perf(ops): fast path for SMI return values (denoland#15033)

ops/lib.rs

@@ -359,9 +359,19 @@ fn codegen_sync_ret(
  return quote! {};
  }
 
+ if is_u32_rv(output) {
+ return quote! {
+ rv.set_uint32(result as u32);
+ };
+ }
+
  // Optimize Result<(), Err> to skip serde_v8 when Ok(...)
  let ok_block = if is_unit_result(output) {
  quote! {}
+ } else if is_u32_rv_result(output) {
+ quote! {
+ rv.set_uint32(result as u32);
+ }
  } else {
  quote! {
  match #core::serde_v8::to_v8(scope, result) {
@@ -408,11 +418,31 @@ fn is_result(ty: impl ToTokens) -> bool {
  }
 }
 
+/// Detects if the type can be set using `rv.set_uint32` fast path
+fn is_u32_rv(ty: impl ToTokens) -> bool {
+ ["u32", "u8", "u16"].iter().any(|&s| tokens(&ty) == s) || is_resource_id(&ty)
+}
+
+/// Detects if the type is of the format Result<u32/u8/u16, Err>
+fn is_u32_rv_result(ty: impl ToTokens) -> bool {
+ is_result(&ty)
+ && (tokens(&ty).contains("Result < u32")
+ || tokens(&ty).contains("Result < u8")
+ || tokens(&ty).contains("Result < u16")
+ || is_resource_id(&ty))
+}
+
 /// Detects if a type is of the form Result<(), Err>
 fn is_unit_result(ty: impl ToTokens) -> bool {
  is_result(&ty) && tokens(&ty).contains("Result < ()")
 }
 
+fn is_resource_id(arg: impl ToTokens) -> bool {
+ static RE: Lazy<Regex> =
+ Lazy::new(|| Regex::new(r#": (?:deno_core :: )?ResourceId$"#).unwrap());
+ RE.is_match(&tokens(arg))
+}
+
 fn is_mut_ref_opstate(arg: &syn::FnArg) -> bool {
  static RE: Lazy<Regex> =
  Lazy::new(|| Regex::new(r#": & mut (?:deno_core :: )?OpState$"#).unwrap());