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-rw-r--r--src/db/update/InotifySource.cxx116
1 files changed, 116 insertions, 0 deletions
diff --git a/src/db/update/InotifySource.cxx b/src/db/update/InotifySource.cxx
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+++ b/src/db/update/InotifySource.cxx
@@ -0,0 +1,116 @@
+/*
+ * 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 <algorithm>
+
+#include <sys/inotify.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdint.h>
+#include <limits.h>
+
+bool
+InotifySource::OnSocketReady(gcc_unused unsigned flags)
+{
+ uint8_t buffer[4096];
+ static_assert(sizeof(buffer) >= sizeof(struct inotify_event) + NAME_MAX + 1,
+ "inotify buffer too small");
+
+ ssize_t nbytes = read(Get(), buffer, sizeof(buffer));
+ if (nbytes < 0)
+ FatalSystemError("Failed to read from inotify");
+ if (nbytes == 0)
+ FatalError("end of file from inotify");
+
+ const uint8_t *p = buffer, *const end = p + nbytes;
+
+ while (true) {
+ const size_t remaining = end - p;
+ const struct inotify_event *event =
+ (const struct inotify_event *)p;
+ if (remaining < sizeof(*event) ||
+ remaining < sizeof(*event) + event->len)
+ break;
+
+ const char *name;
+ if (event->len > 0 && event->name[event->len - 1] == 0)
+ name = event->name;
+ else
+ name = nullptr;
+
+ callback(event->wd, event->mask, name, callback_ctx);
+ p += 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 */
+}