walkero
/
harfbuzz
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[subset] switch sort_shortest_distance() to use priority queue.

This commit is contained in:
Garret Rieger 2020-11-05 11:22:16 -08:00
parent 5d3511e5b1
commit 519ae96617
1 changed files with 13 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
src/hb-repacker.hh
View File

@ -165,7 +165,7 @@ struct graph_t
hb_vector_t<int64_t> distance_to;
compute_distances (&distance_to);
hb_set_t queue;
hb_priority_queue_t queue;
hb_vector_t<hb_serialize_context_t::object_t> sorted_graph;
hb_map_t id_map;
hb_map_t edge_count;
@ -174,13 +174,12 @@ struct graph_t
// Object graphs are in reverse order, the first object is at the end
// of the vector. Since the graph is topologically sorted it's safe to
// assume the first object has no incoming edges.
queue.add (objects_.length - 1);
queue.insert (objects_.length - 1, add_order(distance_to[objects_.length - 1], 0));
int new_id = objects_.length - 1;
while (queue.get_population ())
unsigned order = 1;
while (!queue.is_empty ())
{
unsigned next_id = closest_object (queue, distance_to);
queue.del (next_id);
unsigned next_id = queue.extract_minimum().first;
hb_serialize_context_t::object_t& next = objects_[next_id];
sorted_graph.push (next);
@ -189,7 +188,12 @@ struct graph_t
for (const auto& link : next.links) {
edge_count.set (link.objidx, edge_count.get (link.objidx) - 1);
if (!edge_count.get (link.objidx))
queue.add (link.objidx);
// Add the order that the links were encountered to the priority.
// This ensures that ties between priorities objects are broken in a consistent
// way. More specifically this is set up so that if a set of objects have the same
// distance they'll be added to the topolical order in the order that they are
// referenced from the parent object.
queue.insert (link.objidx, add_order(distance_to[link.objidx], order++));
}
}
@ -242,22 +246,9 @@ struct graph_t
private:
unsigned closest_object (const hb_set_t& queue,
const hb_vector_t<int64_t> distance_to)
int64_t add_order (int64_t distance, unsigned order)
{
// TODO(garretrieger): use a priority queue.
int64_t closest_distance = hb_int_max (int64_t);
unsigned closest_index = -1;
for (unsigned i : queue)
{
if (distance_to[i] < closest_distance)
{
closest_distance = distance_to[i];
closest_index = i;
}
}
assert (closest_index != (unsigned) -1);
return closest_index;
return (distance << 24) | (0x00FFFFFF & order);
}
/*