SERVER-48478 Replace PipelineProxyStage with PlanExecutorPipeline

4 files changed, 0 insertions, 464 deletions

diff --git a/src/mongo/db/exec/change_stream_proxy.cpp b/src/mongo/db/exec/change_stream_proxy.cpp
deleted file mode 100644
index c16255a897b..00000000000
--- a/src/mongo/db/exec/change_stream_proxy.cpp
+++ /dev/null
@@ -1,116 +0,0 @@
-/**
- *    Copyright (C) 2018-present MongoDB, Inc.
- *
- *    This program is free software: you can redistribute it and/or modify
- *    it under the terms of the Server Side Public License, version 1,
- *    as published by MongoDB, Inc.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    Server Side Public License for more details.
- *
- *    You should have received a copy of the Server Side Public License
- *    along with this program. If not, see
- *    <http://www.mongodb.com/licensing/server-side-public-license>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the Server Side Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#include "mongo/platform/basic.h"
-
-#include "mongo/db/exec/change_stream_proxy.h"
-
-#include "mongo/db/pipeline/pipeline_d.h"
-#include "mongo/db/pipeline/resume_token.h"
-#include "mongo/db/repl/speculative_majority_read_info.h"
-
-namespace mongo {
-
-const char* ChangeStreamProxyStage::kStageType = "CHANGE_STREAM_PROXY";
-
-ChangeStreamProxyStage::ChangeStreamProxyStage(ExpressionContext* expCtx,
-                                               std::unique_ptr<Pipeline, PipelineDeleter> pipeline,
-                                               WorkingSet* ws)
-    : PipelineProxyStage(expCtx, std::move(pipeline), ws, kStageType) {
-    // Set _postBatchResumeToken to the initial PBRT that was added to the expression context during
-    // pipeline construction, and use it to obtain the starting time for _latestOplogTimestamp.
-    invariant(!_pipeline->getContext()->initialPostBatchResumeToken.isEmpty());
-    _postBatchResumeToken = _pipeline->getContext()->initialPostBatchResumeToken.getOwned();
-    _latestOplogTimestamp = ResumeToken::parse(_postBatchResumeToken).getData().clusterTime;
-}
-
-boost::optional<Document> ChangeStreamProxyStage::getNext() {
-    if (auto next = _pipeline->getNext()) {
-        // While we have more results to return, we track both the timestamp and the resume token of
-        // the latest event observed in the oplog, the latter via its sort key metadata field.
-        _validateResumeToken(*next);
-        _latestOplogTimestamp = PipelineD::getLatestOplogTimestamp(_pipeline.get());
-        _postBatchResumeToken = next->metadata().getSortKey().getDocument().toBson();
-        _setSpeculativeReadTimestamp();
-        return next;
-    }
-
-    // We ran out of results to return. Check whether the oplog cursor has moved forward since the
-    // last recorded timestamp. Because we advance _latestOplogTimestamp for every event we return,
-    // if the new time is higher than the last then we are guaranteed not to have already returned
-    // any events at this timestamp. We can set _postBatchResumeToken to a new high-water-mark token
-    // at the current clusterTime.
-    auto highWaterMark = PipelineD::getLatestOplogTimestamp(_pipeline.get());
-    if (highWaterMark > _latestOplogTimestamp) {
-        auto token = ResumeToken::makeHighWaterMarkToken(highWaterMark);
-        _postBatchResumeToken = token.toDocument().toBson();
-        _latestOplogTimestamp = highWaterMark;
-        _setSpeculativeReadTimestamp();
-    }
-    return boost::none;
-}
-
-void ChangeStreamProxyStage::_validateResumeToken(const Document& event) const {
-    // If we are producing output to be merged on mongoS, then no stages can have modified the _id.
-    if (_includeMetaData) {
-        return;
-    }
-    // Confirm that the document _id field matches the original resume token in the sort key field.
