blockstore: add DoubleMerkleMeta column

Author: AshwinSekar

ledger/src/blockstore.rs

@@ -275,6 +275,7 @@ pub struct Blockstore {
     alt_data_shred_cf: LedgerColumn<cf::AlternateShredData>,
     alt_merkle_root_meta_cf: LedgerColumn<cf::AlternateMerkleRootMeta>,
     parent_meta_cf: LedgerColumn<cf::ParentMeta>,
+    double_merkle_meta_cf: LedgerColumn<cf::DoubleMerkleMeta>,
 
     highest_primary_index_slot: RwLock<Option<Slot>>,
     max_root: AtomicU64,
@@ -458,6 +459,7 @@ impl Blockstore {
         let alt_data_shred_cf = db.column();
         let alt_merkle_root_meta_cf = db.column();
         let parent_meta_cf = db.column();
+        let double_merkle_meta_cf = db.column();
 
         // Get max root or 0 if it doesn't exist
         let max_root = roots_cf
@@ -499,6 +501,7 @@ impl Blockstore {
             alt_data_shred_cf,
             alt_merkle_root_meta_cf,
             parent_meta_cf,
+            double_merkle_meta_cf,
 
             highest_primary_index_slot: RwLock::<Option<Slot>>::default(),
             new_shreds_signals: Mutex::default(),

ledger/src/blockstore/blockstore_purge.rs

@@ -332,6 +332,10 @@ impl Blockstore {
             & self
                 .parent_meta_cf
                 .delete_range_in_batch(write_batch, from_slot, to_slot)
+                .is_ok()
+            & self
+                .double_merkle_meta_cf
+                .delete_range_in_batch(write_batch, from_slot, to_slot)
                 .is_ok();
 
         match purge_type {
@@ -437,6 +441,14 @@ impl Blockstore {
                 .alt_merkle_root_meta_cf
                 .delete_file_in_range(from_slot, to_slot)
                 .is_ok()
+            & self
+                .parent_meta_cf
+                .delete_file_in_range(from_slot, to_slot)
+                .is_ok()
+            & self
+                .double_merkle_meta_cf
+                .delete_file_in_range(from_slot, to_slot)
+                .is_ok()
     }
 
     /// Returns true if the special columns, TransactionStatus and

ledger/src/blockstore/column.rs

@@ -288,6 +288,16 @@ pub mod columns {
     /// * index type: `(Slot, BlockLocation)`
     /// * value type: [`blockstore_meta::ParentMeta`]
     pub struct ParentMeta;
+
+    #[derive(Debug)]
+    /// The double merkle root metadata column
+    ///
+    /// This column stores details about the double merkle root of a block.
+    /// We update this column when we finish ingesting all the shreds of the block.
+    ///
+    /// * index type: `(Slot, BlockLocation)`
+    /// * value type: [`blockstore_meta::DoubleMerkleMeta`]
+    pub struct DoubleMerkleMeta;
 }
 
 macro_rules! convert_column_index_to_key_bytes {
@@ -1118,3 +1128,52 @@ impl ColumnName for columns::ParentMeta {
 impl TypedColumn for columns::ParentMeta {
     type Type = blockstore_meta::ParentMeta;
 }
+
+impl Column for columns::DoubleMerkleMeta {
+    type Index = (Slot, BlockLocation);
+    // Key size: Slot (8 bytes) + Hash (32 bytes)
+    // When BlockLocation::Original, the hash is Hash::default().
+    type Key = [u8; std::mem::size_of::<Slot>() + HASH_BYTES];
+
+    #[inline]
+    fn key((slot, location): &Self::Index) -> Self::Key {
+        let mut key = [0u8; std::mem::size_of::<Slot>() + HASH_BYTES];
+        key[..8].copy_from_slice(&slot.to_le_bytes());
+
+        let hash_bytes = match location {
+            BlockLocation::Original => &Hash::default().to_bytes(),
+            BlockLocation::Alternate { block_id } => &block_id.to_bytes(),
+        };
+
+        key[8..40].copy_from_slice(hash_bytes);
+
+        key
+    }
+
+    fn index(key: &[u8]) -> Self::Index {
+        let slot = Slot::from_le_bytes(key[0..8].try_into().unwrap());
+        let hash = Hash::new_from_array(key[8..40].try_into().unwrap());
+        let location = match hash == Hash::default() {
+            true => BlockLocation::Original,
+            false => BlockLocation::Alternate { block_id: hash },
+        };
+
+        (slot, location)
+    }
+
+    fn as_index(slot: Slot) -> Self::Index {
+        (slot, BlockLocation::Original)
+    }
+
+    fn slot((slot, _location): Self::Index) -> Slot {
+        slot
+    }
+}
+
+impl ColumnName for columns::DoubleMerkleMeta {
+    const NAME: &'static str = "double_merkle_meta";
+}
+
+impl TypedColumn for columns::DoubleMerkleMeta {
+    type Type = blockstore_meta::DoubleMerkleMeta;
+}

