lidavidm commented on code in PR #12620: URL: https://github.com/apache/arrow/pull/12620#discussion_r931155402
########## cpp/examples/arrow/dataset_skyhook_scan_example.cc: ########## @@ -0,0 +1,201 @@ +// 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 <arrow/api.h> +#include <arrow/compute/exec/expression.h> +#include <arrow/dataset/dataset.h> +#include <arrow/dataset/discovery.h> +#include <arrow/dataset/file_base.h> +#include <arrow/dataset/scanner.h> +#include <arrow/filesystem/filesystem.h> +#include <arrow/filesystem/path_util.h> +#include <skyhook/client/file_skyhook.h> + +#include <cstdlib> +#include <iostream> + +using arrow::field; +using arrow::int16; +using arrow::Schema; +using arrow::Table; + +namespace fs = arrow::fs; + +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); + +struct Configuration { + // Increase the ds::DataSet by repeating `repeat` times the ds::Dataset. + size_t repeat = 1; + + // Indicates if the Scanner::ToTable should consume in parallel. + bool use_threads = true; + + // Indicates to the Scan operator which columns are requested. This + // optimization avoid deserializing unneeded columns. + std::vector<std::string> projected_columns = {"total_amount"}; + + // Indicates the filter by which rows will be filtered. This optimization can + // make use of partition information and/or file metadata if possible. + cp::Expression filter = cp::greater(cp::field_ref("payment_type"), cp::literal(1)); + + ds::InspectOptions inspect_options{}; + ds::FinishOptions finish_options{}; +} kConf; + +arrow::Result<std::shared_ptr<ds::Dataset>> GetDatasetFromDirectory( + std::shared_ptr<fs::FileSystem> fs, std::shared_ptr<ds::FileFormat> format, + std::string dir) { + // Find all files under `path` + fs::FileSelector s; + s.base_dir = dir; + s.recursive = true; + + // Set partitioning strategy + ds::FileSystemFactoryOptions options; + options.partitioning = std::make_shared<ds::HivePartitioning>( + arrow::schema({arrow::field("payment_type", arrow::int32()), + arrow::field("VendorID", arrow::int32())})); + + // The factory will try to build a child dataset. + ARROW_ASSIGN_OR_RAISE(auto factory, + ds::FileSystemDatasetFactory::Make(fs, s, format, options)); + + // Try to infer a common schema for all files. + ARROW_ASSIGN_OR_RAISE(auto schema, factory->Inspect(kConf.inspect_options)); + // Caller can optionally decide another schema as long as it is compatible + // with the previous one, e.g. `factory->Finish(compatible_schema)`. + ARROW_ASSIGN_OR_RAISE(auto child, factory->Finish(kConf.finish_options)); + + ds::DatasetVector children{kConf.repeat, child}; Review Comment: IMO instead of complicating it with the repeat, let's just return the dataset directly (ditto below) ########## cpp/examples/arrow/dataset_skyhook_scan_example.cc: ########## @@ -0,0 +1,201 @@ +// 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 <arrow/api.h> +#include <arrow/compute/exec/expression.h> +#include <arrow/dataset/dataset.h> +#include <arrow/dataset/discovery.h> +#include <arrow/dataset/file_base.h> +#include <arrow/dataset/scanner.h> +#include <arrow/filesystem/filesystem.h> +#include <arrow/filesystem/path_util.h> +#include <skyhook/client/file_skyhook.h> + +#include <cstdlib> +#include <iostream> + +using arrow::field; +using arrow::int16; +using arrow::Schema; +using arrow::Table; + +namespace fs = arrow::fs; + +namespace ds = arrow::dataset; + +namespace cp = arrow::compute; + +#define ABORT_ON_FAILURE(expr) \ Review Comment: We recently rewrote the examples to avoid this style - instead functions appropriately return `arrow::Status` or `arrow::Result`, and then we have a `Status Main()`; finally in `int main()` we check the status of `Main()` and print/exit as appropriate. For reference