Alert on frequent network errors (#7410)

* Introduce is_frequent util

* Add dirty warn_if_frequent! implementation

* Add freq

* Fix order in condition

* Update

* Update docs

* Fix

* Remove old impl

* Fix errors

* Add wif to av-distr

* Add wif to col prot

* Rename

* Add wif to state-distr

* Address review comments

* Change Freq implementation

* Remove the zero division check

* Make rate explicit

* Fix typo

* Update rate constant

* Introduce explicit rates

* Update docs

* Split errors freq

* Downgrade coarsetime

polkadot/node/gum/proc-macro/src/lib.rs

@@ -43,6 +43,27 @@ pub fn warn(item: proc_macro::TokenStream) -> proc_macro::TokenStream {
 	gum(item, Level::Warn)
 }
 
+/// Print a warning or debug level message depending on their frequency
+#[proc_macro]
+pub fn warn_if_frequent(item: proc_macro::TokenStream) -> proc_macro::TokenStream {
+	let ArgsIfFrequent { freq, max_rate, rest } = parse2(item.into()).unwrap();
+
+	let freq_expr = freq.expr;
+	let max_rate_expr = max_rate.expr;
+	let debug: proc_macro2::TokenStream = gum(rest.clone().into(), Level::Debug).into();
+	let warn: proc_macro2::TokenStream = gum(rest.into(), Level::Warn).into();
+
+	let stream = quote! {
+		if #freq_expr .is_frequent(#max_rate_expr) {
+			#warn
+		} else {
+			#debug
+		}
+	};
+
+	stream.into()
+}
+
 /// Print a info level message.
 #[proc_macro]
 pub fn info(item: proc_macro::TokenStream) -> proc_macro::TokenStream {

polkadot/node/gum/proc-macro/src/types.rs

@@ -23,6 +23,8 @@ use syn::{
 
 pub(crate) mod kw {
 	syn::custom_keyword!(target);
+	syn::custom_keyword!(freq);
+	syn::custom_keyword!(max_rate);
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -248,6 +250,50 @@ impl ToTokens for FmtGroup {
 	}
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct Freq {
+	kw: kw::freq,
+	colon: Token![:],
+	pub expr: syn::Expr,
+}
+
+impl Parse for Freq {
+	fn parse(input: ParseStream) -> Result<Self> {
+		Ok(Self { kw: input.parse()?, colon: input.parse()?, expr: input.parse()? })
+	}
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct MaxRate {
+	kw: kw::max_rate,
+	colon: Token![:],
+	pub expr: syn::Expr,
+}
+
+impl Parse for MaxRate {
+	fn parse(input: ParseStream) -> Result<Self> {
+		Ok(Self { kw: input.parse()?, colon: input.parse()?, expr: input.parse()? })
+	}
+}
+
+pub(crate) struct ArgsIfFrequent {
+	pub freq: Freq,
+	pub max_rate: MaxRate,
+	pub rest: TokenStream,
+}
+
+impl Parse for ArgsIfFrequent {
+	fn parse(input: ParseStream) -> Result<Self> {
+		let freq = input.parse()?;
+		let _: Token![,] = input.parse()?;
+		let max_rate = input.parse()?;
+		let _: Token![,] = input.parse()?;
+		let rest = input.parse()?;
+
+		Ok(Self { freq, max_rate, rest })
+	}
+}
+
 /// Full set of arguments as provided to the `gum::warn!` call.
 #[derive(Debug, Clone)]
 pub(crate) struct Args {