kevingurney commented on code in PR #36190: URL: https://github.com/apache/arrow/pull/36190#discussion_r1238765801
########## matlab/src/cpp/arrow/matlab/tabular/proxy/record_batch.cc: ########## @@ -0,0 +1,116 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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 "libmexclass/proxy/ProxyManager.h" + +#include "arrow/matlab/array/proxy/array.h" +#include "arrow/matlab/error/error.h" +#include "arrow/matlab/tabular/proxy/record_batch.h" +#include "arrow/type.h" +#include "arrow/util/utf8.h" + +namespace arrow::matlab::tabular::proxy { + + RecordBatch::RecordBatch(std::shared_ptr<arrow::RecordBatch> record_batch) : record_batch{record_batch} { + REGISTER_METHOD(RecordBatch, toString); + REGISTER_METHOD(RecordBatch, numColumns); + REGISTER_METHOD(RecordBatch, columnNames); + } + + void RecordBatch::toString(libmexclass::proxy::method::Context& context) { + namespace mda = ::matlab::data; + mda::ArrayFactory factory; + const auto maybe_utf16_string = arrow::util::UTF8StringToUTF16(record_batch->ToString()); + // TODO: Add a helper macro to avoid having to write out an explicit if-statement here when handling errors. + if (!maybe_utf16_string.ok()) { + // TODO: This error message could probably be improved. + context.error = libmexclass::error::Error{error::UNICODE_CONVERSION_ERROR_ID, maybe_utf16_string.status().message()}; + return; + } + auto str_mda = factory.createScalar(*maybe_utf16_string); + context.outputs[0] = str_mda; + } + + libmexclass::proxy::MakeResult RecordBatch::make(const libmexclass::proxy::FunctionArguments& constructor_arguments) { + namespace mda = ::matlab::data; + mda::StructArray opts = constructor_arguments[0]; + const mda::TypedArray<uint64_t> arrow_array_proxy_ids = opts[0]["ArrayProxyIDs"]; + const mda::StringArray column_names = opts[0]["ColumnNames"]; + + std::vector<std::shared_ptr<arrow::Array>> arrow_arrays; + // Retrieve all of the Arrow Array Proxy instances from the libmexclass ProxyManager. + for (const auto& arrow_array_proxy_id : arrow_array_proxy_ids) { + auto proxy = libmexclass::proxy::ProxyManager::getProxy(arrow_array_proxy_id); + auto arrow_array_proxy = std::static_pointer_cast<arrow::matlab::array::proxy::Array>(proxy); + auto arrow_array = arrow_array_proxy->getArray(); + arrow_arrays.push_back(arrow_array); + } + + std::vector<std::shared_ptr<Field>> fields; + for (size_t i = 0; i < arrow_arrays.size(); ++i) { + const auto type = arrow_arrays[i]->type(); + const auto column_name_str = std::u16string(column_names[i]); + const auto maybe_column_name_str = arrow::util::UTF16StringToUTF8(column_name_str); + MATLAB_ERROR_IF_NOT_OK(maybe_column_name_str.status(), error::UNICODE_CONVERSION_ERROR_ID); + fields.push_back(std::make_shared<arrow::Field>(maybe_column_name_str.ValueOrDie(), type)); Review Comment: Thanks for suggesting this change! Sorry for not using the dereference operator (*). We knew that the dereference operator (*) was preferred when implementing this. However, for some reason we were running into compiler errors before, so we ended up using `ValueOrDie()` because that seemed to work at the time. However, looking back, it seems like the errors we were seeing must have been related to something else because we were changing a lot of code at the same time. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