-    auto eventBSON = event.toBson();
-    auto resumeToken = event.metadata().getSortKey();
-    auto idField = eventBSON.getObjectField("_id");
-    invariant(!resumeToken.missing());
-    uassert(ErrorCodes::ChangeStreamFatalError,
-            str::stream() << "Encountered an event whose _id field, which contains the resume "
-                             "token, was modified by the pipeline. Modifying the _id field of an "
-                             "event makes it impossible to resume the stream from that point. Only "
-                             "transformations that retain the unmodified _id field are allowed. "
-                             "Expected: "
-                          << BSON("_id" << resumeToken) << " but found: "
-                          << (eventBSON["_id"] ? BSON("_id" << eventBSON["_id"]) : BSONObj()),
-            (resumeToken.getType() == BSONType::Object) &&
-                idField.binaryEqual(resumeToken.getDocument().toBson()));
-}
-
-void ChangeStreamProxyStage::_setSpeculativeReadTimestamp() {
-    repl::SpeculativeMajorityReadInfo& speculativeMajorityReadInfo =
-        repl::SpeculativeMajorityReadInfo::get(_pipeline->getContext()->opCtx);
-    if (speculativeMajorityReadInfo.isSpeculativeRead() && !_latestOplogTimestamp.isNull()) {
-        speculativeMajorityReadInfo.setSpeculativeReadTimestampForward(_latestOplogTimestamp);
-    }
-}
-
-std::unique_ptr<PlanStageStats> ChangeStreamProxyStage::getStats() {
-    std::unique_ptr<PlanStageStats> ret =
-        std::make_unique<PlanStageStats>(CommonStats(kStageType), STAGE_CHANGE_STREAM_PROXY);
-    ret->specific = std::make_unique<CollectionScanStats>();
-    return ret;
-}
-
-}  // namespace mongo
diff --git a/src/mongo/db/exec/change_stream_proxy.h b/src/mongo/db/exec/change_stream_proxy.h
deleted file mode 100644
index 6d115b78885..00000000000
--- a/src/mongo/db/exec/change_stream_proxy.h
+++ /dev/null
@@ -1,97 +0,0 @@
-/**
- *    Copyright (C) 2018-present MongoDB, Inc.
- *
- *    This program is free software: you can redistribute it and/or modify
- *    it under the terms of the Server Side Public License, version 1,
- *    as published by MongoDB, Inc.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    Server Side Public License for more details.
- *
- *    You should have received a copy of the Server Side Public License
- *    along with this program. If not, see
- *    <http://www.mongodb.com/licensing/server-side-public-license>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the Server Side Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#pragma once
-
-#include "mongo/db/exec/pipeline_proxy.h"
-
-namespace mongo {
-
-/**
- * ChangeStreamProxyStage is a drop-in replacement for PipelineProxyStage, intended to manage the
- * serialization of change stream pipeline output from Document to BSON. In particular, it is
- * additionally responsible for tracking the latestOplogTimestamps and postBatchResumeTokens that
- * are necessary for correct merging on mongoS and, in the latter case, must also be provided to
- * mongoD clients.
- */
-class ChangeStreamProxyStage final : public PipelineProxyStage {
-public:
-    static const char* kStageType;
-
-    /**
-     * The 'pipeline' argument must be a $changeStream pipeline. Passing a non-$changeStream into
-     * the constructor will cause an invariant() to fail.
-     */
-    ChangeStreamProxyStage(ExpressionContext* expCtx,
-                           std::unique_ptr<Pipeline, PipelineDeleter> pipeline,
-                           WorkingSet* ws);
-
-    /**
-     * Returns an empty PlanStageStats object.
-     */
-    std::unique_ptr<PlanStageStats> getStats() final;
-
-    /**
-     * Passes through the latest oplog timestamp from the proxied pipeline. We only expose the oplog
-     * timestamp in the event that we need to merge on mongoS.
-     */
-    Timestamp getLatestOplogTimestamp() const {
-        return _includeMetaData ? _latestOplogTimestamp : Timestamp();
-    }
-
-    /**
-     * Passes through the most recent resume token from the proxied pipeline.
-     */
-    BSONObj getPostBatchResumeToken() const {
-        return _postBatchResumeToken;
-    }
-
-    StageType stageType() const final {
-        return STAGE_CHANGE_STREAM_PROXY;
-    }
-
-protected:
-    boost::optional<Document> getNext() final;
-
-private:
-    /**
-     * Verifies that the docs's resume token has not been modified.
-     */
-    void _validateResumeToken(const Document& event) const;
-
-    /**
-     * Set the speculative majority read timestamp if we have scanned up to a certain oplog
-     * timestamp.
