use proc_macro::TokenStream;
use quote::quote;
use syn::{ItemFn, parse_macro_input};
#[proc_macro_attribute]
pub fn trace_time(_attr: TokenStream, item: TokenStream) -> TokenStream {
let input = parse_macro_input!(item as ItemFn);
let fn_name = &input.sig.ident;
let asyncness = &input.sig.asyncness;
let inputs = &input.sig.inputs;
let output = &input.sig.output;
let block = &input.block;
let vis = &input.vis;
let attrs = &input.attrs;
let expanded = if asyncness.is_some() {
quote! {
#(#attrs)*
#vis #asyncness fn #fn_name(#inputs) #output {
let __start = std::time::Instant::now();
let result = (async move #block).await;
let duration = __start.elapsed();
if duration.as_secs() > 5 {
tracing::info!(target: "trace_time", "Function `{}` took {:?}", stringify!(#fn_name), duration);
}
result
}
}
} else {
quote! {
#(#attrs)*
#vis fn #fn_name(#inputs) #output {
let __start = std::time::Instant::now();
let result = #block;
let duration = __start.elapsed();
if duration.as_secs() > 5 {
tracing::info!(target: "trace_time", "Function `{}` took {:?}", stringify!(#fn_name), duration);
}
result
}
}
};
TokenStream::from(expanded)
}