// Functionality:
// Request UDT to send out a file described as "fd", starting from "offset", with size of "size".
// Parameters:
// 0) [in] ifs: The input file stream.
// 1) [in] offset: From where to read and send data;
// 2) [in] size: How many data to be sent.
// 3) [in] block: size of block per read from disk
// Returned value:
// Actual size of data sent.
public Int64 sendfile(Stream ifs, Int64 offset, Int64 size, int block)
{
if (UDT_DGRAM == m_iSockType)
throw new CUDTException(5, 10, 0);
if (m_bBroken || m_bClosing)
throw new CUDTException(2, 1, 0);
else if (!m_bConnected)
throw new CUDTException(2, 2, 0);
if (size <= 0)
return 0;
CGuard sendguard = new CGuard(m_SendLock);
long tosend = size;
int unitsize;
// positioning...
try
{
ifs.seekg((streamoff)offset);
}
catch (Exception e)
{
throw new CUDTException(4, 1);
}
// sending block by block
while (tosend > 0)
{
if (ifs.bad() || ifs.fail() || ifs.eof())
break;
unitsize = (int)((tosend >= block) ? block : tosend);
while (!m_bBroken && m_bConnected && !m_bClosing && (m_iSndBufSize <= m_pSndBuffer.getCurrBufSize()))
WaitForSingleObject(m_SendBlockCond, INFINITE);
if (m_bBroken || m_bClosing)
throw new CUDTException(2, 1, 0);
else if (!m_bConnected)
throw new CUDTException(2, 2, 0);
// record total time used for sending
if (0 == m_pSndBuffer.getCurrBufSize())
m_llSndDurationCounter = CClock.getTime();
tosend -= m_pSndBuffer.addBufferFromFile(ifs, unitsize);
// insert this socket to snd list if it is not on the list yet
m_pSndQueue.m_pSndUList.update(this, false);
}
return size - tosend;
}