Optionally check DB invariants at runtime (#8952)

Co-Authored-By: dapplion <35266934+dapplion@users.noreply.github.com>

beacon_node/beacon_chain/src/invariants.rs

@@ -0,0 +1,56 @@
+//! Beacon chain database invariant checks.
+//!
+//! Builds the `InvariantContext` from beacon chain state and delegates all checks
+//! to `HotColdDB::check_invariants`.
+
+use crate::BeaconChain;
+use crate::beacon_chain::BeaconChainTypes;
+use store::invariants::{InvariantCheckResult, InvariantContext};
+
+impl<T: BeaconChainTypes> BeaconChain<T> {
+    /// Run all database invariant checks.
+    ///
+    /// Collects context from fork choice, state cache, custody columns, and pubkey cache,
+    /// then delegates to the store-level `check_invariants` method.
+    pub fn check_database_invariants(&self) -> Result<InvariantCheckResult, store::Error> {
+        let fork_choice_blocks = {
+            let fc = self.canonical_head.fork_choice_read_lock();
+            let proto_array = fc.proto_array().core_proto_array();
+            proto_array
+                .nodes
+                .iter()
+                .filter(|node| {
+                    // Only check blocks that are descendants of the finalized checkpoint.
+                    // Pruned non-canonical fork blocks may linger in the proto-array but
+                    // are legitimately absent from the database.
+                    fc.is_finalized_checkpoint_or_descendant(node.root)
+                })
+                .map(|node| (node.root, node.slot))
+                .collect()
+        };
+
+        let custody_context = self.data_availability_checker.custody_context();
+
+        let ctx = InvariantContext {
+            fork_choice_blocks,
+            state_cache_roots: self.store.state_cache.lock().state_roots(),
+            custody_columns: custody_context
+                .custody_columns_for_epoch(None, &self.spec)
+                .to_vec(),
+            pubkey_cache_pubkeys: {
+                let cache = self.validator_pubkey_cache.read();
+                (0..cache.len())
+                    .filter_map(|i| {
+                        cache.get(i).map(|pk| {
+                            use store::StoreItem;
+                            crate::validator_pubkey_cache::DatabasePubkey::from_pubkey(pk)
+                                .as_store_bytes()
+                        })
+                    })
+                    .collect()
+            },
+        };
+
+        self.store.check_invariants(&ctx)
+    }
+}