RageFileDriverReadAhead.h

/* RageFileDriverReadAhead - Read-ahead hinting for seamless rewinding. */
 
#ifndef RAGE_FILE_DRIVER_READ_AHEAD_H
#define RAGE_FILE_DRIVER_READ_AHEAD_H
 
#include "RageFileBasic.h"
 
class RageFileDriverReadAhead : public RageFileObj
{
  public:
    /* This filter can only be used on supported files; test before using. */
    static bool FileSupported(RageFileBasic* pFile);
 
    /* pFile will be freed if DeleteFileWhenFinished is called. */
    RageFileDriverReadAhead(RageFileBasic* pFile,
                            int iCacheBytes,
                            int iPostBufferReadAhead = -1);
    RageFileDriverReadAhead(const RageFileDriverReadAhead& cpy);
    ~RageFileDriverReadAhead() override;
    RageFileDriverReadAhead* Copy() const override;
 
    void DeleteFileWhenFinished() { m_bFileOwned = true; }
 
    std::string GetError() const override { return m_pFile->GetError(); }
    void ClearError() override { return m_pFile->ClearError(); }
 
    int ReadInternal(void* pBuffer, size_t iBytes) override;
    int WriteInternal(const void* pBuffer, size_t iBytes) override
    {
        return m_pFile->Write(pBuffer, iBytes);
    }
    int SeekInternal(int iOffset) override;
    int GetFileSize() const override { return m_pFile->GetFileSize(); }
    int GetFD() override { return m_pFile->GetFD(); }
    int Tell() const override { return m_iFilePos; }
 
  private:
    void FillBuffer(int iBytes);
 
    RageFileBasic* m_pFile;
    int m_iFilePos;
    bool m_bFileOwned;
    std::string m_sBuffer;
    int m_iPostBufferReadAhead;
    bool m_bReadAheadNeeded = false;
};
 
#endif