Channel.cpp 50.6 KB
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/**************************************************************************/
/*                                                                        */
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/* Copyright (c) 2001, 2011 NoMachine (http://www.nomachine.com)          */
/* Copyright (c) 2008-2014 Oleksandr Shneyder <o.shneyder@phoca-gmbh.de>  */
/* Copyright (c) 2014-2016 Ulrich Sibiller <uli42@gmx.de>                 */
/* Copyright (c) 2014-2016 Mihai Moldovan <ionic@ionic.de>                */
/* Copyright (c) 2011-2016 Mike Gabriel <mike.gabriel@das-netzwerkteam.de>*/
/* Copyright (c) 2015-2016 Qindel Group (http://www.qindel.com)           */
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/*                                                                        */
/* NXCOMP, NX protocol compression and NX extensions to this software     */
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/* are copyright of the aforementioned persons and companies.             */
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/*                                                                        */
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/* Redistribution and use of the present software is allowed according    */
/* to terms specified in the file LICENSE.nxcomp which comes in the       */
/* source distribution.                                                   */
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/*                                                                        */
/* All rights reserved.                                                   */
/*                                                                        */
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/* NOTE: This software has received contributions from various other      */
/* contributors, only the core maintainers and supporters are listed as   */
/* copyright holders. Please contact us, if you feel you should be listed */
/* as copyright holder, as well.                                          */
/*                                                                        */
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/**************************************************************************/

#include "Channel.h"

#include "List.h"
#include "Proxy.h"
#include "Statistics.h"

#include "StaticCompressor.h"

#include "NXalert.h"

extern Proxy *proxy;

//
// Set the verbosity level.
//

#define PANIC
#define WARNING
#undef  TEST
#undef  DEBUG
#undef  DUMP

//
// Log the operations related to splits.
//

#undef  SPLIT

#undef  COUNT

#define COUNT_MAJOR_OPCODE     154

#undef  MONITOR

#define MONITOR_MAJOR_OPCODE   154
#define MONITOR_MINOR_OPCODE   23

#undef  CLEAR

#define CLEAR_MAJOR_OPCODE     154
#define CLEAR_MINOR_OPCODE     23

//
// Define this to know how many messages
// are allocated and deallocated.
//

#undef  REFERENCES

//
// Set to the descriptor of the first X
// channel successfully connected.
//

int Channel::firstClient_ = -1;

//
// Port used for font server connections.
//

int Channel::fontPort_ = -1;

//
// This is used for reference count.
//

#ifdef REFERENCES

int Channel::references_ = 0;

#endif

Channel::Channel(Transport *transport, StaticCompressor *compressor)

    : transport_(transport), compressor_(compressor)
{
  fd_ = transport_ -> fd();

  finish_     = 0;
  closing_    = 0;
  drop_       = 0;
  congestion_ = 0;
  priority_   = 0;

  alert_ = 0;

  firstRequest_ = 1;
  firstReply_   = 1;

  enableCache_ = 1;
  enableSplit_ = 1;
  enableSave_  = 1;
  enableLoad_  = 1;

  //
  // Must be set by proxy.
  //

  opcodeStore_ = NULL;
 
  clientStore_ = NULL;
  serverStore_ = NULL;

  clientCache_ = NULL;
  serverCache_ = NULL;

  #ifdef REFERENCES
  *logofs << "Channel: Created new Channel at " 
          << this << " out of " << ++references_ 
          << " allocated references.\n" << logofs_flush;
  #endif
}

Channel::~Channel()
{
  if (firstClient_ == fd_)
  {
    firstClient_ = -1;
  }

  #ifdef REFERENCES
  *logofs << "Channel: Deleted Channel at " 
          << this << " out of " << --references_ 
          << " allocated references.\n" << logofs_flush;
  #endif
}

int Channel::handleEncode(EncodeBuffer &encodeBuffer, ChannelCache *channelCache,
                              MessageStore *store, const unsigned char opcode,
                                  const unsigned char *buffer, const unsigned int size)
{
  #ifdef MONITOR

  static float totalMessages = 0;
  static float totalBits     = 0;

  int bits;
  int diff;

  bits = encodeBuffer.getBits();

