deno/ops/attrs.rs
Divy Srivastava ca66978a5a
feat(ops): fast calls for Wasm (#16776)
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]>,
) {
  // ...
}
```
2022-11-27 19:24:28 +05:30

42 lines
1.1 KiB
Rust

// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use syn::{
parse::{Parse, ParseStream},
punctuated::Punctuated,
Error, Ident, Result, Token,
};
#[derive(Copy, Clone, Debug, Default)]
pub struct Attributes {
pub is_unstable: bool,
pub is_v8: bool,
pub must_be_fast: bool,
pub deferred: bool,
pub is_wasm: bool,
}
impl Parse for Attributes {
fn parse(input: ParseStream) -> Result<Self> {
let vars = Punctuated::<Ident, Token![,]>::parse_terminated(input)?;
let vars: Vec<_> = vars.iter().map(Ident::to_string).collect();
let vars: Vec<_> = vars.iter().map(String::as_str).collect();
for var in vars.iter() {
if !["unstable", "v8", "fast", "deferred", "wasm"].contains(var) {
return Err(Error::new(
input.span(),
"invalid attribute, expected one of: unstable, v8, fast, deferred, wasm",
));
}
}
let is_wasm = vars.contains(&"wasm");
Ok(Self {
is_unstable: vars.contains(&"unstable"),
is_v8: vars.contains(&"v8"),
deferred: vars.contains(&"deferred"),
must_be_fast: is_wasm || vars.contains(&"fast"),
is_wasm,
})
}
}