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/**
* Copyright (C) 2022-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/config.h"
#include "mongo/db/exec/sbe/expressions/expression.h"
#include "mongo/db/exec/sbe/stages/collection_helpers.h"
#include "mongo/db/exec/sbe/stages/stages.h"
#include "mongo/db/storage/column_store.h"
namespace mongo {
namespace sbe {
/**
* A stage that scans provided columnar index. A set of paths is retrieved from the index and values
* are put in output slots.
*/
class ColumnScanStage final : public PlanStage {
public:
ColumnScanStage(UUID collectionUuid,
StringData columnIndexName,
value::SlotVector fieldSlots,
std::vector<std::string> paths,
boost::optional<value::SlotId> recordSlot,
boost::optional<value::SlotId> recordIdSlot,
std::unique_ptr<EExpression> internalExpr,
std::vector<std::unique_ptr<EExpression>> pathExprs,
value::SlotId internalSlot,
PlanYieldPolicy* yieldPolicy,
PlanNodeId planNodeId,
bool participateInTrialRunTracking = true);
std::unique_ptr<PlanStage> clone() const final;
void prepare(CompileCtx& ctx) final;
value::SlotAccessor* getAccessor(CompileCtx& ctx, value::SlotId slot) final;
void open(bool reOpen) final;
PlanState getNext() final;
void close() final;
std::unique_ptr<PlanStageStats> getStats(bool includeDebugInfo) const final;
const SpecificStats* getSpecificStats() const final;
std::vector<DebugPrinter::Block> debugPrint() const final;
size_t estimateCompileTimeSize() const final;
protected:
void doSaveState(bool relinquishCursor) override;
void doRestoreState(bool relinquishCursor) override;
void doDetachFromOperationContext() override;
void doAttachToOperationContext(OperationContext* opCtx) override;
void doDetachFromTrialRunTracker() override;
TrialRunTrackerAttachResultMask doAttachToTrialRunTracker(
TrialRunTracker* tracker, TrialRunTrackerAttachResultMask childrenAttachResult) override;
private:
class ColumnCursor {
public:
ColumnCursor(std::unique_ptr<ColumnStore::CursorForPath> curs, bool includeInResult)
: _cursor(std::move(curs)), _includeInOutput(includeInResult) {}
boost::optional<FullCellView>& next() {
// TODO For some reason the destructor of 'lastCell' is not called
// on my local asan build unless we explicitly reset it. Maybe
// the same compiler bug Nikita ran into?
_lastCell.reset();
_lastCell = _cursor->next();
clearOwned();
return _lastCell;
}
boost::optional<FullCellView>& seekAtOrPast(RecordId id) {
_lastCell.reset();
_lastCell = _cursor->seekAtOrPast(id);
clearOwned();
return _lastCell;
}
const PathValue& path() const {
return _cursor->path();
}
/*
* Copies any data owned by the storage engine into a locally owned buffer.
*/
void makeOwned() {
if (_lastCell && _pathOwned.empty() && _cellOwned.empty()) {
_pathOwned.insert(
_pathOwned.begin(), _lastCell->path.begin(), _lastCell->path.end());
_lastCell->path = StringData(_pathOwned);
_cellOwned.insert(
_cellOwned.begin(), _lastCell->value.begin(), _lastCell->value.end());
_lastCell->value = StringData(_cellOwned.data(), _cellOwned.size());
}
}
ColumnStore::CursorForPath& cursor() {
return *_cursor;
}
bool includeInOutput() const {
return _includeInOutput;
}
boost::optional<FullCellView>& lastCell() {
return _lastCell;
}
private:
void clearOwned() {
_pathOwned.clear();
_cellOwned.clear();
}
std::unique_ptr<ColumnStore::CursorForPath> _cursor;
bool _includeInOutput = false;
boost::optional<FullCellView> _lastCell;
// These members are used to store owned copies of the path and the cell data when preparing
// for yield.
std::string _pathOwned;
std::vector<char> _cellOwned;
};
void readParentsIntoObj(StringData path,
value::Object* out,
StringDataSet* pathsReadSetOut,
bool first = true);
const UUID _collUuid;
const std::string _columnIndexName;
const value::SlotVector _fieldSlots;
const std::vector<std::string> _paths;
const boost::optional<value::SlotId> _recordSlot;
const boost::optional<value::SlotId> _recordIdSlot;
// An optional expression used to reconstruct the output document.
const std::unique_ptr<EExpression> _recordExpr;
// Expressions to get values from the row store document.
const std::vector<std::unique_ptr<EExpression>> _pathExprs;
// An internal slot that points to the row store document.
const value::SlotId _rowStoreSlot;
std::vector<value::OwnedValueAccessor> _outputFields;
value::SlotAccessorMap _outputFieldsMap;
std::unique_ptr<value::OwnedValueAccessor> _recordAccessor;
std::unique_ptr<value::OwnedValueAccessor> _recordIdAccessor;
std::unique_ptr<vm::CodeFragment> _recordExprCode;
std::vector<std::unique_ptr<vm::CodeFragment>> _pathExprsCode;
std::unique_ptr<value::OwnedValueAccessor> _rowStoreAccessor;
vm::ByteCode _bytecode;
// These members are default constructed to boost::none and are initialized when 'prepare()'
// is called. Once they are set, they are never modified again.
boost::optional<NamespaceString> _collName;
boost::optional<uint64_t> _catalogEpoch;
CollectionPtr _coll;
std::weak_ptr<const IndexCatalogEntry> _weakIndexCatalogEntry;
std::unique_ptr<SeekableRecordCursor> _rowStoreCursor;
std::vector<ColumnCursor> _columnCursors;
StringMap<std::unique_ptr<ColumnStore::CursorForPath>> _parentPathCursors;
RecordId _recordId;
bool _open{false};
// If provided, used during a trial run to accumulate certain execution stats. Once the trial
// run is complete, this pointer is reset to nullptr.
TrialRunTracker* _tracker{nullptr};
ScanStats _specificStats;
};
} // namespace sbe
} // namespace mongo
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