ObjectSpace::WeakMap

An ObjectSpace::WeakMap object holds references to any objects, but those objects can get garbage collected.

This class is mostly used internally by WeakRef, please use lib/weakref.rb for the public interface.

Public Instance Methods

[](p1) click to toggle source

Retrieves a weakly referenced object with the given key

 
 static VALUE
wmap_aref(VALUE self, VALUE wmap)
{
 st_data_t data;
 VALUE obj;
 struct weakmap *w;
 rb_objspace_t *objspace = &rb_objspace;
 TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
 if (!st_lookup(w->wmap2obj, (st_data_t)wmap, &data)) return Qnil;
 obj = (VALUE)data;
 if (!is_id_value(objspace, obj)) return Qnil;
 if (!is_live_object(objspace, obj)) return Qnil;
 return obj;
}

[]=(p1, p2) click to toggle source

Creates a weak reference from the given key to the given value

 
 static VALUE
wmap_aset(VALUE self, VALUE wmap, VALUE orig)
{
 st_data_t data;
 VALUE rids;
 struct weakmap *w;
 TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
 rb_define_final(orig, w->final);
 rb_define_final(wmap, w->final);
 if (st_lookup(w->obj2wmap, (st_data_t)orig, &data)) {
 rids = (VALUE)data;
 }
 else {
 rids = rb_ary_tmp_new(1);
 st_insert(w->obj2wmap, (st_data_t)orig, (st_data_t)rids);
 }
 rb_ary_push(rids, wmap);
 st_insert(w->wmap2obj, (st_data_t)wmap, (st_data_t)orig);
 return nonspecial_obj_id(orig);
}

Private Instance Methods

finalize(p1) click to toggle source

 
 static VALUE
wmap_finalize(VALUE self, VALUE objid)
{
 st_data_t orig, wmap, data;
 VALUE obj, rids;
 long i;
 struct weakmap *w;
 TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
 /* Get reference from object id. */
 obj = obj_id_to_ref(objid);
 /* obj is original referenced object and/or weak reference. */
 orig = (st_data_t)obj;
 if (st_delete(w->obj2wmap, &orig, &data)) {
 rids = (VALUE)data;
 for (i = 0; i < RARRAY_LEN(rids); ++i) {
 wmap = (st_data_t)RARRAY_PTR(rids)[i];
 st_delete(w->wmap2obj, &wmap, NULL);
 }
 }
 wmap = (st_data_t)obj;
 if (st_delete(w->wmap2obj, &wmap, &orig)) {
 wmap = (st_data_t)obj;
 st_update(w->obj2wmap, orig, wmap_final_func, wmap);
 }
 return self;
}