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| # Copyright DataStax, 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. | |
| include "ioutils.pyx" | |
| from cassandra import DriverException | |
| from cassandra.bytesio cimport BytesIOReader | |
| from cassandra.deserializers cimport Deserializer, from_binary | |
| from cassandra.deserializers import find_deserializer | |
| from cassandra.parsing cimport ParseDesc, ColumnParser, RowParser | |
| from cassandra.tuple cimport tuple_new, tuple_set | |
| from cpython.bytes cimport PyBytes_AsStringAndSize | |
| cdef class ListParser(ColumnParser): | |
| """Decode a ResultMessage into a list of tuples (or other objects)""" | |
| cpdef parse_rows(self, BytesIOReader reader, ParseDesc desc): | |
| cdef Py_ssize_t i, rowcount | |
| rowcount = read_int(reader) | |
| cdef RowParser rowparser = TupleRowParser() | |
| return [rowparser.unpack_row(reader, desc) for i in range(rowcount)] | |
| cdef class LazyParser(ColumnParser): | |
| """Decode a ResultMessage lazily using a generator""" | |
| cpdef parse_rows(self, BytesIOReader reader, ParseDesc desc): | |
| # Use a little helper function as closures (generators) are not | |
| # supported in cpdef methods | |
| return parse_rows_lazy(reader, desc) | |
| def parse_rows_lazy(BytesIOReader reader, ParseDesc desc): | |
| cdef Py_ssize_t i, rowcount | |
| rowcount = read_int(reader) | |
| cdef RowParser rowparser = TupleRowParser() | |
| return (rowparser.unpack_row(reader, desc) for i in range(rowcount)) | |
| cdef class TupleRowParser(RowParser): | |
| """ | |
| Parse a single returned row into a tuple of objects: | |
| (obj1, ..., objN) | |
| """ | |
| cpdef unpack_row(self, BytesIOReader reader, ParseDesc desc): | |
| assert desc.rowsize >= 0 | |
| cdef Buffer buf | |
| cdef Buffer newbuf | |
| cdef Py_ssize_t i, rowsize = desc.rowsize | |
| cdef Deserializer deserializer | |
| cdef tuple res = tuple_new(desc.rowsize) | |
| ce_policy = desc.column_encryption_policy | |
| for i in range(rowsize): | |
| # Read the next few bytes | |
| get_buf(reader, &buf) | |
| # Deserialize bytes to python object | |
| deserializer = desc.deserializers[i] | |
| coldesc = desc.coldescs[i] | |
| uses_ce = ce_policy and ce_policy.contains_column(coldesc) | |
| try: | |
| if uses_ce: | |
| col_type = ce_policy.column_type(coldesc) | |
| decrypted_bytes = ce_policy.decrypt(coldesc, to_bytes(&buf)) | |
| PyBytes_AsStringAndSize(decrypted_bytes, &newbuf.ptr, &newbuf.size) | |
| deserializer = find_deserializer(ce_policy.column_type(coldesc)) | |
| val = from_binary(deserializer, &newbuf, desc.protocol_version) | |
| else: | |
| val = from_binary(deserializer, &buf, desc.protocol_version) | |
| except Exception as e: | |
| raise DriverException('Failed decoding result column "%s" of type %s: %s' % (desc.colnames[i], | |
| desc.coltypes[i].cql_parameterized_type(), | |
| str(e))) | |
| # Insert new object into tuple | |
| tuple_set(res, i, val) | |
| return res | |