1 files changed, 338 insertions, 0 deletions
diff --git a/src/db/update/InotifyUpdate.cxx b/src/db/update/InotifyUpdate.cxx
new file mode 100644
index 000000000..3ba92ebf0
--- /dev/null
+++ b/src/db/update/InotifyUpdate.cxx
@@ -0,0 +1,338 @@
+/*
+ * 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" /* must be first for large file support */
+#include "InotifyUpdate.hxx"
+#include "InotifySource.hxx"
+#include "InotifyQueue.hxx"
+#include "InotifyDomain.hxx"
+#include "Mapper.hxx"
+#include "fs/AllocatedPath.hxx"
+#include "fs/FileSystem.hxx"
+#include "util/Error.hxx"
+#include "Log.hxx"
+
+#include <string>
+#include <map>
+#include <forward_list>
+
+#include <assert.h>
+#include <sys/inotify.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <dirent.h>
+
+static constexpr unsigned IN_MASK =
+#ifdef IN_ONLYDIR
+	IN_ONLYDIR|
+#endif
+	IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_DELETE_SELF
+	|IN_MOVE|IN_MOVE_SELF;
+
+struct WatchDirectory {
+	WatchDirectory *parent;
+
+	AllocatedPath name;
+
+	int descriptor;
+
+	std::forward_list<WatchDirectory> children;
+
+	template<typename N>
+	WatchDirectory(WatchDirectory *_parent, N &&_name,
+		       int _descriptor)
+		:parent(_parent), name(std::forward<N>(_name)),
+		 descriptor(_descriptor) {}
+
+	WatchDirectory(const WatchDirectory &) = delete;
+	WatchDirectory &operator=(const WatchDirectory &) = delete;
+};
+
+static InotifySource *inotify_source;
+static InotifyQueue *inotify_queue;
+
+static unsigned inotify_max_depth;
+static WatchDirectory *inotify_root;
+static std::map<int, WatchDirectory *> inotify_directories;
+
+static void
+tree_add_watch_directory(WatchDirectory *directory)
+{
+	inotify_directories.insert(std::make_pair(directory->descriptor,
+						  directory));
+}
+
+static void
+tree_remove_watch_directory(WatchDirectory *directory)
+{
+	auto i = inotify_directories.find(directory->descriptor);
+	assert(i != inotify_directories.end());
+	inotify_directories.erase(i);
+}
+
+static WatchDirectory *
+tree_find_watch_directory(int wd)
+{
+	auto i = inotify_directories.find(wd);
+	if (i == inotify_directories.end())
+		return nullptr;
+
+	return i->second;
+}
+
+static void
+disable_watch_directory(WatchDirectory &directory)
+{
+	tree_remove_watch_directory(&directory);
+
+	for (WatchDirectory &child : directory.children)
+		disable_watch_directory(child);
+
+	inotify_source->Remove(directory.descriptor);
+}
+
+static void
+remove_watch_directory(WatchDirectory *directory)
+{
+	assert(directory != nullptr);
+
+	if (directory->parent == nullptr) {
+		LogWarning(inotify_domain,
+			   "music directory was removed - "
+			   "cannot continue to watch it");
+		return;
+	}
+
+	disable_watch_directory(*directory);
+
+	/* remove it from the parent, which effectively deletes it */
+	directory->parent->children.remove_if([directory](const WatchDirectory &child){
+			return &child == directory;
+		});
+}
+
+static AllocatedPath
+watch_directory_get_uri_fs(const WatchDirectory *directory)
+{
+	if (directory->parent == nullptr)
+		return AllocatedPath::Null();
+
+	const auto uri = watch_directory_get_uri_fs(directory->parent);
+	if (uri.IsNull())
+		return directory->name;
+
+	return AllocatedPath::Build(uri, directory->name);
+}
+
+/* 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') != nullptr;
+}
+
+static void
+recursive_watch_subdirectories(WatchDirectory *directory,
+			       const AllocatedPath &path_fs, unsigned depth)
+{
+	Error error;
+	DIR *dir;
+	struct dirent *ent;
+
+	assert(directory != nullptr);
+	assert(depth <= inotify_max_depth);
+	assert(!path_fs.IsNull());
+
+	++depth;
+
+	if (depth > inotify_max_depth)
+		return;
+
+	dir = opendir(path_fs.c_str());
+	if (dir == nullptr) {
+		FormatErrno(inotify_domain,
+			    "Failed to open directory %s", path_fs.c_str());
