#include <userver/storages/mongo/pool.hpp>

Detailed Description

MongoDB client pool.

Use constructor only for tests, in production the pool should be retrieved from the components via components::Mongo::GetPool() or components::MultiMongo::GetPool().

Example usage:

inline void SampleMongoPool(storages::mongo::Pool& pool) {
    using formats::bson::MakeArray;
    using formats::bson::MakeDoc;
 
    auto in_coll = pool.GetCollection("aggregate_in");
 
    in_coll.InsertMany({
        formats::bson::MakeDoc("_id", 1, "x", 0),
        formats::bson::MakeDoc("_id", 2, "x", 1),
        formats::bson::MakeDoc("_id", 3, "x", 2),
    });
 
    auto cursor = in_coll.Aggregate(
        MakeArray(
            MakeDoc("$match", MakeDoc("_id", MakeDoc("$gte", 2))),
            MakeDoc("$addFields", MakeDoc("check", true)),
            MakeDoc("$out", "aggregate_out")
        ),
        storages::mongo::options::ReadPreference::kSecondaryPreferred,
        storages::mongo::options::WriteConcern::kMajority
    );
    EXPECT_FALSE(cursor);
 
    auto out_coll = pool.GetCollection("aggregate_out");
    EXPECT_EQ(2, out_coll.CountApprox());
    for (const auto& doc : out_coll.Find({})) {
        EXPECT_EQ(doc["_id"].As<int>(), doc["x"].As<int>() + 1);
        EXPECT_TRUE(doc["check"].As<bool>());
    }
}

Definition at line 37 of file pool.hpp.

Public Member Functions
	Pool (Pool &&) noexcept

Pool &	operator= (Pool &&) noexcept

bool	HasCollection (utils::zstring_view name) const
	Checks whether a collection exists.

Collection	GetCollection (std::string name) const
	Returns a handle for the specified collection.

void	DropDatabase ()

std::vector< std::string >	ListCollectionNames () const
	Get a list of all the collection names in the associated database.

void	Ping ()

Transaction	BeginTransaction () const
	Begin a new transaction.

Member Function Documentation

◆ BeginTransaction()

Transaction storages::mongo::Pool::BeginTransaction ( ) const

Begin a new transaction.

Returns: Transaction handle for executing operations within transaction context

Exceptions

MongoException if transaction cannot be started

◆ DropDatabase()

void storages::mongo::Pool::DropDatabase ( )

Drops the associated database if it exists. New modifications of collections will attempt to re-create the database automatically.

◆ Ping()

void storages::mongo::Pool::Ping ( )