feat(trie): database trie witness

crates/trie/db/src/lib.rs

@@ -3,7 +3,9 @@
 mod proof;
 mod state;
 mod storage;
+mod witness;
 
 pub use proof::DatabaseProof;
 pub use state::DatabaseStateRoot;
 pub use storage::DatabaseStorageRoot;
+pub use witness::DatabaseTrieWitness;

crates/trie/db/src/witness.rs

@@ -0,0 +1,46 @@
+use reth_db_api::transaction::DbTx;
+use reth_execution_errors::TrieWitnessError;
+use reth_primitives::{Bytes, B256};
+use reth_trie::{
+    hashed_cursor::{DatabaseHashedCursorFactory, HashedPostStateCursorFactory},
+    trie_cursor::DatabaseTrieCursorFactory,
+    witness::TrieWitness,
+    HashedPostState,
+};
+use std::collections::HashMap;
+
+/// Extends [`TrieWitness`] with operations specific for working with a database transaction.
+pub trait DatabaseTrieWitness<'a, TX> {
+    /// Create a new [`TrieWitness`] from database transaction.
+    fn from_tx(tx: &'a TX) -> Self;
+
+    /// Generates trie witness for target state on top of this [`HashedPostState`].
+    fn overlay_witness(
+        tx: &'a TX,
+        post_state: HashedPostState,
+        target: HashedPostState,
+    ) -> Result<HashMap<B256, Bytes>, TrieWitnessError>;
+}
+
+impl<'a, TX: DbTx> DatabaseTrieWitness<'a, TX>
+    for TrieWitness<DatabaseTrieCursorFactory<'a, TX>, DatabaseHashedCursorFactory<'a, TX>>
+{
+    fn from_tx(tx: &'a TX) -> Self {
+        Self::new(DatabaseTrieCursorFactory::new(tx), DatabaseHashedCursorFactory::new(tx))
+    }
+
+    fn overlay_witness(
+        tx: &'a TX,
+        post_state: HashedPostState,
+        target: HashedPostState,
+    ) -> Result<HashMap<B256, Bytes>, TrieWitnessError> {
+        let prefix_sets = post_state.construct_prefix_sets();
+        let sorted = post_state.into_sorted();
+        let hashed_cursor_factory =
+            HashedPostStateCursorFactory::new(DatabaseHashedCursorFactory::new(tx), &sorted);
+        Self::from_tx(tx)
+            .with_hashed_cursor_factory(hashed_cursor_factory)
+            .with_prefix_sets_mut(prefix_sets)
+            .compute(target)
+    }
+}