diff options
Diffstat (limited to 'src/InotifySource.cxx')
| -rw-r--r-- | src/InotifySource.cxx | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/InotifySource.cxx b/src/InotifySource.cxx new file mode 100644 index 000000000..16fd62511 --- /dev/null +++ b/src/InotifySource.cxx @@ -0,0 +1,173 @@ +/* + * Copyright (C) 2003-2013 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" + +extern "C" { +#include "fifo_buffer.h" +} + +#include "fd_util.h" +#include "mpd_error.h" + +#include <glib.h> + +#include <sys/inotify.h> +#include <unistd.h> +#include <errno.h> + +#undef G_LOG_DOMAIN +#define G_LOG_DOMAIN "inotify" + +struct mpd_inotify_source { + int fd; + + GIOChannel *channel; + + /** + * The channel's source id in the GLib main loop. + */ + guint id; + + struct fifo_buffer *buffer; + + mpd_inotify_callback_t callback; + void *callback_ctx; +}; + +/** + * A GQuark for GError instances. + */ +static inline GQuark +mpd_inotify_quark(void) +{ + return g_quark_from_static_string("inotify"); +} + +static gboolean +mpd_inotify_in_event(G_GNUC_UNUSED GIOChannel *_source, + G_GNUC_UNUSED GIOCondition condition, + gpointer data) +{ + struct mpd_inotify_source *source = (struct mpd_inotify_source *)data; + void *dest; + size_t length; + ssize_t nbytes; + + dest = fifo_buffer_write(source->buffer, &length); + if (dest == NULL) + MPD_ERROR("buffer full"); + + nbytes = read(source->fd, dest, length); + if (nbytes < 0) + MPD_ERROR("failed to read from inotify: %s", + g_strerror(errno)); + if (nbytes == 0) + MPD_ERROR("end of file from inotify"); + + fifo_buffer_append(source->buffer, nbytes); + + while (true) { + const char *name; + + const struct inotify_event *event = + (const struct inotify_event *) + fifo_buffer_read(source->buffer, &length); + if (event == NULL || length < sizeof(*event) || + length < sizeof(*event) + event->len) + break; + + if (event->len > 0 && event->name[event->len - 1] == 0) + name = event->name; + else + name = NULL; + + source->callback(event->wd, event->mask, name, + source->callback_ctx); + fifo_buffer_consume(source->buffer, + sizeof(*event) + event->len); + } + + return true; +} + +struct mpd_inotify_source * +mpd_inotify_source_new(mpd_inotify_callback_t callback, void *callback_ctx, + GError **error_r) +{ + struct mpd_inotify_source *source = + g_new(struct mpd_inotify_source, 1); + + source->fd = inotify_init_cloexec(); + if (source->fd < 0) { + g_set_error(error_r, mpd_inotify_quark(), errno, + "inotify_init() has failed: %s", + g_strerror(errno)); + g_free(source); + return NULL; + } + + source->buffer = fifo_buffer_new(4096); + + source->channel = g_io_channel_unix_new(source->fd); + source->id = g_io_add_watch(source->channel, G_IO_IN, + mpd_inotify_in_event, source); + + source->callback = callback; + source->callback_ctx = callback_ctx; + + return source; +} + +void +mpd_inotify_source_free(struct mpd_inotify_source *source) +{ + g_source_remove(source->id); + g_io_channel_unref(source->channel); + fifo_buffer_free(source->buffer); + close(source->fd); + g_free(source); +} + +int +mpd_inotify_source_add(struct mpd_inotify_source *source, + const char *path_fs, unsigned mask, + GError **error_r) +{ + int wd = inotify_add_watch(source->fd, path_fs, mask); + if (wd < 0) + g_set_error(error_r, mpd_inotify_quark(), errno, + "inotify_add_watch() has failed: %s", + g_strerror(errno)); + + return wd; +} + +void +mpd_inotify_source_rm(struct mpd_inotify_source *source, unsigned wd) +{ + int ret = inotify_rm_watch(source->fd, wd); + if (ret < 0 && errno != EINVAL) + g_warning("inotify_rm_watch() has failed: %s", + g_strerror(errno)); + + /* EINVAL may happen here when the file has been deleted; the + kernel seems to auto-unregister deleted files */ +} |