mscab.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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef MSCAB_H
#define MSCAB_H

#include "common/hashmap.h"
#include "common/hash-str.h"
#include "common/stream.h"
#include "common/archive.h"
#include "common/str.h"
#include "common/util.h"

namespace Grim {

class MsCabinet : public Common::Archive {
public:
    MsCabinet(Common::SeekableReadStream *data);
    ~MsCabinet();

    // Common::Archive API implementation
    bool hasFile(const Common::Path &path) const override;
    int listMembers(Common::ArchiveMemberList &list) const override;
    const Common::ArchiveMemberPtr getMember(const Common::Path &path) const override;
    Common::SeekableReadStream *createReadStreamForMember(const Common::Path &path) const override;

private:
    Common::SeekableReadStream *_data;

    struct FolderEntry {
        uint16 comp_type;           // The compression type
        uint16 num_blocks;          // The total number of data blocks used by this folder
        uint32 offset;              // The cabinet offset of first datablock
    };

    struct FileEntry {
        uint32 length;              // Uncompressed size of the file in bytes
        FolderEntry *folder;        // Folder holding this file
        uint32 folderOffset;        // Uncompressed offset in the folder
    };

    typedef Common::HashMap<Common::Path, FileEntry, Common::Path::IgnoreCase_Hash, Common::Path::IgnoreCase_EqualTo> FileMap;
    FileMap _fileMap;

    typedef Common::HashMap<uint16, FolderEntry> FolderMap;
    FolderMap _folderMap;

    Common::String readString(Common::ReadStream *stream);

    // Decompressor
    class Decompressor {
    public:
        Decompressor(const FolderEntry *folder, Common::SeekableReadStream *_data);
        ~Decompressor();
        bool decompressFile(byte *&fileBuf, const FileEntry &entry);
        const FolderEntry *getFolder() const {
            return _curFolder;
        }
    private:
        Common::SeekableReadStream *_data;
        const FolderEntry *_curFolder;
        int16 _curBlock;
        byte *_compressedBlock, *_decompressedBlock;
        byte *_fileBuf;
        uint16 _startBlock, _inBlockStart, _endBlock, _inBlockEnd;

        void copyBlock(byte *&data_ptr) const;

        enum {
            kMszipCompression = 1,
            kCabBlockSize = 0x8000,
            kCabInputmax = kCabBlockSize + 12
        };
    };

    mutable Decompressor *_decompressor;

    // Cache
    typedef Common::HashMap<Common::Path, byte *, Common::Path::IgnoreCase_Hash, Common::Path::IgnoreCase_EqualTo> CacheMap;
    mutable CacheMap _cache;
};

} // End of namespace Grim

#endif