westonpace commented on code in PR #12672: URL: https://github.com/apache/arrow/pull/12672#discussion_r873843884
########## cpp/src/arrow/engine/substrait/util.cc: ########## @@ -0,0 +1,132 @@ +// 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/engine/substrait/util.h" +#include "arrow/util/async_generator.h" +#include "arrow/util/async_util.h" + +namespace arrow { + +namespace engine { + +namespace substrait { + +namespace { +/// \brief A SinkNodeConsumer specialized to output ExecBatches via PushGenerator +class SubstraitSinkConsumer : public compute::SinkNodeConsumer { + public: + explicit SubstraitSinkConsumer( + arrow::PushGenerator<util::optional<compute::ExecBatch>>::Producer producer) + : producer_(std::move(producer)) {} + + Status Consume(compute::ExecBatch batch) override { + // Consume a batch of data + bool did_push = producer_.Push(batch); + if (!did_push) return Status::Invalid("Producer closed already"); + return Status::OK(); + } + + Status Init(const std::shared_ptr<Schema>& schema, + compute::BackpressureControl* backpressure_control) override { + schema_ = schema; + return Status::OK(); + } + + Future<> Finish() override { + ARROW_UNUSED(producer_.Close()); + return Future<>::MakeFinished(); + } + + std::shared_ptr<Schema> schema() { return schema_; } + + private: + arrow::PushGenerator<util::optional<compute::ExecBatch>>::Producer producer_; + std::shared_ptr<Schema> schema_; +}; + +/// \brief An executor to run a Substrait Query +/// This interface is provided as a utility when creating language +/// bindings for consuming a Substrait plan. +class SubstraitExecutor { + public: + explicit SubstraitExecutor(std::shared_ptr<compute::ExecPlan> plan, + compute::ExecContext exec_context) + : plan_(std::move(plan)), exec_context_(exec_context) {} + + ~SubstraitExecutor() { ARROW_CHECK_OK(this->Close()); } + + Result<std::shared_ptr<RecordBatchReader>> Execute() { + for (const compute::Declaration& decl : declarations_) { + RETURN_NOT_OK(decl.AddToPlan(plan_.get()).status()); + } + RETURN_NOT_OK(plan_->Validate()); + RETURN_NOT_OK(plan_->StartProducing()); + // schema of the output can be obtained by the output_schema + // of the input to the sink node. Review Comment: ```suggestion ``` -- 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]
