feat: Versionable Merkle metadata

CHANGELOG.md

@@ -25,6 +25,7 @@ Description of the upcoming release here.
 - [#1601](https://github.com/FuelLabs/fuel-core/pull/1601): Fix formatting in docs and check that `cargo doc` passes in the CI.
 
 #### Breaking
+- [#1639](https://github.com/FuelLabs/fuel-core/pull/1639): Make Merkle metadata, i.e. `SparseMerkleMetadata` and `DenseMerkleMetadata` type version-able enums
 - [#16232](https://github.com/FuelLabs/fuel-core/pull/1632): Make `Message` type a version-able enum
 - [#1628](https://github.com/FuelLabs/fuel-core/pull/1628): Make `CompressedCoin` type a version-able enum
 - [#1616](https://github.com/FuelLabs/fuel-core/pull/1616): Make `BlockHeader` type a version-able enum

crates/fuel-core/src/database/block.rs

@@ -119,14 +119,14 @@ impl StorageMutate<FuelBlocks> for Database {
 
         let storage = self.borrow_mut();
         let mut tree: MerkleTree<FuelBlockMerkleData, _> =
-            MerkleTree::load(storage, prev_metadata.version)
+            MerkleTree::load(storage, prev_metadata.version())
                 .map_err(|err| StorageError::Other(anyhow::anyhow!(err)))?;
         tree.push(block_id.as_slice())?;
 
         // Generate new metadata for the updated tree
-        let version = tree.leaves_count();
         let root = tree.root();
-        let metadata = DenseMerkleMetadata { version, root };
+        let version = tree.leaves_count();
+        let metadata = DenseMerkleMetadata::new(root, version);
         self.storage::<FuelBlockMerkleMetadata>()
             .insert(height, &metadata)?;
 
@@ -222,7 +222,7 @@ impl MerkleRootStorage<BlockHeight, FuelBlocks> for Database {
             .storage::<FuelBlockMerkleMetadata>()
             .get(key)?
             .ok_or(not_found!(FuelBlocks))?;
-        Ok(metadata.root)
+        Ok(*metadata.root())
     }
 }
 
@@ -250,11 +250,11 @@ impl Database {
 
         let storage = self;
         let tree: MerkleTree<FuelBlockMerkleData, _> =
-            MerkleTree::load(storage, commit_merkle_metadata.version)
+            MerkleTree::load(storage, commit_merkle_metadata.version())
                 .map_err(|err| StorageError::Other(anyhow::anyhow!(err)))?;
 
         let proof_index = message_merkle_metadata
-            .version
+            .version()
             .checked_sub(1)
             .ok_or(anyhow::anyhow!("The count of leafs - messages is zero"))?;
         let (_, proof_set) = tree

crates/storage/src/blueprint/sparse.rs

@@ -104,7 +104,7 @@ where
             .get(primary_key)?
             .unwrap_or_default();
 
-        let root = prev_metadata.root;
+        let root = *prev_metadata.root();
         let mut tree: MerkleTree<Nodes, _> = MerkleTree::load(&mut storage, &root)
             .map_err(|err| StorageError::Other(anyhow::anyhow!("{err:?}")))?;
 
@@ -113,7 +113,7 @@ where
 
         // Generate new metadata for the updated tree
         let root = tree.root();
-        let metadata = SparseMerkleMetadata { root };
+        let metadata = SparseMerkleMetadata::new(root);
         storage
             .storage::<Metadata>()
             .insert(primary_key, &metadata)?;
@@ -138,7 +138,7 @@ where
             storage.storage::<Metadata>().get(primary_key)?;
 
         if let Some(prev_metadata) = prev_metadata {
-            let root = prev_metadata.root;
+            let root = *prev_metadata.root();
 
             let mut tree: MerkleTree<Nodes, _> = MerkleTree::load(&mut storage, &root)
                 .map_err(|err| StorageError::Other(anyhow::anyhow!("{err:?}")))?;
@@ -152,7 +152,7 @@ where
                 storage.storage::<Metadata>().remove(primary_key)?;
             } else {
                 // Generate new metadata for the updated tree
-                let metadata = SparseMerkleMetadata { root };
+                let metadata = SparseMerkleMetadata::new(root);
                 storage
                     .storage::<Metadata>()
                     .insert(primary_key, &metadata)?;
@@ -259,7 +259,7 @@ where
         let metadata: Option<Cow<SparseMerkleMetadata>> =
             self.storage_as_ref::<Metadata>().get(key)?;
         let root = metadata
-            .map(|metadata| metadata.root)
+            .map(|metadata| *metadata.root())
             .unwrap_or_else(|| in_memory::MerkleTree::new().root());
         Ok(root)
     }
@@ -346,7 +346,7 @@ where
         });
         storage.as_mut().batch_write(&mut nodes)?;
 
-        let metadata = SparseMerkleMetadata { root };
+        let metadata = SparseMerkleMetadata::new(root);
         storage
             .storage::<Metadata>()
             .insert(primary_key, &metadata)?;
@@ -379,7 +379,7 @@ where
             .get(primary_key)?
             .unwrap_or_default();
 
-        let root = prev_metadata.root;
+        let root = *prev_metadata.root();
         let mut tree: MerkleTree<Nodes, _> = MerkleTree::load(&mut storage, &root)
             .map_err(|err| StorageError::Other(anyhow::anyhow!("{err:?}")))?;
 
