Upstream tarball 9882

[amule.git] / src / EMSocket.cpp

//
// This file is part of the aMule Project.
//
// Copyright (c) 2003-2008 aMule Team ( admin@amule.org / http://www.amule.org )
// Copyright (c) 2002-2008 Merkur ( devs@emule-project.net / http://www.emule-project.net )
//
// Any parts of this program derived from the xMule, lMule or eMule project,
// or contributed by third-party developers are copyrighted by their
// respective authors.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
//


#include "EMSocket.h"           // Interface declarations.

#include <protocol/Protocols.h>
#include <protocol/ed2k/Constants.h>

#include "Packet.h"             // Needed for CPacket
#include "amule.h"
#include "GetTickCount.h"
#include "UploadBandwidthThrottler.h"
#include "Logger.h"
#include "Preferences.h"


const uint32 MAX_SIZE = 2000000;

CEMSocket::CEMSocket(const CProxyData *ProxyData)
        : CEncryptedStreamSocket(wxSOCKET_NOWAIT, ProxyData)
{
        // If an interface has been specified,
        // then we need to bind to it.
        if (!thePrefs::GetAddress().IsEmpty()) {
                amuleIPV4Address host;
                
                // No need to warn here, in case of failure to
                // assign the hostname. That is already done
                // in amule.cpp when starting ...
                if (host.Hostname(thePrefs::GetAddress())) {
                        SetLocal(host);
                }
        }

        byConnected = ES_NOTCONNECTED;
        m_uTimeOut = CONNECTION_TIMEOUT; // default timeout for ed2k sockets

        // Download (pseudo) rate control       
        downloadLimit = 0;
        downloadLimitEnable = false;
        pendingOnReceive = false;

        // Download partial header
        pendingHeaderSize = 0;

        // Download partial packet
        pendingPacket = NULL;
        pendingPacketSize = 0;

        // Upload control
        sendbuffer = NULL;
        sendblen = 0;
        sent = 0;

    m_currentPacket_is_controlpacket = false;
        m_currentPackageIsFromPartFile = false;

    m_numberOfSentBytesCompleteFile = 0;
    m_numberOfSentBytesPartFile = 0;
    m_numberOfSentBytesControlPacket = 0;

    lastCalledSend = ::GetTickCount();
    lastSent = ::GetTickCount()-1000;

        m_bAccelerateUpload = false;

    m_actualPayloadSize = 0;
    m_actualPayloadSizeSent = 0;

    m_bBusy = false;
    m_hasSent = false;

        lastFinishedStandard = 0;

        DoingDestroy = false;
        
}

CEMSocket::~CEMSocket()
{
    // need to be locked here to know that the other methods
    // won't be in the middle of things
    {
        wxMutexLocker lock(m_sendLocker);
                byConnected = ES_DISCONNECTED;
        }

    // now that we know no other method will keep adding to the queue
    // we can remove ourself from the queue
        if (theApp->uploadBandwidthThrottler) {
            theApp->uploadBandwidthThrottler->RemoveFromAllQueues(this);
        }

    ClearQueues();
        
        SetNotify(0);
        Notify(FALSE);
}

void CEMSocket::Destroy() {
        if (!DoingDestroy) {            
                DoingDestroy = true;
                wxSocketClient::Destroy();
        }       
}


void CEMSocket::ClearQueues()
{
        wxMutexLocker lock(m_sendLocker);

        DeleteContents(m_control_queue);

        {
                CStdPacketQueue::iterator it = m_standard_queue.begin();
                for (; it != m_standard_queue.end(); ++it) {
                        delete it->packet;
                }
                m_standard_queue.clear();
        }
        
        // Download (pseudo) rate control       
        downloadLimit = 0;
        downloadLimitEnable = false;
        pendingOnReceive = false;

        // Download partial header
        pendingHeaderSize = 0;

        // Download partial packet
        delete pendingPacket;
        pendingPacket = NULL;
        pendingPacketSize = 0;