  #endif

  //
  // Check if message can be differentially
  // encoded using a similar message in the
  // message store.
  // 

  #ifdef COUNT

  if (*(buffer) == COUNT_MAJOR_OPCODE)
  {
    if (*(buffer) < 128)
    {
      *logofs << "handleEncode: Handling OPCODE#" << (unsigned int) *(buffer)
              << ".\n" << logofs_flush;
    }
    else
    {
      *logofs << "handleEncode: Handling OPCODE#" << (unsigned int) *(buffer)
              << " MINOR#" << (unsigned int) *(buffer + 1) << ".\n"
              << logofs_flush;
    }
  }

  #endif

  #ifdef CLEAR

  if (*(buffer) == CLEAR_MAJOR_OPCODE &&
          (CLEAR_MINOR_OPCODE == -1 || *(buffer + 1) == CLEAR_MINOR_OPCODE))
  {
    *((unsigned char *) buffer) = X_NoOperation;

    *((unsigned char *) buffer + 1) = '\0';

    CleanData((unsigned char *) buffer + 4, size - 4);
  }

  #endif

  if (handleEncodeCached(encodeBuffer, channelCache,
                             store, buffer, size) == 1)
  {
    #ifdef MONITOR

    diff = encodeBuffer.getBits() - bits;

    if (*(buffer) == MONITOR_MAJOR_OPCODE &&
            (MONITOR_MINOR_OPCODE == -1 || *(buffer + 1) == MONITOR_MINOR_OPCODE))
    {
      totalMessages++;

      totalBits += diff;

      *logofs << "handleEncode: Handled cached OPCODE#" << (unsigned int) *(buffer)
              << " MINOR#" << (unsigned int) *(buffer + 1) << ". " << size
              << " bytes in, " << diff << " bits (" << ((float) diff) / 8
              << " bytes) out. Average " << totalBits / totalMessages
              << "/1.\n" << logofs_flush;
    }

    #endif

    //
    // Let the channel update the split store
    // and notify the agent in the case of a
    // cache hit.
    //

    if (store -> enableSplit)
    {
      handleSplit(encodeBuffer, store, store -> lastAction,
                      store -> lastHit, opcode, buffer, size);
    }

    return 1;
  }

  //
  // A similar message could not be found in
  // cache or message must be discarded. Must
  // transmit the message using the field by
  // field differential encoding.
  //

  handleEncodeIdentity(encodeBuffer, channelCache,
                           store, buffer, size, bigEndian_);

  //
  // Check if message has a distinct data part.
  //

  if (store -> enableData)
  {
    //
    // If message split was requested by agent then send data
    // out-of-band, dividing it in small chunks. Until message
    // is completely transferred, keep in the split store a
    // dummy version of the message, with data replaced with a
    // pattern.
    //
    // While data is being transferred, agent should have put
    // the resource (for example its client) asleep. It can
    // happen, though, that a different client would reference
    // the same message. We cannot issue a cache hit for images
    // being split (such images are put in store in 'incomplete'
    // state), so we need to handle this case.
    //

    if (store -> enableSplit == 1)
    {
      //
      // Let the channel decide what to do with the
      // message. If the split can't take place be-
      // cause the split store is full, the channel
      // will tell the remote side that the data is
      // going to follow.
      //

      if (handleSplit(encodeBuffer, store, store -> lastAction,
                          (store -> lastAction == IS_ADDED ? store -> lastAdded : 0),
                              opcode, buffer, size) == 1)
      {
        #ifdef MONITOR

        diff = encodeBuffer.getBits() - bits;

        if (*(buffer) == MONITOR_MAJOR_OPCODE &&
                (MONITOR_MINOR_OPCODE == -1 || *(buffer + 1) == MONITOR_MINOR_OPCODE))
        {
          totalMessages++;

          totalBits += diff;

          *logofs << "handleEncode: Handled split OPCODE#" << (unsigned int) *(buffer)
                  << " MINOR#" << (unsigned int) *(buffer + 1) << ". " << size
                  << " bytes in, " << diff << " bits (" << ((float) diff) / 8
                  << " bytes) out. Average " << totalBits / totalMessages
                  << "/1.\n" << logofs_flush;
        }

