db/simple: create dedicated directory

src/db/plugins/simple/DirectorySave.cxx

@@ -0,0 +1,207 @@
+/*
+ * 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 "DirectorySave.hxx"
+#include "Directory.hxx"
+#include "Song.hxx"
+#include "SongSave.hxx"
+#include "DetachedSong.hxx"
+#include "PlaylistDatabase.hxx"
+#include "fs/TextFile.hxx"
+#include "util/StringUtil.hxx"
+#include "util/NumberParser.hxx"
+#include "util/Error.hxx"
+#include "util/Domain.hxx"
+
+#include <stddef.h>
+#include <string.h>
+
+#define DIRECTORY_DIR "directory: "
+#define DIRECTORY_TYPE "type: "
+#define DIRECTORY_MTIME "mtime: "
+#define DIRECTORY_BEGIN "begin: "
+#define DIRECTORY_END "end: "
+
+static constexpr Domain directory_domain("directory");
+
+gcc_const
+static const char *
+DeviceToTypeString(unsigned device)
+{
+	switch (device) {
+	case DEVICE_INARCHIVE:
+		return "archive";
+
+	case DEVICE_CONTAINER:
+		return "container";
+
+	default:
+		return nullptr;
+	}
+}
+
+gcc_pure
+static unsigned
+ParseTypeString(const char *type)
+{
+	if (strcmp(type, "archive") == 0)
+		return DEVICE_INARCHIVE;
+	else if (strcmp(type, "container") == 0)
+		return DEVICE_CONTAINER;
+	else
+		return 0;
+}
+
+void
+directory_save(FILE *fp, const Directory &directory)
+{
+	if (!directory.IsRoot()) {
+		const char *type = DeviceToTypeString(directory.device);
+		if (type != nullptr)
+			fprintf(fp, DIRECTORY_TYPE "%s\n", type);
+
+		if (directory.mtime != 0)
+			fprintf(fp, DIRECTORY_MTIME "%lu\n",
+				(unsigned long)directory.mtime);
+
+		fprintf(fp, "%s%s\n", DIRECTORY_BEGIN, directory.GetPath());
+	}
+
+	Directory *cur;
+	directory_for_each_child(cur, directory) {
+		fprintf(fp, DIRECTORY_DIR "%s\n", cur->GetName());
+
+		directory_save(fp, *cur);
+
+		if (ferror(fp))
+			return;
+	}
+
+	Song *song;
+	directory_for_each_song(song, directory)
+		song_save(fp, *song);
+
+	playlist_vector_save(fp, directory.playlists);
+
+	if (!directory.IsRoot())
+		fprintf(fp, DIRECTORY_END "%s\n", directory.GetPath());
+}
+
+static bool
+ParseLine(Directory &directory, const char *line)
+{
+	if (StringStartsWith(line, DIRECTORY_MTIME)) {
+		directory.mtime =
+			ParseUint64(line + sizeof(DIRECTORY_MTIME) - 1);
+	} else if (StringStartsWith(line, DIRECTORY_TYPE)) {
+		directory.device =
+			ParseTypeString(line + sizeof(DIRECTORY_TYPE) - 1);
+	} else
+		return false;
+
+	return true;
+}
+
+static Directory *
+directory_load_subdir(TextFile &file, Directory &parent, const char *name,
+		      Error &error)
+{
+	bool success;
+
+	if (parent.FindChild(name) != nullptr) {
+		error.Format(directory_domain,
+			     "Duplicate subdirectory '%s'", name);
+		return nullptr;
+	}
+
+	Directory *directory = parent.CreateChild(name);
+
+	while (true) {
+		const char *line = file.ReadLine();
+		if (line == nullptr) {
+			error.Set(directory_domain, "Unexpected end of file");
+			directory->Delete();
+			return nullptr;
+		}
+
+		if (StringStartsWith(line, DIRECTORY_BEGIN))
+			break;
+
+		if (!ParseLine(*directory, line)) {
+			error.Format(directory_domain,
+				     "Malformed line: %s", line);
+			directory->Delete();
+			return nullptr;
+		}
+	}
+
+	success = directory_load(file, *directory, error);
+	if (!success) {
+		directory->Delete();
+		return nullptr;
+	}
+
+	return directory;
+}
+
+bool
+directory_load(TextFile &file, Directory &directory, Error &error)
+{
+	const char *line;
+
+	while ((line = file.ReadLine()) != nullptr &&
+	       !StringStartsWith(line, DIRECTORY_END)) {
+		if (StringStartsWith(line, DIRECTORY_DIR)) {
+			Directory *subdir =
+				directory_load_subdir(file, directory,
+						      line + sizeof(DIRECTORY_DIR) - 1,
+						      error);
+			if (subdir == nullptr)
+				return false;
+		} else if (StringStartsWith(line, SONG_BEGIN)) {
+			const char *name = line + sizeof(SONG_BEGIN) - 1;
+
+			if (directory.FindSong(name) != nullptr) {
+				error.Format(directory_domain,
+					     "Duplicate song '%s'", name);
+				return false;
+			}
+
+			DetachedSong *song = song_load(file, name, error);
+			if (song == nullptr)
+				return false;
+
+			directory.AddSong(Song::NewFrom(std::move(*song),
+							directory));
+			delete song;
+		} else if (StringStartsWith(line, PLAYLIST_META_BEGIN)) {
+			const char *name = line + sizeof(PLAYLIST_META_BEGIN) - 1;
+			if (!playlist_metadata_load(file, directory.playlists,
+						    name, error))
+				return false;
+		} else {
+			error.Format(directory_domain,
+				     "Malformed line: %s", line);
+			return false;
+		}
+	}
+
+	return true;
+}