1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
pub(crate) use objects::{InternalStoreHandle, StoreObject};
pub use objects::{StoreHandle, StoreObjects};
mod objects {
use std::{fmt, marker::PhantomData, num::NonZeroUsize};
use wasm_bindgen::JsValue;
use crate::js::vm::{VMFunctionEnvironment, VMGlobal};
pub use wasmer_types::StoreId;
/// Trait to represent an object managed by a context. This is implemented on
/// the VM types managed by the context.
pub trait StoreObject: Sized {
fn list(store: &StoreObjects) -> &Vec<Self>;
fn list_mut(store: &mut StoreObjects) -> &mut Vec<Self>;
}
macro_rules! impl_store_object {
($($field:ident => $ty:ty,)*) => {
$(
impl StoreObject for $ty {
fn list(store: &StoreObjects) -> &Vec<Self> {
&store.$field
}
fn list_mut(store: &mut StoreObjects) -> &mut Vec<Self> {
&mut store.$field
}
}
)*
};
}
impl_store_object! {
// Note: we store the globals in order to be able to access them later via
// `StoreObjects::iter_globals`.
globals => VMGlobal,
// functions => VMFunction,
// tables => VMTable,
// memories => VMMemory,
// The function environments are the only things attached to a store,
// since the other JS objects (table, globals, memory and functions)
// live in the JS VM Store by default
function_environments => VMFunctionEnvironment,
}
/// Set of objects managed by a context.
#[derive(Default, Debug)]
pub struct StoreObjects {
id: StoreId,
globals: Vec<VMGlobal>,
function_environments: Vec<VMFunctionEnvironment>,
}
impl StoreObjects {
/// Returns the ID of this context.
pub fn id(&self) -> StoreId {
self.id
}
/// Sets the ID of this store
pub fn set_id(&mut self, id: StoreId) {
self.id = id;
}
/// Returns a pair of mutable references from two handles.
///
/// Panics if both handles point to the same object.
pub fn get_2_mut<T: StoreObject>(
&mut self,
a: InternalStoreHandle<T>,
b: InternalStoreHandle<T>,
) -> (&mut T, &mut T) {
assert_ne!(a.index(), b.index());
let list = T::list_mut(self);
if a.index() < b.index() {
let (low, high) = list.split_at_mut(b.index());
(&mut low[a.index()], &mut high[0])
} else {
let (low, high) = list.split_at_mut(a.index());
(&mut high[0], &mut low[a.index()])
}
}
/// Return an immutable iterator over all globals
pub fn iter_globals(&self) -> core::slice::Iter<VMGlobal> {
self.globals.iter()
}
/// Return an vector of all globals and converted to u128
pub fn as_u128_globals(&self) -> Vec<u128> {
self.iter_globals()
.map(|v| v.global.value().as_f64().unwrap() as u128)
.collect()
}
/// Set a global, at index idx. Will panic if idx is out of range
/// Safety: the caller should check that the raw value is compatible
/// with destination VMGlobal type
pub fn set_global_unchecked(&self, idx: usize, new_val: u128) {
assert!(idx < self.globals.len());
let g = &self.globals[idx].global;
let cur_val = g.value().as_f64().unwrap();
let new_val = new_val as f64;
if cur_val != new_val {
let new_value = JsValue::from(new_val);
g.set_value(&new_value);
}
}
}
/// Handle to an object managed by a context.
///
/// Internally this is just an integer index into a context. A reference to the
/// context must be passed in separately to access the actual object.
pub struct StoreHandle<T> {
id: StoreId,
internal: InternalStoreHandle<T>,
}
impl<T> core::cmp::PartialEq for StoreHandle<T> {
fn eq(&self, other: &Self) -> bool {
self.id == other.id
}
}
impl<T> std::hash::Hash for StoreHandle<T> {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
self.id.hash(state);
self.internal.idx.hash(state);
}
}
impl<T> Clone for StoreHandle<T> {
fn clone(&self) -> Self {
Self {
id: self.id,
internal: self.internal,
}
}
}
impl<T: StoreObject> fmt::Debug for StoreHandle<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("StoreHandle")
.field("id", &self.id)
.field("internal", &self.internal.index())
.finish()
}
}
impl<T: StoreObject> StoreHandle<T> {
/// Moves the given object into a context and returns a handle to it.
pub fn new(store: &mut StoreObjects, val: T) -> Self {
Self {
id: store.id,
internal: InternalStoreHandle::new(store, val),
}
}
/// Returns a reference to the object that this handle points to.
pub fn get<'a>(&self, store: &'a StoreObjects) -> &'a T {
assert_eq!(self.id, store.id, "object used with the wrong context");
self.internal.get(store)
}
/// Returns a mutable reference to the object that this handle points to.
pub fn get_mut<'a>(&self, store: &'a mut StoreObjects) -> &'a mut T {
assert_eq!(self.id, store.id, "object used with the wrong context");
self.internal.get_mut(store)
}
/// Returns the internal handle contains within this handle.
pub fn internal_handle(&self) -> InternalStoreHandle<T> {
self.internal
}
/// Returns the ID of the context associated with the handle.
#[allow(unused)]
pub fn store_id(&self) -> StoreId {
self.id
}
/// Overrides the store id with a new ID
#[allow(unused)]
pub fn set_store_id(&mut self, id: StoreId) {
self.id = id;
}
/// Constructs a `StoreHandle` from a `StoreId` and an `InternalStoreHandle`.
///
/// # Safety
/// Handling `InternalStoreHandle` values is unsafe because they do not track context ID.
pub unsafe fn from_internal(id: StoreId, internal: InternalStoreHandle<T>) -> Self {
Self { id, internal }
}
}
/// Internal handle to an object owned by the current context.
///
/// Unlike `StoreHandle` this does not track the context ID: it is only
/// intended to be used within objects already owned by a context.
#[repr(transparent)]
pub struct InternalStoreHandle<T> {
// Use a NonZero here to reduce the size of Option<InternalStoreHandle>.
idx: NonZeroUsize,
marker: PhantomData<fn() -> T>,
}
impl<T> Clone for InternalStoreHandle<T> {
fn clone(&self) -> Self {
*self
}
}
impl<T> Copy for InternalStoreHandle<T> {}
impl<T> fmt::Debug for InternalStoreHandle<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("InternalStoreHandle")
.field("idx", &self.idx)
.finish()
}
}
impl<T> PartialEq for InternalStoreHandle<T> {
fn eq(&self, other: &Self) -> bool {
self.idx == other.idx
}
}
impl<T> Eq for InternalStoreHandle<T> {}
impl<T: StoreObject> InternalStoreHandle<T> {
/// Moves the given object into a context and returns a handle to it.
pub fn new(store: &mut StoreObjects, val: T) -> Self {
let list = T::list_mut(store);
let idx = NonZeroUsize::new(list.len() + 1).unwrap();
list.push(val);
Self {
idx,
marker: PhantomData,
}
}
/// Returns a reference to the object that this handle points to.
pub fn get<'a>(&self, store: &'a StoreObjects) -> &'a T {
&T::list(store)[self.idx.get() - 1]
}
/// Returns a mutable reference to the object that this handle points to.
pub fn get_mut<'a>(&self, store: &'a mut StoreObjects) -> &'a mut T {
&mut T::list_mut(store)[self.idx.get() - 1]
}
pub(crate) fn index(&self) -> usize {
self.idx.get()
}
pub(crate) fn from_index(idx: usize) -> Option<Self> {
NonZeroUsize::new(idx).map(|idx| Self {
idx,
marker: PhantomData,
})
}
}
}