reth_beacon_consensus/engine/
invalid_headers.rs

1use alloy_eips::eip1898::BlockWithParent;
2use alloy_primitives::B256;
3use reth_metrics::{
4    metrics::{Counter, Gauge},
5    Metrics,
6};
7use schnellru::{ByLength, LruMap};
8use std::fmt::Debug;
9use tracing::warn;
10
11/// The max hit counter for invalid headers in the cache before it is forcefully evicted.
12///
13/// In other words, if a header is referenced more than this number of times, it will be evicted to
14/// allow for reprocessing.
15const INVALID_HEADER_HIT_EVICTION_THRESHOLD: u8 = 128;
16
17/// Keeps track of invalid headers.
18#[derive(Debug)]
19pub struct InvalidHeaderCache {
20    /// This maps a header hash to a reference to its invalid ancestor.
21    headers: LruMap<B256, HeaderEntry>,
22    /// Metrics for the cache.
23    metrics: InvalidHeaderCacheMetrics,
24}
25
26impl InvalidHeaderCache {
27    /// Invalid header cache constructor.
28    pub fn new(max_length: u32) -> Self {
29        Self { headers: LruMap::new(ByLength::new(max_length)), metrics: Default::default() }
30    }
31
32    fn insert_entry(&mut self, hash: B256, header: BlockWithParent) {
33        self.headers.insert(hash, HeaderEntry { header, hit_count: 0 });
34    }
35
36    /// Returns the invalid ancestor's header if it exists in the cache.
37    ///
38    /// If this is called, the hit count for the entry is incremented.
39    /// If the hit count exceeds the threshold, the entry is evicted and `None` is returned.
40    pub fn get(&mut self, hash: &B256) -> Option<BlockWithParent> {
41        {
42            let entry = self.headers.get(hash)?;
43            entry.hit_count += 1;
44            if entry.hit_count < INVALID_HEADER_HIT_EVICTION_THRESHOLD {
45                return Some(entry.header)
46            }
47        }
48        // if we get here, the entry has been hit too many times, so we evict it
49        self.headers.remove(hash);
50        self.metrics.hit_evictions.increment(1);
51        None
52    }
53
54    /// Inserts an invalid block into the cache, with a given invalid ancestor.
55    pub fn insert_with_invalid_ancestor(
56        &mut self,
57        header_hash: B256,
58        invalid_ancestor: BlockWithParent,
59    ) {
60        if self.get(&header_hash).is_none() {
61            warn!(target: "consensus::engine", hash=?header_hash, ?invalid_ancestor, "Bad block with existing invalid ancestor");
62            self.insert_entry(header_hash, invalid_ancestor);
63
64            // update metrics
65            self.metrics.known_ancestor_inserts.increment(1);
66            self.metrics.count.set(self.headers.len() as f64);
67        }
68    }
69
70    /// Inserts an invalid ancestor into the map.
71    pub fn insert(&mut self, invalid_ancestor: BlockWithParent) {
72        if self.get(&invalid_ancestor.block.hash).is_none() {
73            warn!(target: "consensus::engine", ?invalid_ancestor, "Bad block with hash");
74            self.insert_entry(invalid_ancestor.block.hash, invalid_ancestor);
75
76            // update metrics
77            self.metrics.unique_inserts.increment(1);
78            self.metrics.count.set(self.headers.len() as f64);
79        }
80    }
81}
82
83struct HeaderEntry {
84    /// Keeps track how many times this header has been hit.
85    hit_count: u8,
86    /// The actual header entry
87    header: BlockWithParent,
88}
89
90/// Metrics for the invalid headers cache.
91#[derive(Metrics)]
92#[metrics(scope = "consensus.engine.beacon.invalid_headers")]
93struct InvalidHeaderCacheMetrics {
94    /// The total number of invalid headers in the cache.
95    count: Gauge,
96    /// The number of inserts with a known ancestor.
97    known_ancestor_inserts: Counter,
98    /// The number of unique invalid header inserts (i.e. without a known ancestor).
99    unique_inserts: Counter,
100    /// The number of times a header was evicted from the cache because it was hit too many times.
101    hit_evictions: Counter,
102}
103
104#[cfg(test)]
105mod tests {
106    use super::*;
107    use alloy_consensus::Header;
108    use reth_primitives::SealedHeader;
109
110    #[test]
111    fn test_hit_eviction() {
112        let mut cache = InvalidHeaderCache::new(10);
113        let header = Header::default();
114        let header = SealedHeader::seal(header);
115        cache.insert(header.block_with_parent());
116        assert_eq!(cache.headers.get(&header.hash()).unwrap().hit_count, 0);
117
118        for hit in 1..INVALID_HEADER_HIT_EVICTION_THRESHOLD {
119            assert!(cache.get(&header.hash()).is_some());
120            assert_eq!(cache.headers.get(&header.hash()).unwrap().hit_count, hit);
121        }
122
123        assert!(cache.get(&header.hash()).is_none());
124    }
125}
reth_beacon_consensus/engine/invalid_headers.rs

reth_beacon_consensus/engine/
invalid_headers.rs
