Faster Array Allocation (#1999)

* Allocate arrays more efficiently.

* Update CHANGELOG

Author: ni-jfitzger

CHANGELOG.md

@@ -37,6 +37,7 @@ All notable changes to this project will be documented in this file.
     * #### Added
     * #### Changed
         * Fix [#1970](https://github.com/ni/nimi-python/issues/1970): Incorrect error when driver runtime not installed.
+        * Fix [#1998](https://github.com/ni/nimi-python/issues/1998): nimi-python APIs inefficiently allocate Python arrays.
     * #### Removed
         * Support for Python 3.7
 * ### `nidcpower` (NI-DCPower)

build/helper/codegen_helper.py

@@ -411,10 +411,10 @@ def _get_ctype_variable_definition_snippet_for_buffers(parameter, parameters, iv
         B560. Output buffer with mechanism python-code:                            _get_ctypes_pointer_for_buffer(value=array.array('d'), library_type=ViInt32)
         B570. Output buffer with mechanism fixed-size:                             _get_ctypes_pointer_for_buffer(library_type=ViInt32, size=256)
         B580. Output buffer with mechanism ivi-dance, QUERY_SIZE:                  None
-        B590. Output buffer with mechanism ivi-dance, GET_DATA:                    _get_ctypes_pointer_for_buffer(value=array.array('d', [0] * buffer_size_ctype.value, library_type=ViInt32)
-        B600. Output buffer with mechanism passed-in:                              _get_ctypes_pointer_for_buffer(value-array.array('d', [0] * buffer_size, library_type=ViInt32)
+        B590. Output buffer with mechanism ivi-dance, GET_DATA:                    _get_ctypes_pointer_for_buffer(value=array.array('d', [0]) * buffer_size_ctype.value, library_type=ViInt32)
+        B600. Output buffer with mechanism passed-in:                              _get_ctypes_pointer_for_buffer(value-array.array('d', [0]) * buffer_size, library_type=ViInt32)
         B610. Output buffer with mechanism ivi-dance-with-a-twist, QUERY_SIZE:     None
-        B620. Output buffer with mechanism ivi-dance-with-a-twist, GET_DATA:       _get_ctypes_pointer_for_buffer(value=array.array('d', [0] * buffer_size_ctype.value, library_type=ViInt32)
+        B620. Output buffer with mechanism ivi-dance-with-a-twist, GET_DATA:       _get_ctypes_pointer_for_buffer(value=array.array('d', [0]) * buffer_size_ctype.value, library_type=ViInt32)
 
     Return Value (list): each item in the list will be one line needed for the declaration of that parameter
 
