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/*
* Copyright 2003-2020 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_NFS_MANAGER_HXX
#define MPD_NFS_MANAGER_HXX
#include "Connection.hxx"
#include "util/Compiler.h"
#include "event/IdleEvent.hxx"
#include <boost/intrusive/set.hpp>
#include <boost/intrusive/slist.hpp>
/**
* A manager for NFS connections. Handles multiple connections to
* multiple NFS servers.
*/
class NfsManager final {
struct LookupKey {
const char *server;
const char *export_name;
};
class ManagedConnection final
: public NfsConnection,
public boost::intrusive::slist_base_hook<boost::intrusive::link_mode<boost::intrusive::normal_link>>,
public boost::intrusive::set_base_hook<boost::intrusive::link_mode<boost::intrusive::normal_link>> {
NfsManager &manager;
public:
ManagedConnection(NfsManager &_manager, EventLoop &_loop,
const char *_server,
const char *_export_name) noexcept
:NfsConnection(_loop, _server, _export_name),
manager(_manager) {}
protected:
/* virtual methods from NfsConnection */
void OnNfsConnectionError(std::exception_ptr &&e) noexcept override;
};
struct Compare {
gcc_pure
bool operator()(const LookupKey a,
const ManagedConnection &b) const noexcept;
gcc_pure
bool operator()(const ManagedConnection &a,
const LookupKey b) const noexcept;
gcc_pure
bool operator()(const ManagedConnection &a,
const ManagedConnection &b) const noexcept;
};
/**
* Maps server and export_name to #ManagedConnection.
*/
typedef boost::intrusive::set<ManagedConnection,
boost::intrusive::compare<Compare>,
boost::intrusive::constant_time_size<false>> Map;
Map connections;
typedef boost::intrusive::slist<ManagedConnection> List;
/**
* A list of "garbage" connection objects. Their destruction
* is postponed because they were thrown into the garbage list
* when callers on the stack were still using them.
*/
List garbage;
IdleEvent idle_event;
public:
explicit NfsManager(EventLoop &_loop) noexcept
:idle_event(_loop, BIND_THIS_METHOD(OnIdle)) {}
/**
* Must be run from EventLoop's thread.
*/
~NfsManager() noexcept;
auto &GetEventLoop() const noexcept {
return idle_event.GetEventLoop();
}
gcc_pure
NfsConnection &GetConnection(const char *server,
const char *export_name) noexcept;
private:
void ScheduleDelete(ManagedConnection &c) noexcept {
connections.erase(connections.iterator_to(c));
garbage.push_front(c);
idle_event.Schedule();
}
/**
* Delete all connections on the #garbage list.
*/
void CollectGarbage() noexcept;
/* virtual methods from IdleMonitor */
void OnIdle() noexcept;
};
#endif