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/**
* Copyright (C) 2019 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/optional.hpp>
#include "mongo/base/string_data.h"
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/stdx/variant.h"
namespace mongo {
/**
* Wraps a boost::optional<bool> to provide consistent semantics. A standard boost::optional<bool>
* can introduce ambiguity because its 'operator bool' will resolve to 'true' if the optional is
* populated, even if is populated with boolean 'false'. By contrast, an instance of this class
* always resolves to the populated value, or false if not yet populated. This class will also
* serialize to BSON via the IDL only if the value has been explicitly set.
*/
class OptionalBool {
public:
static OptionalBool parseFromBSON(BSONElement element) {
uassert(ErrorCodes::BadValue,
str::stream() << "Field '" << element.fieldNameStringData()
<< "' should be a boolean value, but found: " << element.type(),
!element || element.type() == BSONType::Bool);
return element ? OptionalBool{element.boolean()} : OptionalBool{};
}
OptionalBool(boost::optional<bool> value) : _value(std::move(value)) {}
OptionalBool(bool value) : _value(value) {}
OptionalBool() : OptionalBool(boost::none) {}
/**
* Returns true only if _value is populated with a value of true.
*/
operator bool() const {
return _value.value_or(false);
}
/**
* Returns true if the value has been populated, false otherwise.
*/
bool has_value() const {
return _value.has_value();
}
/**
* Serialize this object as a field in a document. If _value is empty, omit the field.
*/
void serializeToBSON(StringData fieldName, BSONObjBuilder* builder) const {
if (_value) {
builder->appendBool(fieldName, *_value);
}
}
/**
* Serialize this object as an element of a BSON array. If _value is empty, omit the entry.
*/
void serializeToBSON(BSONArrayBuilder* builder) const {
if (_value) {
builder->append(*_value);
}
}
/**
* Returns a string representation of the current value.
*/
std::string toString() const {
return *this ? "1" : "0";
}
operator std::string() const {
return toString();
}
private:
boost::optional<bool> _value;
};
/**
* Class to represent a BSON element with any type from IDL. The caller must ensure that the backing
* BSON stays alive while this type is in use.
*/
class IDLAnyType {
public:
static IDLAnyType parseFromBSON(const BSONElement& element) {
return IDLAnyType(element);
}
IDLAnyType() = default;
IDLAnyType(const BSONElement& element) : _element(element) {}
void serializeToBSON(StringData fieldName, BSONObjBuilder* builder) const {
builder->appendAs(_element, fieldName);
}
void serializeToBSON(BSONArrayBuilder* builder) const {
builder->append(_element);
}
const BSONElement& getElement() const {
return _element;
}
private:
BSONElement _element;
};
class WriteConcernW {
public:
static WriteConcernW deserializeWriteConcernW(BSONElement wEl) {
if (wEl.isNumber()) {
return WriteConcernW{wEl.safeNumberLong()};
} else if (wEl.type() == BSONType::String) {
return WriteConcernW{wEl.valuestrsafe()};
} else if (wEl.eoo() || wEl.type() == BSONType::jstNULL ||
wEl.type() == BSONType::Undefined) {
return WriteConcernW{};
}
uasserted(ErrorCodes::FailedToParse, "w has to be a number or string");
}
void serializeWriteConcernW(BSONObjBuilder* builder) const {
if (auto stringVal = stdx::get_if<std::string>(&_w)) {
builder->append("w", *stringVal);
return;
}
auto intVal = stdx::get_if<std::int64_t>(&_w);
invariant(intVal);
builder->appendIntOrLL("w", *intVal);
}
WriteConcernW() : _w{1}, _usedDefault{true} {};
bool usedDefault() const {
return _usedDefault;
}
stdx::variant<std::string, std::int64_t> getValue() const {
return _w;
}
private:
WriteConcernW(std::int64_t w) : _w{w}, _usedDefault{false} {};
WriteConcernW(std::string&& w) : _w(std::move(w)), _usedDefault{false} {};
stdx::variant<std::string, std::int64_t> _w;
bool _usedDefault;
};
} // namespace mongo
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