@@ -447,7 +447,7 @@ def _get_ctype_variable_definition_snippet_for_buffers(parameter, parameters, iv
             line1 = '{0}_size = {1}  # case B560'.format(parameter['python_name'], parameter['size']['value'])
             definitions.append(line1)
             if parameter['use_array']:
-                line2 = '{0}_array = array.array("{1}", [0] * {0}_size)  # case B560'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
+                line2 = '{0}_array = array.array("{1}", [0]) * {0}_size  # case B560'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
                 definitions.append(line2)
                 definition = '_get_ctypes_pointer_for_buffer(value={1}_array, library_type={0}.{2})  # case B560'.format(module_name, parameter['python_name'], parameter['ctypes_type'])
             elif parameter['use_list']:
@@ -459,7 +459,7 @@ def _get_ctype_variable_definition_snippet_for_buffers(parameter, parameters, iv
             line1 = '{0}_size = {1}  # case B570'.format(parameter['python_name'], parameter['size']['value'])
             definitions.append(line1)
             if parameter['use_array']:
-                line2 = '{0}_array = array.array("{1}", [0] * {0}_size)  # case B570'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
+                line2 = '{0}_array = array.array("{1}", [0]) * {0}_size  # case B570'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
                 definitions.append(line2)
                 definition = '_get_ctypes_pointer_for_buffer(value={1}_array, library_type={0}.{2})  # case B570'.format(module_name, parameter['python_name'], parameter['ctypes_type'])
             elif parameter['use_list']:
@@ -474,7 +474,7 @@ def _get_ctype_variable_definition_snippet_for_buffers(parameter, parameters, iv
                 line1 = '{0}_size = {1}.value  # case B590'.format(parameter['python_name'], size_parameter['ctypes_variable_name'])
                 definitions.append(line1)
                 if parameter['use_array']:
-                    line2 = '{0}_array = array.array("{1}", [0] * {0}_size)  # case B590'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
+                    line2 = '{0}_array = array.array("{1}", [0]) * {0}_size  # case B590'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
                     definition = '_get_ctypes_pointer_for_buffer(value={1}_array, library_type={0}.{2})  # case B590'.format(module_name, parameter['python_name'], parameter['ctypes_type'])
                     definitions.append(line2)
                 elif parameter['use_list']:
@@ -491,7 +491,7 @@ def _get_ctype_variable_definition_snippet_for_buffers(parameter, parameters, iv
                 line1 = '{0}_size = {1}.value  # case B620'.format(parameter['python_name'], size_parameter_twist['ctypes_variable_name'])
                 definitions.append(line1)
                 if parameter['use_array']:
-                    line2 = '{0}_array = array.array("{1}", [0] * {0}_size)  # case B620'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
+                    line2 = '{0}_array = array.array("{1}", [0]) * {0}_size  # case B620'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
                     definitions.append(line2)
                     definition = '_get_ctypes_pointer_for_buffer(value={1}_array, library_type={0}.{2})  # case B620'.format(module_name, parameter['python_name'], parameter['ctypes_type'])
                 elif parameter['use_list']:
@@ -505,7 +505,7 @@ def _get_ctype_variable_definition_snippet_for_buffers(parameter, parameters, iv
             line1 = '{0}_size = {1}  # case B600'.format(parameter['python_name'], size_parameter['python_name'])
             definitions.append(line1)
             if parameter['use_array']:
-                line2 = '{0}_array = array.array("{1}", [0] * {0}_size)  # case B600'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
+                line2 = '{0}_array = array.array("{1}", [0]) * {0}_size  # case B600'.format(parameter['python_name'], get_array_type_for_api_type(parameter['ctypes_type']))
                 definition = '_get_ctypes_pointer_for_buffer(value={1}_array, library_type={0}.{2})  # case B600'.format(module_name, parameter['python_name'], parameter['ctypes_type'])
                 definitions.append(line2)
             elif parameter['use_list']:

build/unit_tests/test_codegen_helper.py

@@ -1220,7 +1220,7 @@ def test_get_ctype_variable_declaration_snippet_case_b570():
     actual = get_ctype_variable_declaration_snippet(parameters_for_testing[18], parameters_for_testing, IviDanceStep.NOT_APPLICABLE, config_for_testing, use_numpy_array=False)
     expected = [
         'an_int_size = 256  # case B570',
-        'an_int_array = array.array("h", [0] * an_int_size)  # case B570',
+        'an_int_array = array.array("h", [0]) * an_int_size  # case B570',
         'an_int_ctype = _get_ctypes_pointer_for_buffer(value=an_int_array, library_type=_visatype.ViInt16)  # case B570',
     ]
     assert len(actual) == len(expected)
@@ -1237,7 +1237,7 @@ def test_get_ctype_variable_declaration_snippet_case_b590_array():
     actual = get_ctype_variable_declaration_snippet(parameters_for_testing[24], parameters_for_testing, IviDanceStep.GET_DATA, config_for_testing, use_numpy_array=False)
     expected = [
         'a_buffer_array_size = string_size_ctype.value  # case B590',
-        'a_buffer_array_array = array.array("l", [0] * a_buffer_array_size)  # case B590',
+        'a_buffer_array_array = array.array("l", [0]) * a_buffer_array_size  # case B590',
         'a_buffer_array_ctype = _get_ctypes_pointer_for_buffer(value=a_buffer_array_array, library_type=_visatype.ViInt32)  # case B590',
     ]
     assert len(actual) == len(expected)
@@ -1265,7 +1265,7 @@ def test_get_ctype_variable_declaration_snippet_case_b600():
     actual = get_ctype_variable_declaration_snippet(parameters_for_testing[7], parameters_for_testing, IviDanceStep.NOT_APPLICABLE, config_for_testing, use_numpy_array=False)
     expected = [
         'output_size = number_of_elements  # case B600',
-        'output_array = array.array("q", [0] * output_size)  # case B600',
+        'output_array = array.array("q", [0]) * output_size  # case B600',
         'output_ctype = _get_ctypes_pointer_for_buffer(value=output_array, library_type=_visatype.ViInt64)  # case B600',
     ]
     assert len(actual) == len(expected)
@@ -1282,7 +1282,7 @@ def test_get_ctype_variable_declaration_snippet_case_b620_array():
     actual = get_ctype_variable_declaration_snippet(parameters_for_testing[26], parameters_for_testing, IviDanceStep.GET_DATA, config_for_testing, use_numpy_array=False)
     expected = [
         'a_buffer_twist_array_size = output_twist_ctype.value  # case B620',
-        'a_buffer_twist_array_array = array.array("l", [0] * a_buffer_twist_array_size)  # case B620',
+        'a_buffer_twist_array_array = array.array("l", [0]) * a_buffer_twist_array_size  # case B620',
         'a_buffer_twist_array_ctype = _get_ctypes_pointer_for_buffer(value=a_buffer_twist_array_array, library_type=_visatype.ViInt32)  # case B620',
     ]
     assert len(actual) == len(expected)

