Improve tracing (#5698)

* Improve tracing implementation

* Enable tracing in runtime interfaces

* Switch to `TRACE` level

substrate/primitives/runtime-interface/Cargo.toml

@@ -15,6 +15,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 [dependencies]
 sp-wasm-interface = { version = "2.0.0-dev", path = "../wasm-interface", default-features = false }
 sp-std = { version = "2.0.0-dev", default-features = false, path = "../std" }
+sp-tracing = { version = "2.0.0-dev", default-features = false, path = "../tracing" }
 sp-runtime-interface-proc-macro = { version = "2.0.0-dev", path = "proc-macro" }
 sp-externalities = { version = "0.8.0-dev", optional = true, path = "../externalities" }
 codec = { package = "parity-scale-codec", version = "1.3.0", default-features = false }
@@ -34,6 +35,7 @@ default = [ "std" ]
 std = [
 	"sp-wasm-interface/std",
 	"sp-std/std",
+	"sp-tracing/std",
 	"codec/std",
 	"sp-externalities",
 	"primitive-types/std",

substrate/primitives/runtime-interface/proc-macro/src/runtime_interface/bare_function_interface.rs

@@ -146,6 +146,7 @@ fn function_std_impl(
 	is_wasm_only: bool,
 ) -> Result<TokenStream> {
 	let function_name = create_function_ident_with_version(&method.sig.ident, version);
+	let function_name_str = function_name.to_string();
 
 	let crate_ = generate_crate_access();
 	let args = get_function_arguments(&method.sig).map(FnArg::Typed).chain(
@@ -172,6 +173,7 @@ fn function_std_impl(
 			#[cfg(feature = "std")]
 			#( #attrs )*
 			fn #function_name( #( #args, )* ) #return_value {
+				#crate_::sp_tracing::enter_span!(#function_name_str);
 				#call_to_trait
 			}
 		}

substrate/primitives/runtime-interface/proc-macro/src/runtime_interface/host_function_interface.rs

@@ -226,6 +226,7 @@ fn generate_host_function_implementation(
 						__function_context__: &mut dyn #crate_::sp_wasm_interface::FunctionContext,
 						args: &mut dyn Iterator<Item = #crate_::sp_wasm_interface::Value>,
 					) -> std::result::Result<Option<#crate_::sp_wasm_interface::Value>, String> {
+						#crate_::sp_tracing::enter_span!(#name);
 						#( #wasm_to_ffi_values )*
 						#( #ffi_to_host_values )*
 						#host_function_call

substrate/primitives/runtime-interface/src/lib.rs

@@ -109,6 +109,9 @@ extern crate self as sp_runtime_interface;
 #[cfg(feature = "std")]
 pub use sp_wasm_interface;
 
+#[doc(hidden)]
+pub use sp_tracing;
+
 #[doc(hidden)]
 pub use sp_std;
 

substrate/primitives/runtime-interface/test/Cargo.toml

@@ -19,3 +19,4 @@ sp-runtime-interface-test-wasm-deprecated = { version = "2.0.0-dev", path = "../
 sp-state-machine = { version = "0.8.0-dev", path = "../../../primitives/state-machine" }
 sp-runtime = { version = "2.0.0-dev", path = "../../runtime" }
 sp-io = { version = "2.0.0-dev", path = "../../io" }
+tracing = "0.1.13"

substrate/primitives/runtime-interface/test/src/lib.rs

@@ -27,6 +27,8 @@ use sp_runtime_interface_test_wasm_deprecated::WASM_BINARY as WASM_BINARY_DEPREC
 use sp_wasm_interface::HostFunctions as HostFunctionsT;
 use sc_executor::CallInWasm;
 
+use std::{collections::HashSet, sync::{Arc, Mutex}};
+
 type TestExternalities = sp_state_machine::TestExternalities<sp_runtime::traits::BlakeTwo256, u64>;
 
 fn call_wasm_method<HF: HostFunctionsT>(binary: &[u8], method: &str) -> TestExternalities {
@@ -150,3 +152,47 @@ fn test_versionining_with_new_host_works() {
 		"test_versionning_works",
 	);
 }
+
+#[test]
+fn test_tracing() {
+	use tracing::span::Id as SpanId;
+
+	#[derive(Clone)]
+	struct TracingSubscriber(Arc<Mutex<Inner>>);
+
+	#[derive(Default)]
+	struct Inner {
+		spans: HashSet<&'static str>,
+	}
+
+	impl tracing::subscriber::Subscriber for TracingSubscriber {
+		fn enabled(&self, _: &tracing::Metadata) -> bool { true }
+
+		fn new_span(&self, span: &tracing::span::Attributes) -> tracing::Id {
+			let mut inner = self.0.lock().unwrap();
+			let id = SpanId::from_u64((inner.spans.len() + 1) as _);
+			inner.spans.insert(span.metadata().name());
+			id
+		}
+
+		fn record(&self, _: &SpanId, _: &tracing::span::Record) {}
+
+		fn record_follows_from(&self, _: &SpanId, _: &SpanId) {}
+
+		fn event(&self, _: &tracing::Event) {}
+
+		fn enter(&self, _: &SpanId) {}
+
+		fn exit(&self, _: &SpanId) {}
+	}
+
+	let subscriber = TracingSubscriber(Default::default());
+	let _guard = tracing::subscriber::set_default(subscriber.clone());
+
+	// Call some method to generate a trace
+	call_wasm_method::<HostFunctions>(&WASM_BINARY[..], "test_return_data");
+
+	let inner = subscriber.0.lock().unwrap();
+	assert!(inner.spans.contains("return_input_version_1"));
+	assert!(inner.spans.contains("ext_test_api_return_input_version_1"));
+}