        // Upload control
        delete[] sendbuffer;
        sendbuffer = NULL;
        sendblen = 0;
        sent = 0;
}


void CEMSocket::OnClose(int WXUNUSED(nErrorCode))
{
    // need to be locked here to know that the other methods
    // won't be in the middle of things
    {
        wxMutexLocker lock(m_sendLocker);
                byConnected = ES_DISCONNECTED;
        }

    // now that we know no other method will keep adding to the queue
    // we can remove ourself from the queue
    theApp->uploadBandwidthThrottler->RemoveFromAllQueues(this);
        
        ClearQueues();
}


void CEMSocket::OnReceive(int nErrorCode)
{
        // the 2 meg size was taken from another place
        static byte GlobalReadBuffer[MAX_SIZE];

        if(nErrorCode) {
                uint32 error = LastError(); 
                if (error != wxSOCKET_WOULDBLOCK) {
                        OnError(nErrorCode);
                        return;
                }
        }
        
        // Check current connection state
        if (byConnected == ES_DISCONNECTED) {
                return;
        } else {        
                byConnected = ES_CONNECTED; // ES_DISCONNECTED, ES_NOTCONNECTED, ES_CONNECTED
        }

        // CPU load improvement
        if(downloadLimitEnable == true && downloadLimit == 0){
                pendingOnReceive = true;
                return;
        }

        // Remark: an overflow can not occur here
        uint32 readMax = sizeof(GlobalReadBuffer) - pendingHeaderSize; 
        if((downloadLimitEnable == true) && (readMax > downloadLimit)) {
                readMax = downloadLimit;
        }

        
        // We attempt to read up to 2 megs at a time (minus whatever is in our internal read buffer)
        uint32 ret;

        {
                wxMutexLocker lock(m_sendLocker);
                ret = Read(GlobalReadBuffer + pendingHeaderSize, readMax);
                if (Error() || (ret == 0)) {
                        if (LastError() == wxSOCKET_WOULDBLOCK) {
                                pendingOnReceive = true;
                        }
                        return;
                }
        }
        
        
        // Bandwidth control
        if(downloadLimitEnable == true){
                // Update limit
                downloadLimit -= GetRealReceivedBytes();
        }

        // CPU load improvement
        // Detect if the socket's buffer is empty (or the size did match...)
        pendingOnReceive = (ret == readMax);

        // Copy back the partial header into the global read buffer for processing
        if(pendingHeaderSize > 0) {
                memcpy(GlobalReadBuffer, pendingHeader, pendingHeaderSize);
                ret += pendingHeaderSize;
                pendingHeaderSize = 0;
        }

        byte* rptr = GlobalReadBuffer; // floating index initialized with begin of buffer
        const byte* rend = GlobalReadBuffer + ret; // end of buffer

        // Loop, processing packets until we run out of them
        while((rend - rptr >= PACKET_HEADER_SIZE) ||
              ((pendingPacket != NULL) && (rend - rptr > 0 ))){ 

                // Two possibilities here: 
                //
                // 1. There is no pending incoming packet
                // 2. There is already a partial pending incoming packet
                //
                // It's important to remember that emule exchange two kinds of packet
                // - The control packet
                // - The data packet for the transport of the block
                // 
                // The biggest part of the traffic is done with the data packets. 
                // The default size of one block is 10240 bytes (or less if compressed), but the
                // maximal size for one packet on the network is 1300 bytes. It's the reason
                // why most of the Blocks are splitted before to be sent. 
                //
                // Conclusion: When the download limit is disabled, this method can be at least 
                // called 8 times (10240/1300) by the lower layer before a splitted packet is 
                // rebuild and transferred to the above layer for processing.
                //
                // The purpose of this algorithm is to limit the amount of data exchanged between buffers

                if(pendingPacket == NULL){
                        pendingPacket = new CPacket(rptr); // Create new packet container. 
                        rptr += 6;                        // Only the header is initialized so far

