Added support for connecting to CMAN using "(SOURCE_ROUTE=YES)" in the

connect string (#81).

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -24,6 +24,9 @@ Thin Mode Changes
 #)  Added support for using a wallet for one-way TLS connections, rather than
     requiring OS recognition of certificates
     (`issue 65 <https://github.com/oracle/python-oracledb/issues/65>`__).
+#)  Added support for connecting to CMAN using `(SOURCE_ROUTE=YES)` in the
+    connect string
+    (`issue 81 <https://github.com/oracle/python-oracledb/issues/81>`__).
 #)  Fixed bug when fetching nested cursors with more columns than the parent
     cursor.
 #)  Fixed bug preventing a cursor from being reused after it was bound as a

src/oracledb/base_impl.pxd

@@ -111,6 +111,7 @@ cdef class Address:
 cdef class AddressList:
     cdef:
         public list addresses
+        bint source_route
         bint load_balance
         int lru_index
 
@@ -120,6 +121,7 @@ cdef class AddressList:
 cdef class Description:
     cdef:
         public list address_lists
+        public bint source_route
         public bint load_balance
         public int lru_index
         public uint32_t expire_time
@@ -142,6 +144,7 @@ cdef class Description:
 cdef class DescriptionList:
     cdef:
         public list descriptions
+        bint source_route
         bint load_balance
         int lru_index
 

src/oracledb/impl/base/connect_params.pyx

@@ -681,6 +681,7 @@ cdef class AddressList:
         node in a connect descriptor.
         """
         _set_bool_param(args, "load_balance", &self.load_balance)
+        _set_bool_param(args, "source_route", &self.source_route)
 
 
 cdef class Description:
@@ -746,6 +747,8 @@ cdef class Description:
         parts = []
         if self.load_balance:
             parts.append("(LOAD_BALANCE=ON)")
+        if self.source_route:
+            parts.append("(SOURCE_ROUTE=ON)")
         if self.retry_count != 0:
             parts.append(f"(RETRY_COUNT={self.retry_count})")
         if self.retry_delay != 0:
@@ -775,6 +778,7 @@ cdef class Description:
         description.purity = self.purity
         description.expire_time = self.expire_time
         description.load_balance = self.load_balance
+        description.source_route = self.source_route
         description.retry_count = self.retry_count
         description.retry_delay = self.retry_delay
         description.tcp_connect_timeout = self.tcp_connect_timeout
@@ -802,6 +806,7 @@ cdef class Description:
         cdef Address address
         _set_uint_param(args, "expire_time", &self.expire_time)
         _set_bool_param(args, "load_balance", &self.load_balance)
+        _set_bool_param(args, "source_route", &self.source_route)
         _set_uint_param(args, "retry_count", &self.retry_count)
         _set_uint_param(args, "retry_delay", &self.retry_delay)
         _set_duration_param(args, "tcp_connect_timeout",
@@ -844,6 +849,7 @@ cdef class DescriptionList:
         node in a connect descriptor.
         """
         _set_bool_param(args, "load_balance", &self.load_balance)
+        _set_bool_param(args, "source_route", &self.source_route)
 
 
 cdef class TnsnamesFile:

