functions.  The former runs traverse_trees() with info->fn set to
> traverse_trees_wrapper_callback, in order to simply save all the entries
> without processing or recursing into any of them.  This step allows
> extra computation to be done (e.g. checking some condition across all
> files) that can be used later.  Then, after that is completed, it
> iterates over all the saved entries and calls the original info->fn
> callback with the saved data.
> 
> Currently, this does nothing more than marginally slowing down the tree
> traversal since we do not take advantage of the opportunity to compute
> anything special in traverse_trees_wrapper_callback(), and thus the real
> callback will be called identically as it would have been without this
> extra wrapper.  However, a subsequent commit will add some special
> computation of some values that the real callback will be able to use.

I'm glad that you use the normal callback in the appropriate case.

It took me a couple reads to understand this last sentence, but I think
I'm with you now.

> +	info->traverse_path = renames->callback_data_traverse_path;
> +	info->fn = old_fn;
> +	for (i = old_offset; i < renames->callback_data_nr; ++i) {
> +		info->fn(n,
> +			 renames->callback_data[i].mask,
> +			 renames->callback_data[i].dirmask,
> +			 renames->callback_data[i].names,
> +			 info);
> +

nit: extraneous newline.

Thanks,
-Stolee
```