doc

Signed-off-by: Delweng <[email protected]>

Author: jsvisa

triedb/pathdb/database.go

@@ -749,7 +749,7 @@ func (db *Database) StorageIterator(root common.Hash, account common.Hash, seek
 	return newFastStorageIterator(db, root, account, seek)
 }
 
-// FirstStateBlock returns the block number of the oldest state snapshot in the freezer or disk layer.
+// FirstStateBlock returns the block number of the oldest state in the freezer.
 func (db *Database) FirstStateBlock() (uint64, error) {
 	if db.freezer == nil {
 		return 0, errors.New("freezer is not available")
@@ -760,7 +760,7 @@ func (db *Database) FirstStateBlock() (uint64, error) {
 		return 0, err
 	}
 
-	// No state has been persistent
+	// No state has been persistent, return the genesis block number.
 	if tailID == 0 {
 		return 0, nil
 	}