/*
 * Copyright 2007, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Copyright 2019-2024, Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT license.
 */
#ifndef DATA_CONTAINER_H
#define DATA_CONTAINER_H


#include <OS.h>


struct vm_page;
class VMCache;
class Volume;


class DataContainer {
public:
        DataContainer(Volume *volume);
        virtual ~DataContainer();

        status_t InitCheck() const;

        Volume *GetVolume() const       { return fVolume; }

        status_t Resize(off_t newSize);
        off_t GetSize() const { return fSize; }
        off_t GetCommittedSize() const;

        VMCache* GetCache(struct vnode* vnode);

        virtual status_t ReadAt(off_t offset, void *buffer, size_t size,
                                                        size_t *bytesRead);
        virtual status_t WriteAt(off_t offset, const void *buffer, size_t size,
                                                         size_t *bytesWritten);

private:
        inline bool _RequiresCacheMode(size_t size);
        inline bool _IsCacheMode() const;
        status_t _SwitchToCacheMode();
        status_t _DoCacheIO(off_t offset, uint8* buffer, ssize_t length,
                size_t* bytesProcessed, bool isWrite, bool retriesAllowed = true);

        inline int32 _CountBlocks() const;

private:
        Volume                          *fVolume;
        off_t                           fSize;
        VMCache*                        fCache;

        uint8*                          fSmallBuffer;
        off_t                           fSmallBufferSize;
};


#endif  // DATA_CONTAINER_H