+		return;
+	}
+
+	while ((ent = readdir(dir))) {
+		struct stat st;
+		int ret;
+
+		if (skip_path(ent->d_name))
+			continue;
+
+		const auto child_path_fs =
+			AllocatedPath::Build(path_fs, ent->d_name);
+		ret = StatFile(child_path_fs, st);
+		if (ret < 0) {
+			FormatErrno(inotify_domain,
+				    "Failed to stat %s",
+				    child_path_fs.c_str());
+			continue;
+		}
+
+		if (!S_ISDIR(st.st_mode))
+			continue;
+
+		ret = inotify_source->Add(child_path_fs.c_str(), IN_MASK,
+					  error);
+		if (ret < 0) {
+			FormatError(error,
+				    "Failed to register %s",
+				    child_path_fs.c_str());
+			error.Clear();
+			continue;
+		}
+
+		WatchDirectory *child = tree_find_watch_directory(ret);
+		if (child != nullptr)
+			/* already being watched */
+			continue;
+
+		directory->children.emplace_front(directory,
+						  AllocatedPath::FromFS(ent->d_name),
+						  ret);
+		child = &directory->children.front();
+
+		tree_add_watch_directory(child);
+
+		recursive_watch_subdirectories(child, child_path_fs, depth);
+	}
+
+	closedir(dir);
+}
+
+gcc_pure
+static unsigned
+watch_directory_depth(const WatchDirectory *d)
+{
+	assert(d != nullptr);
+
+	unsigned depth = 0;
+	while ((d = d->parent) != nullptr)
+		++depth;
+
+	return depth;
+}
+
+static void
+mpd_inotify_callback(int wd, unsigned mask,
+		     gcc_unused const char *name, gcc_unused void *ctx)
+{
+	WatchDirectory *directory;
+
+	/*FormatDebug(inotify_domain, "wd=%d mask=0x%x name='%s'", wd, mask, name);*/
+
+	directory = tree_find_watch_directory(wd);
+	if (directory == nullptr)
+		return;
+
+	const auto uri_fs = watch_directory_get_uri_fs(directory);
+
+	if ((mask & (IN_DELETE_SELF|IN_MOVE_SELF)) != 0) {
+		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 */
+		const auto &root = mapper_get_music_directory_fs();
+
+		const auto path_fs = uri_fs.IsNull()
+			? root
+			: AllocatedPath::Build(root, uri_fs.c_str());
+
+		recursive_watch_subdirectories(directory, path_fs,
+					       watch_directory_depth(directory));
+	}
+
+	if ((mask & (IN_CLOSE_WRITE|IN_MOVE|IN_DELETE)) != 0 ||
+	    /* at the maximum depth, we watch out for newly created
+	       directories */
+	    (watch_directory_depth(directory) == inotify_max_depth &&
+	     (mask & (IN_CREATE|IN_ISDIR)) == (IN_CREATE|IN_ISDIR))) {
+		/* a file was changed, or a directory was
+		   moved/deleted: queue a database update */
+
+		if (!uri_fs.IsNull()) {
+			const std::string uri_utf8 = uri_fs.ToUTF8();
+			if (!uri_utf8.empty())
+				inotify_queue->Enqueue(uri_utf8.c_str());
+		}
+		else
+			inotify_queue->Enqueue("");
+	}
+}
+
+void
+mpd_inotify_init(EventLoop &loop, UpdateService &update, unsigned max_depth)
+{
+	LogDebug(inotify_domain, "initializing inotify");
+
+	const auto &path = mapper_get_music_directory_fs();
+	if (path.IsNull()) {
+		LogDebug(inotify_domain, "no music directory configured");
+		return;
+	}
+
+	Error error;
+	inotify_source = InotifySource::Create(loop,
+					       mpd_inotify_callback, nullptr,
+					       error);
+	if (inotify_source == nullptr) {
+		LogError(error);
+		return;
+	}
+
+	inotify_max_depth = max_depth;
+
+	int descriptor = inotify_source->Add(path.c_str(), IN_MASK, error);
+	if (descriptor < 0) {
+		LogError(error);
+		delete inotify_source;
+		inotify_source = nullptr;
+		return;
+	}
+
+	inotify_root = new WatchDirectory(nullptr, path, descriptor);
+
+	tree_add_watch_directory(inotify_root);
+
+	recursive_watch_subdirectories(inotify_root, path, 0);
+
+	inotify_queue = new InotifyQueue(loop, update);
+
+	LogDebug(inotify_domain, "watching music directory");
+}
+
+void
+mpd_inotify_finish(void)
+{
+	if (inotify_source == nullptr)
+		return;
+
+	delete inotify_queue;
+	delete inotify_source;
+	delete inotify_root;
+	inotify_directories.clear();
+}