generated/nidcpower/nidcpower/_library_interpreter.py

@@ -220,7 +220,7 @@ def export_attribute_configuration_buffer(self):  # noqa: N802
         errors.handle_error(self, error_code, ignore_warnings=True, is_error_handling=False)
         size_ctype = _visatype.ViInt32(error_code)  # case S180
         configuration_size = size_ctype.value  # case B590
-        configuration_array = array.array("b", [0] * configuration_size)  # case B590
+        configuration_array = array.array("b", [0]) * configuration_size  # case B590
         configuration_ctype = _get_ctypes_pointer_for_buffer(value=configuration_array, library_type=_visatype.ViInt8)  # case B590
         error_code = self._library.niDCPower_ExportAttributeConfigurationBuffer(vi_ctype, size_ctype, configuration_ctype)
         errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
@@ -250,10 +250,10 @@ def fetch_multiple(self, channel_name, timeout, count):  # noqa: N802
         timeout_ctype = _visatype.ViReal64(timeout)  # case S150
         count_ctype = _visatype.ViInt32(count)  # case S210
         voltage_measurements_size = count  # case B600
-        voltage_measurements_array = array.array("d", [0] * voltage_measurements_size)  # case B600
+        voltage_measurements_array = array.array("d", [0]) * voltage_measurements_size  # case B600
         voltage_measurements_ctype = _get_ctypes_pointer_for_buffer(value=voltage_measurements_array, library_type=_visatype.ViReal64)  # case B600
         current_measurements_size = count  # case B600
-        current_measurements_array = array.array("d", [0] * current_measurements_size)  # case B600
+        current_measurements_array = array.array("d", [0]) * current_measurements_size  # case B600
         current_measurements_ctype = _get_ctypes_pointer_for_buffer(value=current_measurements_array, library_type=_visatype.ViReal64)  # case B600
         in_compliance_size = count  # case B600
         in_compliance_ctype = _get_ctypes_pointer_for_buffer(library_type=_visatype.ViBoolean, size=in_compliance_size)  # case B600
@@ -397,7 +397,7 @@ def get_lcr_compensation_data(self, channel_name):  # noqa: N802
         errors.handle_error(self, error_code, ignore_warnings=True, is_error_handling=False)
         compensation_data_size_ctype = _visatype.ViInt32(error_code)  # case S180
         compensation_data_size = compensation_data_size_ctype.value  # case B590
-        compensation_data_array = array.array("b", [0] * compensation_data_size)  # case B590
+        compensation_data_array = array.array("b", [0]) * compensation_data_size  # case B590
         compensation_data_ctype = _get_ctypes_pointer_for_buffer(value=compensation_data_array, library_type=_visatype.ViInt8)  # case B590
         error_code = self._library.niDCPower_GetLCRCompensationData(vi_ctype, channel_name_ctype, compensation_data_size_ctype, compensation_data_ctype)
         errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
@@ -425,7 +425,7 @@ def get_lcr_custom_cable_compensation_data(self, channel_name):  # noqa: N802
         errors.handle_error(self, error_code, ignore_warnings=True, is_error_handling=False)
         custom_cable_compensation_data_size_ctype = _visatype.ViInt32(error_code)  # case S180
         custom_cable_compensation_data_size = custom_cable_compensation_data_size_ctype.value  # case B590
-        custom_cable_compensation_data_array = array.array("b", [0] * custom_cable_compensation_data_size)  # case B590
+        custom_cable_compensation_data_array = array.array("b", [0]) * custom_cable_compensation_data_size  # case B590
         custom_cable_compensation_data_ctype = _get_ctypes_pointer_for_buffer(value=custom_cable_compensation_data_array, library_type=_visatype.ViInt8)  # case B590
         error_code = self._library.niDCPower_GetLCRCustomCableCompensationData(vi_ctype, channel_name_ctype, custom_cable_compensation_data_size_ctype, custom_cable_compensation_data_ctype)
         errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
@@ -511,10 +511,10 @@ def measure_multiple(self, channel_name):  # noqa: N802
         vi_ctype = _visatype.ViSession(self._vi)  # case S110
         channel_name_ctype = ctypes.create_string_buffer(channel_name.encode(self._encoding))  # case C010
         voltage_measurements_size = self.parse_channel_count(channel_name)  # case B560
-        voltage_measurements_array = array.array("d", [0] * voltage_measurements_size)  # case B560
+        voltage_measurements_array = array.array("d", [0]) * voltage_measurements_size  # case B560
         voltage_measurements_ctype = _get_ctypes_pointer_for_buffer(value=voltage_measurements_array, library_type=_visatype.ViReal64)  # case B560
         current_measurements_size = self.parse_channel_count(channel_name)  # case B560
-        current_measurements_array = array.array("d", [0] * current_measurements_size)  # case B560
+        current_measurements_array = array.array("d", [0]) * current_measurements_size  # case B560
         current_measurements_ctype = _get_ctypes_pointer_for_buffer(value=current_measurements_array, library_type=_visatype.ViReal64)  # case B560
         error_code = self._library.niDCPower_MeasureMultiple(vi_ctype, channel_name_ctype, voltage_measurements_ctype, current_measurements_ctype)
         errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)

