Remove head_proposer_shuffling_decision_root

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -3698,10 +3698,15 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         // any longer than necessary.
         let (head_slot, head_root, head_decision_root, head_random, forkchoice_update_params) = {
             let canonical_head = self.canonical_head.read();
+            let head_block_root = canonical_head.head_block_root();
+            let decision_root = canonical_head
+                .head_snapshot
+                .beacon_state
+                .proposer_shuffling_decision_root(head_block_root)?;
             (
                 canonical_head.head_slot(),
-                canonical_head.head_block_root(),
-                canonical_head.head_proposer_shuffling_decision_root,
+                head_block_root,
+                decision_root,
                 canonical_head.head_random()?,
                 canonical_head
                     .fork_choice

beacon_node/beacon_chain/src/builder.rs

@@ -732,10 +732,6 @@ where
         let canonical_head = CanonicalHead {
             fork_choice,
             fork_choice_view,
-            head_proposer_shuffling_decision_root: head_snapshot
-                .beacon_state
-                .proposer_shuffling_decision_root(head_snapshot.beacon_block_root)
-                .map_err(|e| format!("Failed to determine shuffling root: {:?}", e))?,
             head_snapshot,
         };
 

beacon_node/beacon_chain/src/canonical_head.rs

@@ -36,8 +36,6 @@ pub struct CanonicalHead<T: BeaconChainTypes> {
     pub fork_choice_view: ForkChoiceView,
     /// Provides the head block and state from the last time the head was updated.
     pub head_snapshot: BeaconSnapshot<T::EthSpec>,
-    /// This value is pre-computed to make life simpler for downstream users.
-    pub head_proposer_shuffling_decision_root: Hash256,
 }
 
 impl<T: BeaconChainTypes> CanonicalHead<T> {
@@ -53,8 +51,6 @@ impl<T: BeaconChainTypes> CanonicalHead<T> {
         let beacon_state = store
             .get_state(&beacon_state_root, Some(beacon_block.slot()))?
             .ok_or(Error::MissingBeaconState(beacon_state_root))?;
-        let head_proposer_shuffling_decision_root =
-            beacon_state.proposer_shuffling_decision_root(beacon_block_root)?;
         let head_snapshot = BeaconSnapshot {
             beacon_block_root,
             beacon_block,
@@ -65,7 +61,6 @@ impl<T: BeaconChainTypes> CanonicalHead<T> {
             fork_choice,
             fork_choice_view,
             head_snapshot,
-            head_proposer_shuffling_decision_root,
         })
     }
 
@@ -340,9 +335,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 })?;
 
             // Enshrine the new value as the head.
-            canonical_head_write_lock.head_proposer_shuffling_decision_root = new_head
-                .beacon_state
-                .proposer_shuffling_decision_root(new_head.beacon_block_root)?;
             let old_head = mem::replace(&mut canonical_head_write_lock.head_snapshot, new_head);
 
             // Clear the early attester cache in case it conflicts with `self.canonical_head`.

beacon_node/http_api/src/proposer_duties.rs

@@ -90,11 +90,13 @@ fn try_proposer_duties_from_cache<T: BeaconChainTypes>(
 ) -> Result<Option<ApiDuties>, warp::reject::Rejection> {
     let (head_slot, head_block_root, head_decision_root) = {
         let head = chain.canonical_head.read();
-        (
-            head.head_slot(),
-            head.head_block_root(),
-            head.head_proposer_shuffling_decision_root,
-        )
+        let head_block_root = head.head_block_root();
+        let decision_root = head
+            .head_snapshot
+            .beacon_state
+            .proposer_shuffling_decision_root(head_block_root)
+            .map_err(warp_utils::reject::beacon_state_error)?;
+        (head.head_slot(), head_block_root, decision_root)
     };
     let head_epoch = head_slot.epoch(T::EthSpec::slots_per_epoch());