        #endif

        return 0;
      }
    }

    //
    // The split did not take place and we are going
    // to transfer the data part. Check if the static
    // compression of the data section is enabled.
    // This is the case of all messages not having a
    // special differential encoding or messages that
    // we want to store in cache in compressed form.
    //

    unsigned int offset = store -> identitySize(buffer, size);

    if (store -> enableCompress)
    {
      unsigned char *data   = NULL;
      unsigned int dataSize = 0;

      int compressed = handleCompress(encodeBuffer, opcode, offset,
                                          buffer, size, data, dataSize);
      if (compressed < 0)
      {
        return -1;
      }
      else if (compressed > 0)
      {
        //
        // Update the size of the message according
        // to the result of the data compression.
        //

        handleUpdate(store, size - offset, dataSize);
      }
    }
    else
    {
      handleCopy(encodeBuffer, opcode, offset, buffer, size);
    }
  }

  #ifdef MONITOR

  diff = encodeBuffer.getBits() - bits;

  if (*(buffer) == MONITOR_MAJOR_OPCODE &&
          (MONITOR_MINOR_OPCODE == -1 || *(buffer + 1) == MONITOR_MINOR_OPCODE))
  {
    totalMessages++;

    totalBits += diff;

    *logofs << "handleEncode: Handled OPCODE#" << (unsigned int) *(buffer)
            << " MINOR#" << (unsigned int) *(buffer + 1) << ". " << size
            << " bytes in, " << diff << " bits (" << ((float) diff) / 8
            << " bytes) out. Average " << totalBits / totalMessages
            << "/1.\n" << logofs_flush;
  }

  #endif

  return 0;
}

int Channel::handleDecode(DecodeBuffer &decodeBuffer, ChannelCache *channelCache,
                              MessageStore *store, unsigned char &opcode,
                                  unsigned char *&buffer, unsigned int &size)
{
  //
  // Check first if the message is in the
  // message store.
  //

  unsigned int split = 0;

  if (handleDecodeCached(decodeBuffer, channelCache,
                             store, buffer, size) == 1)
  {
    //
    // Let the channel update the split store
    // in the case of a message being cached.
    //

    if (store -> enableSplit == 1)
    {
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      // Since ProtoStep7 (#issue 108)
      #ifdef DEBUG
      *logofs << "handleDecode: " << store -> name()
              << ": Checking if the message was split.\n"
              << logofs_flush;
      #endif
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      decodeBuffer.decodeBoolValue(split);
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      if (split == 1)
      {
        handleSplit(decodeBuffer, store, store -> lastAction,
                        store -> lastHit, opcode, buffer, size);

        handleCleanAndNullRequest(opcode, buffer, size);
      }
    }

    return 1;
  }

  //
  // Decode the full identity.
  //

  handleDecodeIdentity(decodeBuffer, channelCache, store, buffer,
                           size, bigEndian_, &writeBuffer_);

  //
  // Check if the message has a distinct
  // data part.
  //

  if (store -> enableData)
  {
    //
    // Check if message has been split.
    //

    if (store -> enableSplit)
    {
      #ifdef DEBUG
      *logofs << "handleDecode: " << store -> name() 
              << ": Checking if the message was split.\n" 
              << logofs_flush;
      #endif
      
      decodeBuffer.decodeBoolValue(split);

      if (split == 1)
      {
        //
        // If the message was added to the store,
        // create the entry without the data part.
        //

        handleSaveSplit(store, buffer, size);

        handleSplit(decodeBuffer, store, store -> lastAction,
                        (store -> lastAction == IS_ADDED ? store -> lastAdded : 0),
                            opcode, buffer, size);

        handleCleanAndNullRequest(opcode, buffer, size);

        return 0;
      }
    }

    //
    // Decode the data part.
    //

    unsigned int offset = store -> identitySize(buffer, size);

    if (store -> enableCompress)
    {
      const unsigned char *data = NULL;
      unsigned int dataSize = 0;