generated/nidigital/nidigital/_library_interpreter.py

@@ -392,7 +392,7 @@ def fetch_capture_waveform(self, site_list, waveform_name, samples_to_read, time
         errors.handle_error(self, error_code, ignore_warnings=True, is_error_handling=False)
         data_buffer_size_ctype = _visatype.ViInt32(actual_num_waveforms_ctype.value * actual_samples_per_waveform_ctype.value)  # case S200 (modified)
         data_size = actual_num_waveforms_ctype.value * actual_samples_per_waveform_ctype.value  # case B620 (modified)
-        data_array = array.array("L", [0] * data_size)  # case B620
+        data_array = array.array("L", [0]) * data_size  # case B620
         data_ctype = _get_ctypes_pointer_for_buffer(value=data_array, library_type=_visatype.ViUInt32)  # case B620
         error_code = self._library.niDigital_FetchCaptureWaveformU32(vi_ctype, site_list_ctype, waveform_name_ctype, samples_to_read_ctype, timeout_ctype, data_buffer_size_ctype, data_ctype, None if actual_num_waveforms_ctype is None else (ctypes.pointer(actual_num_waveforms_ctype)), None if actual_samples_per_waveform_ctype is None else (ctypes.pointer(actual_samples_per_waveform_ctype)))
         errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)

generated/nidigital/nidigital/session.py

@@ -3523,7 +3523,7 @@ def write_source_waveform_site_unique(self, waveform_name, waveform_data):
             actual_samples_per_waveform = 0
         else:
             actual_samples_per_waveform = len(waveform_data[next(iter(waveform_data))])
-        data = array.array('L', [0] * (len(waveform_data) * actual_samples_per_waveform))
+        data = array.array('L', [0]) * (len(waveform_data) * actual_samples_per_waveform)
         mv = memoryview(data)
 
         i = 0