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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/base/string_data.h"
#include "mongo/bson/bsonelement.h"
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/db/pipeline/value.h"
namespace mongo {
namespace write_ops {
// Conservative per array element overhead. This value was calculated as 1 byte (element type) + 5
// bytes (max string encoding of the array index encoded as string and the maximum key is 99999) + 1
// byte (zero terminator) = 7 bytes
constexpr int kWriteCommandBSONArrayPerElementOverheadBytes = 7;
/**
* Parses the 'limit' property of a delete entry, which has inverted meaning from the 'multi'
* property of an update.
*/
bool readMultiDeleteProperty(const BSONElement& limitElement);
/**
* Writes the 'isMulti' value as a limit property.
*/
void writeMultiDeleteProperty(bool isMulti, StringData fieldName, BSONObjBuilder* builder);
class UpdateModification {
public:
enum class Type { kClassic, kPipeline };
static StringData typeToString(Type type) {
return (type == Type::kClassic ? "Classic"_sd : "Pipeline"_sd);
}
UpdateModification() = default;
UpdateModification(BSONElement update);
UpdateModification(std::vector<BSONObj> pipeline);
// This constructor exists only to provide a fast-path for constructing classic-style updates.
UpdateModification(const BSONObj& update);
/**
* These methods support IDL parsing of the "u" field from the update command and OP_UPDATE.
*/
static UpdateModification parseFromBSON(BSONElement elem);
void serializeToBSON(StringData fieldName, BSONObjBuilder* bob) const;
// When parsing from legacy OP_UPDATE messages, we receive the "u" field as an object. When an
// array is parsed, we receive it as an object with numeric fields names and can't differentiate
// between a user constructed object and an array. For that reason, we don't support pipeline
// style update via OP_UPDATE and 'obj' is assumed to be a classic update.
//
// If a user did send a pipeline-style update via OP_UPDATE, it would fail parsing a field
// representing an aggregation stage, due to the leading '$'' character.
static UpdateModification parseLegacyOpUpdateFromBSON(const BSONObj& obj);
int objsize() const {
if (_type == Type::kClassic) {
return _classicUpdate->objsize();
}
int size = 0;
std::for_each(_pipeline->begin(), _pipeline->end(), [&size](const BSONObj& obj) {
size += obj.objsize() + kWriteCommandBSONArrayPerElementOverheadBytes;
});
return size + kWriteCommandBSONArrayPerElementOverheadBytes;
}
Type type() const {
return _type;
}
BSONObj getUpdateClassic() const {
invariant(_type == Type::kClassic);
return *_classicUpdate;
}
const std::vector<BSONObj>& getUpdatePipeline() const {
invariant(_type == Type::kPipeline);
return *_pipeline;
}
std::string toString() const {
StringBuilder sb;
sb << "{type: " << typeToString(_type) << ", update: ";
if (_type == Type::kClassic) {
sb << *_classicUpdate << "}";
} else {
sb << Value(*_pipeline).toString();
}
return sb.str();
}
private:
Type _type = Type::kClassic;
boost::optional<BSONObj> _classicUpdate;
boost::optional<std::vector<BSONObj>> _pipeline;
};
} // namespace write_ops
} // namespace mongo
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