      int decompressed = handleDecompress(decodeBuffer, opcode, offset,
                                              buffer, size, data, dataSize);
      if (decompressed < 0)
      {
        return -1;
      }
      else if (decompressed > 0)
      {
        //
        // The message has been transferred
        // in compressed format.
        //

        handleSave(store, buffer, size, data, dataSize);

        if (store -> enableSplit)
        {
          if (split == 1)
          {
            handleSplit(decodeBuffer, store, store -> lastAction,
                            (store -> lastAction == IS_ADDED ? store -> lastAdded : 0),
                                opcode, buffer, size);

            handleCleanAndNullRequest(opcode, buffer, size);
          }
        }

        return 0;
      }
    }
    else
    {
      //
      // Static compression of the data part
      // was not enabled for this message.
      //

      handleCopy(decodeBuffer, opcode, offset, buffer, size);
    }
  }

  //
  // The message doesn't have a data part
  // or the data was not compressed.
  //

  handleSave(store, buffer, size);

  if (store -> enableSplit)
  {
    if (split == 1)
    {
      handleSplit(decodeBuffer, store, store -> lastAction,
                      (store -> lastAction == IS_ADDED ? store -> lastAdded : 0),
                          opcode, buffer, size);

      handleCleanAndNullRequest(opcode, buffer, size);
    }
  }

  return 0;
}

int Channel::handleEncodeCached(EncodeBuffer &encodeBuffer, ChannelCache *channelCache,
                                    MessageStore *store,  const unsigned char *buffer,
                                        const unsigned int size)
{
  if (control -> LocalDeltaCompression == 0 ||
          enableCache_ ==  0 || store -> enableCache == 0)
  {
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    // Since ProtoStep7 (#issue 108)
    encodeBuffer.encodeActionValue(is_discarded,
                       store -> lastActionCache);
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    store -> lastAction = is_discarded;

    return 0;
  }

  #ifdef DEBUG
  *logofs << "handleEncodeCached: " << store -> name() 
          << ": Going to handle a new message of this class.\n" 
          << logofs_flush;
  #endif

  //
  // Check if the estimated size of cache is greater
  // than the requested limit. If it is the case make
  // some room by deleting one or more messages.
  //

  int position;

  while (mustCleanStore(store) == 1 && canCleanStore(store) == 1)
  {
    #ifdef DEBUG
    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Trying to reduce size of message store.\n"
            << logofs_flush;
    #endif

    position = store -> clean(use_checksum);

    if (position == nothing)
    {
      #ifdef TEST
      *logofs << "handleEncodeCached: " << store -> name() 
              << ": WARNING! No message found to be "
              << "actually removed.\n" << logofs_flush;
      #endif

      break;
    }

    #ifdef DEBUG
    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Message at position " << position
            << " will be removed.\n" << logofs_flush;
    #endif

    //
    // Encode the position of message to
    // be discarded.
    //

    store -> lastRemoved = position;

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    // Since ProtoStep7 (#issue 108)
    encodeBuffer.encodeActionValue(is_removed, store -> lastRemoved,
                       store -> lastActionCache);
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    #ifdef DEBUG
    *logofs << "handleEncodeCached: " << store -> name() << ": Going to "
            << "clean up message at position " << position << ".\n" 
            << logofs_flush;
    #endif

    store -> remove(position, use_checksum, discard_data);

    #ifdef DEBUG
    *logofs << "handleEncodeCached: " << store -> name() << ": There are " 
            << store -> getSize() << " messages in the store out of " 
            << store -> cacheSlots << " slots.\n" << logofs_flush;

    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Size of store is " << store -> getLocalStorageSize() 
            << " bytes locally and " << store -> getRemoteStorageSize() 
            << " bytes remotely.\n" << logofs_flush;

    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Size of total cache is " << store -> getLocalTotalStorageSize()
            << " bytes locally and " << store -> getRemoteTotalStorageSize()
            << " bytes remotely.\n" << logofs_flush;
    #endif
  }

  #ifdef DEBUG

  if (mustCleanStore(store) == 1 && canCleanStore(store) == 0)
  {
    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Store would need a clean but operation will be delayed.\n" 
            << logofs_flush;

