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denoland-deno/ops/attrs.rs
Divy Srivastava 0910be4d64
feat(ops): relational ops (#18023)
Join two independent ops into one. A fast impl of one + a slow callback
of another. Here's an example showing optimized paths for latin-1 via
fast call and the next-best fallback using V8 apis.

```rust
#[op(v8)]
fn op_encoding_encode_into_fallback(
  scope: &mut v8::HandleScope,
  input: serde_v8::Value,
// ...

#[op(fast, slow = op_encoding_encode_into_fallback)]
fn op_encoding_encode_into(
  input: Cow<'_, str>,
// ...
```

Benchmark results of the fallback path:
```
time target/release/deno run -A --unstable ./cli/tests/testdata/benches/text_encoder_into_perf.js
________________________________________________________
Executed in   70.90 millis    fish           external
   usr time   57.76 millis    0.23 millis   57.53 millis
   sys time   17.02 millis    1.28 millis   15.74 millis

target/release/deno_main run -A --unstable ./cli/tests/testdata/benches/text_encoder_into_perf.js
________________________________________________________
Executed in  154.00 millis    fish           external
   usr time   67.14 millis    0.26 millis   66.88 millis
   sys time   38.82 millis    1.47 millis   37.35 millis
```
2023-03-05 13:30:22 +05:30

54 lines
1.4 KiB
Rust

// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
use syn::parse::Parse;
use syn::parse::ParseStream;
use syn::Error;
use syn::Ident;
use syn::Result;
use syn::Token;
#[derive(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,
pub relation: Option<Ident>,
}
impl Parse for Attributes {
fn parse(input: ParseStream) -> Result<Self> {
let mut self_ = Self::default();
let mut fast = false;
while let Ok(v) = input.parse::<Ident>() {
match v.to_string().as_str() {
"unstable" => self_.is_unstable = true,
"v8" => self_.is_v8 = true,
"fast" => fast = true,
"deferred" => self_.deferred = true,
"wasm" => self_.is_wasm = true,
"slow" => {
if !fast {
return Err(Error::new(
input.span(),
"relational attributes can only be used with fast attribute",
));
}
input.parse::<Token![=]>()?;
self_.relation = Some(input.parse()?);
}
_ => {
return Err(Error::new(
input.span(),
"invalid attribute, expected one of: unstable, v8, fast, deferred, wasm",
));
}
};
let _ = input.parse::<Token![,]>();
}
self_.must_be_fast = self_.is_wasm || fast;
Ok(self_)
}
}