don't calc checksum for read-only transactions

IlyaFaer · IlyaFaer · commit 8332d4977e65 · 2021-08-06T11:34:07.000+03:00
diff --git a/google/cloud/spanner_dbapi/connection.py b/google/cloud/spanner_dbapi/connection.py
@@ -217,7 +217,7 @@ def _rerun_previous_statements(self):
         for statement in self._statements:
             res_iter, retried_checksum = self.run_statement(statement, retried=True)
             # executing all the completed statements
-            if statement != self._statements[-1]:
+            if statement != self._statements[-1] and not self.read_only:
                 for res in res_iter:
                     retried_checksum.consume_result(res)
 
@@ -229,11 +229,13 @@ def _rerun_previous_statements(self):
                 while len(retried_checksum) < len(statement.checksum):
                     try:
                         res = next(iter(res_iter))
-                        retried_checksum.consume_result(res)
+                        if not self.read_only:
+                            retried_checksum.consume_result(res)
                     except StopIteration:
                         break
 
-                _compare_checksums(statement.checksum, retried_checksum)
+                if not self.read_only:
+                    _compare_checksums(statement.checksum, retried_checksum)
 
     def transaction_checkout(self):
         """Get a Cloud Spanner transaction.
diff --git a/google/cloud/spanner_dbapi/cursor.py b/google/cloud/spanner_dbapi/cursor.py
@@ -272,7 +272,7 @@ def fetchone(self):
 
         try:
             res = next(self)
-            if not self.connection.autocommit:
+            if not self.connection.autocommit and not self.connection.read_only:
                 self._checksum.consume_result(res)
             return res
         except StopIteration:
@@ -290,7 +290,7 @@ def fetchall(self):
         res = []
         try:
             for row in self:
-                if not self.connection.autocommit:
+                if not self.connection.autocommit and not self.connection.read_only:
                     self._checksum.consume_result(row)
                 res.append(row)
         except Aborted:
@@ -319,7 +319,7 @@ def fetchmany(self, size=None):
         for i in range(size):
             try:
                 res = next(self)
-                if not self.connection.autocommit:
+                if not self.connection.autocommit and not self.connection.read_only:
                     self._checksum.consume_result(res)
                 items.append(res)
             except StopIteration:
