WDU_StreamRead()

DWORD DLLCALLCONV WDU_StreamRead	(	_In_ HANDLE	hStream,
		_Outptr_ PVOID	pBuffer,
		_In_ DWORD	bytes,
		_Outptr_ DWORD *	pdwBytesRead
	)

Reads data from a read stream to the application.

For a blocking stream (fBlocking=TRUE - see WDU_StreamOpen()), the call to this function is blocked until the specified amount of data is read, or until the stream's attempt to read from the device times out (i.e the timeout period for transfers between the stream and the device, as set in the dwRxTxTimeout WDU_StreamOpen() parameter, expires). For a non-blocking stream, the function transfers to the application as much of the requested data as possible, subject to the amount of data currently available in the stream's data buffer, and returns immediately. For both blocking and non-blocking transfers, the function returns the amount of bytes that were actually read from the stream within the pdwBytesRead parameter.

Parameters

[in]	hStream	A unique identifier for the stream, as returned by WDU_StreamOpen().
[out]	pBuffer	Pointer to a data buffer to be filled with the data read from the stream.
[in]	bytes	Number of bytes to read from the stream.
[out]	pdwBytesRead	Pointer to a value indicating the number of bytes actually read from the stream.

Returns

WinDriver Error Code

 
DWORD dwStatus;
DWORD dwPipeNum, dwSize, dwBytesTransferred, cmd = MENU_RW_READ_PIPE;
VOID *pBuffer = NULL;
WDU_STREAM_HANDLE stream;
DWORD dwBufferSize = 0x20000;
 
dwStatus = WDU_StreamOpen(hDevice, dwPipeNum, dwBufferSize,
                    dwSize, TRUE, 0, TRANSFER_TIMEOUT, &stream);
if (dwStatus)
{
    ERR("ReadWritePipesMenu: WDU_StreamOpen() failed. "
        "error 0x%lx (\"%s\")\n", dwStatus, Stat2Str(dwStatus));
    goto End_transfer;
}
 
dwStatus = WDU_StreamStart(stream);
if (dwStatus)
{
    ERR("ReadWritePipesMenu: WDU_StreamStart() failed. error "
        "0x%lx (\"%s\")\n", dwStatus, Stat2Str(dwStatus));
    goto End_transfer;
}
 
if (cmd == MENU_RW_READ_PIPE)
{
    dwStatus = WDU_StreamRead(stream, pBuffer, dwSize,
        &dwBytesTransferred);
}
else
{
    dwStatus = WDU_StreamWrite(stream, pBuffer, dwSize,
        &dwBytesTransferred);
}
if (dwStatus)
{
    BOOL fIsRunning;
    DWORD dwLastError;
    DWORD dwBytesInBuffer;
 
    dwStatus = WDU_StreamGetStatus(stream, &fIsRunning,
        &dwLastError, &dwBytesInBuffer);
    if (!dwStatus)
        dwStatus = dwLastError;
}
 
WDU_StreamClose(stream);