resolve merge conflict and migrate il service to new pardigmn

consensus/proto_array/src/proto_array.rs

@@ -6,11 +6,11 @@ use ssz::Encode;
 use ssz_derive::{Decode, Encode};
 use std::collections::{HashMap, HashSet};
 use superstruct::superstruct;
+use tracing::info;
 use types::{
     AttestationShufflingId, ChainSpec, Checkpoint, Epoch, EthSpec, ExecutionBlockHash,
     FixedBytesExtended, Hash256, Slot,
 };
-use tracing::info;
 
 // Define a "legacy" implementation of `Option<usize>` which uses four bytes for encoding the union
 // selector.
@@ -1075,6 +1075,21 @@ impl ProtoArray {
             })
             .map(|node| node.root)
     }
+
+    /// Returns all nodes that have zero children and are descended from the finalized checkpoint.
+    ///
+    /// For informational purposes like the beacon HTTP API, we use this as the list of known heads,
+    /// even though some of them might not be viable. We do this to maintain consistency between the
+    /// definition of "head" used by pruning (which does not consider viability) and fork choice.
+    pub fn heads_descended_from_finalization<E: EthSpec>(&self) -> Vec<&ProtoNode> {
+        self.nodes
+            .iter()
+            .filter(|node| {
+                node.best_child.is_none()
+                    && self.is_finalized_checkpoint_or_descendant::<E>(node.root)
+            })
+            .collect()
+    }
 }
 
 /// A helper method to calculate the proposer boost based on the given `justified_balances`.

consensus/proto_array/src/proto_array_fork_choice.rs

@@ -858,10 +858,18 @@ impl ProtoArrayForkChoice {
     }
 
     /// See `ProtoArray::iter_nodes`
-    pub fn iter_nodes<'a>(&'a self, block_root: &Hash256) -> Iter<'a> {
+    pub fn iter_nodes(&self, block_root: &Hash256) -> Iter {
         self.proto_array.iter_nodes(block_root)
     }
 
+    /// See `ProtoArray::iter_block_roots`
+    pub fn iter_block_roots(
+        &self,
+        block_root: &Hash256,
+    ) -> impl Iterator<Item = (Hash256, Slot)> + use<'_> {
+        self.proto_array.iter_block_roots(block_root)
+    }
+
     pub fn as_bytes(&self) -> Vec<u8> {
         SszContainer::from(self).as_ssz_bytes()
     }
@@ -887,6 +895,11 @@ impl ProtoArrayForkChoice {
     pub fn core_proto_array_mut(&mut self) -> &mut ProtoArray {
         &mut self.proto_array
     }
+
+    /// Returns all nodes that have zero children and are descended from the finalized checkpoint.
+    pub fn heads_descended_from_finalization<E: EthSpec>(&self) -> Vec<&ProtoNode> {
+        self.proto_array.heads_descended_from_finalization::<E>()
+    }
 }
 
 /// Returns a list of `deltas`, where there is one delta for each of the indices in