                        // Bugfix We still need to check for a valid protocol
                        // Remark: the default eMule v0.26b had removed this test......
                        switch (pendingPacket->GetProtocol()){
                                case OP_EDONKEYPROT:
                                case OP_PACKEDPROT:
                                case OP_EMULEPROT:
                                case OP_ED2KV2HEADER:
                                case OP_ED2KV2PACKEDPROT:
                                        break;
                                default:
                                        delete pendingPacket;
                                        pendingPacket = NULL;
                                        OnError(ERR_WRONGHEADER);
                                        return;
                        }

                        // Security: Check for buffer overflow (2MB)
                        if(pendingPacket->GetPacketSize() > sizeof(GlobalReadBuffer)) {
                                delete pendingPacket;
                                pendingPacket = NULL;
                                OnError(ERR_TOOBIG);
                                return;
                        }

                        // Init data buffer
                        pendingPacket->AllocDataBuffer();
                        pendingPacketSize = 0;
                }

                // Bytes ready to be copied into packet's internal buffer
                wxASSERT(rptr <= rend);
                uint32 toCopy = ((pendingPacket->GetPacketSize() - pendingPacketSize) < (uint32)(rend - rptr)) ? 
                                        (pendingPacket->GetPacketSize() - pendingPacketSize) : (uint32)(rend - rptr);

                // Copy Bytes from Global buffer to packet's internal buffer
                pendingPacket->CopyToDataBuffer(pendingPacketSize, rptr, toCopy);
                pendingPacketSize += toCopy;
                rptr += toCopy;
                
                // Check if packet is complet
                wxASSERT(pendingPacket->GetPacketSize() >= pendingPacketSize);
                if(pendingPacket->GetPacketSize() == pendingPacketSize) {
                        // Process packet
                        bool bPacketResult = PacketReceived(pendingPacket);
                        delete pendingPacket;   
                        pendingPacket = NULL;
                        pendingPacketSize = 0;
                        
                        if (!bPacketResult) {
                                return;
                        }
                }
        }

        // Finally, if there is any data left over, save it for next time
        wxASSERT(rptr <= rend);
        wxASSERT(rend - rptr < PACKET_HEADER_SIZE);
        if(rptr != rend) {
                // Keep the partial head
                pendingHeaderSize = rend - rptr;
                memcpy(pendingHeader, rptr, pendingHeaderSize);
        }       
}


void CEMSocket::SetDownloadLimit(uint32 limit)
{
        downloadLimit = limit;
        downloadLimitEnable = true;     
        
        // CPU load improvement
        if(limit > 0 && pendingOnReceive == true){
                OnReceive(0);
        }
}


void CEMSocket::DisableDownloadLimit()
{
        downloadLimitEnable = false;

        // CPU load improvement
        if (pendingOnReceive == true){
                OnReceive(0);
        }
}


/**
 * Queues up the packet to be sent. Another thread will actually send the packet.
 *
 * If the packet is not a control packet, and if the socket decides that its queue is
 * full and forceAdd is false, then the socket is allowed to refuse to add the packet
 * to its queue. It will then return false and it is up to the calling thread to try
 * to call SendPacket for that packet again at a later time.
 *
 * @param packet address to the packet that should be added to the queue
 *
 * @param delpacket if true, the responsibility for deleting the packet after it has been sent
 *                  has been transferred to this object. If false, don't delete the packet after it
 *                  has been sent.
 *
 * @param controlpacket the packet is a controlpacket
 *
 * @param forceAdd this packet must be added to the queue, even if it is full. If this flag is true
 *                 then the method can not refuse to add the packet, and therefore not return false.
 *
 * @return true if the packet was added to the queue, false otherwise
 */
void CEMSocket::SendPacket(CPacket* packet, bool delpacket, bool controlpacket, uint32 actualPayloadSize)
{
        //printf("* SendPacket called on socket %p\n", this);
        wxMutexLocker lock(m_sendLocker);

        if (byConnected == ES_DISCONNECTED) {
                //printf("* Disconnected, drop packet\n");
        if(delpacket) {
                        delete packet;
        }
    } else {
        if (!delpacket){
            packet = new CPacket(*packet);
            }

        if (controlpacket) {
                        //printf("* Adding a control packet\n");
                m_control_queue.push_back(packet);

