mavinfo.cpp

基于EP7312的MP3播放器源代码,包括MCU和PC端代码.

CMaverickInfo::GetDriveName(unsigned long ulDrive, WCHAR *pcName,
                            unsigned long ulLength)
{
    //
    // Obtain the critical section.
    //
    m_CriticalSection.Lock();

    //
    // Make sure that:
    //   1) the specified drive is valid, and
    //   2) we have a string of drive names.
    //
    if((ulDrive >= m_ulNumDrives) || !m_ppcDriveNames)
    {
        m_CriticalSection.Unlock();
        pcName[0] = L'\0';
        return;
    }

    //
    // Return the name of this drive.
    //
    wcsncpy(pcName, m_ppcDriveNames[ulDrive], ulLength);

    //
    // Release the critical section.
    //
    m_CriticalSection.Unlock();
}

//****************************************************************************
//
// Returns the number of files on the given drive.
//
//****************************************************************************
unsigned long
CMaverickInfo::GetNumFiles(unsigned long ulDrive)
{
    unsigned long ulNumFiles;

    //
    // Obtain the critical section.
    //
    m_CriticalSection.Lock();

    //
    // Make sure that:
    //   1) the specified drive is valid, and
    //   2) we have an array of the number of files per drive.
    //
    if((ulDrive >= m_ulNumDrives) || !m_pulNumFiles)
    {
        m_CriticalSection.Unlock();
        return(0);
    }

    //
    // Get the number of files on this drive.
    //
    ulNumFiles = m_pulNumFiles[ulDrive];

    //
    // Release the critical section.
    //
    m_CriticalSection.Unlock();

    //
    // Return the number of files on this drive.
    //
    return(ulNumFiles);
}

//****************************************************************************
//
// Returns the name of the given file on the given drive.
//
//****************************************************************************
void
CMaverickInfo::GetFileName(unsigned long ulDrive, unsigned long ulFile,
                           WCHAR *pcName, unsigned long ulLength)
{
    WCHAR *pcFileName;

    //
    // Obtain the critical section.
    //
    m_CriticalSection.Lock();

    //
    // Make sure that:
    //   1) the specified drive is valid,
    //   2) we have an array of the number of files per drive,
    //   3) the specified file is valid,
    //   4) we have an array of the names of the files on each drive, and
    //   5) we have a string of the file names on this drive.
    //
    if((ulDrive >= m_ulNumDrives) || !m_pulNumFiles ||
       (ulFile >= m_pulNumFiles[ulDrive]) || !m_ppcFileNames ||
       !m_ppcFileNames[ulDrive])
    {
        m_CriticalSection.Unlock();
        pcName[0] = L'\0';
        return;
    }

    //
    // Get a local copy of the file name string.
    //
    pcFileName = m_ppcFileNames[ulDrive];

    //
    // Find the specified file.
    //
    while(ulFile--)
    {
        //
        // Skip to the next file name.
        //
        pcFileName += wcslen(pcFileName) + 1;
    }

    //
    // Return the name of this file.
    //
    wcsncpy(pcName, pcFileName, ulLength);

    //
    // Release the critical section.
    //
    m_CriticalSection.Unlock();
}

//****************************************************************************
//
// Returns the length of the given file on the given drive.
//
//****************************************************************************
unsigned long
CMaverickInfo::GetFileLength(unsigned long ulDrive, unsigned long ulFile)
{
    unsigned long ulFileSize;

    //
    // Obtain the critical section.
    //
    m_CriticalSection.Lock();

    //
    // Make sure that:
    //   1) the specified drive is valid,
    //   2) we have an array of the number of files per drive,
    //   3) the specified file is valid,
    //   4) we have an array of file sizes per drive, and
    //   5) we have an array of file sizes for this drive.
    //
    if((ulDrive >= m_ulNumDrives) || !m_pulNumFiles ||
       (ulFile >= m_pulNumFiles[ulDrive]) || !m_ppulFileSizes ||
       !m_ppulFileSizes[ulDrive])
    {
        ulFileSize = 0;
    }
    else
    {
        //
        // Get the length of this file.
        //
        ulFileSize = m_ppulFileSizes[ulDrive][ulFile];
    }

    //
    // Release the critical section.
    //
    m_CriticalSection.Unlock();

    //
    // Return the length of this file.
    //
    return(ulFileSize);
}

//****************************************************************************
//
// Returns the modification date/time of the given file on the given drive.
//
//****************************************************************************
unsigned long
CMaverickInfo::GetFileDate(unsigned long ulDrive, unsigned long ulFile)
{
    unsigned long ulFileSize;

    //
    // Obtain the critical section.
    //
    m_CriticalSection.Lock();

