From 8f261af5c1cfd6f922df009e17756fa3bef71458 Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Fri, 25 Sep 2009 18:32:00 +0200 Subject: automatically update the database with Linux inotify This patch implements a light-weight inotify library, and watches all directories below the music directory. It updates all directories where files changed after a delay of 5 seconds. --- src/inotify_update.c | 349 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 349 insertions(+) create mode 100644 src/inotify_update.c (limited to 'src/inotify_update.c') diff --git a/src/inotify_update.c b/src/inotify_update.c new file mode 100644 index 000000000..996afb0aa --- /dev/null +++ b/src/inotify_update.c @@ -0,0 +1,349 @@ +/* + * Copyright (C) 2003-2009 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 "inotify_update.h" +#include "inotify_source.h" +#include "inotify_queue.h" +#include "database.h" +#include "mapper.h" +#include "path.h" + +#include +#include +#include +#include +#include +#include +#include + +#undef G_LOG_DOMAIN +#define G_LOG_DOMAIN "inotify" + +enum { + IN_MASK = IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_DELETE_SELF + |IN_MOVE|IN_MOVE_SELF +#ifdef IN_ONLYDIR + |IN_ONLYDIR +#endif +}; + +struct watch_directory { + struct watch_directory *parent; + + char *name; + + int descriptor; + + GList *children; +}; + +static struct mpd_inotify_source *inotify_source; + +static struct watch_directory inotify_root; +static GTree *inotify_directories; + +static gint +compare(gconstpointer a, gconstpointer b) +{ + if (a < b) + return -1; + else if (a > b) + return 1; + else + return 0; +} + +static void +tree_add_watch_directory(struct watch_directory *directory) +{ + g_tree_insert(inotify_directories, + GINT_TO_POINTER(directory->descriptor), directory); +} + +static void +tree_remove_watch_directory(struct watch_directory *directory) +{ + bool found = g_tree_remove(inotify_directories, + GINT_TO_POINTER(directory->descriptor)); + assert(found); +} + +static struct watch_directory * +tree_find_watch_directory(int wd) +{ + return g_tree_lookup(inotify_directories, GINT_TO_POINTER(wd)); +} + +static void +remove_watch_directory(struct watch_directory *directory) +{ + assert(directory != NULL); + assert(directory->parent != NULL); + assert(directory->parent->children != NULL); + + tree_remove_watch_directory(directory); + + while (directory->children != NULL) + remove_watch_directory(directory->children->data); + + directory->parent->children = + g_list_remove(directory->parent->children, directory); + + mpd_inotify_source_rm(inotify_source, directory->descriptor); + g_free(directory->name); + g_slice_free(struct watch_directory, directory); +} + +static char * +watch_directory_get_uri_fs(const struct watch_directory *directory) +{ + char *parent_uri, *uri; + + if (directory->parent == NULL) + return NULL; + + parent_uri = watch_directory_get_uri_fs(directory->parent); + if (parent_uri == NULL) + return g_strdup(directory->name); + + uri = g_strconcat(parent_uri, "/", directory->name, NULL); + g_free(parent_uri); + + return uri; +} + +/* we don't look at "." / ".." nor files with newlines in their name */ +static bool skip_path(const char *path) +{ + return (path[0] == '.' && path[1] == 0) || + (path[0] == '.' && path[1] == '.' && path[2] == 0) || + strchr(path, '\n') != NULL; +} + +static void +recursive_watch_subdirectories(struct watch_directory *directory, + const char *path_fs) +{ + GError *error = NULL; + DIR *dir; + struct dirent *ent; + + assert(directory != NULL); + assert(path_fs != NULL); + + dir = opendir(path_fs); + if (dir == NULL) { + g_warning("Failed to open directory %s: %s", + path_fs, g_strerror(errno)); + return; + } + + while ((ent = readdir(dir))) { + char *child_path_fs; + struct stat st; + int ret; + struct watch_directory *child; + + if (skip_path(ent->d_name)) + continue; + + child_path_fs = g_strconcat(path_fs, "/", ent->d_name, NULL); + /* XXX what about symlinks? */ + ret = lstat(child_path_fs, &st); + if (ret < 0) { + g_warning("Failed to stat %s: %s", + child_path_fs, g_strerror(errno)); + g_free(child_path_fs); + continue; + } + + if (!S_ISDIR(st.st_mode)) { + g_free(child_path_fs); + continue; + } + + ret = mpd_inotify_source_add(inotify_source, child_path_fs, + IN_MASK, &error); + if (ret < 0) { + g_warning("Failed to register %s: %s", + child_path_fs, error->message); + g_error_free(error); + error = NULL; + g_free(child_path_fs); + continue; + } + + child = tree_find_watch_directory(ret); + if (child != NULL) { + /* already being watched */ + g_free(child_path_fs); + continue; + } + + child = g_slice_new(struct watch_directory); + child->parent = directory; + child->name = g_strdup(ent->d_name); + child->descriptor = ret; + child->children = NULL; + + directory->children = g_list_prepend(directory->children, + child); + + tree_add_watch_directory(child); + + recursive_watch_subdirectories(child, child_path_fs); + g_free(child_path_fs); + } + + closedir(dir); +} + +static void +mpd_inotify_callback(int wd, unsigned mask, + G_GNUC_UNUSED const char *name, G_GNUC_UNUSED void *ctx) +{ + struct watch_directory *directory; + char *uri_fs; + + /*g_debug("wd=%d mask=0x%x name='%s'", wd, mask, name);*/ + + directory = tree_find_watch_directory(wd); + if (directory == NULL) + return; + + uri_fs = watch_directory_get_uri_fs(directory); + + if ((mask & (IN_DELETE_SELF|IN_MOVE_SELF)) != 0) { + g_free(uri_fs); + remove_watch_directory(directory); + return; + } + + if ((mask & (IN_ATTRIB|IN_CREATE|IN_MOVE)) != 0 && + (mask & IN_ISDIR) != 0) { + /* a sub directory was changed: register those in + inotify */ + char *root = map_directory_fs(db_get_root()); + char *path_fs; + + if (uri_fs != NULL) { + path_fs = g_strconcat(root, "/", uri_fs, NULL); + g_free(root); + } else + path_fs = root; + + recursive_watch_subdirectories(directory, path_fs); + g_free(path_fs); + } + + if ((mask & (IN_CLOSE_WRITE|IN_MOVE|IN_DELETE)) != 0) { + /* a file was changed, or a direectory was + moved/deleted: queue a database update */ + char *uri_utf8 = uri_fs != NULL + ? fs_charset_to_utf8(uri_fs) + : g_strdup(""); + + if (uri_utf8 != NULL) + /* this function will take care of freeing + uri_utf8 */ + mpd_inotify_enqueue(uri_utf8); + } + + g_free(uri_fs); +} + +void +mpd_inotify_init(void) +{ + struct directory *root; + char *path; + GError *error = NULL; + + g_debug("initializing inotify"); + + root = db_get_root(); + if (root == NULL) { + g_debug("no music directory configured"); + return; + } + + path = map_directory_fs(root); + if (path == NULL) { + g_warning("mapper has failed"); + return; + } + + inotify_source = mpd_inotify_source_new(mpd_inotify_callback, NULL, + &error); + if (inotify_source == NULL) { + g_warning("%s", error->message); + g_error_free(error); + g_free(path); + return; + } + + inotify_root.name = path; + inotify_root.descriptor = mpd_inotify_source_add(inotify_source, path, + IN_MASK, &error); + if (inotify_root.descriptor < 0) { + g_warning("%s", error->message); + g_error_free(error); + mpd_inotify_source_free(inotify_source); + inotify_source = NULL; + g_free(path); + return; + } + + inotify_directories = g_tree_new(compare); + tree_add_watch_directory(&inotify_root); + + recursive_watch_subdirectories(&inotify_root, path); + + mpd_inotify_queue_init(); + + g_debug("watching music directory"); +} + +static gboolean +free_watch_directory(G_GNUC_UNUSED gpointer key, gpointer value, + G_GNUC_UNUSED gpointer data) +{ + struct watch_directory *directory = value; + + g_free(directory->name); + g_list_free(directory->children); + + if (directory != &inotify_root) + g_slice_free(struct watch_directory, directory); + + return false; +} + +void +mpd_inotify_finish(void) +{ + if (inotify_source == NULL) + return; + + mpd_inotify_queue_finish(); + mpd_inotify_source_free(inotify_source); + + g_tree_foreach(inotify_directories, free_watch_directory, NULL); + g_tree_destroy(inotify_directories); +} -- cgit v1.2.3