SongLoader.hxx

/*
 * Copyright 2003-2018 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_SONG_LOADER_HXX
#define MPD_SONG_LOADER_HXX

#include "util/Compiler.h"
#include "config.h"

#include <cstddef>

class Client;
class Database;
class Storage;
class DetachedSong;
class Path;
struct LocatedUri;

/**
 * A utility class that loads a #DetachedSong object by its URI.  If
 * the URI is an absolute local file, it applies security checks via
 * Client::AllowFile().  If no #Client pointer was specified, then it
 * is assumed that all local files are allowed.
 */
class SongLoader {
	const Client *const client;

#ifdef ENABLE_DATABASE
	const Database *const db;
	const Storage *const storage;
#endif

public:
#ifdef ENABLE_DATABASE
	explicit SongLoader(const Client &_client);
	SongLoader(const Database *_db, const Storage *_storage)
		:client(nullptr), db(_db), storage(_storage) {}
	SongLoader(const Client &_client, const Database *_db,
		   const Storage *_storage)
		:client(&_client), db(_db), storage(_storage) {}
#else
	explicit SongLoader(const Client &_client)
		:client(&_client) {}
	explicit SongLoader(std::nullptr_t, std::nullptr_t)
		:client(nullptr) {}
#endif

#ifdef ENABLE_DATABASE
	const Storage *GetStorage() const {
		return storage;
	}
#endif

	DetachedSong LoadSong(const LocatedUri &uri) const;

	/**
	 * Throws #std::runtime_error on error.
	 */
	gcc_nonnull_all
	DetachedSong LoadSong(const char *uri_utf8) const;

private:
	gcc_nonnull_all
	DetachedSong LoadFromDatabase(const char *uri) const;

	gcc_nonnull_all
	DetachedSong LoadFile(const char *path_utf8, Path path_fs) const;
};

#endif