GC secondary map periodically.
diff --git a/ruby/ext/google/protobuf_c/protobuf.c b/ruby/ext/google/protobuf_c/protobuf.c
index c27f30a..0626319 100644
--- a/ruby/ext/google/protobuf_c/protobuf.c
+++ b/ruby/ext/google/protobuf_c/protobuf.c
@@ -251,14 +251,36 @@
// The object is used only for its identity; it does not contain any data.
VALUE secondary_map = Qnil;
+// Lambda that will GC entries from the secondary map that are no longer present
+// in the primary map.
+VALUE gc_secondary_map = Qnil;
+
+extern VALUE weak_obj_cache;
+
static void SecondaryMap_Init() {
rb_gc_register_address(&secondary_map);
+ rb_gc_register_address(&gc_secondary_map);
secondary_map = rb_hash_new();
+ gc_secondary_map = rb_eval_string(
+ "->(secondary, weak) {\n"
+ " secondary.delete_if { |k, v| !weak.key?(v) }\n"
+ "}\n");
+}
+
+static void SecondaryMap_MaybeGC() {
+ size_t weak_len = NUM2ULL(rb_funcall(weak_obj_cache, rb_intern("length"), 0));
+ size_t secondary_len = RHASH_SIZE(secondary_map);
+ size_t waste = secondary_len - weak_len;
+ PBRUBY_ASSERT(secondary_len >= weak_len);
+ if (waste > 1000 && waste > secondary_len * 0.2) {
+ rb_funcall(gc_secondary_map, rb_intern("call"), 2, secondary_map, weak_obj_cache);
+ }
}
static VALUE SecondaryMap_Get(VALUE key) {
VALUE ret = rb_hash_lookup(secondary_map, key);
if (ret == Qnil) {
+ SecondaryMap_MaybeGC();
ret = rb_eval_string("Object.new");
rb_hash_aset(secondary_map, key, ret);
}