-     */
-    void _setSpeculativeReadTimestamp();
-
-    Timestamp _latestOplogTimestamp;
-    BSONObj _postBatchResumeToken;
-};
-}  // namespace mongo
diff --git a/src/mongo/db/exec/pipeline_proxy.cpp b/src/mongo/db/exec/pipeline_proxy.cpp
deleted file mode 100644
index c3014ce34a5..00000000000
--- a/src/mongo/db/exec/pipeline_proxy.cpp
+++ /dev/null
@@ -1,145 +0,0 @@
-/**
- *    Copyright (C) 2018-present MongoDB, Inc.
- *
- *    This program is free software: you can redistribute it and/or modify
- *    it under the terms of the Server Side Public License, version 1,
- *    as published by MongoDB, Inc.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    Server Side Public License for more details.
- *
- *    You should have received a copy of the Server Side Public License
- *    along with this program. If not, see
- *    <http://www.mongodb.com/licensing/server-side-public-license>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the Server Side Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#include "mongo/platform/basic.h"
-
-#include "mongo/db/exec/pipeline_proxy.h"
-
-#include <memory>
-
-#include "mongo/db/pipeline/document_source.h"
-#include "mongo/db/pipeline/expression_context.h"
-#include "mongo/db/pipeline/pipeline_d.h"
-
-namespace mongo {
-
-using boost::intrusive_ptr;
-using std::shared_ptr;
-using std::unique_ptr;
-using std::vector;
-
-const char* PipelineProxyStage::kStageType = "PIPELINE_PROXY";
-
-PipelineProxyStage::PipelineProxyStage(ExpressionContext* expCtx,
-                                       std::unique_ptr<Pipeline, PipelineDeleter> pipeline,
-                                       WorkingSet* ws)
-    : PipelineProxyStage(expCtx, std::move(pipeline), ws, kStageType) {}
-
-PipelineProxyStage::PipelineProxyStage(ExpressionContext* expCtx,
-                                       std::unique_ptr<Pipeline, PipelineDeleter> pipeline,
-                                       WorkingSet* ws,
-                                       const char* stageTypeName)
-    : PlanStage(stageTypeName, expCtx),
-      _pipeline(std::move(pipeline)),
-      _includeMetaData(_pipeline->getContext()->needsMerge),  // send metadata to merger
-      _ws(ws) {
-    // We take over responsibility for disposing of the Pipeline, since it is required that
-    // doDispose() will be called before destruction of this PipelineProxyStage.
-    _pipeline.get_deleter().dismissDisposal();
-}
-
-PlanStage::StageState PipelineProxyStage::doWork(WorkingSetID* out) {
-    invariant(out);
-
-    if (!_stash.empty()) {
-        *out = _ws->allocate();
-        WorkingSetMember* member = _ws->get(*out);
-        if (_includeMetaData && _stash.back().metadata()) {
-            member->metadata() = _stash.back().metadata();
-        }
-        member->doc = {SnapshotId(), std::move(_stash.back())};
-        _stash.pop_back();
-        member->transitionToOwnedObj();
-        return PlanStage::ADVANCED;
-    }
-
-    if (auto next = getNext()) {
-        *out = _ws->allocate();
-        WorkingSetMember* member = _ws->get(*out);
-        if (_includeMetaData && next->metadata()) {
-            member->metadata() = next->metadata();
-        }
-        member->doc = {SnapshotId(), std::move(*next)};
-        member->transitionToOwnedObj();
-        return PlanStage::ADVANCED;
-    }
-
-    return PlanStage::IS_EOF;
-}
-
-bool PipelineProxyStage::isEOF() {
-    if (!_stash.empty())
-        return false;
-
-    if (auto next = getNext()) {
-        _stash.emplace_back(*next);
-        return false;
-    }
-
-    return true;
-}
-
-void PipelineProxyStage::doDetachFromOperationContext() {
-    _pipeline->detachFromOperationContext();
-}
-
-void PipelineProxyStage::doReattachToOperationContext() {
-    _pipeline->reattachToOperationContext(opCtx());
-}
-
-void PipelineProxyStage::doDispose() {
-    _pipeline->dispose(opCtx());
-}
-
-unique_ptr<PlanStageStats> PipelineProxyStage::getStats() {