    *logofs << "handleEncodeCached: " << store -> name() << ": There are " 
            << store -> getSize() << " messages in the store out of " 
            << store -> cacheSlots << " slots.\n"  << logofs_flush;

    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Size of store is " << store -> getLocalStorageSize() 
            << " bytes locally and " << store -> getRemoteStorageSize() 
            << " bytes remotely.\n" << logofs_flush;

    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Size of total cache is " << store -> getLocalTotalStorageSize()
            << " bytes locally and " << store -> getRemoteTotalStorageSize()
            << " bytes remotely.\n" << logofs_flush;
  }

  #endif

  //
  // If 'on the wire' size of message exceeds the
  // allowed limit then avoid to store it in the
  // cache.
  //

  if (store -> validateMessage(buffer, size) == 0)
  {
    #ifdef TEST
    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Message with size " << size << " ignored.\n" 
            << logofs_flush;
    #endif

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    // Since ProtoStep7 (#issue 108)
    encodeBuffer.encodeActionValue(is_discarded,
                       store -> lastActionCache);
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    store -> lastAction = is_discarded;

    return 0;
  }

  //
  // Fill the message object with the
  // received data.
  //

  Message *message = store -> getTemporary();

  if (message == NULL)
  {
    #ifdef PANIC
    *logofs << "handleEncodeCached: " << store -> name()
            << ": PANIC! Can't allocate memory for "
            << "a new message.\n" << logofs_flush;
    #endif

    cerr << "Error" << ": Can't allocate memory for "
         << "a new message in context [D].\n";

    HandleCleanup();
  }

  //
  // As we are at encoding side, it is enough to store the
  // checksum for the object while data can be erased. Both
  // the identity and the data will never be sent through
  // the wire again as long as they are stored in the cache
  // at the decoding side. The split parameter is always
  // set to 0 as the data will not be stored in any case.
  //

  store -> parse(message, 0, buffer, size, use_checksum,
                     discard_data, bigEndian_);

  #ifdef DUMP

  store -> dump(message);

  #endif

  //
  // Search the object in the message
  // store. If found get the position.
  //

  #ifdef DEBUG
  *logofs << "handleEncodeCached: " << store -> name() 
          << ": Searching object of size " << size
          << " in the cache.\n" << logofs_flush;
  #endif

  int added;
  int locked;

  position = store -> findOrAdd(message, use_checksum,
                                    discard_data, added, locked);

  if (position == nothing)
  {
    #ifdef WARNING
    *logofs << "handleEncodeCached: " << store -> name() 
            << ": WARNING! Can't store object in the cache.\n"
            << logofs_flush;
    #endif

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    // Since ProtoStep7 (#issue 108)
    encodeBuffer.encodeActionValue(is_discarded,
                       store -> lastActionCache);
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    store -> lastAction = is_discarded;

    return 0;
  }
  else if (locked == 1)
  {
    //
    // We can't issue a cache hit. Encoding identity
    // differences while message it's being split
    // would later result in agent to commit a wrong
    // version of message.
    //

    #ifdef WARNING
    *logofs << "handleEncodeCached: " << store -> name() 
            << ": WARNING! Message of size " << store -> plainSize(position)
            << " at position " << position << " is locked.\n"
            << logofs_flush;
    #endif

    cerr << "Warning" << ": Message of size " << store -> plainSize(position)
         << " at position " << position << " is locked.\n";

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    // Since ProtoStep7 (#issue 108)
    encodeBuffer.encodeActionValue(is_discarded,
                       store -> lastActionCache);
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    store -> lastAction = is_discarded;

    return 0;
  }
  else if (added == 1)
  {
    store -> resetTemporary();

    #ifdef DEBUG
    *logofs << "handleEncodeCached: " << store -> name() << ": Message of size "
            << store -> plainSize(position) << " has been stored at position "
            << position << ".\n" << logofs_flush;

    *logofs << "handleEncodeCached: " << store -> name() << ": There are " 
            << store -> getSize() << " messages in the store out of " 
            << store -> cacheSlots << " slots.\n" << logofs_flush;

