implement scoring mechanisms and plumbing

consensus/proto_array/src/ssz_container.rs

@@ -1,7 +1,7 @@
 use crate::proto_array::ProposerBoost;
 use crate::{
     Error, JustifiedBalances,
-    proto_array::{ProtoArray, ProtoNodeV17},
+    proto_array::{ProtoArray, ProtoNode, ProtoNodeV17},
     proto_array_fork_choice::{ElasticList, ProtoArrayForkChoice, VoteTracker},
 };
 use ssz::{Encode, four_byte_option_impl};
@@ -14,14 +14,15 @@ use types::{Checkpoint, Hash256};
 // selector.
 four_byte_option_impl!(four_byte_option_checkpoint, Checkpoint);
 
-pub type SszContainer = SszContainerV28;
+pub type SszContainer = SszContainerV29;
 
+// Legacy containers (V17/V28) for backward compatibility with older schema versions.
 #[superstruct(
     variants(V17, V28),
     variant_attributes(derive(Encode, Decode, Clone)),
     no_enum
 )]
-pub struct SszContainer {
+pub struct SszContainerLegacy {
     pub votes: Vec<VoteTracker>,
     #[superstruct(only(V17))]
     pub balances: Vec<u64>,
@@ -35,7 +36,21 @@ pub struct SszContainer {
     pub previous_proposer_boost: ProposerBoost,
 }
 
-impl SszContainer {
+/// Current container version. Uses union-encoded `ProtoNode` to support mixed V17/V29 nodes.
+#[derive(Encode, Decode, Clone)]
+pub struct SszContainerV29 {
+    pub votes: Vec<VoteTracker>,
+    pub prune_threshold: usize,
+    // Deprecated, remove in a future schema migration
+    justified_checkpoint: Checkpoint,
+    // Deprecated, remove in a future schema migration
+    finalized_checkpoint: Checkpoint,
+    pub nodes: Vec<ProtoNode>,
+    pub indices: Vec<(Hash256, usize)>,
+    pub previous_proposer_boost: ProposerBoost,
+}
+
+impl SszContainerV29 {
     pub fn from_proto_array(
         from: &ProtoArrayForkChoice,
         justified_checkpoint: Checkpoint,
@@ -55,10 +70,10 @@ impl SszContainer {
     }
 }
 
-impl TryFrom<(SszContainer, JustifiedBalances)> for ProtoArrayForkChoice {
+impl TryFrom<(SszContainerV29, JustifiedBalances)> for ProtoArrayForkChoice {
     type Error = Error;
 
-    fn try_from((from, balances): (SszContainer, JustifiedBalances)) -> Result<Self, Error> {
+    fn try_from((from, balances): (SszContainerV29, JustifiedBalances)) -> Result<Self, Error> {
         let proto_array = ProtoArray {
             prune_threshold: from.prune_threshold,
             nodes: from.nodes,
@@ -74,9 +89,9 @@ impl TryFrom<(SszContainer, JustifiedBalances)> for ProtoArrayForkChoice {
     }
 }
 
-// Convert V17 to V28 by dropping balances.
-impl From<SszContainerV17> for SszContainerV28 {
-    fn from(v17: SszContainerV17) -> Self {
+// Convert legacy V17 to V28 by dropping balances.
+impl From<SszContainerLegacyV17> for SszContainerLegacyV28 {
+    fn from(v17: SszContainerLegacyV17) -> Self {
         Self {
             votes: v17.votes,
             prune_threshold: v17.prune_threshold,
@@ -89,9 +104,9 @@ impl From<SszContainerV17> for SszContainerV28 {
     }
 }
 
-// Convert V28 to V17 by re-adding balances.
-impl From<(SszContainerV28, JustifiedBalances)> for SszContainerV17 {
-    fn from((v28, balances): (SszContainerV28, JustifiedBalances)) -> Self {
+// Convert legacy V28 to V17 by re-adding balances.
+impl From<(SszContainerLegacyV28, JustifiedBalances)> for SszContainerLegacyV17 {
+    fn from((v28, balances): (SszContainerLegacyV28, JustifiedBalances)) -> Self {
         Self {
             votes: v28.votes,
             balances: balances.effective_balances.clone(),
@@ -104,3 +119,40 @@ impl From<(SszContainerV28, JustifiedBalances)> for SszContainerV17 {
         }
     }
 }
+
+// Convert legacy V28 to current V29.
+impl From<SszContainerLegacyV28> for SszContainerV29 {
+    fn from(v28: SszContainerLegacyV28) -> Self {
+        Self {
+            votes: v28.votes,
+            prune_threshold: v28.prune_threshold,
+            justified_checkpoint: v28.justified_checkpoint,
+            finalized_checkpoint: v28.finalized_checkpoint,
+            nodes: v28.nodes.into_iter().map(ProtoNode::V17).collect(),
+            indices: v28.indices,
+            previous_proposer_boost: v28.previous_proposer_boost,
+        }
+    }
+}
+
+// Downgrade current V29 to legacy V28 (lossy: V29 nodes lose payload-specific fields).
+impl From<SszContainerV29> for SszContainerLegacyV28 {
+    fn from(v29: SszContainerV29) -> Self {
+        Self {
+            votes: v29.votes,
+            prune_threshold: v29.prune_threshold,
+            justified_checkpoint: v29.justified_checkpoint,
+            finalized_checkpoint: v29.finalized_checkpoint,
+            nodes: v29
+                .nodes
+                .into_iter()
+                .filter_map(|node| match node {
+                    ProtoNode::V17(v17) => Some(v17),
+                    ProtoNode::V29(_) => None,
+                })
+                .collect(),
+            indices: v29.indices,
+            previous_proposer_boost: v29.previous_proposer_boost,
+        }
+    }
+}