db/update: convert to OO API

Move global variables into the new classes.  That may allow multiple
update threads for multiple databases one day.

src/db/update/Walk.hxx

@@ -0,0 +1,134 @@
+/*
+ * 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.
+ */
+
+#ifndef MPD_UPDATE_WALK_HXX
+#define MPD_UPDATE_WALK_HXX
+
+#include "check.h"
+#include "Editor.hxx"
+
+#include <sys/stat.h>
+
+struct stat;
+struct Directory;
+struct archive_plugin;
+class ExcludeList;
+
+class UpdateWalk final {
+#ifdef ENABLE_ARCHIVE
+	friend class UpdateArchiveVisitor;
+#endif
+
+#ifndef WIN32
+	static constexpr bool DEFAULT_FOLLOW_INSIDE_SYMLINKS = true;
+	static constexpr bool DEFAULT_FOLLOW_OUTSIDE_SYMLINKS = true;
+
+	bool follow_inside_symlinks;
+	bool follow_outside_symlinks;
+#endif
+
+	bool walk_discard;
+	bool modified;
+
+	DatabaseEditor editor;
+
+public:
+	UpdateWalk(EventLoop &_loop);
+
+	/**
+	 * Returns true if the database was modified.
+	 */
+	bool Walk(const char *path, bool discard);
+
+private:
+	gcc_pure
+	bool SkipSymlink(const Directory *directory,
+			 const char *utf8_name) const;
+
+	void RemoveExcludedFromDirectory(Directory &directory,
+					 const ExcludeList &exclude_list);
+
+	void PurgeDeletedFromDirectory(Directory &directory);
+
+	void UpdateSongFile2(Directory &directory,
+			     const char *name, const char *suffix,
+			     const struct stat *st);
+
+	bool UpdateSongFile(Directory &directory,
+			    const char *name, const char *suffix,
+			    const struct stat *st);
+
+	bool UpdateContainerFile(Directory &directory,
+				 const char *name, const char *suffix,
+				 const struct stat *st);
+
+
+#ifdef ENABLE_ARCHIVE
+	void UpdateArchiveTree(Directory &parent, const char *name);
+
+	bool UpdateArchiveFile(Directory &directory,
+			       const char *name, const char *suffix,
+			       const struct stat *st);
+
+	void UpdateArchiveFile(Directory &directory, const char *name,
+			       const struct stat *st,
+			       const archive_plugin &plugin);
+
+
+#else
+	bool UpdateArchiveFile(gcc_unused Directory &directory,
+			       gcc_unused const char *name,
+			       gcc_unused const char *suffix,
+			       gcc_unused const struct stat *st) {
+		return false;
+	}
+#endif
+
+	bool UpdatePlaylistFile(Directory &directory,
+				const char *name, const char *suffix,
+				const struct stat *st);
+
+	bool UpdateRegularFile(Directory &directory,
+			       const char *name, const struct stat *st);
+
+	void UpdateDirectoryChild(Directory &directory,
+				  const char *name, const struct stat *st);
+
+	bool UpdateDirectory(Directory &directory, const struct stat *st);
+
+	/**
+	 * Create the specified directory object if it does not exist
+	 * already or if the #stat object indicates that it has been
+	 * modified since the last update.  Returns nullptr when it
+	 * exists already and is unmodified.
+	 *
+	 * The caller must lock the database.
+	 */
+	Directory *MakeDirectoryIfModified(Directory &parent, const char *name,
+					   const struct stat *st);
+
+	Directory *DirectoryMakeChildChecked(Directory &parent,
+					     const char *name_utf8);
+
+	Directory *DirectoryMakeUriParentChecked(const char *uri);
+
+	void UpdateUri(const char *uri);
+};
+
+#endif