@@ -404,7 +404,7 @@ where
         )?;
 
         // Generate new metadata for the updated tree
-        let metadata = SparseMerkleMetadata { root };
+        let metadata = SparseMerkleMetadata::new(root);
         storage
             .storage::<Metadata>()
             .insert(primary_key, &metadata)?;
@@ -436,7 +436,7 @@ where
             .get(primary_key)?
             .unwrap_or_default();
 
-        let root = prev_metadata.root;
+        let root = *prev_metadata.root();
         let mut tree: MerkleTree<Nodes, _> = MerkleTree::load(&mut storage, &root)
             .map_err(|err| StorageError::Other(anyhow::anyhow!("{err:?}")))?;
 
@@ -461,7 +461,7 @@ where
             storage.storage::<Metadata>().remove(primary_key)?;
         } else {
             // Generate new metadata for the updated tree
-            let metadata = SparseMerkleMetadata { root };
+            let metadata = SparseMerkleMetadata::new(root);
             storage
                 .storage::<Metadata>()
                 .insert(primary_key, &metadata)?;

crates/storage/src/tables.rs

@@ -148,7 +148,43 @@ pub mod merkle {
 
     /// Metadata for dense Merkle trees
     #[derive(Debug, Clone, serde::Serialize, serde::Deserialize, PartialEq, Eq)]
-    pub struct DenseMerkleMetadata {
+    pub enum DenseMerkleMetadata {
+        /// V1 Dense Merkle Metadata
+        V1(DenseMerkleMetadataV1),
+    }
+
+    impl Default for DenseMerkleMetadata {
+        fn default() -> Self {
+            Self::V1(Default::default())
+        }
+    }
+
+    impl DenseMerkleMetadata {
+        /// Create a new dense Merkle metadata object from the given Merkle
+        /// root and version
+        pub fn new(root: MerkleRoot, version: u64) -> Self {
+            let metadata = DenseMerkleMetadataV1 { root, version };
+            Self::V1(metadata)
+        }
+
+        /// Get the Merkle root of the dense Metadata
+        pub fn root(&self) -> &MerkleRoot {
+            match self {
+                DenseMerkleMetadata::V1(metadata) => &metadata.root,
+            }
+        }
+
+        /// Get the version of the dense Metadata
+        pub fn version(&self) -> u64 {
+            match self {
+                DenseMerkleMetadata::V1(metadata) => metadata.version,
+            }
+        }
+    }
+
+    /// Metadata for dense Merkle trees
+    #[derive(Debug, Clone, serde::Serialize, serde::Deserialize, PartialEq, Eq)]
+    pub struct DenseMerkleMetadataV1 {
         /// The root hash of the dense Merkle tree structure
         pub root: MerkleRoot,
         /// The version of the dense Merkle tree structure is equal to the number of
@@ -157,7 +193,7 @@ pub mod merkle {
         pub version: u64,
     }
 
-    impl Default for DenseMerkleMetadata {
+    impl Default for DenseMerkleMetadataV1 {
         fn default() -> Self {
             let empty_merkle_tree = binary::root_calculator::MerkleRootCalculator::new();
             Self {
@@ -167,14 +203,49 @@ pub mod merkle {
         }
     }
 
+    impl From<DenseMerkleMetadataV1> for DenseMerkleMetadata {
+        fn from(value: DenseMerkleMetadataV1) -> Self {
+            Self::V1(value)
+        }
+    }
+
     /// Metadata for sparse Merkle trees
     #[derive(Debug, Clone, serde::Serialize, serde::Deserialize, PartialEq, Eq)]
-    pub struct SparseMerkleMetadata {
+    pub enum SparseMerkleMetadata {
+        /// V1 Sparse Merkle Metadata
+        V1(SparseMerkleMetadataV1),
+    }
+
+    impl Default for SparseMerkleMetadata {
+        fn default() -> Self {
+            Self::V1(Default::default())
+        }
+    }
+
+    impl SparseMerkleMetadata {
+        /// Create a new sparse Merkle metadata object from the given Merkle
+        /// root
+        pub fn new(root: MerkleRoot) -> Self {
+            let metadata = SparseMerkleMetadataV1 { root };
+            Self::V1(metadata)
+        }
+
+        /// Get the Merkle root stored in the metadata
+        pub fn root(&self) -> &MerkleRoot {
+            match self {
+                SparseMerkleMetadata::V1(metadata) => &metadata.root,
+            }
+        }
+    }
+
+    /// Metadata V1 for sparse Merkle trees
+    #[derive(Debug, Clone, serde::Serialize, serde::Deserialize, PartialEq, Eq)]
+    pub struct SparseMerkleMetadataV1 {
         /// The root hash of the sparse Merkle tree structure
         pub root: MerkleRoot,
     }
 
-    impl Default for SparseMerkleMetadata {
+    impl Default for SparseMerkleMetadataV1 {
         fn default() -> Self {
             let empty_merkle_tree = sparse::in_memory::MerkleTree::new();
             Self {
@@ -183,6 +254,12 @@ pub mod merkle {
         }
     }
 
+    impl From<SparseMerkleMetadataV1> for SparseMerkleMetadata {
+        fn from(value: SparseMerkleMetadataV1) -> Self {
+            Self::V1(value)
+        }
+    }
+
     /// The table of BMT data for Fuel blocks.
     pub struct FuelBlockMerkleData;