refactor: split headers from blocks in storage

bin/ethlambda/src/main.rs

@@ -101,7 +101,7 @@ async fn main() {
 
     let genesis_state = State::from_genesis(genesis_config.genesis_time, validators);
     let backend = Arc::new(RocksDBBackend::open("./data").expect("Failed to open RocksDB"));
-    let store = Store::from_genesis(backend, genesis_state);
+    let store = Store::from_anchor_state(backend, genesis_state);
 
     let (p2p_tx, p2p_rx) = tokio::sync::mpsc::unbounded_channel();
     let blockchain = BlockChain::spawn(store.clone(), p2p_tx, validator_keys);

crates/blockchain/src/lib.rs

@@ -279,8 +279,8 @@ impl BlockChainServer {
         let parent_root = signed_block.message.block.parent_root;
         let proposer = signed_block.message.block.proposer_index;
 
-        // Check if parent block exists before attempting to process
-        if !self.store.contains_block(&parent_root) {
+        // Check if parent state exists before attempting to process
+        if !self.store.has_state(&parent_root) {
             info!(%slot, %parent_root, %block_root, "Block parent missing, storing as pending");
 
             // Store block for later processing

crates/blockchain/src/store.rs

@@ -46,8 +46,14 @@ fn update_head(store: &mut Store) {
     store.update_checkpoints(ForkCheckpoints::head_only(new_head));
 
     if old_head != new_head {
-        let old_slot = store.get_block(&old_head).map(|b| b.slot).unwrap_or(0);
-        let new_slot = store.get_block(&new_head).map(|b| b.slot).unwrap_or(0);
+        let old_slot = store
+            .get_block_header(&old_head)
+            .map(|h| h.slot)
+            .unwrap_or(0);
+        let new_slot = store
+            .get_block_header(&new_head)
+            .map(|h| h.slot)
+            .unwrap_or(0);
         let justified_slot = store.latest_justified().slot;
         let finalized_slot = store.latest_finalized().slot;
         info!(
@@ -91,33 +97,33 @@ fn validate_attestation(store: &Store, attestation: &Attestation) -> Result<(),
     let data = &attestation.data;
 
     // Availability Check - We cannot count a vote if we haven't seen the blocks involved.
-    let source_block = store
-        .get_block(&data.source.root)
+    let source_header = store
+        .get_block_header(&data.source.root)
         .ok_or(StoreError::UnknownSourceBlock(data.source.root))?;
-    let target_block = store
-        .get_block(&data.target.root)
+    let target_header = store
+        .get_block_header(&data.target.root)
         .ok_or(StoreError::UnknownTargetBlock(data.target.root))?;
 
-    if !store.contains_block(&data.head.root) {
-        return Err(StoreError::UnknownHeadBlock(data.head.root));
-    }
+    let _ = store
+        .get_block_header(&data.head.root)
+        .ok_or(StoreError::UnknownHeadBlock(data.head.root))?;
 
     // Topology Check - Source must be older than Target.
     if data.source.slot > data.target.slot {
         return Err(StoreError::SourceExceedsTarget);
     }
 
     // Consistency Check - Validate checkpoint slots match block slots.
-    if source_block.slot != data.source.slot {
+    if source_header.slot != data.source.slot {
         return Err(StoreError::SourceSlotMismatch {
             checkpoint_slot: data.source.slot,
-            block_slot: source_block.slot,
+            block_slot: source_header.slot,
         });
     }
-    if target_block.slot != data.target.slot {
+    if target_header.slot != data.target.slot {
         return Err(StoreError::TargetSlotMismatch {
             checkpoint_slot: data.target.slot,
-            block_slot: target_block.slot,
+            block_slot: target_header.slot,
         });
     }
 
@@ -325,7 +331,7 @@ pub fn on_block(
     let slot = block.slot;
 
     // Skip duplicate blocks (idempotent operation)
-    if store.contains_block(&block_root) {
+    if store.has_state(&block_root) {
         return Ok(());
     }
 
@@ -441,12 +447,12 @@ pub fn on_block(
 pub fn get_attestation_target(store: &Store) -> Checkpoint {
     // Start from current head
     let mut target_block_root = store.head();
-    let mut target_block = store
-        .get_block(&target_block_root)
+    let mut target_header = store
+        .get_block_header(&target_block_root)
         .expect("head block exists");
 
     let safe_target_block_slot = store
-        .get_block(&store.safe_target())
+        .get_block_header(&store.safe_target())
         .expect("safe target exists")
         .slot;
 
