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ca66978a5a
This PR introduces Wasm ops. These calls are optimized for entry from
Wasm land.
The `#[op(wasm)]` attribute is opt-in.
Last parameter `Option<&mut [u8]>` is the memory slice of the Wasm
module *when entered from a Fast API call*. Otherwise, the user is
expected to implement logic to obtain the memory if `None`
```rust
#[op(wasm)]
pub fn op_args_get(
offset: i32,
buffer_offset: i32,
memory: Option<&mut [u8]>,
) {
// ...
}
```
1.6 KiB
1.6 KiB
deno_ops
proc_macro for generating highly optimized V8 functions from Deno ops.
// Declare an op.
#[op(fast)]
pub fn op_add(_: &mut OpState, a: i32, b: i32) -> i32 {
a + b
}
// Register with an extension.
Extension::builder()
.ops(vec![op_add::decl()])
.build();
Performance
The macro can optimize away code, short circuit fast paths and generate a Fast API impl.
Cases where code is optimized away:
-> ()skips serde_v8 andrv.setcalls.-> Result<(), E>skips serde_v8 andrv.setcalls forOk()branch.-> ResourceIdor-> [int]types will use specialized method likev8::ReturnValue::set_uint32. A fast path for SMI.-> Result<ResourceId, E>or-> Result<[int], E>types will be optimized like above for theOk()branch.
Fast calls
The macro will infer and try to auto generate V8 fast API call trait impl for
sync ops with:
- arguments: integers, bool,
&mut OpState,&[u8],&mut [u8],&[u32],&mut [u32] - return_type: integers, bool
The #[op(fast)] attribute should be used to enforce fast call generation at
compile time.
Trait gen for async ops & a ZeroCopyBuf equivalent type is planned and will be
added soon.
Wasm calls
The #[op(wasm)] attribute should be used for calls expected to be called from
Wasm. This enables the fast call generation and allows seamless WasmMemory
integration for generic and fast calls.
#[op(wasm)]
pub fn op_args_get(
offset: i32,
buffer_offset: i32,
memory: Option<&[u8]>, // Must be last parameter. Some(..) when entered from Wasm.
) {
// ...
}