feat(triedb): expose backend for custom use

triedb/database.go

@@ -47,9 +47,9 @@ var HashDefaults = &Config{
 	HashDB:    hashdb.Defaults,
 }
 
-// backend defines the methods needed to access/update trie nodes in different
-// state scheme.
-type backend interface {
+// Backend defines the methods needed to access/update trie nodes in different
+// state schemes.
+type Backend interface {
 	// Scheme returns the identifier of used storage scheme.
 	Scheme() string
 
@@ -87,7 +87,7 @@ type Database struct {
 	config    *Config        // Configuration for trie database
 	diskdb    ethdb.Database // Persistent database to store the snapshot
 	preimages *preimageStore // The store for caching preimages
-	backend   backend        // The backend for managing trie nodes
+	backend   Backend        // The backend for managing trie nodes
 }
 
 // NewDatabase initializes the trie database with default settings, note
@@ -343,3 +343,9 @@ func (db *Database) SetBufferSize(size int) error {
 func (db *Database) IsVerkle() bool {
 	return db.config.IsVerkle
 }
+
+// Backend returns the underlying backend of the trie database, which
+// implements the methods for accessing additional custom methods.
+func (db *Database) Backend() Backend {
+	return db.backend
+}

triedb/database.libevm.go

@@ -29,7 +29,7 @@ import (
 // BackendDB defines the intersection of methods shared by [hashdb.Database] and
 // [pathdb.Database]. It is defined to export an otherwise internal type used by
 // the non-libevm geth implementation.
-type BackendDB backend
+type BackendDB Backend
 
 // A ReaderProvider exposes its underlying Reader as an interface. Both
 // [hashdb.Database] and [pathdb.Database] return concrete types so Go's lack of