vibhatha commented on a change in pull request #12110: URL: https://github.com/apache/arrow/pull/12110#discussion_r788380967
########## File path: cpp/examples/arrow/join_example.cc ########## @@ -0,0 +1,194 @@ +// 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. + +// This example showcases various ways to work with Datasets. It's +// intended to be paired with the documentation. + +#include <arrow/api.h> +#include <arrow/compute/api.h> +#include <arrow/compute/exec/exec_plan.h> +#include <arrow/compute/exec/expression.h> +#include <arrow/csv/api.h> + +#include <arrow/dataset/dataset.h> +#include <arrow/dataset/plan.h> +#include <arrow/dataset/scanner.h> + +#include <arrow/io/interfaces.h> +#include <arrow/io/memory.h> +#include <arrow/io/stdio.h> + +#include <arrow/filesystem/filesystem.h> + +#include <arrow/result.h> +#include <arrow/status.h> + +#include <arrow/util/vector.h> + +#include <iostream> +#include <vector> + +namespace ds = arrow::dataset; +namespace cp = arrow::compute; + +#define ABORT_ON_FAILURE(expr) \ + do { \ + arrow::Status status_ = (expr); \ + if (!status_.ok()) { \ + std::cerr << status_.message() << std::endl; \ + abort(); \ + } \ + } while (0); + +std::string GetDataAsCsvString(std::string relation) { + std::string data_str = ""; + if (relation == "l") { + data_str = R"csv(lkey,shared,ldistinct +1,4,7 +2,5,8 +11,20,21 +3,6,9)csv"; + } else if (relation == "r") { + data_str = R"csv(rkey,shared,rdistinct +1,10,13 +124,10,11 +2,11,14 +3,12,15)csv"; + } else { + return data_str; + } + return data_str; +} + +arrow::Result<std::shared_ptr<arrow::Table>> GetTableFromExecBatches( + const std::shared_ptr<arrow::Schema>& schema, + const std::vector<arrow::compute::ExecBatch>& exec_batches) { + arrow::RecordBatchVector batches; + for (const auto& batch : exec_batches) { + ARROW_ASSIGN_OR_RAISE(auto rb, batch.ToRecordBatch(schema)); + batches.push_back(std::move(rb)); + } + return arrow::Table::FromRecordBatches(schema, batches); +} + +arrow::Result<std::shared_ptr<arrow::dataset::Dataset>> CreateDataSetFromCSVData( + std::string relation) { + arrow::io::IOContext io_context = arrow::io::default_io_context(); + std::shared_ptr<arrow::io::InputStream> input; + std::string csv_data = GetDataAsCsvString(relation); + std::cout << "CSV DATA : " << relation << std::endl; + std::cout << csv_data << std::endl; + arrow::util::string_view sv = csv_data; + input = std::make_shared<arrow::io::BufferReader>(sv); + auto read_options = arrow::csv::ReadOptions::Defaults(); + auto parse_options = arrow::csv::ParseOptions::Defaults(); + auto convert_options = arrow::csv::ConvertOptions::Defaults(); + + // Instantiate TableReader from input stream and options + ARROW_ASSIGN_OR_RAISE(std::shared_ptr<arrow::csv::TableReader> table_reader, + arrow::csv::TableReader::Make(io_context, input, read_options, + parse_options, convert_options)); + + std::shared_ptr<arrow::csv::TableReader> reader = table_reader; + + // Read table from CSV file + ARROW_ASSIGN_OR_RAISE(auto maybe_table, reader->Read()); + auto ds = std::make_shared<arrow::dataset::InMemoryDataset>(maybe_table); + arrow::Result<std::shared_ptr<arrow::dataset::InMemoryDataset>> result(std::move(ds)); + return result; +} + +cp::Expression Materialize(std::vector<std::string> names) { Review comment: absolutely, just the one liner makes more sense since we haven't used it with any args passed. -- 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]