-    unique_ptr<PlanStageStats> ret =
-        std::make_unique<PlanStageStats>(CommonStats(kStageType), STAGE_PIPELINE_PROXY);
-    ret->specific = std::make_unique<CollectionScanStats>();
-    return ret;
-}
-
-boost::optional<Document> PipelineProxyStage::getNext() {
-    return _pipeline->getNext();
-}
-
-std::string PipelineProxyStage::getPlanSummaryStr() const {
-    return PipelineD::getPlanSummaryStr(_pipeline.get());
-}
-
-void PipelineProxyStage::getPlanSummaryStats(PlanSummaryStats* statsOut) const {
-    invariant(statsOut);
-    PipelineD::getPlanSummaryStats(_pipeline.get(), statsOut);
-    statsOut->nReturned = getCommonStats()->advanced;
-}
-
-vector<Value> PipelineProxyStage::writeExplainOps(ExplainOptions::Verbosity verbosity) const {
-    return _pipeline->writeExplainOps(verbosity);
-}
-
-}  // namespace mongo
diff --git a/src/mongo/db/exec/pipeline_proxy.h b/src/mongo/db/exec/pipeline_proxy.h
deleted file mode 100644
index 99f8583f3c0..00000000000
--- a/src/mongo/db/exec/pipeline_proxy.h
+++ /dev/null
@@ -1,106 +0,0 @@
-/**
- *    Copyright (C) 2018-present MongoDB, Inc.
- *
- *    This program is free software: you can redistribute it and/or modify
- *    it under the terms of the Server Side Public License, version 1,
- *    as published by MongoDB, Inc.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    Server Side Public License for more details.
- *
- *    You should have received a copy of the Server Side Public License
- *    along with this program. If not, see
- *    <http://www.mongodb.com/licensing/server-side-public-license>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the Server Side Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#pragma once
-
-#include <boost/intrusive_ptr.hpp>
-#include <boost/optional/optional.hpp>
-
-#include "mongo/db/exec/plan_stage.h"
-#include "mongo/db/exec/plan_stats.h"
-#include "mongo/db/pipeline/pipeline.h"
-#include "mongo/db/query/plan_summary_stats.h"
-#include "mongo/db/record_id.h"
-#include "mongo/util/assert_util.h"
-
-namespace mongo {
-
-/**
- * Stage for pulling results out from an aggregation pipeline.
- */
-class PipelineProxyStage : public PlanStage {
-public:
-    PipelineProxyStage(ExpressionContext* expCtx,
-                       std::unique_ptr<Pipeline, PipelineDeleter> pipeline,
-                       WorkingSet* ws);
-
-    virtual ~PipelineProxyStage() = default;
-
-    PlanStage::StageState doWork(WorkingSetID* out) final;
-
-    bool isEOF() final;
-
-    //
-    // Manage our OperationContext.
-    //
-    void doDetachFromOperationContext() final;
-    void doReattachToOperationContext() final;
-
-    // Returns empty PlanStageStats object
-    std::unique_ptr<PlanStageStats> getStats() override;
-
-    // Not used.
-    SpecificStats* getSpecificStats() const final {
-        MONGO_UNREACHABLE;
-    }
-
-    std::string getPlanSummaryStr() const;
-    void getPlanSummaryStats(PlanSummaryStats* statsOut) const;
-
-    StageType stageType() const override {
-        return STAGE_PIPELINE_PROXY;
-    }
-
-    /**
-     * Writes the pipelineProxyStage's operators to a std::vector<Value>, providing the level of
-     * detail specified by 'verbosity'.
-     */
-    std::vector<Value> writeExplainOps(ExplainOptions::Verbosity verbosity) const;
-
-    static const char* kStageType;
-
-protected:
-    PipelineProxyStage(ExpressionContext* expCtx,
-                       std::unique_ptr<Pipeline, PipelineDeleter> pipeline,
-                       WorkingSet* ws,
-                       const char* stageTypeName);
-
-    virtual boost::optional<Document> getNext();
-    void doDispose() final;
-
-    // Items in the _stash should be returned before pulling items from _pipeline.
-    std::unique_ptr<Pipeline, PipelineDeleter> _pipeline;
-    const bool _includeMetaData;
-
-private:
-    std::vector<Document> _stash;
-    WorkingSet* _ws;
-};
-
-}  // namespace mongo