Fixed memory leak when clickhouse raise error on data send.

CHANGELOG.md

@@ -1,6 +1,8 @@
 # Changelog
 
 ## Unreleased
+### Fixed
+- Memory leak when clickhouse raise exception onBufferedSocketWriter.write_into_stream. Solves issue [#406](https://github.com/mymarilyn/clickhouse-driver/issues/406).
 
 ## [0.2.6] - 2023-05-02
 ### Added

clickhouse_driver/bufferedwriter.pyx

@@ -78,10 +78,10 @@ cdef class BufferedWriter(object):
 
             memcpy(&items_buf[buf_pos], c_value, value_len)
             buf_pos += length
-
-        self.write(PyBytes_FromStringAndSize(items_buf, items_buf_size))
-
-        PyMem_Free(items_buf)
+        try:
+            self.write(PyBytes_FromStringAndSize(items_buf, items_buf_size))
+        finally:
+            PyMem_Free(items_buf)
 
     def write_fixed_strings(self, items, Py_ssize_t length, encoding=None):
         if encoding is None:
@@ -110,10 +110,10 @@ cdef class BufferedWriter(object):
 
             memcpy(&items_buf[buf_pos], c_value, value_len)
             buf_pos += length
-
-        self.write(PyBytes_FromStringAndSize(items_buf, items_buf_size))
-
-        PyMem_Free(items_buf)
+        try:
+            self.write(PyBytes_FromStringAndSize(items_buf, items_buf_size))
+        finally:
+            PyMem_Free(items_buf)
 
 
 cdef class BufferedSocketWriter(BufferedWriter):

clickhouse_driver/client.py

@@ -592,8 +592,8 @@ def process_insert_query(self, query_without_data, data,
         self.connection.send_query(query_without_data, query_id=query_id)
         self.connection.send_external_tables(external_tables,
                                              types_check=types_check)
-
         sample_block = self.receive_sample_block()
+
         if sample_block:
             rv = self.send_data(sample_block, data,
                                 types_check=types_check, columnar=columnar)