Re: [PATCH v2 09/12] attr: (re)introduce git_check_attr() and struct git_attr_check

A common pattern to check N attributes for many paths is to

 (1) prepare an array A of N git_attr_check_elem items;
 (2) call git_attr() to intern the N attribute names and fill A;
 (3) repeatedly call git_check_attrs() for path with N and A;
[...snip...]
Introduce "struct git_attr_check" that contains N, the number of
attributes being sought, and A, the array that holds N
git_attr_check_elem items, and a function git_check_attr() that
takes a path P and this structure as its parameters.  This structure
can later be extended to hold extra data necessary for optimization.

Also, to make it easier to write the first two steps in common
cases, introduce git_attr_check_initl() helper function, which takes
a NULL-terminated list of attribute names and initialize this
structure.
[...snip...]

Signed-off-by: Junio C Hamano <redacted>
---

diff --git a/attr.c b/attr.c

@@ -825,3 +825,37 @@ void git_attr_set_direction(enum git_attr_direction new, struct index_state *ist
+struct git_attr_check *git_attr_check_initl(const char *one, ...)
+{
+       [...]
+       check = xcalloc(1,
+                       sizeof(*check) + cnt * sizeof(*(check->check)));
+       check->check_nr = cnt;
+       check->check = (struct git_attr_check_elem *)(check + 1);
+       [...]
+       return check;
+}

diff --git a/attr.h b/attr.h

@@ -29,6 +29,15 @@ struct git_attr_check_elem {
+struct git_attr_check {
+       int check_nr;
+       int check_alloc;