Add support for OSON containing field names > 255 bytes and relative

offsets in compressed OSON.

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -13,6 +13,10 @@ oracledb 2.0.0 (TBD)
 Thin Mode Changes
 +++++++++++++++++
 
+#)  Added support for an Oracle Database 23c JSON feature allowing for field
+    names with more than 255 UTF-8 encoded bytes.
+#)  Added support for an Oracle Database 23c JSON feature improving JSON
+    storage usage.
 #)  Fixed bug in detecting the current time zone
     (`issue 257 <https://github.com/oracle/python-oracledb/issues/257>`__).
 #)  Added connection establishment parameter :data:`ConnectParams.ssl_context`

src/oracledb/errors.py

@@ -516,7 +516,7 @@ def _raise_from_string(exc_type: Exception, message: str) -> None:
     ),
     ERR_ORACLE_TYPE_NOT_SUPPORTED: "Oracle data type {num} is not supported",
     ERR_OSON_FIELD_NAME_LIMITATION: (
-        "OSON field names may not exceed 255 UTF-8 encoded bytes"
+        "OSON field names may not exceed {max_fname_size} UTF-8 encoded bytes"
     ),
     ERR_OSON_NODE_TYPE_NOT_SUPPORTED: (
         "OSON node type 0x{node_type:x} is not supported"

src/oracledb/impl/thin/capabilities.pyx

@@ -40,6 +40,7 @@ cdef class Capabilities:
         bytearray runtime_caps
         uint32_t max_string_size
         bint supports_oob
+        ssize_t oson_max_fname_size
 
     def __init__(self):
         self._init_compile_caps()
@@ -55,6 +56,9 @@ cdef class Capabilities:
         if server_caps[TNS_CCAP_FIELD_VERSION] < self.ttc_field_version:
             self.ttc_field_version = server_caps[TNS_CCAP_FIELD_VERSION]
             self.compile_caps[TNS_CCAP_FIELD_VERSION] = self.ttc_field_version
+        self.oson_max_fname_size = 65535 \
+                if self.ttc_field_version >= TNS_CCAP_FIELD_VERSION_23_1 \
+                else 255
 
     @cython.boundscheck(False)
     cdef void _adjust_for_server_runtime_caps(self, bytearray server_caps):

src/oracledb/impl/thin/constants.pxi

@@ -564,9 +564,9 @@ cdef enum:
     TNS_JSON_MAGIC_BYTE_1 = 0xff
     TNS_JSON_MAGIC_BYTE_2 = 0x4a        # 'J'
     TNS_JSON_MAGIC_BYTE_3 = 0x5a        # 'Z'
-    TNS_JSON_VERSION = 1
+    TNS_JSON_VERSION_MAX_FNAME_255 = 1
+    TNS_JSON_VERSION_MAX_FNAME_65535 = 3
     TNS_JSON_FLAG_HASH_ID_UINT8 = 0x0100
-    TNS_JSON_FLAG_HASH_ID_UINT16 = 0x0200
     TNS_JSON_FLAG_NUM_FNAMES_UINT16 = 0x0400
     TNS_JSON_FLAG_FNAMES_SEG_UINT32 = 0x0800
     TNS_JSON_FLAG_TINY_NODES_STAT = 0x2000
@@ -576,6 +576,7 @@ cdef enum:
     TNS_JSON_FLAG_LEN_IN_PCODE = 0x04
     TNS_JSON_FLAG_NUM_FNAMES_UINT32 = 0x08
     TNS_JSON_FLAG_IS_SCALAR = 0x10
+    TNS_JSON_FLAG_SEC_FNAMES_SEG_UINT16 = 0x0100
 
 # JSON data types
 cdef enum: