From 2ae6b3fad46af9d0c7a645d70e7adfd0ea2e5c4d Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Mon, 15 Feb 2021 16:49:02 -0500
Subject: [PATCH] Add a trivial benchmark of calculating routes on today's
 graph

Sadly rust upstream never really figured out the benchmark story,
and it looks like the API we use here may not be long for this
world. Luckily, we can switch to criterion with largely the same
API if that happens before upstream finishes ongoing work with the
custom test framework stuff.

Sadly, it requires fetching the current network graph, which I did
using Val's route-testing script written to test the MPP router.
---
 lightning/Cargo.toml            |  1 +
 lightning/src/lib.rs            |  3 +++
 lightning/src/routing/router.rs | 45 +++++++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+)

diff --git a/lightning/Cargo.toml b/lightning/Cargo.toml
index 016399f8..883aee4a 100644
--- a/lightning/Cargo.toml
+++ b/lightning/Cargo.toml
@@ -23,6 +23,7 @@ max_level_debug = []
 # Allow signing of local transactions that may have been revoked or will be revoked, for functional testing (e.g. justice tx handling).
 # This is unsafe to use in production because it may result in the counterparty publishing taking our funds.
 unsafe_revoked_tx_signing = []
+unstable = []
 
 [dependencies]
 bitcoin = "0.24"
diff --git a/lightning/src/lib.rs b/lightning/src/lib.rs
index e466205c..7310a49a 100644
--- a/lightning/src/lib.rs
+++ b/lightning/src/lib.rs
@@ -27,6 +27,9 @@
 #![allow(bare_trait_objects)]
 #![allow(ellipsis_inclusive_range_patterns)]
 
+#![cfg_attr(all(test, feature = "unstable"), feature(test))]
+#[cfg(all(test, feature = "unstable"))] extern crate test;
+
 extern crate bitcoin;
 #[cfg(any(test, feature = "_test_utils"))] extern crate hex;
 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))] extern crate regex;
diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 32084fad..9f1b60e0 100644
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -1279,3 +1279,48 @@ mod tests {
 		assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
 	}
 }
+
+#[cfg(all(test, feature = "unstable"))]
+mod benches {
+	use super::*;
+	use util::logger::{Logger, Record};
+
+	use std::fs::File;
+	use test::Bencher;
+
+	struct DummyLogger {}
+	impl Logger for DummyLogger {
+		fn log(&self, _record: &Record) {}
+	}
+
+	#[bench]
+	fn generate_routes(bench: &mut Bencher) {
+		let mut d = File::open("net_graph-2021-02-12.bin").expect("Please fetch https://bitcoin.ninja/ldk-net_graph-879e309c128-2020-02-12.bin and place it at lightning/net_graph-2021-02-12.bin");
+		let graph = NetworkGraph::read(&mut d).unwrap();
+
+		// First, get 100 (source, destination) pairs for which route-getting actually succeeds...
+		let mut path_endpoints = Vec::new();
+		let mut seed: usize = 0xdeadbeef;
+		'load_endpoints: for _ in 0..100 {
+			loop {
+				seed *= 0xdeadbeef;
+				let src = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+				seed *= 0xdeadbeef;
+				let dst = graph.get_nodes().keys().skip(seed % graph.get_nodes().len()).next().unwrap();
+				let amt = seed as u64 % 1_000_000;
+				if get_route(src, &graph, dst, None, &[], amt, 42, &DummyLogger{}).is_ok() {
+					path_endpoints.push((src, dst, amt));
+					continue 'load_endpoints;
+				}
+			}
+		}
+
+		// ...then benchmark finding paths between the nodes we learned.
+		let mut idx = 0;
+		bench.iter(|| {
+			let (src, dst, amt) = path_endpoints[idx % path_endpoints.len()];
+			assert!(get_route(src, &graph, dst, None, &[], amt, 42, &DummyLogger{}).is_ok());
+			idx += 1;
+		});
+	}
+}
-- 
2.30.2