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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 <string>
#include "mongo/db/jsobj.h"
#include "mongo/db/read_write_concern_provenance.h"
namespace mongo {
class Status;
using WTags = StringMap<int64_t>;
using WriteConcernW = stdx::variant<std::string, std::int64_t, WTags>;
struct WriteConcernOptions {
public:
enum class SyncMode { UNSET, NONE, FSYNC, JOURNAL };
// This specifies the condition to check to satisfy given tags.
// Users can only provide OpTime condition, the others are used internally.
enum class CheckCondition { OpTime, Config };
static constexpr Milliseconds kNoTimeout{0};
static constexpr Milliseconds kNoWaiting{-1};
static const BSONObj Default;
static const BSONObj Acknowledged;
static const BSONObj Unacknowledged;
static const BSONObj Majority;
static const BSONObj kInternalWriteDefault;
static constexpr StringData kWriteConcernField = "writeConcern"_sd;
static const char kMajority[]; // = "majority"
static constexpr Seconds kWriteConcernTimeoutSystem{15};
static constexpr Seconds kWriteConcernTimeoutMigration{30};
static constexpr Seconds kWriteConcernTimeoutSharding{60};
static constexpr Seconds kWriteConcernTimeoutUserCommand{60};
WriteConcernOptions() = default;
explicit WriteConcernOptions(int numNodes, SyncMode sync, Milliseconds timeout);
explicit WriteConcernOptions(const std::string& mode, SyncMode sync, Milliseconds timeout);
static StatusWith<WriteConcernOptions> parse(const BSONObj& obj);
/**
* Returns an instance of WriteConcernOptions from a BSONObj.
*
* uasserts() if the obj cannot be deserialized.
*/
static WriteConcernOptions deserializerForIDL(const BSONObj& obj);
/**
* Attempts to extract a writeConcern from cmdObj.
* Verifies that the writeConcern is of type Object (BSON type).
*/
static StatusWith<WriteConcernOptions> extractWCFromCommand(const BSONObj& cmdObj);
/**
* Return true if the server needs to wait for other secondary nodes to satisfy this
* write concern setting. Errs on the false positive for non-empty wMode.
*/
bool needToWaitForOtherNodes() const;
ReadWriteConcernProvenance& getProvenance() {
return _provenance;
}
const ReadWriteConcernProvenance& getProvenance() const {
return _provenance;
}
// Returns the BSON representation of this object.
// Warning: does not return the same object passed on the last parse() call.
BSONObj toBSON() const;
bool operator==(const WriteConcernOptions& other) const;
bool operator!=(const WriteConcernOptions& other) const {
return !operator==(other);
}
/**
* Return true if the default write concern is being used.
* - Default constructed WC (w:1) is being used.
* - Implicit default majority WC is being used.
*/
bool isImplicitDefaultWriteConcern() const {
return usedDefaultConstructedWC || _provenance.isImplicitDefault();
}
bool hasCustomWriteMode() const {
return stdx::holds_alternative<std::string>(w) &&
stdx::get<std::string>(w) != WriteConcernOptions::kMajority;
}
/**
* Returns whether this write concern's w parameter is the number 0.
*/
bool isUnacknowledged() const {
return stdx::holds_alternative<int64_t>(w) && stdx::get<int64_t>(w) < 1;
}
/**
* Returns whether this write concern's w parameter is the string "majority".
*/
bool isMajority() const {
return stdx::holds_alternative<std::string>(w) && stdx::get<std::string>(w) == kMajority;
}
// The w parameter for this write concern.
WriteConcernW w{1};
// Corresponds to the `j` or `fsync` parameters for write concern.
SyncMode syncMode{SyncMode::UNSET};
// Timeout in milliseconds.
Milliseconds wTimeout{kNoTimeout};
// Deadline. If this is set to something other than Date_t::max(), this takes precedence over
// wTimeout.
Date_t wDeadline{Date_t::max()};
// True if the default constructed WC ({w:1}) was used.
// - Implicit default WC when value of w is {w:1}.
// - Internal commands set empty WC ({writeConcern: {}}), then default constructed WC (w:1)
// is used.
// False otherwise:
// - Implicit default WC when value of w is {w:"majority"}.
// - Cluster-wide WC.
// - with (w) value set, for example ({writeConcern: {w:1}}).
// - without (w) value set, for example ({writeConcern: {j: true}}).
// - Client-supplied WC.
// - with (w) value set, for example ({writeConcern: {w:1}}).
// - without (w) value set, for example ({writeConcern: {j: true}}).
bool usedDefaultConstructedWC{true};
// Used only for tracking opWriteConcernCounters metric.
// True if the (w) value of the write concern used is not set explicitly by client:
// - Default constructed WC ({w:1})
// - Implicit default majority WC.
// - Cluster-wide WC.
// - with (w) value set, for example ({writeConcern: {w:1}}).
// - without (w) value set, for example ({writeConcern: {j: true}}).
// - Client-supplied WC without (w) value set, for example ({writeConcern: {j: true}}).
// - Internal commands set empty WC ({writeConcern: {}}).
bool notExplicitWValue{true};
CheckCondition checkCondition{CheckCondition::OpTime};
private:
ReadWriteConcernProvenance _provenance;
};
// Helpers for IDL parsing
WriteConcernW deserializeWriteConcernW(BSONElement wEl);
void serializeWriteConcernW(const WriteConcernW& w, StringData fieldName, BSONObjBuilder* builder);
std::int64_t parseWTimeoutFromBSON(BSONElement element);
} // namespace mongo
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