    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Size of store is " << store -> getLocalStorageSize() 
            << " bytes locally and " << store -> getRemoteStorageSize() 
            << " bytes remotely.\n" << logofs_flush;

    *logofs << "handleEncodeCached: " << store -> name() 
            << ": Size of total cache is " << store -> getLocalTotalStorageSize()
            << " bytes locally and " << store -> getRemoteTotalStorageSize()
            << " bytes remotely.\n" << logofs_flush;
    #endif

    //
    // Inform the decoding side that message 
    // must be inserted in cache and encode
    // the position where the insertion took
    // place.
    //

    store -> lastAction = IS_ADDED;

    store -> lastAdded = position;

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    // Since ProtoStep7 (#issue 108)
    encodeBuffer.encodeActionValue(IS_ADDED, store -> lastAdded,
                       store -> lastActionCache);
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    return 0;
  }
  else
  {
    #ifdef DEBUG
    *logofs << "handleEncodeCached: " << store -> name()
            << ": Cache hit. Found object at position " 
            << position << ".\n" << logofs_flush;
    #endif

    //
    // Must abort the connection if the
    // the position is invalid.
    //

    Message *cachedMessage = store -> get(position);

    //
    // Increase the rating of the cached
    // message.
    //

    store -> touch(cachedMessage);

    #ifdef DEBUG
    *logofs << "handleEncodeCached: " << store -> name() << ": Hits for "
            << "object at position " << position << " are now " 
            << store -> getTouches(position) << ".\n"
            << logofs_flush;
    #endif

    //
    // Send to the decoding side position
    // where object can be found in cache.
    //

    store -> lastAction = IS_HIT;

    store -> lastHit = position;

858 859 860
    // Since ProtoStep7 (#issue 108)
    encodeBuffer.encodeActionValue(IS_HIT, store -> lastHit,
                       store -> lastActionCache);
861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946

    //
    // Send the field by field differences in
    // respect to the original message stored
    // in cache.
    //

    store -> updateIdentity(encodeBuffer, message, cachedMessage, channelCache);

    return 1;
  }
}

void Channel::handleUpdateAdded(MessageStore *store, unsigned int dataSize,
                                    unsigned int compressedDataSize)
{
  #ifdef TEST

  if (store -> lastAction != IS_ADDED)
  {
    #ifdef PANIC
    *logofs << "handleUpdateAdded: " << store -> name()
            << ": PANIC! Function called for action '"
            << store -> lastAction << "'.\n"
            << logofs_flush;
    #endif

    cerr << "Error" << ": Update function called for "
         << "store '" << store -> name() << "' with "
         << "action '" << store -> lastAction
         << "'.\n";

    HandleCleanup();
  }

  #endif

  #ifdef DEBUG
  *logofs << "handleUpdateAdded: " << store -> name() << ": Updating "
          << "object at position " << store -> lastAdded << " of size "
          << store -> plainSize(store -> lastAdded) << " (" << dataSize
          << "/" << compressedDataSize << ").\n" << logofs_flush;
  #endif

  store -> updateData(store -> lastAdded, dataSize, compressedDataSize);

  #ifdef DEBUG
  *logofs << "handleUpdateAdded: " << store -> name() << ": There are " 
          << store -> getSize() << " messages in the store out of " 
          << store -> cacheSlots << " slots.\n" << logofs_flush;

  *logofs << "handleUpdateAdded: " << store -> name() 
          << ": Size of store is " << store -> getLocalStorageSize() 
          << " bytes locally and " << store -> getRemoteStorageSize() 
          << " bytes remotely.\n" << logofs_flush;

  *logofs << "handleUpdateAdded: " << store -> name() 
          << ": Size of total cache is " << store -> getLocalTotalStorageSize()
          << " bytes locally and " << store -> getRemoteTotalStorageSize()
          << " bytes remotely.\n" << logofs_flush;
  #endif
}

int Channel::handleDecodeCached(DecodeBuffer &decodeBuffer, ChannelCache *channelCache,
                                    MessageStore *store, unsigned char *&buffer,
                                        unsigned int &size)
{
  //
  // Create a new message object and 
  // fill it with received data.
  //

