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/*
* Copyright (C) 2003-2014 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_CONNECTION_HXX
#define MPD_NFS_CONNECTION_HXX
#include "Lease.hxx"
#include "Cancellable.hxx"
#include "thread/Mutex.hxx"
#include "event/SocketMonitor.hxx"
#include "event/DeferredMonitor.hxx"
#include "util/Error.hxx"
#include <string>
#include <list>
struct nfs_context;
class NfsCallback;
/**
* An asynchronous connection to a NFS server.
*/
class NfsConnection : SocketMonitor, DeferredMonitor {
class CancellableCallback : public CancellablePointer<NfsCallback> {
NfsConnection &connection;
public:
explicit constexpr CancellableCallback(NfsCallback &_callback,
NfsConnection &_connection)
:CancellablePointer<NfsCallback>(_callback),
connection(_connection) {}
bool Open(nfs_context *context, const char *path, int flags,
Error &error);
bool Stat(nfs_context *context, struct nfsfh *fh,
Error &error);
bool Read(nfs_context *context, struct nfsfh *fh,
uint64_t offset, size_t size,
Error &error);
private:
static void Callback(int err, struct nfs_context *nfs,
void *data, void *private_data);
void Callback(int err, void *data);
};
std::string server, export_name;
nfs_context *context;
Mutex mutex;
typedef std::list<NfsLease *> LeaseList;
LeaseList new_leases, active_leases;
typedef CancellableList<NfsCallback, CancellableCallback> CallbackList;
CallbackList callbacks;
Error postponed_mount_error;
/**
* True when nfs_service() is being called. During that,
* nfs_client_free() is postponed, or libnfs will crash. See
* #postponed_destroy.
*/
bool in_service;
/**
* True when OnSocketReady() is being called. During that,
* event updates are omitted.
*/
bool in_event;
/**
* True when nfs_client_free() has been called while #in_service
* was true.
*/
bool postponed_destroy;
bool mount_finished;
public:
gcc_nonnull_all
NfsConnection(EventLoop &_loop,
const char *_server, const char *_export_name)
:SocketMonitor(_loop), DeferredMonitor(_loop),
server(_server), export_name(_export_name),
context(nullptr) {}
#if defined(__GNUC__) && !defined(__clang__) && !GCC_CHECK_VERSION(4,8)
/* needed for NfsManager::GetConnection() due to lack of
std::map::emplace() */
NfsConnection(NfsConnection &&other)
:SocketMonitor(((SocketMonitor &)other).GetEventLoop()),
DeferredMonitor(((DeferredMonitor &)other).GetEventLoop()),
server(std::move(other.server)),
export_name(std::move(other.export_name)),
context(nullptr) {
assert(other.context == nullptr);
assert(other.new_leases.empty());
assert(other.active_leases.empty());
assert(other.callbacks.IsEmpty());
}
#endif
~NfsConnection();
gcc_pure
const char *GetServer() const {
return server.c_str();
}
gcc_pure
const char *GetExportName() const {
return export_name.c_str();
}
/**
* Ensure that the connection is established. The connection
* is kept up while at least one #NfsLease is registered.
*
* This method is thread-safe. However, #NfsLease's methods
* will be invoked from within the #EventLoop's thread.
*/
void AddLease(NfsLease &lease);
void RemoveLease(NfsLease &lease);
bool Open(const char *path, int flags, NfsCallback &callback,
Error &error);
bool Stat(struct nfsfh *fh, NfsCallback &callback, Error &error);
bool Read(struct nfsfh *fh, uint64_t offset, size_t size,
NfsCallback &callback, Error &error);
void Cancel(NfsCallback &callback);
void Close(struct nfsfh *fh);
protected:
virtual void OnNfsConnectionError(Error &&error) = 0;
private:
void DestroyContext();
bool MountInternal(Error &error);
void BroadcastMountSuccess();
void BroadcastMountError(Error &&error);
void BroadcastError(Error &&error);
static void MountCallback(int status, nfs_context *nfs, void *data,
void *private_data);
void MountCallback(int status, nfs_context *nfs, void *data);
void ScheduleSocket();
/* virtual methods from SocketMonitor */
virtual bool OnSocketReady(unsigned flags) override;
/* virtual methods from DeferredMonitor */
virtual void RunDeferred() override;
};
#endif
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