akit-macros 0.0.1

上帝工具箱-宏
Documentation 
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use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, LitInt};

/// 并发限制属性宏
#[proc_macro_attribute]
pub fn concurrency_limit(attr: TokenStream, item: TokenStream) -> TokenStream {
    let limit = parse_macro_input!(attr as LitInt);
    let input = parse_macro_input!(item as syn::ItemFn);

    let fn_name = &input.sig.ident;
    let semaphore_name = quote::format_ident!("SEMAPHORE_{}", fn_name);

    quote! {
        static #semaphore_name: ::once_cell::sync::Lazy<::tokio::sync::Semaphore> =
            ::once_cell::sync::Lazy::new(|| ::tokio::sync::Semaphore::new(#limit));

        #input
        
        impl #fn_name {
            pub async fn acquire() -> ::tokio::sync::SemaphorePermit<'static> {
                #semaphore_name.acquire().await.unwrap()
            }
        }
    }.into()
}