  #ifdef DEBUG
  *logofs << "handleDecodeCached: " << store -> name() 
          << ": Going to handle a new message of this class.\n" 
          << logofs_flush;
  #endif

  //
  // Decode bits telling how to handle
  // this message.
  //

  unsigned char action;
  unsigned short int position;

947 948 949
  // Since ProtoStep7 (#issue 108)
  decodeBuffer.decodeActionValue(action, position,
                     store -> lastActionCache);
950 951 952 953 954 955 956 957

  //
  // Clean operations must always come 
  // before any operation on message.
  //

  while (action == is_removed)
  {
958 959
    // Since ProtoStep7 (#issue 108)
    store -> lastRemoved = position;
960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981

    #ifdef DEBUG

    if (store -> get(store -> lastRemoved))
    {
      *logofs << "handleDecodeCached: " << store -> name() << ": Cleaning up "
              << "object at position " << store -> lastRemoved
              << " of size " << store -> plainSize(store -> lastRemoved)
              << " (" << store -> plainSize(store -> lastRemoved) << "/"
              << store -> compressedSize(store -> lastRemoved) << ").\n"
              << logofs_flush;
    }

    #endif

    //
    // If the message can't be found we
    // will abort the connection.
    //

    store -> remove(store -> lastRemoved, discard_checksum, use_data);

982 983 984
    // Since ProtoStep7 (#issue 108)
    decodeBuffer.decodeActionValue(action, position,
                       store -> lastActionCache);
985 986 987 988 989 990 991 992 993
  }

  //
  // If it's a cache hit, the position
  // where object can be found follows.
  //

  if ((T_store_action) action == IS_HIT)
  {
994 995
    // Since ProtoStep7 (#issue 108)
    store -> lastHit = position;
996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060

    //
    // Get data from the cache at given position.
    //

    #ifdef DEBUG

    if (store -> get(store -> lastHit))
    {
      *logofs << "handleDecodeCached: " << store -> name() << ": Retrieving "
              << "object at position " << store -> lastHit
              << " of size " << store -> plainSize(store -> lastHit)
              << " (" << store -> plainSize(store -> lastHit)  << "/"
              << store -> compressedSize(store -> lastHit) << ").\n"
              << logofs_flush;
    }

    #endif

    //
    // Must abort the connection if the
    // the position is invalid.
    //

    Message *message = store -> get(store -> lastHit);

    //
    // Make room for the outgoing message.
    //

    size = store -> plainSize(store -> lastHit);

    buffer = writeBuffer_.addMessage(size);

    #ifdef DEBUG
    *logofs << "handleDecodeCached: " << store -> name() 
            << ": Prepared an outgoing buffer of " 
            << size << " bytes.\n" << logofs_flush;
    #endif

    //
    // Decode the variant part. Pass client
    // or server cache to the message store.
    //

    store -> updateIdentity(decodeBuffer, message, channelCache);

    //
    // Write each field in the outgoing buffer.
    //

    store -> unparse(message, buffer, size, bigEndian_);

    #ifdef DUMP

    store -> dump(message);

    #endif

    store -> lastAction = IS_HIT;

    return 1;
  }
  else if ((T_store_action) action == IS_ADDED)
  {
1061 1062
    // Since ProtoStep7 (#issue 108)
    store -> lastAdded = position;
1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951

    #ifdef DEBUG
    *logofs << "handleDecodeCached: " << store -> name() 
            << ": Message will be later stored at position "
             << store -> lastAdded << ".\n" << logofs_flush;
    #endif

    store -> lastAction = IS_ADDED;

    return 0;
  }
  else
  {
    #ifdef DEBUG
    *logofs << "handleDecodeCached: " << store -> name() 
            << ": Message will be later discarded.\n"
            << logofs_flush;
    #endif

    store -> lastAction = is_discarded;

    return 0;
  }
}

void Channel::handleSaveAdded(MessageStore *store, int split, unsigned char *buffer,
                                  unsigned int size, const unsigned char *compressedData,
                                      const unsigned int compressedDataSize)
{
  #ifdef TEST

  if (store -> lastAction != IS_ADDED)
  {
    #ifdef PANIC
    *logofs << "handleSaveAdded: " << store -> name()
            << ": PANIC! Function called for action '"
            << store -> lastAction << "'.\n"
            << logofs_flush;
    #endif

    cerr << "Error" << ": Save function called for "
         << "store '" << store -> name() << "' with "
         << "action '" << store -> lastAction
         << "'.\n";

