westonpace commented on code in PR #35902: URL: https://github.com/apache/arrow/pull/35902#discussion_r1221652744
########## cpp/src/arrow/acero/source_node_test.cc: ########## @@ -0,0 +1,109 @@ +// 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 <gtest/gtest.h> + +#include "arrow/acero/exec_plan.h" +#include "arrow/acero/map_node.h" +#include "arrow/acero/options.h" +#include "arrow/acero/test_nodes.h" + +namespace arrow { +namespace acero { + +struct PauseThenStopNodeOptions : public ExecNodeOptions { + explicit PauseThenStopNodeOptions(int num_pass) : num_pass(num_pass) {} + + int num_pass; +}; + +struct PauseThenStopNode : public MapNode { + static constexpr const char* kKindName = "PauseThenStopNode"; + static constexpr const char* kFactoryName = "pause_then_stop"; + + static void Register() { + auto exec_reg = default_exec_factory_registry(); + if (!exec_reg->GetFactory(kFactoryName).ok()) { + ASSERT_OK(exec_reg->AddFactory(kFactoryName, PauseThenStopNode::Make)); + } + } + + PauseThenStopNode(ExecPlan* plan, std::vector<ExecNode*> inputs, + std::shared_ptr<Schema> output_schema, + const PauseThenStopNodeOptions& options) + : MapNode(plan, inputs, output_schema), num_pass(options.num_pass) {} + + static Result<ExecNode*> Make(ExecPlan* plan, std::vector<ExecNode*> inputs, + const ExecNodeOptions& options) { + RETURN_NOT_OK(ValidateExecNodeInputs(plan, inputs, 1, kKindName)); + auto bp_options = static_cast<const PauseThenStopNodeOptions&>(options); + if (bp_options.num_pass < 2) { + return Status::Invalid("num_pass must be at least 2"); + } + return plan->EmplaceNode<PauseThenStopNode>(plan, inputs, inputs[0]->output_schema(), + bp_options); + } + + const char* kind_name() const override { return kKindName; } + Result<ExecBatch> ProcessBatch(ExecBatch batch) override { + if (num_pass == 2) { + inputs()[0]->PauseProducing(this, 1); + } else if (num_pass == 1) { + ARROW_RETURN_NOT_OK(inputs()[0]->StopProducing()); + } + if (num_pass > 0) --num_pass; + return batch; + } + + int num_pass; +}; + +TEST(SourceNode, PauseThenStop) { + PauseThenStopNode::Register(); + + constexpr int num_pass = 2, num_batches = 10, batch_size = 1; + ASSERT_GE(num_pass, 2); + ASSERT_GT(num_batches, num_pass); + auto t_schema = schema({field("time", int32()), field("value", int32())}); + ASSERT_OK_AND_ASSIGN(auto t_batches, + MakeIntegerBatches({[](int row) -> int64_t { return row; }, + [](int row) -> int64_t { return row + 1; }}, + t_schema, num_batches, batch_size)); + + Declaration t_src = { + "source", SourceNodeOptions(t_batches.schema, + MakeDelayedGen(t_batches, "t_src", /*delay_sec=*/0.5, + /*noisy=*/false))}; + Declaration ctrl = { + PauseThenStopNode::kFactoryName, {t_src}, PauseThenStopNodeOptions(num_pass)}; + + ASSERT_OK_AND_ASSIGN(std::unique_ptr<RecordBatchReader> batch_reader, + DeclarationToReader(ctrl, /*use_threads=*/false)); + + int64_t total_length = 0; + for (;;) { + ASSERT_OK_AND_ASSIGN(auto batch, batch_reader->Next()); + if (!batch) { + break; + } + total_length += batch->num_rows(); + } + ASSERT_EQ(static_cast<int64_t>(num_pass * batch_size), total_length); Review Comment: I don't think there is any way, at the moment, to assert that the source node is truly paused and no longer looping. If I had to try and think of something I would say... * Create a thread pool and custom exec context * Start the plan, using the custom exec context, have the PauseThenStop node be just a PauseNode that calls PauseProducing as soon as it receives input * When you start the plan, actually create an ExecPlan, and don't use one of the `DeclarationToXyz` methods. * Wait for the thread pool to be idle (`ThreadPool::WaitForIdle`). This way we know that the source node has truly paused. * Call `StopProducing` on the created `ExecPlan`. -- 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]
