nova_vm/ecmascript/builtins/
weak_map.rs

1// This Source Code Form is subject to the terms of the Mozilla Public
2// License, v. 2.0. If a copy of the MPL was not distributed with this
3// file, You can obtain one at https://mozilla.org/MPL/2.0/.
4
5mod data;
6
7pub(crate) use data::*;
8
9use crate::{
10    ecmascript::{
11        Agent, InternalMethods, InternalSlots, OrdinaryObject, ProtoIntrinsics, Value, WeakKey,
12        object_handle,
13    },
14    engine::Bindable,
15    heap::{
16        ArenaAccess, ArenaAccessMut, BaseIndex, CompactionLists, CreateHeapData, Heap,
17        HeapMarkAndSweep, HeapSweepWeakReference, WorkQueues, arena_vec_access,
18    },
19};
20
21/// ## [24.3 WeakMap Objects](https://tc39.es/ecma262/#sec-weakmap-objects)
22///
23/// WeakMaps are collections of key/value pairs where the keys are objects
24/// and/or symbols and values may be arbitrary ECMAScript language values. A
25/// WeakMap may be queried to see if it contains a key/value pair with a
26/// specific key, but no mechanism is provided for enumerating the values it
27/// holds as keys. In certain conditions, values which are not live are removed
28/// as WeakMap keys.
29#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
30#[repr(transparent)]
31pub struct WeakMap<'a>(BaseIndex<'a, WeakMapRecord<'static>>);
32object_handle!(WeakMap);
33arena_vec_access!(WeakMap, 'a, WeakMapRecord, weak_maps);
34
35impl<'m> WeakMap<'m> {
36    pub(crate) fn delete(self, agent: &mut Agent, key: WeakKey<'m>) -> bool {
37        self.get_mut(agent).delete(key)
38    }
39
40    pub(crate) fn get_v(self, agent: &mut Agent, key: WeakKey<'m>) -> Option<Value<'m>> {
41        self.get_mut(agent).get(key)
42    }
43
44    pub(crate) fn has(self, agent: &mut Agent, key: WeakKey<'m>) -> bool {
45        self.get_mut(agent).has(key)
46    }
47
48    pub(crate) fn set(self, agent: &mut Agent, key: WeakKey<'m>, value: Value<'m>) {
49        self.get_mut(agent).set(key, value)
50    }
51}
52
53impl<'a> InternalSlots<'a> for WeakMap<'a> {
54    const DEFAULT_PROTOTYPE: ProtoIntrinsics = ProtoIntrinsics::WeakMap;
55
56    #[inline(always)]
57    fn get_backing_object(self, agent: &Agent) -> Option<OrdinaryObject<'static>> {
58        self.get(agent).object_index.unbind()
59    }
60
61    fn set_backing_object(self, agent: &mut Agent, backing_object: OrdinaryObject<'static>) {
62        assert!(
63            self.get_mut(agent)
64                .object_index
65                .replace(backing_object.unbind())
66                .is_none()
67        );
68    }
69}
70
71impl<'a> InternalMethods<'a> for WeakMap<'a> {}
72
73impl<'a> CreateHeapData<WeakMapRecord<'a>, WeakMap<'a>> for Heap {
74    fn create(&mut self, data: WeakMapRecord<'a>) -> WeakMap<'a> {
75        self.weak_maps.push(data.unbind());
76        self.alloc_counter += core::mem::size_of::<WeakMapRecord<'static>>();
77        WeakMap(BaseIndex::last(&self.weak_maps))
78    }
79}
80
81impl HeapMarkAndSweep for WeakMap<'static> {
82    fn mark_values(&self, queues: &mut WorkQueues) {
83        queues.weak_maps.push(*self);
84    }
85
86    fn sweep_values(&mut self, compactions: &CompactionLists) {
87        compactions.weak_maps.shift_index(&mut self.0);
88    }
89}
90
91impl HeapSweepWeakReference for WeakMap<'static> {
92    fn sweep_weak_reference(self, compactions: &CompactionLists) -> Option<Self> {
93        compactions.weak_maps.shift_weak_index(self.0).map(Self)
94    }
95}
nova_vm/ecmascript/builtins/weak_map.rs

nova_vm/ecmascript/builtins/
weak_map.rs
