commit 9d0b2da51bc529f0690e64c8f2edbd63c54d27d9
author Garret Rieger <grieger@google.com> Mon Jul 25 20:46:49 2022 +0000
committer Garret Rieger <grieger@google.com> Tue Jul 26 12:22:17 2022 -0600
tree 10c5004a474be7ed33d1d66f31134994f7f04561
parent 3d37b9f4db848a4fb9d99d00b0bffff22c813cac

[repacker] count subtable size in each group of consecutive layers for extension promotion decisions.

Enforce that the following groups are all <64k in size:
- LookupList + Lookups
- Lookups + SubTables
- SubTables + Descendants

src/graph/graph.hh

diff --git a/src/graph/graph.hh b/src/graph/graph.hh
index 5c5b5a4..f760448 100644
--- a/src/graph/graph.hh
+++ b/src/graph/graph.hh
@@ -484,15 +484,18 @@
       find_subgraph (link.objidx, subgraph);
   }
 
-  size_t find_subgraph_size (unsigned node_idx, hb_set_t& subgraph)
+  size_t find_subgraph_size (unsigned node_idx, hb_set_t& subgraph, unsigned max_depth = -1)
   {
     if (subgraph.has (node_idx)) return 0;
     subgraph.add (node_idx);
 
     const auto& o = vertices_[node_idx].obj;
     size_t size = o.tail - o.head;
+    if (max_depth == 0)
+      return size;
+
     for (const auto& link : o.all_links ())
-      size += find_subgraph_size (link.objidx, subgraph);
+      size += find_subgraph_size (link.objidx, subgraph, max_depth - 1);
     return size;
   }