On Fri, Mar 10 2023, Derrick Stolee via GitGitGadget wrote:
> From: Derrick Stolee <derrickstolee@xxxxxxxxxx>
> +{
> + size_t i;
Ditto the decl suggestion in an earlier commit, i.e...
> + struct commit_and_index *commits;
> + unsigned int min_generation_index = 0;
> + timestamp_t min_generation;
> + struct commit_list *stack = NULL;
> +
> + if (!bases || !tips || !tips_nr)
> + return;
> +
> + /*
> + * Do a depth-first search starting at 'bases' to search for the
> + * tips. Stop at the lowest (un-found) generation number. When
> + * finding the lowest commit, increase the minimum generation
> + * number to the next lowest (un-found) generation number.
> + */
> +
> + CALLOC_ARRAY(commits, tips_nr);
> +
> + for (i = 0; i < tips_nr; i++) {
...move this here?
> + commits[i].commit = tips[i];
> + commits[i].index = i;
> + commits[i].generation = commit_graph_generation(tips[i]);
> + }
> +
> + /* Sort with generation number ascending. */
> + QSORT(commits, tips_nr, compare_commit_and_index_by_generation);
> + min_generation = commits[0].generation;
> +
> + while (bases) {
> + parse_commit(bases->item);
> + commit_list_insert(bases->item, &stack);
> + bases = bases->next;
> + }
> +
> + while (stack) {
> + unsigned int j;
...ditto...
> + int explored_all_parents = 1;
> + struct commit_list *p;
> + struct commit *c = stack->item;
> + timestamp_t c_gen = commit_graph_generation(c);
> +
> + /* Does it match any of our tips? */
> + for (j = min_generation_index; j < tips_nr; j++) {
...to here...
> + if (c_gen < commits[j].generation)
> + break;
> +
> + if (commits[j].commit == c) {
> + tips[commits[j].index]->object.flags |= mark;
> +
> + if (j == min_generation_index) {
> + unsigned int k = j + 1;
> + while (k < tips_nr &&
> + (tips[commits[k].index]->object.flags & mark))
> + k++;
> +
> + /* Terminate early if all found. */
> + if (k >= tips_nr)
> + goto done;
> +
> + min_generation_index = k;
> + min_generation = commits[k].generation;
> + }
> + }
> + }
> +
> + for (p = c->parents; p; p = p->next) {
> + parse_commit(p->item);
> +
> + /* Have we already explored this parent? */
> + if (p->item->object.flags & SEEN)
> + continue;
> +
> + /* Is it below the current minimum generation? */
> + if (commit_graph_generation(p->item) < min_generation)
> + continue;
> +
> + /* Ok, we will explore from here on. */
> + p->item->object.flags |= SEEN;
> + explored_all_parents = 0;
> + commit_list_insert(p->item, &stack);
> + break;
> + }
> +
> + if (explored_all_parents)
> + pop_commit(&stack);
> + }
> +
> +done:
> + free(commits);
> + repo_clear_commit_marks(the_repository, SEEN);
I didn't see this in my earlier suggestion for passing "struct
repository", but I think we should do the same here, i.e. have this
function take a "r" argument.
> [...]
> @@ -2390,33 +2390,21 @@ static void reach_filter(struct ref_array *array,
> struct commit_list *check_reachable,
> int include_reached)
> {
> - struct rev_info revs;
> int i, old_nr;
> struct commit **to_clear;
> - struct commit_list *cr;
>
> if (!check_reachable)
> return;
>
> CALLOC_ARRAY(to_clear, array->nr);
> -
> - repo_init_revisions(the_repository, &revs, NULL);
> -
> for (i = 0; i < array->nr; i++) {
> struct ref_array_item *item = array->items[i];
> - add_pending_object(&revs, &item->commit->object, item->refname);
> to_clear[i] = item->commit;
> }
>
> - for (cr = check_reachable; cr; cr = cr->next) {
> - struct commit *merge_commit = cr->item;
> - merge_commit->object.flags |= UNINTERESTING;
> - add_pending_object(&revs, &merge_commit->object, "");
> - }
> -
> - revs.limited = 1;
> - if (prepare_revision_walk(&revs))
> - die(_("revision walk setup failed"));
> + tips_reachable_from_bases(check_reachable,
> + to_clear, array->nr,
> + UNINTERESTING);
I.e. it's not ideal, but we had a the_repository in this function before
(should probably have passed it from further up, but whatever), so we
could pass that to the new tips_reachable_from_bases() still.
> -test_perf 'ahead-behind counts: git rev-list' '
> - for r in $(cat refs)
> - do
> - git rev-list --count "HEAD..$r" || return 1
> - done
Why does this change require deleting the old perf test? Your commit 7/8
notes this test, but here we're deleting it, let's keep it and instead
note if the results changed, or stayed the same?
More generally, your commit message says:
> Add extra tests for this behavior in t6600-test-reach.sh as the
> interesting data shape of that repository can sometimes demonstrate
> corner case bugs.
And here for a supposed optimization commit you're adding new tests, but
when I try them with the C code at 7/8 they pass.
So it seems we should add them earlier, and this is a pure-optimization
commit, but one that's a bit confused about what goes where? :)
