[PATCH 18/30] revision: create mark_trees_uninteresting_dense()

["Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com>]

From: Derrick Stolee <stolee@gmail.com>

The sparse tree walk algorithm was created in d5d2e93577e (revision:
implement sparse algorithm, 2019-01-16) and involves using the
mark_trees_uninteresting_sparse() method. This method takes a repository
and an oidset of tree IDs, some of which have the UNINTERESTING flag and
some of which do not.

Create a method that has an equivalent set of preconditions but uses a
"dense" walk (recursively visits all reachable trees, as long as they
have not previously been marked UNINTERESTING). This is an important
difference from mark_tree_uninteresting(), which short-circuits if the
given tree has the UNINTERESTING flag.

A use of this method will be added in a later change, with a condition
set whether the sparse or dense approach should be used.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
---
 revision.c | 15 +++++++++++++++
 revision.h |  1 +
 2 files changed, 16 insertions(+)

diff --git a/revision.c b/revision.c
index ac94f8d4292..21c8b6d1bc0 100644
--- a/revision.c
+++ b/revision.c
@@ -219,6 +219,21 @@ static void add_children_by_path(struct repository *r,
 	free_tree_buffer(tree);
 }
 
+void mark_trees_uninteresting_dense(struct repository *r,
+				    struct oidset *trees)
+{
+	struct object_id *oid;
+	struct oidset_iter iter;
+
+	oidset_iter_init(trees, &iter);
+	while ((oid = oidset_iter_next(&iter))) {
+		struct tree *tree = lookup_tree(r, oid);
+
+		if (tree->object.flags & UNINTERESTING)
+			mark_tree_contents_uninteresting(r, tree);
+	}
+}
+
 void mark_trees_uninteresting_sparse(struct repository *r,
 				     struct oidset *trees)
 {
diff --git a/revision.h b/revision.h
index 0e470d1df19..6c3df8e42bf 100644
--- a/revision.h
+++ b/revision.h
@@ -487,6 +487,7 @@ void put_revision_mark(const struct rev_info *revs,
 
 void mark_parents_uninteresting(struct rev_info *revs, struct commit *commit);
 void mark_tree_uninteresting(struct repository *r, struct tree *tree);
+void mark_trees_uninteresting_dense(struct repository *r, struct oidset *trees);
 void mark_trees_uninteresting_sparse(struct repository *r, struct oidset *trees);
 
 void show_object_with_name(FILE *, struct object *, const char *);
-- 
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