ledger/src/blockstore_db.rs

@@ -201,6 +201,7 @@ impl Rocks {
             new_cf_descriptor::<columns::AlternateShredData>(options, oldest_slot),
             new_cf_descriptor::<columns::AlternateMerkleRootMeta>(options, oldest_slot),
             new_cf_descriptor::<columns::ParentMeta>(options, oldest_slot),
+            new_cf_descriptor::<columns::DoubleMerkleMeta>(options, oldest_slot),
         ];
 
         // If the access type is Secondary, we don't need to open all of the
@@ -249,7 +250,7 @@ impl Rocks {
         cf_descriptors
     }
 
-    const fn columns() -> [&'static str; 27] {
+    const fn columns() -> [&'static str; 28] {
         [
             columns::ErasureMeta::NAME,
             columns::DeadSlots::NAME,
@@ -278,6 +279,7 @@ impl Rocks {
             columns::AlternateShredData::NAME,
             columns::AlternateMerkleRootMeta::NAME,
             columns::ParentMeta::NAME,
+            columns::DoubleMerkleMeta::NAME,
         ]
     }
 

ledger/src/blockstore_meta.rs

@@ -11,6 +11,7 @@ use {
     solana_hash::Hash,
     std::{
         collections::BTreeSet,
+        fmt::Display,
         ops::{Range, RangeBounds},
     },
 };
@@ -464,6 +465,15 @@ impl BlockVersions {
     }
 }
 
+impl Display for BlockLocation {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            BlockLocation::Original => write!(f, "Original"),
+            BlockLocation::Alternate { block_id } => write!(f, "Alternate({block_id})"),
+        }
+    }
+}
+
 #[derive(Deserialize, Serialize, Debug, PartialEq, Eq)]
 pub enum FrozenHashVersioned {
     Current(FrozenHashStatus),
@@ -1000,6 +1010,24 @@ impl ParentMeta {
     }
 }
 
+#[derive(Clone, Debug, Default, Deserialize, Serialize, PartialEq, Eq)]
+pub struct DoubleMerkleMeta {
+    /// The double merkle root computed as the root of the merkle tree
+    /// containing the merkle roots of each fec set + the parent info (parent_slot, parent_double_merkle_root)
+    pub double_merkle_root: Hash,
+
+    /// The number of fec sets in this block
+    pub fec_set_count: usize,
+
+    /// The merkle proofs
+    /// index of [0, fec_set_count) corresponds to the proofs for each fec set leaf node
+    /// index of fec_set_count corresponds to the proof for the parent info node
+    ///
+    /// The size of this vec is `fec_set_count + 1`
+    /// Each inner Vec<u8> contains concatenated proof entries for that leaf
+    pub proofs: Vec<Vec<u8>>,
+}
+
 #[cfg(test)]
 mod test {
     use {

ledger/src/shred.rs

@@ -85,7 +85,7 @@ use {solana_keypair::Keypair, solana_perf::packet::Packet, solana_signer::Signer
 
 mod common;
 pub(crate) mod merkle;
-mod merkle_tree;
+pub(crate) mod merkle_tree;
 mod payload;
 mod shred_code;
 mod shred_data;