@@ -455,10 +461,10 @@ pub fn get_attestation_target(store: &Store) -> Checkpoint {
     // This ensures the target doesn't advance too far ahead of safe target,
     // providing a balance between liveness and safety.
     for _ in 0..JUSTIFICATION_LOOKBACK_SLOTS {
-        if target_block.slot > safe_target_block_slot {
-            target_block_root = target_block.parent_root;
-            target_block = store
-                .get_block(&target_block_root)
+        if target_header.slot > safe_target_block_slot {
+            target_block_root = target_header.parent_root;
+            target_header = store
+                .get_block_header(&target_block_root)
                 .expect("parent block exists");
         } else {
             break;
@@ -471,12 +477,12 @@ pub fn get_attestation_target(store: &Store) -> Checkpoint {
     //
     // Walk back until we find a slot that satisfies justifiability rules
     // relative to the latest finalized checkpoint.
-    while target_block.slot > finalized_slot
-        && !slot_is_justifiable_after(target_block.slot, finalized_slot)
+    while target_header.slot > finalized_slot
+        && !slot_is_justifiable_after(target_header.slot, finalized_slot)
     {
-        target_block_root = target_block.parent_root;
-        target_block = store
-            .get_block(&target_block_root)
+        target_block_root = target_header.parent_root;
+        target_header = store
+            .get_block_header(&target_block_root)
             .expect("parent block exists");
     }
     // Ensure target is at or after the source (latest_justified) to maintain
@@ -486,9 +492,9 @@ pub fn get_attestation_target(store: &Store) -> Checkpoint {
     //
     // See https://github.com/blockblaz/zeam/blob/697c293879e922942965cdb1da3c6044187ae00e/pkgs/node/src/forkchoice.zig#L654-L659
     let latest_justified = store.latest_justified();
-    if target_block.slot < latest_justified.slot {
+    if target_header.slot < latest_justified.slot {
         warn!(
-            target_slot = target_block.slot,
+            target_slot = target_header.slot,
             justified_slot = latest_justified.slot,
             "Attestation target walked behind justified source, clamping to justified"
         );
@@ -497,7 +503,7 @@ pub fn get_attestation_target(store: &Store) -> Checkpoint {
 
     Checkpoint {
         root: target_block_root,
-        slot: target_block.slot,
+        slot: target_header.slot,
     }
 }
 
@@ -507,7 +513,7 @@ pub fn produce_attestation_data(store: &Store, slot: u64) -> AttestationData {
     let head_checkpoint = Checkpoint {
         root: store.head(),
         slot: store
-            .get_block(&store.head())
+            .get_block_header(&store.head())
             .expect("head block exists")
             .slot,
     };
@@ -1075,16 +1081,16 @@ fn is_reorg(old_head: H256, new_head: H256, store: &Store) -> bool {
         return false;
     }
 
-    let Some(old_head_block) = store.get_block(&old_head) else {
+    let Some(old_head_header) = store.get_block_header(&old_head) else {
         return false;
     };
 
-    let Some(new_head_block) = store.get_block(&new_head) else {
+    let Some(new_head_header) = store.get_block_header(&new_head) else {
         return false;
     };
 
-    let old_slot = old_head_block.slot;
-    let new_slot = new_head_block.slot;
+    let old_slot = old_head_header.slot;
+    let new_slot = new_head_header.slot;
 
     // Determine which head has the higher slot and walk back from it
     let (mut current_root, target_slot, target_root) = if new_slot >= old_slot {
@@ -1094,12 +1100,12 @@ fn is_reorg(old_head: H256, new_head: H256, store: &Store) -> bool {
     };
 
     // Walk back through the chain until we reach the target slot
-    while let Some(current_block) = store.get_block(&current_root) {
-        if current_block.slot <= target_slot {
+    while let Some(current_header) = store.get_block_header(&current_root) {
+        if current_header.slot <= target_slot {
             // We've reached the target slot - check if we're at the target block
             return current_root != target_root;
         }
-        current_root = current_block.parent_root;
+        current_root = current_header.parent_root;
     }
 
     // Couldn't walk back far enough (missing blocks in chain)

crates/blockchain/tests/forkchoice_spectests.rs

@@ -187,13 +187,13 @@ fn validate_checks(
     // Validate headSlot
     if let Some(expected_slot) = checks.head_slot {
         let head_root = st.head();
-        let head_block = st
-            .get_block(&head_root)
+        let head_header = st
+            .get_block_header(&head_root)
             .ok_or_else(|| format!("Step {}: head block not found", step_idx))?;
-        if head_block.slot != expected_slot {
+        if head_header.slot != expected_slot {
             return Err(format!(
                 "Step {}: headSlot mismatch: expected {}, got {}",
-                step_idx, expected_slot, head_block.slot
+                step_idx, expected_slot, head_header.slot
             )
             .into());
         }

crates/common/types/src/block.rs

@@ -176,7 +176,7 @@ impl BlockSignaturesWithAttestation {
 ///
 /// Headers are smaller than full blocks. They're useful for tracking the chain
 /// without storing everything.
-#[derive(Debug, Clone, Serialize, Encode, Decode, TreeHash)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Encode, Decode, TreeHash)]
 pub struct BlockHeader {
     /// The slot in which the block was proposed
     pub slot: u64,
@@ -205,6 +205,38 @@ pub struct Block {
     pub body: BlockBody,
 }
 
