wasmedge_sys/
frame.rs

1//! Defines WasmEdge CallingFrame.
2
3use crate::{
4    ffi,
5    instance::{memory::InnerMemory, InnerRef},
6    Memory,
7};
8
9/// Represents a calling frame on top of stack.
10#[derive(Debug)]
11pub struct CallingFrame {
12    pub(crate) inner: InnerCallingFrame,
13}
14
15impl CallingFrame {
16    /// Creates a CallingFrame instance.
17    pub(crate) fn create(ctx: *const ffi::WasmEdge_CallingFrameContext) -> Self {
18        Self {
19            inner: InnerCallingFrame(ctx),
20        }
21    }
22
23    /// Returns an immutable smart pointer borrowing the [memory instance](crate::Memory) by the given index from the module instance of the current
24    /// calling frame. If the memory instance is not found, returns `None`.
25    ///
26    /// By default, a WASM module has only one memory instance after instantiation. Therefore, users can pass in `0` as
27    /// the index to get the memory instance in host function body. When the [MultiMemories](crate::Config::multi_memories)
28    /// config option is enabled, there would be more than one memory instances in the wasm module. Users can retrieve
29    /// the target memory instance by specifying the index of the memory instance in the wasm module instance.
30    ///
31    /// # Arguments
32    ///
33    /// * idx - The index of the memory instance.
34    pub fn memory_ref(&self, idx: u32) -> Option<InnerRef<Memory, &Self>> {
35        unsafe {
36            let ctx = ffi::WasmEdge_CallingFrameGetMemoryInstance(self.inner.0, idx);
37
38            if ctx.is_null() {
39                None
40            } else {
41                let mem = Memory {
42                    inner: InnerMemory(ctx),
43                };
44                Some(InnerRef::create_from_ref(
45                    std::mem::ManuallyDrop::new(mem),
46                    self,
47                ))
48            }
49        }
50    }
51
52    /// Returns an mutable smart pointer borrowing the [memory instance](crate::Memory) by the given index from the module instance of the current
53    /// calling frame. If the memory instance is not found, returns `None`.
54    ///
55    /// By default, a WASM module has only one memory instance after instantiation. Therefore, users can pass in `0` as
56    /// the index to get the memory instance in host function body. When the [MultiMemories](crate::Config::multi_memories)
57    /// config option is enabled, there would be more than one memory instances in the wasm module. Users can retrieve
58    /// the target memory instance by specifying the index of the memory instance in the wasm module instance.
59    ///
60    /// # Arguments
61    ///
62    /// * idx - The index of the memory instance.
63    pub fn memory_mut(&mut self, idx: u32) -> Option<InnerRef<Memory, &mut Self>> {
64        unsafe {
65            let ctx = ffi::WasmEdge_CallingFrameGetMemoryInstance(self.inner.0, idx);
66
67            if ctx.is_null() {
68                None
69            } else {
70                let mem = Memory {
71                    inner: InnerMemory(ctx),
72                };
73                Some(InnerRef::create_from_mut(
74                    std::mem::ManuallyDrop::new(mem),
75                    self,
76                ))
77            }
78        }
79    }
80}
81
82#[derive(Debug)]
83pub(crate) struct InnerCallingFrame(pub(crate) *const ffi::WasmEdge_CallingFrameContext);
84unsafe impl Send for InnerCallingFrame {}
85unsafe impl Sync for InnerCallingFrame {}
wasmedge_sys/frame.rs

wasmedge_sys/
frame.rs
