class 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 key)
{
    VALUE obj = wmap_lookup(self, key);
    return !UNDEF_P(obj) ? obj : Qnil;
}
[]=(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 key, VALUE value)
{
    struct weakmap *w;

    TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
    if (FL_ABLE(value)) {
        define_final0(value, w->final);
    }
    if (FL_ABLE(key)) {
        define_final0(key, w->final);
    }

    struct wmap_aset_replace_args aset_args = {
        .new_value = value,
        .old_value = Qundef,
    };
    st_update(w->wmap2obj, (st_data_t)key, wmap_aset_replace_value, (st_data_t)&aset_args);

    // If the value is unchanged, we have nothing to do.
    if (value != aset_args.old_value) {
        if (!UNDEF_P(aset_args.old_value) && FL_ABLE(aset_args.old_value)) {
            // That key existed and had an inverse reference, we need to clear the outdated inverse reference.
            st_update(w->obj2wmap, (st_data_t)aset_args.old_value, wmap_remove_inverse_ref, key);
        }

        if (FL_ABLE(value)) {
            // If the value has no finalizer, we don't need to keep the inverse reference
            st_update(w->obj2wmap, (st_data_t)value, wmap_aset_update, key);
        }
    }

    return nonspecial_obj_id(value);
}
each() click to toggle source

Iterates over keys and objects in a weakly referenced object

static VALUE
wmap_each(VALUE self)
{
    struct weakmap *w;
    rb_objspace_t *objspace = &rb_objspace;

    TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
    st_foreach(w->wmap2obj, wmap_each_i, (st_data_t)objspace);
    return self;
}
Also aliased as: each_pair
each_key() click to toggle source

Iterates over keys and objects in a weakly referenced object

static VALUE
wmap_each_key(VALUE self)
{
    struct weakmap *w;
    rb_objspace_t *objspace = &rb_objspace;

    TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
    st_foreach(w->wmap2obj, wmap_each_key_i, (st_data_t)objspace);
    return self;
}
each_pair()

Iterates over keys and objects in a weakly referenced object

Alias for: each
each_value() click to toggle source

Iterates over keys and objects in a weakly referenced object

static VALUE
wmap_each_value(VALUE self)
{
    struct weakmap *w;
    rb_objspace_t *objspace = &rb_objspace;

    TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
    st_foreach(w->wmap2obj, wmap_each_value_i, (st_data_t)objspace);
    return self;
}
include?(p1) click to toggle source

Returns true if key is registered

static VALUE
wmap_has_key(VALUE self, VALUE key)
{
    return RBOOL(!UNDEF_P(wmap_lookup(self, key)));
}
Also aliased as: member?, key?
inspect() click to toggle source 
static VALUE
wmap_inspect(VALUE self)
{
    VALUE str;
    VALUE c = rb_class_name(CLASS_OF(self));
    struct weakmap *w;
    struct wmap_iter_arg args;

    TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
    str = rb_sprintf("-<%"PRIsVALUE":%p", c, (void *)self);
    if (w->wmap2obj) {
        args.objspace = &rb_objspace;
        args.value = str;
        st_foreach(w->wmap2obj, wmap_inspect_i, (st_data_t)&args);
    }
    RSTRING_PTR(str)[0] = '#';
    rb_str_cat2(str, ">");
    return str;
}
key?(p1)

Returns true if key is registered

Alias for: include?
keys() click to toggle source

Iterates over keys and objects in a weakly referenced object

static VALUE
wmap_keys(VALUE self)
{
    struct weakmap *w;
    struct wmap_iter_arg args;

    TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
    args.objspace = &rb_objspace;
    args.value = rb_ary_new();
    st_foreach(w->wmap2obj, wmap_keys_i, (st_data_t)&args);
    return args.value;
}
length()

Returns the number of referenced objects

Alias for: size
member?(p1)

Returns true if key is registered

Alias for: include?
size() click to toggle source

Returns the number of referenced objects

static VALUE
wmap_size(VALUE self)
{
    struct weakmap *w;
    st_index_t n;

    TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
    n = w->wmap2obj->num_entries;
#if SIZEOF_ST_INDEX_T <= SIZEOF_LONG
    return ULONG2NUM(n);
#else
    return ULL2NUM(n);
#endif
}
Also aliased as: length
values() click to toggle source

Iterates over values and objects in a weakly referenced object

static VALUE
wmap_values(VALUE self)
{
    struct weakmap *w;
    struct wmap_iter_arg args;

    TypedData_Get_Struct(self, struct weakmap, &weakmap_type, w);
    args.objspace = &rb_objspace;
    args.value = rb_ary_new();
    st_foreach(w->wmap2obj, wmap_values_i, (st_data_t)&args);
    return args.value;
}