Check if server supports OOB check at connect (#419).

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -21,6 +21,12 @@ Thin Mode Changes
     :data:`oracledb.DB_TYPE_LONG` or :data:`oracledb.DB_TYPE_LONG_RAW` to
     to a different compatible type
     (`issue 424 <https://github.com/oracle/python-oracledb/issues/424>`__).
+#)  If the database states that an out-of-band break check should not take
+    place during connect (by setting the `DISABLE_OOB_AUTO
+    <https://www.oracle.com/pls/topic/lookup?ctx=dblatest&
+    id=GUID-490A0B3B-FEF3-425A-81B0-6FA29D4B8C0E>`__ parameter to TRUE),
+    python-oracledb no longer attempts to do so
+    (`issue 419 <https://github.com/oracle/python-oracledb/issues/419>`__).
 #)  All exceptions subclassed from ``OSError`` now cause connection retry
     attempts, subject to the connection ``retry_count`` and ``retry_delay``
     parameters

src/oracledb/impl/thin/capabilities.pyx

@@ -41,6 +41,7 @@ cdef class Capabilities:
         uint32_t max_string_size
         bint supports_fast_auth
         bint supports_oob
+        bint supports_oob_check
         bint supports_end_of_response
         bint supports_pipelining
         uint32_t sdu
@@ -60,6 +61,8 @@ cdef class Capabilities:
         self.supports_oob = protocol_options & TNS_GSO_CAN_RECV_ATTENTION
         if flags & TNS_ACCEPT_FLAG_FAST_AUTH:
             self.supports_fast_auth = True
+        if flags & TNS_ACCEPT_FLAG_CHECK_OOB:
+            self.supports_oob_check = True
         if protocol_version >= TNS_VERSION_MIN_END_OF_RESPONSE:
             if flags & TNS_ACCEPT_FLAG_HAS_END_OF_RESPONSE:
                 self.compile_caps[TNS_CCAP_TTC4] |= TNS_CCAP_END_OF_RESPONSE

src/oracledb/impl/thin/constants.pxi

@@ -762,6 +762,7 @@ cdef enum:
 
 # accept flags
 cdef enum:
+    TNS_ACCEPT_FLAG_CHECK_OOB = 0x00000001
     TNS_ACCEPT_FLAG_FAST_AUTH = 0x10000000
     TNS_ACCEPT_FLAG_HAS_END_OF_RESPONSE = 0x02000000
 

src/oracledb/impl/thin/protocol.pyx

@@ -291,8 +291,7 @@ cdef class Protocol(BaseProtocol):
 
         # if we can use OOB, send an urgent message now followed by a reset
         # marker to see if the server understands it
-        if self._caps.supports_oob \
-                and self._caps.protocol_version >= TNS_VERSION_MIN_OOB_CHECK:
+        if self._caps.supports_oob and self._caps.supports_oob_check:
             self._transport.send_oob_break()
             self._send_marker(self._write_buf, TNS_MARKER_TYPE_RESET)