            // queue up for controlpacket
            theApp->uploadBandwidthThrottler->QueueForSendingControlPacket(this, HasSent());
            } else {
                        //printf("* Adding a normal packet to the queue\n");
            bool first = !((sendbuffer && !m_currentPacket_is_controlpacket) || !m_standard_queue.empty());
            StandardPacketQueueEntry queueEntry = { actualPayloadSize, packet };
                    m_standard_queue.push_back(queueEntry);

            // reset timeout for the first time
            if (first) {
                lastFinishedStandard = ::GetTickCount();
                m_bAccelerateUpload = true;     // Always accelerate first packet in a block
            }
            }
    }
}


uint64 CEMSocket::GetSentBytesCompleteFileSinceLastCallAndReset()
{
        wxMutexLocker lock( m_sendLocker );

        uint64 sentBytes = m_numberOfSentBytesCompleteFile;
    m_numberOfSentBytesCompleteFile = 0;

    return sentBytes;
}


uint64 CEMSocket::GetSentBytesPartFileSinceLastCallAndReset()
{
        wxMutexLocker lock( m_sendLocker );

        uint64 sentBytes = m_numberOfSentBytesPartFile;
    m_numberOfSentBytesPartFile = 0;

    return sentBytes;
}

uint64 CEMSocket::GetSentBytesControlPacketSinceLastCallAndReset()
{
        wxMutexLocker lock( m_sendLocker );

        uint64 sentBytes = m_numberOfSentBytesControlPacket;
    m_numberOfSentBytesControlPacket = 0;

    return sentBytes;
}

uint64 CEMSocket::GetSentPayloadSinceLastCallAndReset()
{
        wxMutexLocker lock( m_sendLocker );

        uint64 sentBytes = m_actualPayloadSizeSent;
    m_actualPayloadSizeSent = 0;

    return sentBytes;
}


void CEMSocket::OnSend(int nErrorCode)
{
    if (nErrorCode){
                OnError(nErrorCode);
                return;
        }

        CEncryptedStreamSocket::OnSend(0);      
        
        wxMutexLocker lock( m_sendLocker );
    m_bBusy = false;

    if (byConnected != ES_DISCONNECTED) {
                byConnected = ES_CONNECTED;

            if (m_currentPacket_is_controlpacket) {
                // queue up for control packet
            theApp->uploadBandwidthThrottler->QueueForSendingControlPacket(this, HasSent());
                }
    }
}


/**
 * Try to put queued up data on the socket.
 *
 * Control packets have higher priority, and will be sent first, if possible.
 * Standard packets can be split up in several package containers. In that case
 * all the parts of a split package must be sent in a row, without any control packet
 * in between.
 *
 * @param maxNumberOfBytesToSend This is the maximum number of bytes that is allowed to be put on the socket
 *                               this call. The actual number of sent bytes will be returned from the method.
 *
 * @param onlyAllowedToSendControlPacket This call we only try to put control packets on the sockets.
 *                                       If there's a standard packet "in the way", and we think that this socket
 *                                       is no longer an upload slot, then it is ok to send the standard packet to
 *                                       get it out of the way. But it is not allowed to pick a new standard packet
 *                                       from the queue during this call. Several split packets are counted as one
 *                                       standard packet though, so it is ok to finish them all off if necessary.
 *
 * @return the actual number of bytes that were put on the socket.
 */
SocketSentBytes CEMSocket::Send(uint32 maxNumberOfBytesToSend, uint32 minFragSize, bool onlyAllowedToSendControlPacket)
{
        wxMutexLocker lock(m_sendLocker);

