1 2 /** 3 * Copyright (C) 2018-present MongoDB, Inc. 4 * 5 * This program is free software: you can redistribute it and/or modify 6 * it under the terms of the Server Side Public License, version 1, 7 * as published by MongoDB, Inc. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * Server Side Public License for more details. 13 * 14 * You should have received a copy of the Server Side Public License 15 * along with this program. If not, see 16 * <http://www.mongodb.com/licensing/server-side-public-license>. 17 * 18 * As a special exception, the copyright holders give permission to link the 19 * code of portions of this program with the OpenSSL library under certain 20 * conditions as described in each individual source file and distribute 21 * linked combinations including the program with the OpenSSL library. You 22 * must comply with the Server Side Public License in all respects for 23 * all of the code used other than as permitted herein. If you modify file(s) 24 * with this exception, you may extend this exception to your version of the 25 * file(s), but you are not obligated to do so. If you do not wish to do so, 26 * delete this exception statement from your version. If you delete this 27 * exception statement from all source files in the program, then also delete 28 * it in the license file. 29 */ 30 31 #pragma once 32 33 #include <boost/intrusive_ptr.hpp> 34 #include <boost/optional/optional.hpp> 35 36 #include "mongo/db/catalog/collection.h" 37 #include "mongo/db/exec/plan_stage.h" 38 #include "mongo/db/exec/plan_stats.h" 39 #include "mongo/db/pipeline/pipeline.h" 40 #include "mongo/db/query/plan_summary_stats.h" 41 #include "mongo/db/record_id.h" 42 #include "mongo/util/assert_util.h" 43 44 namespace mongo { 45 46 /** 47 * Stage for pulling results out from an aggregation pipeline. 48 */ 49 class PipelineProxyStage final : public PlanStage { 50 public: 51 PipelineProxyStage(OperationContext* opCtx, 52 std::unique_ptr<Pipeline, Pipeline::Deleter> pipeline, 53 WorkingSet* ws); 54 55 PlanStage::StageState doWork(WorkingSetID* out) final; 56 57 bool isEOF() final; 58 59 // 60 // Manage our OperationContext. 61 // 62 void doDetachFromOperationContext() final; 63 void doReattachToOperationContext() final; 64 65 // Returns empty PlanStageStats object 66 std::unique_ptr<PlanStageStats> getStats() final; 67 68 // Not used. getSpecificStats()69 SpecificStats* getSpecificStats() const final { 70 MONGO_UNREACHABLE; 71 } 72 doInvalidate(OperationContext * opCtx,const RecordId & rid,InvalidationType type)73 void doInvalidate(OperationContext* opCtx, const RecordId& rid, InvalidationType type) final { 74 // A PlanExecutor with a PipelineProxyStage should be registered with the global cursor 75 // manager, so should not receive invalidations. 76 MONGO_UNREACHABLE; 77 } 78 79 /** 80 * Pass through the last oplog timestamp from the proxied pipeline. 81 */ 82 Timestamp getLatestOplogTimestamp() const; 83 84 std::string getPlanSummaryStr() const; 85 void getPlanSummaryStats(PlanSummaryStats* statsOut) const; 86 stageType()87 StageType stageType() const final { 88 return STAGE_PIPELINE_PROXY; 89 } 90 91 static const char* kStageType; 92 93 protected: 94 void doDispose() final; 95 96 private: 97 boost::optional<BSONObj> getNextBson(); 98 99 // Things in the _stash should be returned before pulling items from _pipeline. 100 std::unique_ptr<Pipeline, Pipeline::Deleter> _pipeline; 101 std::vector<BSONObj> _stash; 102 const bool _includeMetaData; 103 104 // When the aggregation request is from a 3.4 mongos, the merge may happen on a 3.4 shard (which 105 // does not understand sort key metadata), so we should not serialize the sort key, and 106 // '_includeSortKey' is set to false. 107 // TODO SERVER-30924: remove this. 108 const bool _includeSortKey; 109 110 // Not owned by us. 111 WorkingSet* _ws; 112 }; 113 114 } // namespace mongo 115