    //
    // Make sure that:
    //   1) the specified drive is valid,
    //   2) we have an array of the number of files per drive,
    //   3) the specified file is valid,
    //   4) we have an array of file sizes per drive, and
    //   5) we have an array of file sizes for this drive.
    //
    if((ulDrive >= m_ulNumDrives) || !m_pulNumFiles ||
       (ulFile >= m_pulNumFiles[ulDrive]) || !m_ppulFileDates ||
       !m_ppulFileDates[ulDrive])
    {
        ulFileSize = 0;
    }
    else
    {
        //
        // Get the modification date/time of this file.
        //
        ulFileSize = m_ppulFileDates[ulDrive][ulFile];
    }

    //
    // Release the critical section.
    //
    m_CriticalSection.Unlock();

    //
    // Return the length of this file.
    //
    return(ulFileSize);
}

//****************************************************************************
//
// Returns the storage globals object for the given drive.
//
//****************************************************************************
IMDSPStorageGlobals *
CMaverickInfo::GetStorageGlobals(unsigned long ulDrive)
{
    CComObject<CMDSPStorageGlobals> *pObj;
    IMDSPStorageGlobals *pGlobals;
    HRESULT hr;

    //
    // Obtain the critical section.
    //
    m_CriticalSection.Lock();

    //
    // Make sure that:
    //   1) the specified drive is valid, and
    //   2) we have an array of storage globals objects.
    //
    if((ulDrive >= m_ulNumDrives) || !m_ppStorageGlobals)
    {
        m_CriticalSection.Unlock();
        return(NULL);
    }

    //
    // See if there is already a storage globals object for this drive.
    //
    if(m_ppStorageGlobals[ulDrive])
    {
        //
        // There is already a storage globals object for this drive, so add a
        // reference to that object.
        //
        m_ppStorageGlobals[ulDrive]->AddRef();

        //
        // Release the critical section.
        //
        m_CriticalSection.Unlock();

        //
        // Return the storage globals object for this drive.
        //
        return(m_ppStorageGlobals[ulDrive]);
    }

    //
    // Create a new storage globals object.
    //
    hr = CComObject<CMDSPStorageGlobals>::CreateInstance(&pObj);
    if(FAILED(hr))
    {
        m_CriticalSection.Unlock();
        return(NULL);
    }

    //
    // Get a pointer to the IMDSPStorageGlobals interface of the object.
    //
    hr = pObj->QueryInterface(IID_IMDSPStorageGlobals,
                              reinterpret_cast<void **>(&pGlobals));
    if(FAILED(hr))
    {
        delete pObj;
        m_CriticalSection.Unlock();
        return(NULL);
    }

    //
    // Since we'll be saving a pointer to this object and use it for subsequent
    // calls, add a reference so it doesn't get deleted when the caller
    // releases the object.
    //
    pGlobals->AddRef();

    //
    // Initialize the storage globals object.
    //
    pObj->SetDrive(ulDrive);

    //
    // Save this object in our array.
    //
    m_ppStorageGlobals[ulDrive] = pGlobals;

    //
    // Release the critical section.
    //
    m_CriticalSection.Unlock();

    //
    // Return the storage globals object.
    //
    return(pGlobals);
}

//****************************************************************************
//
// Returns the device object for the device.
//
//****************************************************************************
IMDSPDevice *
CMaverickInfo::GetDevice(unsigned long ulDrive)
{
    CComObject<CMDSPDevice> *pObj;
    IMDSPDevice *pDevice;
    HRESULT hr;

    //
    // Obtain the critical section.
    //
    m_CriticalSection.Lock();

    //
    // Make sure that:
    //   1) the specified drive is valid, and
    //   2) we have an array of device objects.
    //
    if((ulDrive >= m_ulNumDrives) || !m_ppDevice)
    {
        m_CriticalSection.Unlock();
        return(NULL);
    }

    //
    // See if there is already a device object for this drive.
    //
    if(m_ppDevice[ulDrive])
    {
        //
        // There is already a device object for this drive, so add a reference
        // to that object.
        //
        m_ppDevice[ulDrive]->AddRef();

        //
        // Release the critical section.
        //
        m_CriticalSection.Unlock();

        //
        // Return the device object for this drive.
        //
        return(m_ppDevice[ulDrive]);
    }

    //
    // Create a new device object.
    //
    hr = CComObject<CMDSPDevice>::CreateInstance(&pObj);
    if(FAILED(hr))
    {
        m_CriticalSection.Unlock();
        return(NULL);
    }

    //
    // Get a pointer to the IMDSPDevice interface of the object.
    //
    hr = pObj->QueryInterface(IID_IMDSPDevice,
                              reinterpret_cast<void **>(&pDevice));
    if(FAILED(hr))
    {
        delete pObj;
        m_CriticalSection.Unlock();
        return(NULL);
    }

    //
    // Since we'll be saving a pointer to this object and use it for subsequent
    // calls, add a reference so it doesn't get deleted when the caller
    // releases the object.
    //
    pDevice->AddRef();

    //
    // Initialize the device object.
    //
    pObj->SetDrive(ulDrive);

    //
    // Save this object.
    //
    m_ppDevice[ulDrive] = pDevice;

    //
    // Release the critical section.
    //
    m_CriticalSection.Unlock();

    //
    // Return the device object.
    //
    return(pDevice);
}