Store execution block hash in fork choice (#2643)

* - Update the fork choice `ProtoNode` to include `is_merge_complete`
- Add database migration for the persisted fork choice

* update tests

* Small cleanup

* lints

* store execution block hash in fork choice rather than bool

consensus/proto_array/src/proto_array_fork_choice.rs

@@ -1,6 +1,6 @@
 use crate::error::Error;
 use crate::proto_array::ProtoArray;
-use crate::ssz_container::SszContainer;
+use crate::ssz_container::{LegacySszContainer, SszContainer};
 use ssz::{Decode, Encode};
 use ssz_derive::{Decode, Encode};
 use std::collections::HashMap;
@@ -29,6 +29,7 @@ pub struct Block {
     pub next_epoch_shuffling_id: AttestationShufflingId,
     pub justified_epoch: Epoch,
     pub finalized_epoch: Epoch,
+    pub execution_block_hash: Hash256,
 }
 
 /// A Vec-wrapper which will grow to match any request.
@@ -66,6 +67,7 @@ pub struct ProtoArrayForkChoice {
 }
 
 impl ProtoArrayForkChoice {
+    #[allow(clippy::too_many_arguments)]
     pub fn new(
         finalized_block_slot: Slot,
         finalized_block_state_root: Hash256,
@@ -74,6 +76,7 @@ impl ProtoArrayForkChoice {
         finalized_root: Hash256,
         current_epoch_shuffling_id: AttestationShufflingId,
         next_epoch_shuffling_id: AttestationShufflingId,
+        execution_block_hash: Hash256,
     ) -> Result<Self, String> {
         let mut proto_array = ProtoArray {
             prune_threshold: DEFAULT_PRUNE_THRESHOLD,
@@ -95,6 +98,7 @@ impl ProtoArrayForkChoice {
             next_epoch_shuffling_id,
             justified_epoch,
             finalized_epoch,
+            execution_block_hash,
         };
 
         proto_array
@@ -204,6 +208,7 @@ impl ProtoArrayForkChoice {
             next_epoch_shuffling_id: block.next_epoch_shuffling_id.clone(),
             justified_epoch: block.justified_epoch,
             finalized_epoch: block.finalized_epoch,
+            execution_block_hash: block.execution_block_hash,
         })
     }
 
@@ -252,6 +257,22 @@ impl ProtoArrayForkChoice {
             .map_err(|e| format!("Failed to decode ProtoArrayForkChoice: {:?}", e))
     }
 
+    /// Only used for SSZ deserialization of the persisted fork choice during the database migration
+    /// from schema 4 to schema 5.
+    pub fn from_bytes_legacy(bytes: &[u8]) -> Result<Self, String> {
+        LegacySszContainer::from_ssz_bytes(bytes)
+            .map(|legacy_container| {
+                let container: SszContainer = legacy_container.into();
+                container.into()
+            })
+            .map_err(|e| {
+                format!(
+                    "Failed to decode ProtoArrayForkChoice during schema migration: {:?}",
+                    e
+                )
+            })
+    }
+
     /// Returns a read-lock to core `ProtoArray` struct.
     ///
     /// Should only be used when encoding/decoding during troubleshooting.
@@ -351,6 +372,7 @@ mod test_compute_deltas {
         let unknown = Hash256::from_low_u64_be(4);
         let junk_shuffling_id =
             AttestationShufflingId::from_components(Epoch::new(0), Hash256::zero());
+        let execution_block_hash = Hash256::zero();
 
         let mut fc = ProtoArrayForkChoice::new(
             genesis_slot,
@@ -360,6 +382,7 @@ mod test_compute_deltas {
             finalized_root,
             junk_shuffling_id.clone(),
             junk_shuffling_id.clone(),
+            execution_block_hash,
         )
         .unwrap();
 
@@ -375,6 +398,7 @@ mod test_compute_deltas {
                 next_epoch_shuffling_id: junk_shuffling_id.clone(),
                 justified_epoch: genesis_epoch,
                 finalized_epoch: genesis_epoch,
+                execution_block_hash,
             })
             .unwrap();
 
@@ -390,6 +414,7 @@ mod test_compute_deltas {
                 next_epoch_shuffling_id: junk_shuffling_id,
                 justified_epoch: genesis_epoch,
                 finalized_epoch: genesis_epoch,
+                execution_block_hash,
             })
             .unwrap();