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/**
* 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/catalog/collection.h"
#include "mongo/db/exec/requires_collection_stage.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/ops/parsed_update.h"
#include "mongo/db/ops/update_request.h"
#include "mongo/db/ops/update_result.h"
#include "mongo/db/s/collection_sharding_state.h"
#include "mongo/db/update/update_driver.h"
namespace mongo {
class OperationContext;
class OpDebug;
struct PlanSummaryStats;
struct UpdateStageParams {
UpdateStageParams(const UpdateRequest* r, UpdateDriver* d, OpDebug* o)
: request(r), driver(d), opDebug(o), canonicalQuery(nullptr) {}
// Contains update parameters like whether it's a multi update or an upsert. Not owned.
// Must outlive the UpdateStage.
const UpdateRequest* request;
// Contains the logic for applying mods to documents. Not owned. Must outlive
// the UpdateStage.
UpdateDriver* driver;
// Needed to pass to Collection::updateDocument(...).
OpDebug* opDebug;
// Not owned here.
CanonicalQuery* canonicalQuery;
private:
// Default constructor not allowed.
UpdateStageParams();
};
/**
* Execution stage responsible for updates to documents. If the prior or newly-updated version of
* the document was requested to be returned, then ADVANCED is returned after updating a document.
* Otherwise, NEED_TIME is returned after updating a document if further updates are pending,
* and IS_EOF is returned if no documents were found or all updates have been performed.
*
* Callers of doWork() must be holding a write lock.
*/
class UpdateStage : public RequiresMutableCollectionStage {
UpdateStage(const UpdateStage&) = delete;
UpdateStage& operator=(const UpdateStage&) = delete;
public:
UpdateStage(ExpressionContext* expCtx,
const UpdateStageParams& params,
WorkingSet* ws,
Collection* collection,
PlanStage* child);
bool isEOF() override;
StageState doWork(WorkingSetID* out) override;
StageType stageType() const final {
return STAGE_UPDATE;
}
std::unique_ptr<PlanStageStats> getStats() final;
const SpecificStats* getSpecificStats() const final;
static const char* kStageType;
/**
* Gets a pointer to the UpdateStats inside 'exec'.
*
* The 'exec' must have an UPDATE stage as its root stage, and the plan must be EOF before
* calling this method.
*/
static const UpdateStats* getUpdateStats(const PlanExecutor* exec);
/**
* Populate 'opDebug' with stats from 'updateStats' describing the execution of this update.
*/
static void recordUpdateStatsInOpDebug(const UpdateStats* updateStats, OpDebug* opDebug);
/**
* Converts 'updateStats' into an UpdateResult.
*/
static UpdateResult makeUpdateResult(const UpdateStats* updateStats);
/**
* Returns true if an update failure due to a given DuplicateKey error is eligible for retry.
* Requires that parsedUpdate.hasParsedQuery() is true.
*/
static bool shouldRetryDuplicateKeyException(const ParsedUpdate& parsedUpdate,
const DuplicateKeyErrorInfo& errorInfo);
protected:
UpdateStage(ExpressionContext* expCtx,
const UpdateStageParams& params,
WorkingSet* ws,
Collection* collection);
void doSaveStateRequiresCollection() final {}
void doRestoreStateRequiresCollection() final;
void _ensureIdFieldIsFirst(mutablebson::Document* doc, bool generateOIDIfMissing);
void _assertPathsNotArray(const mutablebson::Document& document, const FieldRefSet& paths);
UpdateStageParams _params;
// Not owned by us.
WorkingSet* _ws;
// Stats
UpdateStats _specificStats;
// A user-initiated write is one which is not caused by oplog application and is not part of a
// chunk migration
bool _isUserInitiatedWrite;
// These get reused for each update.
mutablebson::Document& _doc;
mutablebson::DamageVector _damages;
private:
static const UpdateStats kEmptyUpdateStats;
/**
* Returns whether a given MatchExpression contains is a MatchType::EQ or a MatchType::AND node
* with only MatchType::EQ children.
*/
static bool matchContainsOnlyAndedEqualityNodes(const MatchExpression& root);
/**
* Computes the result of applying mods to the document 'oldObj' at RecordId 'recordId' in
* memory, then commits these changes to the database. Returns a possibly unowned copy
* of the newly-updated version of the document.
*/
BSONObj transformAndUpdate(const Snapshotted<BSONObj>& oldObj, RecordId& recordId);
/**
* Stores 'idToRetry' in '_idRetrying' so the update can be retried during the next call to
* doWork(). Always returns NEED_YIELD and sets 'out' to WorkingSet::INVALID_ID.
*/
StageState prepareToRetryWSM(WorkingSetID idToRetry, WorkingSetID* out);
/**
* Checks that the updated doc has all required shard key fields and throws if it does not.
*
* Also checks if the updated doc still belongs to this node and throws if it does not. If the
* doc no longer belongs to this shard, this means that one or more shard key field values have
* been updated to a value belonging to a chunk that is not owned by this shard. We cannot apply
* this update atomically.
*
* If the update changes shard key fields but the new shard key remains on the same node,
* returns true. If the update does not change shard key fields, returns false.
*/
bool checkUpdateChangesShardKeyFields(const Snapshotted<BSONObj>& oldObj);
// If not WorkingSet::INVALID_ID, we use this rather than asking our child what to do next.
WorkingSetID _idRetrying;
// If not WorkingSet::INVALID_ID, we return this member to our caller.
WorkingSetID _idReturning;
// If the update was in-place, we may see it again. This only matters if we're doing
// a multi-update; if we're not doing a multi-update we stop after one update and we
// won't see any more docs.
//
// For example: If we're scanning an index {x:1} and performing {$inc:{x:5}}, we'll keep
// moving the document forward and it will continue to reappear in our index scan.
// Unless the index is multikey, the underlying query machinery won't de-dup.
//
// If the update wasn't in-place we may see it again. Our query may return the new
// document and we wouldn't want to update that.
//
// So, no matter what, we keep track of where the doc wound up.
typedef stdx::unordered_set<RecordId, RecordId::Hasher> RecordIdSet;
const std::unique_ptr<RecordIdSet> _updatedRecordIds;
};
} // namespace mongo
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