see #13598 ########## cpp/examples/arrow/dataset_skyhook_scan_example.cc: ########## @@ -0,0 +1,201 @@ +// 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 <arrow/api.h> +#include <arrow/compute/exec/expression.h> +#include <arrow/dataset/dataset.h> +#include <arrow/dataset/discovery.h> +#include <arrow/dataset/file_base.h> +#include <arrow/dataset/scanner.h> +#include <arrow/filesystem/filesystem.h> +#include <arrow/filesystem/path_util.h> +#include <skyhook/client/file_skyhook.h> + +#include <cstdlib> +#include <iostream> + +using arrow::field; +using arrow::int16; +using arrow::Schema; +using arrow::Table; + +namespace fs = arrow::fs; + +namespace ds = arrow::dataset; + +namespace cp = arrow::compute; + +#define ABORT_ON_FAILURE(expr) \ Review Comment: It looks like things here are already in that style, so can we just inline this macro into `main`? ########## cpp/examples/arrow/dataset_skyhook_scan_example.cc: ########## @@ -0,0 +1,201 @@ +// 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 <arrow/api.h> +#include <arrow/compute/exec/expression.h> +#include <arrow/dataset/dataset.h> +#include <arrow/dataset/discovery.h> +#include <arrow/dataset/file_base.h> +#include <arrow/dataset/scanner.h> +#include <arrow/filesystem/filesystem.h> +#include <arrow/filesystem/path_util.h> +#include <skyhook/client/file_skyhook.h> + +#include <cstdlib> +#include <iostream> + +using arrow::field; +using arrow::int16; +using arrow::Schema; +using arrow::Table; + +namespace fs = arrow::fs; + +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); + +struct Configuration { + // Increase the ds::DataSet by repeating `repeat` times the ds::Dataset. + size_t repeat = 1; + + // Indicates if the Scanner::ToTable should consume in parallel. + bool use_threads = true; + + // Indicates to the Scan operator which columns are requested. This + // optimization avoid deserializing unneeded columns. + std::vector<std::string> projected_columns = {"total_amount"}; + + // Indicates the filter by which rows will be filtered. This optimization can + // make use of partition information and/or file metadata if possible. + cp::Expression filter = cp::greater(cp::field_ref("payment_type"), cp::literal(1)); + + ds::InspectOptions inspect_options{}; + ds::FinishOptions finish_options{}; +} kConf; + +arrow::Result<std::shared_ptr<ds::Dataset>> GetDatasetFromDirectory( + std::shared_ptr<fs::FileSystem> fs, std::shared_ptr<ds::FileFormat> format, + std::string dir) { + // Find all files under `path` + fs::FileSelector s; + s.base_dir = dir; + s.recursive = true; + + // Set partitioning strategy + ds::FileSystemFactoryOptions options; + options.partitioning = std::make_shared<ds::HivePartitioning>( + arrow::schema({arrow::field("payment_type", arrow::int32()), + arrow::field("VendorID", arrow::int32())})); + + // The factory will try to build a child dataset. Review Comment: I'm not sure what's meant by child dataset (here and below) ########## docs/source/cpp/examples/dataset_skyhook_scan_example.rst: ########## @@ -0,0 +1,93 @@ +.. 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. + +.. default-domain:: cpp +.. highlight:: cpp + +===================== +Arrow Skyhook example +===================== + +The file ``cpp/examples/arrow/dataset_skyhook_scan_example.cc`` +located inside the source tree contains an example of using Skyhook to +offload filters and projections to a Ceph cluster. + +Instuctions +=========== + +.. note:: + The instructions below are for ubuntu 20.04 or above. + +1. Install Ceph and Skyhook dependencies. + +.. code-block:: bash Review Comment: I think these need indentation to be properly formatted as part of the list, but I can push a fix later -- 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]