        //printf("* Attempt to send a packet on socket %p\n", this);
        
        if (byConnected == ES_DISCONNECTED) {
                //printf("* Disconnected socket %p\n", this);
        SocketSentBytes returnVal = { false, 0, 0 };
        return returnVal;
    } else if (m_bBusy && onlyAllowedToSendControlPacket) {
                //printf("* Busy socket %p\n", this);
        SocketSentBytes returnVal = { true, 0, 0 };
        return returnVal;
    }   

    bool anErrorHasOccured = false;
    uint32 sentStandardPacketBytesThisCall = 0;
    uint32 sentControlPacketBytesThisCall = 0;
        
    if(byConnected == ES_CONNECTED && IsEncryptionLayerReady() && !(m_bBusy && onlyAllowedToSendControlPacket)) {

                //printf("* Internal attemptto send on %p\n", this);
                
                if(minFragSize < 1) {
                        minFragSize = 1;
                }
        
                maxNumberOfBytesToSend = GetNextFragSize(maxNumberOfBytesToSend, minFragSize);
        
                bool bWasLongTimeSinceSend = (::GetTickCount() - lastSent) > 1000;
        
                lastCalledSend = ::GetTickCount();
        
                        
                while(sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall < maxNumberOfBytesToSend && anErrorHasOccured == false && // don't send more than allowed. Also, there should have been no error in earlier loop
                          (!m_control_queue.empty() || !m_standard_queue.empty() || sendbuffer != NULL) && // there must exist something to send
                          (onlyAllowedToSendControlPacket == false || // this means we are allowed to send both types of packets, so proceed
                           (sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall > 0 && (sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall) % minFragSize != 0) ||
                           (sendbuffer == NULL && !m_control_queue.empty()) || // There's a control packet in queue, and we are not currently sending anything, so we will handle the control packet next
                           (sendbuffer != NULL && m_currentPacket_is_controlpacket == true) || // We are in the progress of sending a control packet. We are always allowed to send those
                           (sendbuffer != NULL && m_currentPacket_is_controlpacket == false && bWasLongTimeSinceSend && !m_control_queue.empty() && m_standard_queue.empty() && (sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall) < minFragSize) // We have waited to long to clean the current packet (which may be a standard packet that is in the way). Proceed no matter what the value of onlyAllowedToSendControlPacket.
                          )
                         ) {
        
                        // If we are currently not in the progress of sending a packet, we will need to find the next one to send
                        if(sendbuffer == NULL) {
                                CPacket* curPacket = NULL;
                                if(!m_control_queue.empty()) {
                                        // There's a control packet to send
                                        m_currentPacket_is_controlpacket = true;
                                        curPacket = m_control_queue.front();
                                        m_control_queue.pop_front();
                                } else if(!m_standard_queue.empty() /*&& onlyAllowedToSendControlPacket == false*/) {
                                        // There's a standard packet to send
                                        m_currentPacket_is_controlpacket = false;
                                        StandardPacketQueueEntry queueEntry = m_standard_queue.front();
                                        m_standard_queue.pop_front();
                                        curPacket = queueEntry.packet;
                                        m_actualPayloadSize = queueEntry.actualPayloadSize;
        
                                        // remember this for statistics purposes.
                                        m_currentPackageIsFromPartFile = curPacket->IsFromPF();
                                } else {
                                        // Just to be safe. Shouldn't happen?
                                        // if we reach this point, then there's something wrong with the while condition above!
                                        wxFAIL;
                                        AddDebugLogLineM(true, logGeneral, wxT("EMSocket: Couldn't get a new packet! There's an error in the first while condition in EMSocket::Send()"));
        
                                        SocketSentBytes returnVal = { true, sentStandardPacketBytesThisCall, sentControlPacketBytesThisCall };
                                        return returnVal;
                                }
        
                                // We found a packet to send. Get the data to send from the
                                // package container and dispose of the container.
                                sendblen = curPacket->GetRealPacketSize();
                                sendbuffer = curPacket->DetachPacket();
                                sent = 0;
                                delete curPacket;
                                