src/oracledb/impl/thin/connection.pyx

@@ -133,26 +133,37 @@ cdef class ThinConnImpl(BaseConnImpl):
             AddressList address_list
             str connect_string
             Address address
+
         # Retry connecting to the socket if an attempt fails and retry_count
         # is specified in the connect string. If an attempt succeeds, return
         # the socket and the valid address object.
         connect_string = _get_connect_data(description)
         for i in range(num_attempts):
-            # Iterate through each address_list in the description. If the
+
+            # iterate through each address_list in the description; if the
             # description level load_balance is on, keep track of the least
-            # recently used address for subsequent connections. If not,
-            # iterate through the list in order.
+            # recently used address for subsequent connections; otherwise,
+            # iterate through the list in order; note that if source_route is
+            # enabled that only the first address list is examined as the rest
+            # are used for routing on the server
+            if description.source_route and num_lists > 0:
+                num_lists = 1
             for j in range(num_lists):
                 if load_balance:
                     idx1 = (j + description.lru_index) % num_lists
                 else:
                     idx1 = j
+
+                # iterate through each address in an address_list; if the
+                # address_list level load_balance is on, keep track of the
+                # least recently used address for subsequent connections;
+                # otherwise, iterate through the list in order; note that if
+                # source_route is enabled that only the first address is
+                # examined and the rest are used for routing on the server
                 address_list = address_lists[idx1]
                 num_addresses = len(address_list.addresses)
-                # Iterate through each address in an address_list. If the
-                # address_list level load_balance is on, keep track of the
-                # least recently used address for subsequent connections. If
-                # not, iterate through the list in order.
+                if address_list.source_route and num_addresses > 0:
+                    num_addresses = 1
                 for k in range(num_addresses):
                     if address_list.load_balance:
                         idx2 = (k + address_list.lru_index) % num_addresses
@@ -182,6 +193,8 @@ cdef class ThinConnImpl(BaseConnImpl):
             ssize_t i, idx, num_descriptions = len(descriptions)
             Description description
             bint final_desc = False
+        if description_list.source_route and num_descriptions > 0:
+            num_descriptions = 1
         for i in range(num_descriptions):
             if i == num_descriptions - 1:
                 final_desc = True

src/oracledb/impl/thin/messages.pyx

@@ -1655,12 +1655,13 @@ cdef class ConnectMessage(Message):
             response = self.error_info.message
             error_code = "unknown"
             error_code_int = 0
-            pos = response.find("(ERR=")
-            if pos > 0:
-                end_pos = response.find(")", pos)
-                if end_pos > 0:
-                    error_code = response[pos + 5:end_pos]
-                    error_code_int = int(error_code)
+            if response is not None:
+                pos = response.find("(ERR=")
+                if pos > 0:
+                    end_pos = response.find(")", pos)
+                    if end_pos > 0:
+                        error_code = response[pos + 5:end_pos]
+                        error_code_int = int(error_code)
             if error_code_int == 0:
                 errors._raise_err(errors.ERR_UNEXPECTED_REFUSE)
             if error_code_int == TNS_ERR_INVALID_SERVICE_NAME:

tests/test_4500_connect_params.py

@@ -553,5 +553,38 @@ def test_4535_connect_descriptor_small_container_second(self):
         self.assertEqual(params.host,
                          ["host1a", "host1b", "host2", "host3a", "host3b"])
 
+    def test_4536_build_connect_string_with_source_route(self):
+        "4536 - test building connect string with source route designation"
+        host = "my_host4536"
+        service_name = "my_service4536"
+        options = [
+            ("on", True),
+            ("off", False),
+            ("true", True),
+            ("false", False),
+            ("yes", True),
+            ("no", False)
+        ]
+
+        for in_val, has_section in options:
+            connect_string = f"""
+                (DESCRIPTION=
+                    (SOURCE_ROUTE={in_val})
+                    (ADDRESS=(PROTOCOL=tcp)(HOST=host1)(PORT=1521))
+                    (ADDRESS=(PROTOCOL=tcp)(HOST=host2)(PORT=1522))
+                    (CONNECT_DATA=(SERVICE_NAME=my_service_35))
+                )"""
+            params = oracledb.ConnectParams()
+            params.parse_connect_string(connect_string)
+            source_route_clause = "(SOURCE_ROUTE=ON)" if has_section else ""
+            connect_string = \
+                    f"(DESCRIPTION={source_route_clause}" + \
+                    f"(ADDRESS_LIST=" + \
+                    f"(ADDRESS=(PROTOCOL=tcp)(HOST=host1)(PORT=1521))" + \
+                    f"(ADDRESS=(PROTOCOL=tcp)(HOST=host2)(PORT=1522)))" + \
+                    f"(CONNECT_DATA=(SERVICE_NAME=my_service_35))" + \
+                    f"(SECURITY=(SSL_SERVER_DN_MATCH=ON)))"
+            self.assertEqual(params.get_connect_string(), connect_string)
+
 if __name__ == "__main__":
     test_env.run_test_cases()