mpd/src/InotifySource.cxx
2014-01-13 22:31:55 +01:00

115 lines
2.9 KiB
C++

/*
* 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.
*/
#include "config.h"
#include "InotifySource.hxx"
#include "InotifyDomain.hxx"
#include "util/Error.hxx"
#include "system/fd_util.h"
#include "system/FatalError.hxx"
#include "Log.hxx"
#include <sys/inotify.h>
#include <unistd.h>
#include <errno.h>
bool
InotifySource::OnSocketReady(gcc_unused unsigned flags)
{
const auto dest = buffer.Write();
if (dest.IsEmpty())
FatalError("buffer full");
ssize_t nbytes = read(Get(), dest.data, dest.size);
if (nbytes < 0)
FatalSystemError("Failed to read from inotify");
if (nbytes == 0)
FatalError("end of file from inotify");
buffer.Append(nbytes);
while (true) {
const char *name;
auto range = buffer.Read();
const struct inotify_event *event =
(const struct inotify_event *)
range.data;
if (range.size < sizeof(*event) ||
range.size < sizeof(*event) + event->len)
break;
if (event->len > 0 && event->name[event->len - 1] == 0)
name = event->name;
else
name = nullptr;
callback(event->wd, event->mask, name, callback_ctx);
buffer.Consume(sizeof(*event) + event->len);
}
return true;
}
inline
InotifySource::InotifySource(EventLoop &_loop,
mpd_inotify_callback_t _callback, void *_ctx,
int _fd)
:SocketMonitor(_fd, _loop),
callback(_callback), callback_ctx(_ctx)
{
ScheduleRead();
}
InotifySource *
InotifySource::Create(EventLoop &loop,
mpd_inotify_callback_t callback, void *callback_ctx,
Error &error)
{
int fd = inotify_init_cloexec();
if (fd < 0) {
error.SetErrno("inotify_init() has failed");
return nullptr;
}
return new InotifySource(loop, callback, callback_ctx, fd);
}
int
InotifySource::Add(const char *path_fs, unsigned mask, Error &error)
{
int wd = inotify_add_watch(Get(), path_fs, mask);
if (wd < 0)
error.SetErrno("inotify_add_watch() has failed");
return wd;
}
void
InotifySource::Remove(unsigned wd)
{
int ret = inotify_rm_watch(Get(), wd);
if (ret < 0 && errno != EINVAL)
LogErrno(inotify_domain, "inotify_rm_watch() has failed");
/* EINVAL may happen here when the file has been deleted; the
kernel seems to auto-unregister deleted files */
}