poco/Data/include/Poco/Data/SessionFactory.h
2022-07-07 04:18:20 -05:00

100 lines
2.9 KiB
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//
// SessionFactory.h
//
// Library: Data
// Package: DataCore
// Module: SessionFactory
//
// Definition of the SessionFactory class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Data_SessionFactory_INCLUDED
#define Data_SessionFactory_INCLUDED
#include "Poco/Data/Data.h"
#include "Poco/Data/Connector.h"
#include "Poco/Data/Session.h"
#include "Poco/Mutex.h"
#include "Poco/SharedPtr.h"
#include "Poco/String.h"
#include <map>
namespace Poco {
namespace Data {
class Data_API SessionFactory
/// A SessionFactory is a singleton class that stores Connectors and allows to
/// create Sessions of the required type:
///
/// Session ses(SessionFactory::instance().create(connector, connectionString));
///
/// where the first param presents the type of session one wants to create (e.g. for SQLite one would choose "SQLite")
/// and the second param is the connection string that the connector requires to connect to the database.
///
/// A concrete example to open an SQLite database stored in the file "dummy.db" would be
///
/// Session ses(SessionFactory::instance().create(SQLite::Connector::KEY, "dummy.db"));
///
/// An even simpler way to create a session is to use the two argument constructor of Session, which
/// automatically invokes the SessionFactory:
///
/// Session ses("SQLite", "dummy.db");
{
public:
static SessionFactory& instance();
/// returns the static instance of the singleton.
void add(Connector* pIn);
/// Registers a Connector under its key at the factory. If a registration for that
/// key is already active, the first registration will be kept, only its reference count will be increased.
/// Always takes ownership of parameter pIn.
void remove(const std::string& key);
/// Lowers the reference count for the Connector registered under that key. If the count reaches zero,
/// the object is removed.
Session create(const std::string& key,
const std::string& connectionString,
std::size_t timeout = Session::LOGIN_TIMEOUT_DEFAULT);
/// Creates a Session for the given key with the connectionString. Throws an Poco:Data::UnknownDataBaseException
/// if no Connector is registered for that key.
Session create(const std::string& uri,
std::size_t timeout = Session::LOGIN_TIMEOUT_DEFAULT);
/// Creates a Session for the given URI (must be in key:///connectionString format).
/// Throws a Poco:Data::UnknownDataBaseException if no Connector is registered for the key.
private:
SessionFactory();
~SessionFactory();
SessionFactory(const SessionFactory&);
SessionFactory& operator = (const SessionFactory&);
struct SessionInfo
{
int cnt;
Poco::SharedPtr<Connector> ptrSI;
SessionInfo(Connector* pSI);
};
typedef std::map<std::string, SessionInfo, Poco::CILess> Connectors;
Connectors _connectors;
Poco::FastMutex _mutex;
};
} } // namespace Poco::Data
#endif // Data_SessionFactory_INCLUDED