scummvm/engines/ultima/shared/engine/data_archive.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 ULTIMA_SHARED_ENGINE_DATA_ARCHIVE_H
#define ULTIMA_SHARED_ENGINE_DATA_ARCHIVE_H

#include "common/archive.h"
#include "common/fs.h"
#include "common/str.h"

namespace Ultima {
namespace Shared {

/**
 * The data archive class encapsulates access to a specific subfolder within
 * the ultima.dat data file for a game. It wraps up the subfolder so it can
 * be accessed in each game as a generic "data" subfolder. This allows the
 * individual games to simplify their data loading code.
 */
class UltimaDataArchive : public Common::Archive {
private:
	Common::Archive *_zip;
	Common::String _publicFolder;
	Common::String _innerfolder;


	UltimaDataArchive(Common::Archive *zip, const Common::String &subfolder) :
		_zip(zip), _publicFolder("data/"), _innerfolder(subfolder + "/") {}

	Common::String innerToPublic(const Common::String &filename) const {
		assert(filename.hasPrefixIgnoreCase(_publicFolder));
		return _innerfolder + Common::String(filename.c_str() + _publicFolder.size());
	}
public:
	/**
	 * Creates a data archive wrapper for the ultima.dat datafile.
	 * Firstly, for debugging purposes, if a "files" folder exists on any path that
	 * has the given subfolder, it will be used first. This will allow for setting
	 * the ScummVM Extra Path to the create_ultima folder, and it will give preference
	 * the files there. Otherwise, it checks for the presence of ultima.dat, and
	 * if the required data is found, it returns the new archive.
	 * Otherwise, returns an error message in the errorMsg field
	 */
	static bool load(const Common::String &subfolder,
		int reqMajorVersion, int reqMinorVersion, Common::U32String &errorMsg);
public:
	~UltimaDataArchive() override {
		delete _zip;
	}

	/**
	 * Check if a member with the given name is present in the Archive.
	 * Patterns are not allowed, as this is meant to be a quick File::exists()
	 * replacement.
	 */
	bool hasFile(const Common::Path &path) const override;

	/**
	 * Add all members of the Archive matching the specified pattern to list.
	 * Must only append to list, and not remove elements from it.
	 *
	 * @return the number of members added to list
	 */
	int listMatchingMembers(Common::ArchiveMemberList &list,
		const Common::Path &pattern) const override;

	/**
	 * Add all members of the Archive to list.
	 * Must only append to list, and not remove elements from it.
	 *
	 * @return the number of names added to list
	 */
	int listMembers(Common::ArchiveMemberList &list) const override;

	/**
	 * Returns a ArchiveMember representation of the given file.
	 */
	const Common::ArchiveMemberPtr getMember(const Common::Path &path)
		const override;

	/**
	 * Create a stream bound to a member with the specified name in the
	 * archive. If no member with this name exists, 0 is returned.
	 * @return the newly created input stream
	 */
	Common::SeekableReadStream *createReadStreamForMember(
		const Common::Path &path) const override;
};

#ifndef RELEASE_BUILD

/**
 * The data archive proxy class is used for debugging purposes to access engine data
 * files when the create_ultima folder is in the search path. It will allow for
 * local mucking around with the data files and committing changes without having to
 * recreate the ultima.dat file every time a change is made. ultima.dat then just has
 * to be recreated prior to a release or when the changes are completed and stable
 */
class UltimaDataArchiveProxy : public Common::Archive {
	friend class UltimaDataArchive;
private:
	Common::FSNode _folder;
	const Common::String _publicFolder;

	UltimaDataArchiveProxy(const Common::FSNode &folder) : _folder(folder), _publicFolder("data/") {}

	/**
	 * Gets a file node from the passed filename
	 */
	Common::FSNode getNode(const Common::String &name) const;
public:
	~UltimaDataArchiveProxy() override {
	}

	/**
	 * Check if a member with the given name is present in the Archive.
	 * Patterns are not allowed, as this is meant to be a quick File::exists()
	 * replacement.
	 */
	bool hasFile(const Common::Path &path) const override {
		Common::String name = path.toString();
		return name.hasPrefixIgnoreCase(_publicFolder) && getNode(name).exists();
	}

	/**
	 * Add all members of the Archive matching the specified pattern to list.
	 * Must only append to list, and not remove elements from it.
	 *
	 * @return the number of members added to list
	 */
	int listMatchingMembers(Common::ArchiveMemberList &list,
			const Common::Path &pattern) const override {
		return 0;
	}

	/**
	 * Add all members of the Archive to list.
	 * Must only append to list, and not remove elements from it.
	 *
	 * @return the number of names added to list
	 */
	int listMembers(Common::ArchiveMemberList &list) const override {
		return 0;
	}

	/**
	 * Returns a ArchiveMember representation of the given file.
	 */
	const Common::ArchiveMemberPtr getMember(const Common::Path &path)
		const override;

	/**
	 * Create a stream bound to a member with the specified name in the
	 * archive. If no member with this name exists, 0 is returned.
	 * @return the newly created input stream
	 */
	Common::SeekableReadStream *createReadStreamForMember(
		const Common::Path &path) const override;
};

#endif

} // End of namespace Shared
} // End of namespace Ultima

#endif