Re: [PATCH v4 04/16] revision.c: --indexed-objects add objects from all worktrees

[Stefan Beller <sbeller@google.com>]

On Wed, Aug 23, 2017 at 5:36 AM, Nguyễn Thái Ngọc Duy <pclouds@gmail.com> wrote:
> This is the result of single_worktree flag never being set (no way to up
> until now). To get objects from current index only, set single_worktree.
>
> The other add_index_objects_to_pending's caller is mark_reachable_objects()
> (e.g. "git prune") which also mark objects from all indexes.
>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> ---
>  revision.c       | 21 +++++++++++++++++++++
>  t/t5304-prune.sh |  9 +++++++++
>  2 files changed, 30 insertions(+)
>
> diff --git a/revision.c b/revision.c
> index 6c46ad6c8a..f35cb49af5 100644
> --- a/revision.c
> +++ b/revision.c
> @@ -19,6 +19,7 @@
>  #include "dir.h"
>  #include "cache-tree.h"
>  #include "bisect.h"
> +#include "worktree.h"
>
>  volatile show_early_output_fn_t show_early_output;
>
> @@ -1290,8 +1291,28 @@ static void do_add_index_objects_to_pending(struct rev_info *revs,
>
>  void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
>  {
> +       struct worktree **worktrees, **p;
> +
>         read_cache();
>         do_add_index_objects_to_pending(revs, &the_index);
> +
> +       if (revs->single_worktree)
> +               return;
> +
> +       worktrees = get_worktrees(0);
> +       for (p = worktrees; *p; p++) {
> +               struct worktree *wt = *p;
> +               struct index_state istate = { NULL };
> +
> +               if (wt->is_current)
> +                       continue; /* current index already taken care of */
> +
> +               if (read_index_from(&istate,
> +                                   worktree_git_path(wt, "index")) > 0)
> +                       do_add_index_objects_to_pending(revs, &istate);
> +               discard_index(&istate);
> +       }
> +       free_worktrees(worktrees);
>  }

The commit (message and code) looks acceptable and easy to read.
I wonder though if another approach would be more feasible:

* factor out anything after the early return into a new function
  "add_wt_index_objects_to_pending", maybe?
* introduce a new function
    for_each_wt_except_current(function, callback_cookie)
  such that this code could use this predefined iterator.
  (I have the impression I have seen this code pattern before,
  hence it may be useful to have such a foreach function; we
  have foreach functions already for various ref things, string
  list items, reflogs, and soon submodule lists)

>
>  static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
> diff --git a/t/t5304-prune.sh b/t/t5304-prune.sh
> index 133b5842b1..cba45c7be9 100755
> --- a/t/t5304-prune.sh
> +++ b/t/t5304-prune.sh
> @@ -283,4 +283,13 @@ test_expect_success 'prune: handle alternate object database' '
>         git -C B prune
>  '
>
> +test_expect_success 'prune: handle index in multiple worktrees' '
> +       git worktree add second-worktree &&
> +       echo "new blob for second-worktree" >second-worktree/blob &&
> +       git -C second-worktree add blob &&
> +       git prune --expire=now &&
> +       git -C second-worktree show :blob >actual &&
> +       test_cmp second-worktree/blob actual
> +'
> +
>  test_done
> --
> 2.11.0.157.gd943d85
>