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/**
* Copyright (C) 2017 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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/base/status.h"
#include "mongo/bson/bsonobj.h"
namespace mongo {
/**
* Represents options passed to the explain command (aside from the command which is being explained
* and its parameters).
*/
class ExplainOptions {
public:
/**
* The various supported verbosity levels for explain. The order is significant: the enum values
* are assigned in order of increasing verbosity.
*/
enum class Verbosity {
// At all verbosities greater than or equal to QUERY_PLANNER, we display information about
// the plan selected and alternate rejected plans. Does not include any execution- related
// info. String alias is "queryPlanner".
kQueryPlanner = 0,
// At all verbosities greater than or equal to EXEC_STATS, we display a section of output
// containing both overall execution stats, and stats per stage in the execution tree.
// String alias is "execStats".
kExecStats = 1,
// At this verbosity level, we generate the execution stats for each rejected plan as well
// as the winning plan. String alias is "allPlansExecution".
kExecAllPlans = 2,
};
static constexpr StringData kVerbosityName = "verbosity"_sd;
// String representations for verbosity levels.
static constexpr StringData kQueryPlannerVerbosityStr = "queryPlanner"_sd;
static constexpr StringData kExecStatsVerbosityStr = "executionStats"_sd;
static constexpr StringData kAllPlansExecutionVerbosityStr = "allPlansExecution"_sd;
/**
* Converts an explain verbosity to its string representation.
*/
static StringData verbosityString(ExplainOptions::Verbosity verbosity);
/**
* Does some basic validation of the command BSON, then extracts and returns the explain
* verbosity.
*
* Returns a non-OK status if parsing fails.
*/
static StatusWith<ExplainOptions::Verbosity> parseCmdBSON(const BSONObj& cmdObj);
/**
* Converts 'verbosity' to its corresponding representation as a BSONObj containing explain
* command parameters.
*/
static BSONObj toBSON(ExplainOptions::Verbosity verbosity);
};
} // namespace mongo
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