starknet_committer,starknet_patricia: enrich subtree trait to support fetch nodes

Author: ArielElp

crates/starknet_committer/src/db/facts_db/types.rs

@@ -1,5 +1,9 @@
 use starknet_api::hash::HashOutput;
-use starknet_patricia::patricia_merkle_tree::filled_tree::node_serde::PatriciaPrefix;
+use starknet_patricia::patricia_merkle_tree::filled_tree::node::FilledNode;
+use starknet_patricia::patricia_merkle_tree::filled_tree::node_serde::{
+    FactNodeDeserializationContext,
+    PatriciaPrefix,
+};
 use starknet_patricia::patricia_merkle_tree::node_data::leaf::Leaf;
 use starknet_patricia::patricia_merkle_tree::traversal::SubTreeTrait;
 use starknet_patricia::patricia_merkle_tree::types::{NodeIndex, SortedLeafIndices};
@@ -13,8 +17,11 @@ pub struct FactsSubTree<'a> {
     pub root_hash: HashOutput,
 }
 
+pub type FactDbFilledNode<L> = FilledNode<L, HashOutput>;
+
 impl<'a> SubTreeTrait<'a> for FactsSubTree<'a> {
     type NodeData = HashOutput;
+    type NodeContext = FactNodeDeserializationContext;
 
     fn create(
         sorted_leaf_indices: SortedLeafIndices<'a>,
@@ -36,6 +43,14 @@ impl<'a> SubTreeTrait<'a> for FactsSubTree<'a> {
         false
     }
 
+    fn unmodified_child_hash(data: Self::NodeData) -> Option<HashOutput> {
+        Some(data)
+    }
+
+    fn get_root_context(&self) -> Self::NodeContext {
+        Self::NodeContext { is_leaf: self.is_leaf(), node_hash: self.root_hash }
+    }
+
     fn get_root_prefix<L: Leaf>(
         &self,
         key_context: &<L as HasStaticPrefix>::KeyContext,
@@ -46,4 +61,8 @@ impl<'a> SubTreeTrait<'a> for FactsSubTree<'a> {
             PatriciaPrefix::InnerNode.into()
         }
     }
+
+    fn get_root_suffix(&self) -> Vec<u8> {
+        self.root_hash.0.to_bytes_be().to_vec()
+    }
 }

crates/starknet_patricia/src/patricia_merkle_tree/traversal.rs

@@ -1,3 +1,4 @@
+use starknet_api::hash::HashOutput;
 use starknet_patricia_storage::db_object::HasStaticPrefix;
 use starknet_patricia_storage::errors::{DeserializationError, StorageError};
 use starknet_patricia_storage::storage_trait::{DbKeyPrefix, PatriciaStorageError};
@@ -29,6 +30,7 @@ pub type TraversalResult<T> = Result<T, TraversalError>;
 pub trait SubTreeTrait<'a>: Sized {
     /// Extra data a node can carry (e.g. its hash).
     type NodeData: Copy;
+    type NodeContext;
 
     /// Creates a concrete child node given its index and data.
     fn create(
@@ -102,9 +104,18 @@ pub trait SubTreeTrait<'a>: Sized {
     /// original skeleton tree.
     fn should_traverse_unmodified_children() -> bool;
 
+    /// When should_traverse_unmodified_children is false, this function is used to get the hash
+    /// of the unmodified child (in this case NodeData will be HashOutput).
+    fn unmodified_child_hash(data: Self::NodeData) -> Option<HashOutput>;
+
     /// Returns the [DbKeyPrefix] of the root node.
     fn get_root_prefix<L: Leaf>(
         &self,
         key_context: &<L as HasStaticPrefix>::KeyContext,
     ) -> DbKeyPrefix;
+
+    fn get_root_suffix(&self) -> Vec<u8>;
+
+    // Need when deserializing the root node from a raw DbValue.
+    fn get_root_context(&self) -> Self::NodeContext;
 }

crates/starknet_patricia/src/patricia_merkle_tree/traversal_test.rs

@@ -1,6 +1,7 @@
 use ethnum::U256;
 use pretty_assertions::assert_eq;
 use rstest::rstest;
+use starknet_api::hash::HashOutput;
 use starknet_patricia_storage::db_object::HasStaticPrefix;
 use starknet_patricia_storage::storage_trait::DbKeyPrefix;
 
@@ -20,6 +21,7 @@ struct TestSubTree<'a> {
 
 impl<'a> SubTreeTrait<'a> for TestSubTree<'a> {
     type NodeData = ();
+    type NodeContext = ();
 
     fn create(
         sorted_leaf_indices: SortedLeafIndices<'a>,
@@ -41,13 +43,23 @@ impl<'a> SubTreeTrait<'a> for TestSubTree<'a> {
         false
     }
 
+    fn unmodified_child_hash(_child_data: Self::NodeData) -> Option<HashOutput> {
+        None
+    }
+
+    fn get_root_context(&self) -> Self::NodeContext {}
+
     fn get_root_prefix<L: Leaf>(
         &self,
         _key_context: &<L as HasStaticPrefix>::KeyContext,
     ) -> DbKeyPrefix {
         // Dummy prefix for testing purposes (we only need a prefix when interacting with storage).
         DbKeyPrefix::new(&[0])
     }
+
+    fn get_root_suffix(&self) -> Vec<u8> {
+        vec![]
+    }
 }
 
 /// case::single_right_child