From b0f57bf97b044f880178dfcd80cff0080a83b0fe Mon Sep 17 00:00:00 2001
From: Dan Cline <6798349+Rjected@users.noreply.github.com>
Date: Thu, 22 Jun 2023 09:36:43 -0400
Subject: [PATCH] feat: add invalid headers metrics (#3314)

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>
---
 .../beacon/src/engine/invalid_headers.rs      | 70 +++++++++++++++++++
 crates/consensus/beacon/src/engine/mod.rs     | 36 +---------
 2 files changed, 73 insertions(+), 33 deletions(-)
 create mode 100644 crates/consensus/beacon/src/engine/invalid_headers.rs

diff --git a/crates/consensus/beacon/src/engine/invalid_headers.rs b/crates/consensus/beacon/src/engine/invalid_headers.rs
new file mode 100644
index 0000000000..129cfefa6f
--- /dev/null
+++ b/crates/consensus/beacon/src/engine/invalid_headers.rs
@@ -0,0 +1,70 @@
+use std::sync::Arc;
+
+use reth_metrics::{
+    metrics::{self, Counter, Gauge},
+    Metrics,
+};
+use reth_primitives::{Header, SealedHeader, H256};
+use schnellru::{ByLength, LruMap};
+use tracing::warn;
+
+/// Metrics for the invalid headers cache.
+#[derive(Metrics)]
+#[metrics(scope = "invalid_header_cache")]
+struct InvalidHeaderCacheMetrics {
+    /// The total number of invalid headers in the cache.
+    invalid_headers: Gauge,
+    /// The number of inserts with a known ancestor.
+    known_ancestor_inserts: Counter,
+    /// The number of unique invalid header inserts (i.e. without a known ancestor).
+    unique_inserts: Counter,
+}
+
+/// Keeps track of invalid headers.
+pub(crate) struct InvalidHeaderCache {
+    /// This maps a header hash to a reference to its invalid ancestor.
+    headers: LruMap<H256, Arc<Header>>,
+    /// Metrics for the cache.
+    metrics: InvalidHeaderCacheMetrics,
+}
+
+impl InvalidHeaderCache {
+    pub(crate) fn new(max_length: u32) -> Self {
+        Self { headers: LruMap::new(ByLength::new(max_length)), metrics: Default::default() }
+    }
+
+    /// Returns the invalid ancestor's header if it exists in the cache.
+    pub(crate) fn get(&mut self, hash: &H256) -> Option<&mut Arc<Header>> {
+        self.headers.get(hash)
+    }
+
+    /// Inserts an invalid block into the cache, with a given invalid ancestor.
+    pub(crate) fn insert_with_invalid_ancestor(
+        &mut self,
+        header_hash: H256,
+        invalid_ancestor: Arc<Header>,
+    ) {
+        if self.headers.get(&header_hash).is_none() {
+            warn!(target: "consensus::engine", hash=?header_hash, ?invalid_ancestor, "Bad block with existing invalid ancestor");
+            self.headers.insert(header_hash, invalid_ancestor);
+
+            // update metrics
+            self.metrics.known_ancestor_inserts.increment(1);
+            self.metrics.invalid_headers.set(self.headers.len() as f64);
+        }
+    }
+
+    /// Inserts an invalid ancestor into the map.
+    pub(crate) fn insert(&mut self, invalid_ancestor: SealedHeader) {
+        if self.headers.get(&invalid_ancestor.hash).is_none() {
+            let hash = invalid_ancestor.hash;
+            let header = invalid_ancestor.unseal();
+            warn!(target: "consensus::engine", ?hash, ?header, "Bad block with hash");
+            self.headers.insert(hash, Arc::new(header));
+
+            // update metrics
+            self.metrics.unique_inserts.increment(1);
+            self.metrics.invalid_headers.set(self.headers.len() as f64);
+        }
+    }
+}
diff --git a/crates/consensus/beacon/src/engine/mod.rs b/crates/consensus/beacon/src/engine/mod.rs
index 7f1bc1749d..ceb022a4a9 100644
--- a/crates/consensus/beacon/src/engine/mod.rs
+++ b/crates/consensus/beacon/src/engine/mod.rs
@@ -18,7 +18,7 @@ use reth_interfaces::{
 use reth_payload_builder::{PayloadBuilderAttributes, PayloadBuilderHandle};
 use reth_primitives::{
     listener::EventListeners, stage::StageId, BlockNumHash, BlockNumber, Head, Header, SealedBlock,
-    SealedHeader, H256, U256,
+    H256, U256,
 };
 use reth_provider::{
     BlockProvider, BlockSource, CanonChainTracker, ProviderError, StageCheckpointReader,
@@ -29,7 +29,6 @@ use reth_rpc_types::engine::{
 };
 use reth_stages::{ControlFlow, Pipeline};
 use reth_tasks::TaskSpawner;
-use schnellru::{ByLength, LruMap};
 use std::{
     pin::Pin,
     sync::Arc,
@@ -52,6 +51,8 @@ pub use error::{
     BeaconOnNewPayloadError,
 };
 
+mod invalid_headers;
+use invalid_headers::InvalidHeaderCache;
 mod metrics;
 
 mod event;
@@ -1350,37 +1351,6 @@ where
     }
 }
 
-/// Keeps track of invalid headers.
-struct InvalidHeaderCache {
-    /// This maps a header hash to a reference to its invalid ancestor.
-    headers: LruMap<H256, Arc<Header>>,
-}
-
-impl InvalidHeaderCache {
-    fn new(max_length: u32) -> Self {
-        Self { headers: LruMap::new(ByLength::new(max_length)) }
-    }
-
-    /// Returns the invalid ancestor's header if it exists in the cache.
-    fn get(&mut self, hash: &H256) -> Option<&mut Arc<Header>> {
-        self.headers.get(hash)
-    }
-
-    /// Inserts an invalid block into the cache, with a given invalid ancestor.
-    fn insert_with_invalid_ancestor(&mut self, header_hash: H256, invalid_ancestor: Arc<Header>) {
-        warn!(target: "consensus::engine", hash=?header_hash, ?invalid_ancestor, "Bad block with existing invalid ancestor");
-        self.headers.insert(header_hash, invalid_ancestor);
-    }
-
-    /// Inserts an invalid ancestor into the map.
-    fn insert(&mut self, invalid_ancestor: SealedHeader) {
-        let hash = invalid_ancestor.hash;
-        let header = invalid_ancestor.unseal();
-        warn!(target: "consensus::engine", ?hash, ?header, "Bad block with hash");
-        self.headers.insert(hash, Arc::new(header));
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;