int git_diff__paired_foreach()

in src/diff_generate.c [1543:1629]

• 59 lines of code
• 34 McCabe index (conditional complexity)

int git_diff__paired_foreach(
	git_diff *head2idx,
	git_diff *idx2wd,
	int (*cb)(git_diff_delta *h2i, git_diff_delta *i2w, void *payload),
	void *payload)
{
	int cmp, error = 0;
	git_diff_delta *h2i, *i2w;
	size_t i, j, i_max, j_max;
	int (*strcomp)(const char *, const char *) = git__strcmp;
	bool h2i_icase, i2w_icase, icase_mismatch;

	i_max = head2idx ? head2idx->deltas.length : 0;
	j_max = idx2wd ? idx2wd->deltas.length : 0;
	if (!i_max && !j_max)
		return 0;

	/* At some point, tree-to-index diffs will probably never ignore case,
	 * even if that isn't true now.  Index-to-workdir diffs may or may not
	 * ignore case, but the index filename for the idx2wd diff should
	 * still be using the canonical case-preserving name.
	 *
	 * Therefore the main thing we need to do here is make sure the diffs
	 * are traversed in a compatible order.  To do this, we temporarily
	 * resort a mismatched diff to get the order correct.
	 *
	 * In order to traverse renames in the index->workdir, we need to
	 * ensure that we compare the index name on both sides, so we
	 * always sort by the old name in the i2w list.
	 */
	h2i_icase = head2idx != NULL && git_diff_is_sorted_icase(head2idx);
	i2w_icase = idx2wd != NULL && git_diff_is_sorted_icase(idx2wd);

	icase_mismatch =
		(head2idx != NULL && idx2wd != NULL && h2i_icase != i2w_icase);

	if (icase_mismatch && h2i_icase) {
		git_vector_set_cmp(&head2idx->deltas, git_diff_delta__cmp);
		git_vector_sort(&head2idx->deltas);
	}

	if (i2w_icase && !icase_mismatch) {
		strcomp = git__strcasecmp;

		git_vector_set_cmp(&idx2wd->deltas, git_diff_delta__i2w_casecmp);
		git_vector_sort(&idx2wd->deltas);
	} else if (idx2wd != NULL) {
		git_vector_set_cmp(&idx2wd->deltas, git_diff_delta__i2w_cmp);
		git_vector_sort(&idx2wd->deltas);
	}

	for (i = 0, j = 0; i < i_max || j < j_max; ) {
		h2i = head2idx ? GIT_VECTOR_GET(&head2idx->deltas, i) : NULL;
		i2w = idx2wd ? GIT_VECTOR_GET(&idx2wd->deltas, j) : NULL;

		cmp = !i2w ? -1 : !h2i ? 1 :
			strcomp(h2i->new_file.path, i2w->old_file.path);

		if (cmp < 0) {
			i++; i2w = NULL;
		} else if (cmp > 0) {
			j++; h2i = NULL;
		} else {
			i++; j++;
		}

		if ((error = cb(h2i, i2w, payload)) != 0) {
			git_error_set_after_callback(error);
			break;
		}
	}

	/* restore case-insensitive delta sort */
	if (icase_mismatch && h2i_icase) {
		git_vector_set_cmp(&head2idx->deltas, git_diff_delta__casecmp);
		git_vector_sort(&head2idx->deltas);
	}

	/* restore idx2wd sort by new path */
	if (idx2wd != NULL) {
		git_vector_set_cmp(&idx2wd->deltas,
			i2w_icase ? git_diff_delta__casecmp : git_diff_delta__cmp);
		git_vector_sort(&idx2wd->deltas);
	}

	return error;
}