Add sync lookup custody request state (#6257)

* Add sync lookup custody request state

* Review PR

* clippy

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into peerdas-network-lookup

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -6852,6 +6852,24 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         self.data_availability_checker.data_availability_boundary()
     }
 
+    /// Returns true if epoch is within the data availability boundary
+    pub fn da_check_required_for_epoch(&self, epoch: Epoch) -> bool {
+        self.data_availability_checker
+            .da_check_required_for_epoch(epoch)
+    }
+
+    /// Returns true if we should fetch blobs for this block
+    pub fn should_fetch_blobs(&self, block_epoch: Epoch) -> bool {
+        self.da_check_required_for_epoch(block_epoch)
+            && !self.spec.is_peer_das_enabled_for_epoch(block_epoch)
+    }
+
+    /// Returns true if we should fetch custody columns for this block
+    pub fn should_fetch_custody_columns(&self, block_epoch: Epoch) -> bool {
+        self.da_check_required_for_epoch(block_epoch)
+            && self.spec.is_peer_das_enabled_for_epoch(block_epoch)
+    }
+
     pub fn logger(&self) -> &Logger {
         &self.log
     }

beacon_node/beacon_chain/src/data_availability_checker.rs

@@ -156,6 +156,15 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
             })
     }
 
+    /// Return the set of imported custody column indexes for `block_root`. Returns None if there is
+    /// no block component for `block_root`.
+    pub fn imported_custody_column_indexes(&self, block_root: &Hash256) -> Option<Vec<u64>> {
+        self.availability_cache
+            .peek_pending_components(block_root, |components| {
+                components.map(|components| components.get_cached_data_columns_indices())
+            })
+    }
+
     /// Get a blob from the availability cache.
     pub fn get_blob(
         &self,

beacon_node/beacon_chain/src/data_availability_checker/overflow_lru_cache.rs

@@ -13,7 +13,7 @@ use ssz_types::{FixedVector, VariableList};
 use std::num::NonZeroUsize;
 use std::sync::Arc;
 use types::blob_sidecar::BlobIdentifier;
-use types::{BlobSidecar, ChainSpec, Epoch, EthSpec, Hash256, SignedBeaconBlock};
+use types::{BlobSidecar, ChainSpec, ColumnIndex, Epoch, EthSpec, Hash256, SignedBeaconBlock};
 
 /// This represents the components of a partially available block
 ///
@@ -108,6 +108,14 @@ impl<E: EthSpec> PendingComponents<E> {
         self.verified_data_columns.len()
     }
 
+    /// Returns the indices of cached custody columns
+    pub fn get_cached_data_columns_indices(&self) -> Vec<ColumnIndex> {
+        self.verified_data_columns
+            .iter()
+            .map(|d| d.index())
+            .collect()
+    }
+
     /// Inserts a block into the cache.
     pub fn insert_block(&mut self, block: DietAvailabilityPendingExecutedBlock<E>) {
         *self.get_cached_block_mut() = Some(block)