wasmtime-c-api-impl 44.0.0

C API to expose the Wasmtime runtime
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

use crate::{CExternType, handle_result, wasm_externtype_t, wasm_limits_t, wasmtime_error_t};
use std::convert::TryFrom;
use std::{cell::OnceCell, mem::MaybeUninit};
use wasmtime::{MemoryType, MemoryTypeBuilder};

#[repr(transparent)]
#[derive(Clone)]
pub struct wasm_memorytype_t {
    ext: wasm_externtype_t,
}

wasmtime_c_api_macros::declare_ty!(wasm_memorytype_t);

#[derive(Clone)]
pub(crate) struct CMemoryType {
    pub(crate) ty: MemoryType,
    limits_cache: OnceCell<wasm_limits_t>,
}

impl wasm_memorytype_t {
    pub(crate) fn new(ty: MemoryType) -> wasm_memorytype_t {
        wasm_memorytype_t {
            ext: wasm_externtype_t::from_extern_type(ty.into()),
        }
    }

    pub(crate) fn try_from(e: &wasm_externtype_t) -> Option<&wasm_memorytype_t> {
        match &e.which {
            CExternType::Memory(_) => Some(unsafe { &*(e as *const _ as *const _) }),
            _ => None,
        }
    }

    pub(crate) fn ty(&self) -> &CMemoryType {
        match &self.ext.which {
            CExternType::Memory(f) => &f,
            _ => unsafe { std::hint::unreachable_unchecked() },
        }
    }
}

impl CMemoryType {
    pub(crate) fn new(ty: MemoryType) -> CMemoryType {
        CMemoryType {
            ty,
            limits_cache: OnceCell::new(),
        }
    }
}

#[unsafe(no_mangle)]
pub extern "C" fn wasm_memorytype_new(limits: &wasm_limits_t) -> Box<wasm_memorytype_t> {
    Box::new(wasm_memorytype_t::new(MemoryType::new(
        limits.min,
        limits.max(),
    )))
}

#[unsafe(no_mangle)]
pub extern "C" fn wasm_memorytype_limits(mt: &wasm_memorytype_t) -> &wasm_limits_t {
    let mt = mt.ty();
    mt.limits_cache.get_or_init(|| wasm_limits_t {
        min: u32::try_from(mt.ty.minimum()).unwrap(),
        max: u32::try_from(mt.ty.maximum().unwrap_or(u64::from(u32::max_value()))).unwrap(),
    })
}

#[unsafe(no_mangle)]
pub extern "C" fn wasmtime_memorytype_new(
    minimum: u64,
    maximum_specified: bool,
    maximum: u64,
    memory64: bool,
    shared: bool,
    page_size_log2: u8,
    ret: &mut MaybeUninit<Box<wasm_memorytype_t>>,
) -> Option<Box<wasmtime_error_t>> {
    let maximum = if maximum_specified {
        Some(maximum)
    } else {
        None
    };

    handle_result(
        MemoryTypeBuilder::default()
            .min(minimum)
            .max(maximum)
            .memory64(memory64)
            .shared(shared)
            .page_size_log2(page_size_log2)
            .build(),
        |ty| {
            ret.write(Box::new(wasm_memorytype_t::new(ty)));
        },
    )
}

#[unsafe(no_mangle)]
pub extern "C" fn wasmtime_memorytype_minimum(mt: &wasm_memorytype_t) -> u64 {
    mt.ty().ty.minimum()
}

#[unsafe(no_mangle)]
pub extern "C" fn wasmtime_memorytype_maximum(mt: &wasm_memorytype_t, out: &mut u64) -> bool {
    match mt.ty().ty.maximum() {
        Some(max) => {
            *out = max;
            true
        }
        None => false,
    }
}

#[unsafe(no_mangle)]
pub extern "C" fn wasmtime_memorytype_is64(mt: &wasm_memorytype_t) -> bool {
    mt.ty().ty.is_64()
}

#[unsafe(no_mangle)]
pub extern "C" fn wasmtime_memorytype_isshared(mt: &wasm_memorytype_t) -> bool {
    mt.ty().ty.is_shared()
}

#[unsafe(no_mangle)]
pub extern "C" fn wasmtime_memorytype_page_size(mt: &wasm_memorytype_t) -> u64 {
    mt.ty().ty.page_size()
}

#[unsafe(no_mangle)]
pub extern "C" fn wasmtime_memorytype_page_size_log2(mt: &wasm_memorytype_t) -> u8 {
    mt.ty().ty.page_size_log2()
}

#[unsafe(no_mangle)]
pub extern "C" fn wasm_memorytype_as_externtype(ty: &wasm_memorytype_t) -> &wasm_externtype_t {
    &ty.ext
}

#[unsafe(no_mangle)]
pub extern "C" fn wasm_memorytype_as_externtype_const(
    ty: &wasm_memorytype_t,
) -> &wasm_externtype_t {
    &ty.ext
}