///////////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2010-2011 Artyom Beilis (Tonkikh) <artyomtnk@yahoo.com>
//
// Distributed under:
//
// the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// or (at your opinion) under:
//
// The MIT License
// (See accompanying file MIT.txt or a copy at
// http://www.opensource.org/licenses/mit-license.php)
//
///////////////////////////////////////////////////////////////////////////////
#ifndef CPPDB_POOL_H
#define CPPDB_POOL_H
#include <cppdb/defs.h>
#include <cppdb/ref_ptr.h>
#include <cppdb/mutex.h>
#include <cppdb/utils.h>
#include <memory>
#include <list>
namespace cppdb {
class connection_info;
namespace backend {
class connection;
}
///
/// \brief Connections pool, allows to handle multiple connections for specific connection string.
///
/// Note connections_manager provide more generic interface and hides pools inside it. So you
/// generally should not use this class directly.
///
/// Unlike connections_manager, it uses pool by default unless its size defined as 0.
///
/// All this class member functions are thread safe to use from several threads for the same object
///
class CPPDB_API pool : public ref_counted {
pool();
pool(pool const &);
void operator=(pool const &);
pool(connection_info const &ci);
public:
/// Create new pool for \a connection_string
static ref_ptr<pool> create(std::string const &connection_string);
/// Create new pool for a parsed connection string \a ci
static ref_ptr<pool> create(connection_info const &ci);
~pool();
///
/// Get a open a connection, it may be fetched either from pool or new one may be created
///
ref_ptr<backend::connection> open();
///
/// Collect connections that were not used for a long time (close them)
///
void gc();
/// \cond INTERNAL
void put(backend::connection *c_in);
/// \endcond
private:
ref_ptr<backend::connection> get();
struct data;
std::auto_ptr<data> d;
struct entry {
entry() : last_used(0) {}
ref_ptr<backend::connection> conn;
time_t last_used;
};
typedef std::list<entry> pool_type;
// non-mutable members
size_t limit_;
int life_time_;
connection_info ci_;
// mutex protected begin
mutex lock_;
size_t size_;
pool_type pool_;
// mutex protected end
};
}
#endif
