wasmi 1.0.9

WebAssembly interpreter
Documentation 
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

use crate::{Engine, Error, Store};

/// A trait used to get shared access to a [`Store`] in Wasmi.
pub trait AsContext {
    /// The user state associated with the [`Store`], aka the `T` in `Store<T>`.
    type Data;

    /// Returns the store context that this type provides access to.
    fn as_context(&self) -> StoreContext<'_, Self::Data>;
}

/// A trait used to get exclusive access to a [`Store`] in Wasmi.
pub trait AsContextMut: AsContext {
    /// Returns the store context that this type provides access to.
    fn as_context_mut(&mut self) -> StoreContextMut<'_, Self::Data>;
}

/// A temporary handle to a [`&Store<T>`][`Store`].
///
/// This type is suitable for [`AsContext`] trait bounds on methods if desired.
/// For more information, see [`Store`].
#[derive(Debug, Copy, Clone)]
#[repr(transparent)]
pub struct StoreContext<'a, T> {
    pub(crate) store: &'a Store<T>,
}

impl<T> StoreContext<'_, T> {
    /// Returns the underlying [`Engine`] this store is connected to.
    pub fn engine(&self) -> &Engine {
        self.store.engine()
    }

    /// Access the underlying data owned by this store.
    ///
    /// Same as [`Store::data`].
    pub fn data(&self) -> &T {
        self.store.data()
    }

    /// Returns the remaining fuel of the [`Store`] if fuel metering is enabled.
    ///
    /// For more information see [`Store::get_fuel`](crate::Store::get_fuel).
    ///
    /// # Errors
    ///
    /// If fuel metering is disabled.
    pub fn get_fuel(&self) -> Result<u64, Error> {
        self.store.get_fuel()
    }
}

impl<'a, T: AsContext> From<&'a T> for StoreContext<'a, T::Data> {
    #[inline]
    fn from(ctx: &'a T) -> Self {
        ctx.as_context()
    }
}

impl<'a, T: AsContext> From<&'a mut T> for StoreContext<'a, T::Data> {
    #[inline]
    fn from(ctx: &'a mut T) -> Self {
        T::as_context(ctx)
    }
}

impl<'a, T: AsContextMut> From<&'a mut T> for StoreContextMut<'a, T::Data> {
    #[inline]
    fn from(ctx: &'a mut T) -> Self {
        ctx.as_context_mut()
    }
}

/// A temporary handle to a [`&mut Store<T>`][`Store`].
///
/// This type is suitable for [`AsContextMut`] or [`AsContext`] trait bounds on methods if desired.
/// For more information, see [`Store`].
#[derive(Debug)]
#[repr(transparent)]
pub struct StoreContextMut<'a, T> {
    pub(crate) store: &'a mut Store<T>,
}

impl<T> StoreContextMut<'_, T> {
    /// Returns the underlying [`Engine`] this store is connected to.
    pub fn engine(&self) -> &Engine {
        self.store.engine()
    }

    /// Access the underlying data owned by this store.
    ///
    /// Same as [`Store::data`].
    pub fn data(&self) -> &T {
        self.store.data()
    }

    /// Access the underlying data owned by this store.
    ///
    /// Same as [`Store::data_mut`].
    pub fn data_mut(&mut self) -> &mut T {
        self.store.data_mut()
    }

    /// Returns the remaining fuel of the [`Store`] if fuel metering is enabled.
    ///
    /// For more information see [`Store::get_fuel`](crate::Store::get_fuel).
    ///
    /// # Errors
    ///
    /// If fuel metering is disabled.
    pub fn get_fuel(&self) -> Result<u64, Error> {
        self.store.get_fuel()
    }

    /// Sets the remaining fuel of the [`Store`] to `value` if fuel metering is enabled.
    ///
    /// For more information see [`Store::get_fuel`](crate::Store::set_fuel).
    ///
    /// # Errors
    ///
    /// If fuel metering is disabled.
    pub fn set_fuel(&mut self, fuel: u64) -> Result<(), Error> {
        self.store.set_fuel(fuel)
    }
}

impl<T> AsContext for &'_ T
where
    T: AsContext,
{
    type Data = T::Data;

    #[inline]
    fn as_context(&self) -> StoreContext<'_, T::Data> {
        T::as_context(*self)
    }
}

impl<T> AsContext for &'_ mut T
where
    T: AsContext,
{
    type Data = T::Data;

    #[inline]
    fn as_context(&self) -> StoreContext<'_, T::Data> {
        T::as_context(*self)
    }
}

impl<T> AsContextMut for &'_ mut T
where
    T: AsContextMut,
{
    #[inline]
    fn as_context_mut(&mut self) -> StoreContextMut<'_, T::Data> {
        T::as_context_mut(*self)
    }
}

impl<T> AsContext for StoreContext<'_, T> {
    type Data = T;

    #[inline]
    fn as_context(&self) -> StoreContext<'_, Self::Data> {
        StoreContext { store: self.store }
    }
}

impl<T> AsContext for StoreContextMut<'_, T> {
    type Data = T;

    #[inline]
    fn as_context(&self) -> StoreContext<'_, Self::Data> {
        StoreContext { store: self.store }
    }
}

impl<T> AsContextMut for StoreContextMut<'_, T> {
    #[inline]
    fn as_context_mut(&mut self) -> StoreContextMut<'_, Self::Data> {
        StoreContextMut {
            store: &mut *self.store,
        }
    }
}

impl<T> AsContext for Store<T> {
    type Data = T;

    #[inline]
    fn as_context(&self) -> StoreContext<'_, Self::Data> {
        StoreContext { store: self }
    }
}

impl<T> AsContextMut for Store<T> {
    #[inline]
    fn as_context_mut(&mut self) -> StoreContextMut<'_, Self::Data> {
        StoreContextMut { store: self }
    }
}