+impl Block {
+    /// Extract the block header, computing the body root.
+    pub fn header(&self) -> BlockHeader {
+        BlockHeader {
+            slot: self.slot,
+            proposer_index: self.proposer_index,
+            parent_root: self.parent_root,
+            state_root: self.state_root,
+            body_root: self.body.tree_hash_root(),
+        }
+    }
+
+    /// Reconstruct a block from header and body.
+    ///
+    /// The caller should ensure that `header.body_root` matches `body.tree_hash_root()`.
+    /// This is verified with a debug assertion but not in release builds.
+    pub fn from_header_and_body(header: BlockHeader, body: BlockBody) -> Self {
+        debug_assert_eq!(
+            header.body_root,
+            body.tree_hash_root(),
+            "body root mismatch"
+        );
+        Self {
+            slot: header.slot,
+            proposer_index: header.proposer_index,
+            parent_root: header.parent_root,
+            state_root: header.state_root,
+            body,
+        }
+    }
+}
+
 /// The body of a block, containing payload data.
 ///
 /// Currently, the main operation is voting. Validators submit attestations which are

crates/net/p2p/src/req_resp/handlers.rs

@@ -169,7 +169,10 @@ async fn handle_blocks_by_root_response(
 pub fn build_status(store: &Store) -> Status {
     let finalized = store.latest_finalized();
     let head_root = store.head();
-    let head_slot = store.get_block(&head_root).expect("head block exists").slot;
+    let head_slot = store
+        .get_block_header(&head_root)
+        .expect("head block exists")
+        .slot;
     Status {
         finalized,
         head: ethlambda_types::state::Checkpoint {

crates/net/rpc/src/lib.rs

@@ -118,7 +118,7 @@ mod tests {
     async fn test_get_latest_justified_checkpoint() {
         let state = create_test_state();
         let backend = Arc::new(InMemoryBackend::new());
-        let store = Store::from_genesis(backend, state);
+        let store = Store::from_anchor_state(backend, state);
 
         let app = build_api_router(store.clone());
 
@@ -154,7 +154,7 @@ mod tests {
 
         let state = create_test_state();
         let backend = Arc::new(InMemoryBackend::new());
-        let store = Store::from_genesis(backend, state);
+        let store = Store::from_anchor_state(backend, state);
 
         // Get the expected state from the store
         let finalized = store.latest_finalized();

crates/storage/src/api/tables.rs

@@ -1,8 +1,10 @@
 /// Tables in the storage layer.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum Table {
-    /// Block storage: H256 -> Block
-    Blocks,
+    /// Block header storage: H256 -> BlockHeader
+    BlockHeaders,
+    /// Block body storage: H256 -> BlockBody
+    BlockBodies,
     /// Block signatures storage: H256 -> BlockSignaturesWithAttestation
     ///
     /// Stored separately from blocks because the genesis block has no signatures.
@@ -29,8 +31,9 @@ pub enum Table {
 }
 
 /// All table variants.
-pub const ALL_TABLES: [Table; 9] = [
-    Table::Blocks,
+pub const ALL_TABLES: [Table; 10] = [
+    Table::BlockHeaders,
+    Table::BlockBodies,
     Table::BlockSignatures,
     Table::States,
     Table::LatestKnownAttestations,

crates/storage/src/backend/rocksdb.rs

@@ -12,7 +12,8 @@ use std::sync::Arc;
 /// Returns the column family name for a table.
 fn cf_name(table: Table) -> &'static str {
     match table {
-        Table::Blocks => "blocks",
+        Table::BlockHeaders => "block_headers",
+        Table::BlockBodies => "block_bodies",
         Table::BlockSignatures => "block_signatures",
         Table::States => "states",
         Table::LatestKnownAttestations => "latest_known_attestations",
@@ -166,7 +167,10 @@ mod tests {
             let backend = RocksDBBackend::open(dir.path()).unwrap();
             let mut batch = backend.begin_write().unwrap();
             batch
-                .put_batch(Table::Blocks, vec![(b"key1".to_vec(), b"value1".to_vec())])
+                .put_batch(
+                    Table::BlockHeaders,
+                    vec![(b"key1".to_vec(), b"value1".to_vec())],
+                )
                 .unwrap();
             batch.commit().unwrap();
         }
@@ -175,7 +179,7 @@ mod tests {
         {
             let backend = RocksDBBackend::open(dir.path()).unwrap();
             let view = backend.begin_read().unwrap();
-            let value = view.get(Table::Blocks, b"key1").unwrap();
+            let value = view.get(Table::BlockHeaders, b"key1").unwrap();
             assert_eq!(value, Some(b"value1".to_vec()));
         }
     }