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# Copyright (c) 2018-2024 Open Text.
# Copyright (c) 2018 Uber Technologies, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Copyright (c) 2013-2017 Uber Technologies, Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
"""
RowDescription message
RowDescription message describes the column layout of the rows that will be
returned in response to a SELECT, FETCH, etc query.
"""
from __future__ import print_function, division, absolute_import, annotations
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from typing import List
from struct import unpack, unpack_from, calcsize
from ..message import BackendMessage
from ...column import Column
from ....datatypes import getTypeName, getComplexElementType
class RowDescription(BackendMessage):
message_id = b'T'
def __init__(self, data, complex_types_enabled):
BackendMessage.__init__(self)
self.fields = []
field_dict = {}
field_count = unpack('!H', data[0:2])[0]
if field_count == 0:
return
# read type mapping pool
# used for user-defined types e.g. GEOMETRY, GEOGRAPHY
user_types = []
type_pool_count = unpack('!I', data[2:6])[0]
pos = 6
for _ in range(type_pool_count):
base_type_oid = unpack('!I', data[pos:(pos + 4)])[0]
pos += 4
type_name = unpack_from("!{0}sx".format(data.find(b'\x00', pos) - pos), data, pos)[0]
pos += len(type_name) + 1
user_types.append((base_type_oid, type_name.decode('utf-8')))
# read info of each field
offset = calcsize("!BIHHHiH")
for _ in range(field_count):
field_name = unpack_from("!{0}sx".format(data.find(b'\x00', pos) - pos), data, pos)[0]
pos += len(field_name) + 1
field_name = field_name.decode('utf-8')
table_oid = unpack('!Q', data[pos:(pos + 8)])[0]
pos += 8
schema_name, table_name = None, None
if table_oid != 0:
schema_name = unpack_from("!{0}sx".format(data.find(b'\x00', pos) - pos), data, pos)[0]
pos += len(schema_name) + 1
schema_name = schema_name.decode('utf-8')
table_name = unpack_from("!{0}sx".format(data.find(b'\x00', pos) - pos), data, pos)[0]
pos += len(table_name) + 1
table_name = table_name.decode('utf-8')
attribute_number = unpack_from("!H", data, pos)[0]
pos += 2
if complex_types_enabled:
parent_attribute_number = unpack_from("!H", data, pos)[0]
pos += 2
else:
parent_attribute_number = 0
field_info = unpack_from("!BIhHHiH", data, pos)
pos += offset
if field_info[0] == 1: # An user-defined type
data_type_oid, data_type_name = user_types[field_info[1]]
else: # A primitive type
data_type_oid = field_info[1]
data_type_name = getTypeName(data_type_oid, field_info[5])
# Create a Column object
metadata = {
'name': field_name,
'table_oid': table_oid,
'schema_name': schema_name,
'table_name': table_name,
'attribute_number': attribute_number,
'data_type_oid': data_type_oid,
'data_type_size': field_info[2],
'data_type_name': data_type_name,
'null_ok': field_info[3] == 1,
'is_identity': field_info[4] == 1,
'type_modifier': field_info[5],
'format_code': field_info[6],
}
column = Column(metadata)
# Add every column description to the dict so we can set the parents later
field_dict[(table_oid, attribute_number)] = column
if parent_attribute_number == 0:
self.fields.append(column)
else:
parent_col = field_dict.get((table_oid, parent_attribute_number))
if not parent_col:
raise KeyError("Complex type parent column not found: table_oid={}, attribute_number={}".format(table_oid, parent_attribute_number))
parent_col.add_child_column(column)
element_type_oid = getComplexElementType(data_type_oid)
if element_type_oid is not None:
metadata['data_type_oid'] = element_type_oid
metadata['name'] = 'elements'
metadata['data_type_name'] = getTypeName(element_type_oid, field_info[5]) # elements may only be primitive types
child_column = Column(metadata)
column.add_child_column(child_column)
def get_description(self) -> List[Column]:
# return a list of Column objects for Cursor.description
return self.fields
def __str__(self):
s = ",\n".join([c.debug_info() for c in self.fields])
return f"RowDescription: [\n{s}]"
BackendMessage.register(RowDescription)
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