ClickHouse/dbms/Client/ConnectionPool.h
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

120 lines
3.2 KiB
C++

#pragma once
#include <Common/PoolBase.h>
#include <Client/Connection.h>
#include <IO/ConnectionTimeouts.h>
namespace DB
{
/** Interface for connection pools.
*
* Usage (using the usual `ConnectionPool` example)
* ConnectionPool pool(...);
*
* void thread()
* {
* auto connection = pool.get();
* connection->sendQuery("SELECT 'Hello, world!' AS world");
* }
*/
class IConnectionPool : private boost::noncopyable
{
public:
using Entry = PoolBase<Connection>::Entry;
public:
virtual ~IConnectionPool() {}
/// Selects the connection to work.
/// If force_connected is false, the client must manually ensure that returned connection is good.
virtual Entry get(const ConnectionTimeouts & timeouts,
const Settings * settings = nullptr,
bool force_connected = true) = 0;
};
using ConnectionPoolPtr = std::shared_ptr<IConnectionPool>;
using ConnectionPoolPtrs = std::vector<ConnectionPoolPtr>;
/** A common connection pool, without fault tolerance.
*/
class ConnectionPool : public IConnectionPool, private PoolBase<Connection>
{
public:
using Entry = IConnectionPool::Entry;
using Base = PoolBase<Connection>;
ConnectionPool(unsigned max_connections_,
const String & host_,
UInt16 port_,
const String & default_database_,
const String & user_,
const String & password_,
const String & client_name_ = "client",
Protocol::Compression compression_ = Protocol::Compression::Enable,
Protocol::Secure secure_ = Protocol::Secure::Disable)
: Base(max_connections_,
&Logger::get("ConnectionPool (" + host_ + ":" + toString(port_) + ")")),
host(host_),
port(port_),
default_database(default_database_),
user(user_),
password(password_),
client_name(client_name_),
compression(compression_),
secure{secure_}
{
}
Entry get(const ConnectionTimeouts & timeouts,
const Settings * settings = nullptr,
bool force_connected = true) override
{
Entry entry;
if (settings)
entry = Base::get(settings->connection_pool_max_wait_ms.totalMilliseconds());
else
entry = Base::get(-1);
if (force_connected)
entry->forceConnected(timeouts);
return entry;
}
const std::string & getHost() const
{
return host;
}
std::string getDescription() const
{
return host + ":" + toString(port);
}
protected:
/** Creates a new object to put in the pool. */
ConnectionPtr allocObject() override
{
return std::make_shared<Connection>(
host, port,
default_database, user, password,
client_name, compression, secure);
}
private:
String host;
UInt16 port;
String default_database;
String user;
String password;
String client_name;
Protocol::Compression compression; /// Whether to compress data when interacting with the server.
Protocol::Secure secure; /// Whether to encrypt data when interacting with the server.
};
}