// This file is part of Substrate.
// Copyright (C) 2020-2022 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see .
use proc_macro::TokenStream;
use proc_macro2::Span;
use proc_macro_crate::{crate_name, FoundCrate};
use quote::quote;
use syn::{Error, Expr, Ident, ItemFn};
/// Add a log prefix to the function.
///
/// This prefixes all the log lines with `[]` (after the timestamp). It works by making a
/// tracing's span that is propagated to all the child calls and child tasks (futures) if they are
/// spawned properly with the `SpawnHandle` (see `TaskManager` in sc-cli) or if the futures use
/// `.in_current_span()` (see tracing-futures).
///
/// See Tokio's [tracing documentation](https://docs.rs/tracing-core/) and
/// [tracing-futures documentation](https://docs.rs/tracing-futures/) for more details.
///
/// # Implementation notes
///
/// If there are multiple spans with a log prefix, only the latest will be shown.
///
/// # Example with a literal
///
/// ```ignore
/// Builds a new service for a light client.
/// #[sc_cli::prefix_logs_with("light")]
/// pub fn new_light(config: Configuration) -> Result {
/// let (client, backend, keystore, mut task_manager, on_demand) =
/// sc_service::new_light_parts::(&config)?;
///
/// ...
/// }
/// ```
///
/// Will produce logs that look like this:
///
/// ```text
/// 2020-10-16 08:03:14 Substrate Node
/// 2020-10-16 08:03:14 ✌️ version 2.0.0-47f7d3f2e-x86_64-linux-gnu
/// 2020-10-16 08:03:14 ❤️ by Anonymous, 2017-2020
/// 2020-10-16 08:03:14 📋 Chain specification: Local Testnet
/// 2020-10-16 08:03:14 🏷 Node name: nice-glove-1401
/// 2020-10-16 08:03:14 👤 Role: LIGHT
/// 2020-10-16 08:03:14 💾 Database: RocksDb at /tmp/substrate95w2Dk/chains/local_testnet/db
/// 2020-10-16 08:03:14 ⛓ Native runtime: node-template-1 (node-template-1.tx1.au1)
/// 2020-10-16 08:03:14 [light] 🔨 Initializing Genesis block/state (state: 0x121d…8e36, header-hash: 0x24ef…8ff6)
/// 2020-10-16 08:03:14 [light] Loading GRANDPA authorities from genesis on what appears to be first startup.
/// 2020-10-16 08:03:15 [light] ⏱ Loaded block-time = 6000 milliseconds from genesis on first-launch
/// 2020-10-16 08:03:15 [light] Using default protocol ID "sup" because none is configured in the chain specs
/// 2020-10-16 08:03:15 [light] 🏷 Local node identity is: 12D3KooWHX4rkWT6a6N55Km7ZnvenGdShSKPkzJ3yj9DU5nqDtWR
/// 2020-10-16 08:03:15 [light] 📦 Highest known block at #0
/// 2020-10-16 08:03:15 [light] 〽️ Prometheus server started at 127.0.0.1:9615
/// 2020-10-16 08:03:15 [light] Listening for new connections on 127.0.0.1:9944.
/// ```
///
/// # Example using the actual node name
///
/// ```ignore
/// Builds a new service for a light client.
/// #[sc_cli::prefix_logs_with(config.network.node_name.as_str())]
/// pub fn new_light(config: Configuration) -> Result {
/// let (client, backend, keystore, mut task_manager, on_demand) =
/// sc_service::new_light_parts::(&config)?;
///
/// ...
/// }
/// ```
///
/// Will produce logs that look like this:
///
/// ```text
/// 2020-10-16 08:12:57 Substrate Node
/// 2020-10-16 08:12:57 ✌️ version 2.0.0-efb9b822a-x86_64-linux-gnu
/// 2020-10-16 08:12:57 ❤️ by Anonymous, 2017-2020
/// 2020-10-16 08:12:57 📋 Chain specification: Local Testnet
/// 2020-10-16 08:12:57 🏷 Node name: open-harbor-1619
/// 2020-10-16 08:12:57 👤 Role: LIGHT
/// 2020-10-16 08:12:57 💾 Database: RocksDb at /tmp/substrate9T9Mtb/chains/local_testnet/db
/// 2020-10-16 08:12:57 ⛓ Native runtime: node-template-1 (node-template-1.tx1.au1)
/// 2020-10-16 08:12:58 [open-harbor-1619] 🔨 Initializing Genesis block/state (state: 0x121d…8e36, header-hash: 0x24ef…8ff6)
/// 2020-10-16 08:12:58 [open-harbor-1619] Loading GRANDPA authorities from genesis on what appears to be first startup.
/// 2020-10-16 08:12:58 [open-harbor-1619] ⏱ Loaded block-time = 6000 milliseconds from genesis on first-launch
/// 2020-10-16 08:12:58 [open-harbor-1619] Using default protocol ID "sup" because none is configured in the chain specs
/// 2020-10-16 08:12:58 [open-harbor-1619] 🏷 Local node identity is: 12D3KooWRzmYC8QTK1Pm8Cfvid3skTS4Hn54jc4AUtje8Rqbfgtp
/// 2020-10-16 08:12:58 [open-harbor-1619] 📦 Highest known block at #0
/// 2020-10-16 08:12:58 [open-harbor-1619] 〽️ Prometheus server started at 127.0.0.1:9615
/// 2020-10-16 08:12:58 [open-harbor-1619] Listening for new connections on 127.0.0.1:9944.
/// ```
#[proc_macro_attribute]
pub fn prefix_logs_with(arg: TokenStream, item: TokenStream) -> TokenStream {
let item_fn = syn::parse_macro_input!(item as ItemFn);
if arg.is_empty() {
return Error::new(
Span::call_site(),
"missing argument: name of the node. Example: sc_cli::prefix_logs_with()",
)
.to_compile_error()
.into()
}
let name = syn::parse_macro_input!(arg as Expr);
let crate_name = match crate_name("sc-tracing") {
Ok(FoundCrate::Itself) => Ident::new("sc_tracing", Span::call_site()),
Ok(FoundCrate::Name(crate_name)) => Ident::new(&crate_name, Span::call_site()),
Err(e) => return Error::new(Span::call_site(), e).to_compile_error().into(),
};
let ItemFn { attrs, vis, sig, block } = item_fn;
(quote! {
#(#attrs)*
#vis #sig {
let span = #crate_name::tracing::info_span!(
#crate_name::logging::PREFIX_LOG_SPAN,
name = #name,
);
let _enter = span.enter();
#block
}
})
.into()
}