                                CryptPrepareSendData((byte*)sendbuffer, sendblen);
                        }
        
                        // At this point we've got a packet to send in sendbuffer. Try to send it. Loop until entire packet
                        // is sent, or until we reach maximum bytes to send for this call, or until we get an error.
                        // NOTE! If send would block (returns WOULDBLOCK), we will return from this method INSIDE this loop.
                        while (sent < sendblen &&
                                   sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall < maxNumberOfBytesToSend &&
                                   (
                                        onlyAllowedToSendControlPacket == false || // this means we are allowed to send both types of packets, so proceed
                                        m_currentPacket_is_controlpacket ||
                                        (bWasLongTimeSinceSend && (sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall) < minFragSize) ||
                                        (sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall) % minFragSize != 0
                                   ) &&
                                   anErrorHasOccured == false) {
                                uint32 tosend = sendblen-sent;
                                if(!onlyAllowedToSendControlPacket || m_currentPacket_is_controlpacket) {
                                        if (maxNumberOfBytesToSend >= sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall && tosend > maxNumberOfBytesToSend-(sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall))
                                                tosend = maxNumberOfBytesToSend-(sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall);
                                } else if(bWasLongTimeSinceSend && (sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall) < minFragSize) {
                                        if (minFragSize >= sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall && tosend > minFragSize-(sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall))
                                                tosend = minFragSize-(sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall);
                                } else {
                                        uint32 nextFragMaxBytesToSent = GetNextFragSize(sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall, minFragSize);
                                        if (nextFragMaxBytesToSent >= sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall && tosend > nextFragMaxBytesToSent-(sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall))
                                                tosend = nextFragMaxBytesToSent-(sentStandardPacketBytesThisCall + sentControlPacketBytesThisCall);
                                }
                                wxASSERT(tosend != 0 && tosend <= sendblen-sent);
                                
                                //DWORD tempStartSendTick = ::GetTickCount();
        
                                lastSent = ::GetTickCount();
        
                                uint32 result = CEncryptedStreamSocket::Write(sendbuffer+sent,tosend);
                                
                                if (Error()){
                                        
                                        uint32 error = LastError();
                                        if (error == wxSOCKET_WOULDBLOCK){
                                                m_bBusy = true;
        
                                                SocketSentBytes returnVal = { true, sentStandardPacketBytesThisCall, sentControlPacketBytesThisCall };
                                                
                                                return returnVal; // Send() blocked, onsend will be called when ready to send again
                                        } else{
                                                // Send() gave an error
                                                anErrorHasOccured = true;
                                        }
                                } else {
                                        // we managed to send some bytes. Perform bookkeeping.
                                        m_bBusy = false;
                                        m_hasSent = true;
        
                                        sent += result;
        
                                        // Log send bytes in correct class
                                        if(m_currentPacket_is_controlpacket == false) {
                                                sentStandardPacketBytesThisCall += result;
        
                                                if(m_currentPackageIsFromPartFile == true) {
                                                        m_numberOfSentBytesPartFile += result;
                                                } else {
                                                        m_numberOfSentBytesCompleteFile += result;
                                                }
                                        } else {
                                                sentControlPacketBytesThisCall += result;
                                                m_numberOfSentBytesControlPacket += result;
                                        }
                                }
                        }
        
                        if (sent == sendblen){
                                // we are done sending the current packet. Delete it and set
                                // sendbuffer to NULL so a new packet can be fetched.
                                delete[] sendbuffer;
                                sendbuffer = NULL;
                                sendblen = 0;
        
                                if(!m_currentPacket_is_controlpacket) {
                                        m_actualPayloadSizeSent += m_actualPayloadSize;
                                        m_actualPayloadSize = 0;
        
                                        lastFinishedStandard = ::GetTickCount(); // reset timeout
                                        m_bAccelerateUpload = false; // Safe until told otherwise
                                }
        
                                sent = 0;
                        }
                }
        }
        
        if(onlyAllowedToSendControlPacket && (!m_control_queue.empty() || (sendbuffer != NULL && m_currentPacket_is_controlpacket))) {
                // enter control packet send queue
                // we might enter control packet queue several times for the same package,
                // but that costs very little overhead. Less overhead than trying to make sure
                // that we only enter the queue once.
                //printf("* Requeueing control packet on %p\n", this);
                theApp->uploadBandwidthThrottler->QueueForSendingControlPacket(this, HasSent());
        }

        //printf("* Finishing send debug on %p\n",this);
        
        SocketSentBytes returnVal = { !anErrorHasOccured, sentStandardPacketBytesThisCall, sentControlPacketBytesThisCall };
        
    return returnVal;
}


uint32 CEMSocket::GetNextFragSize(uint32 current, uint32 minFragSize)
{
    if(current % minFragSize == 0) {
        return current;
    } else {
        return minFragSize*(current/minFragSize+1);
    }
}


/**
 * Decides the (minimum) amount the socket needs to send to prevent timeout.
 * 
 * @author SlugFiller
 */
uint32 CEMSocket::GetNeededBytes()
{
        uint32 sendgap;

        uint64 timetotal;
        uint64 timeleft;
        uint64 sizeleft, sizetotal;

        {
                wxMutexLocker lock(m_sendLocker);

                if (byConnected == ES_DISCONNECTED) {
                        return 0;
                }
        
                if (!((sendbuffer && !m_currentPacket_is_controlpacket) || !m_standard_queue.empty())) {
                        // No standard packet to send. Even if data needs to be sent to prevent timout, there's nothing to send.
                        return 0;
                }
        
                if (((sendbuffer && !m_currentPacket_is_controlpacket)) && !m_control_queue.empty())
                        m_bAccelerateUpload = true;     // We might be trying to send a block request, accelerate packet
        
                sendgap = ::GetTickCount() - lastCalledSend;
        
                timetotal = m_bAccelerateUpload?45000:90000;
                timeleft = ::GetTickCount() - lastFinishedStandard;
                if (sendbuffer && !m_currentPacket_is_controlpacket) {
                        sizeleft = sendblen-sent;
                        sizetotal = sendblen;
                } else {
                        sizeleft = sizetotal = m_standard_queue.front().packet->GetRealPacketSize();
                }
        }

        if (timeleft >= timetotal)
                return sizeleft;
        timeleft = timetotal-timeleft;
        if (timeleft*sizetotal >= timetotal*sizeleft) {
                // don't use 'GetTimeOut' here in case the timeout value is high,
                if (sendgap > SEC2MS(20))
                        return 1;       // Don't let the socket itself time out - Might happen when switching from spread(non-focus) slot to trickle slot
                return 0;
        }
        uint64 decval = timeleft*sizetotal/timetotal;
        if (!decval)
                return sizeleft;
        if (decval < sizeleft)
                return sizeleft-decval+1;       // Round up
        else
                return 1;
}


/**
 * Removes all packets from the standard queue that don't have to be sent for the socket to be able to send a control packet.
 *
 * Before a socket can send a new packet, the current packet has to be finished. If the current packet is part of
 * a split packet, then all parts of that split packet must be sent before the socket can send a control packet.
 *
 * This method keeps in standard queue only those packets that must be sent (rest of split packet), and removes everything
 * after it. The method doesn't touch the control packet queue.
 */
void CEMSocket::TruncateQueues()
{
        wxMutexLocker lock(m_sendLocker);

        // Clear the standard queue totally
    // Please note! There may still be a standardpacket in the sendbuffer variable!
        CStdPacketQueue::iterator it = m_standard_queue.begin();
        for (; it != m_standard_queue.end(); ++it) {
                delete it->packet;
        }
        
        m_standard_queue.clear();
}


uint32 CEMSocket::GetTimeOut() const
{
        return m_uTimeOut;
}


void CEMSocket::SetTimeOut(uint32 uTimeOut)
{
        m_uTimeOut = uTimeOut;
}
// File_checked_for_headers