    HandleCleanup();
  }

  #endif

  Message *message = store -> getTemporary();

  if (message == NULL)
  {
    #ifdef PANIC
    *logofs << "handleSaveAdded: " << store -> name()
            << ": PANIC! Can't access temporary storage "
            << "for message at position " << store -> lastAdded
            << ".\n" << logofs_flush;
    #endif

    cerr << "Error" << ": Can't access temporary storage "
         << "for message  at position " << store -> lastAdded
         << ".\n";

    HandleCleanup();
  }

  if (compressedData == NULL)
  {
    //
    // If the data part has been split
    // avoid to copy it into the message.
    //

    store -> parse(message, split, buffer, size, discard_checksum,
                       use_data, bigEndian_);
  }
  else
  {
    store -> parse(message, buffer, size, compressedData, 
                       compressedDataSize, discard_checksum,
                           use_data, bigEndian_);
  }

  if (store -> add(message, store -> lastAdded,
          discard_checksum, use_data) == nothing)
  {
    #ifdef PANIC
    *logofs << "handleSaveAdded: " << store -> name()
            << ": PANIC! Can't store message in the cache "
            << "at position " << store -> lastAdded << ".\n"
            << logofs_flush;
    #endif

    cerr << "Error" << ": Can't store message of type "
         << store -> name() << "in the cache at position "
         << store -> lastAdded << ".\n";

    HandleCleanup();
  }
  else
  {
    store -> resetTemporary();

    #ifdef DEBUG
    *logofs << "handleSaveAdded: " << store -> name() << ": Stored "
            << (compressedData == NULL ? "plain" : "compressed")
            << " object at position " << store -> lastAdded
            << " of size " << store -> plainSize(store -> lastAdded)
            << " (" << store -> plainSize(store -> lastAdded) << "/"
            << store -> compressedSize(store -> lastAdded) << ").\n"
            << logofs_flush;
    #endif
  }

  #ifdef DEBUG
  *logofs << "handleSaveAdded: " << store -> name()
          << ": Size of store is " << store -> getLocalStorageSize()
          << " bytes locally and " << store -> getRemoteStorageSize()
          << " bytes remotely.\n" << logofs_flush;

  *logofs << "handleSaveAdded: " << store -> name()
          << ": Size of total cache is " << store -> getLocalTotalStorageSize()
          << " bytes locally and " << store -> getRemoteTotalStorageSize()
          << " bytes remotely.\n" << logofs_flush;
  #endif
}

int Channel::handleWait(int timeout)
{
  #ifdef TEST
  *logofs << "handleWait: Going to wait for more data "
          << "on FD#" << fd_ << " at " << strMsTimestamp()
          << ".\n" << logofs_flush;
  #endif

  T_timestamp startTs = getNewTimestamp();

  T_timestamp nowTs = startTs;

  int readable;
  int remaining;

  for (;;)
  {
    remaining = timeout - diffTimestamp(startTs, nowTs);

    if (transport_ -> blocked() == 1)
    {
      #ifdef WARNING
      *logofs << "handleWait: WARNING! Having to drain with "
              << "channel " << "for FD#" << fd_ << " blocked.\n"
              << logofs_flush;
      #endif

      handleDrain(0, remaining);

      continue;
    }

    if (remaining <= 0)
    {
      #ifdef TEST
      *logofs << "handleWait: Timeout raised while waiting "
              << "for more data for FD#" << fd_ << " at "
              << strMsTimestamp() << ".\n"
              << logofs_flush;
      #endif

      return 0;
    }

    #ifdef TEST
    *logofs << "handleWait: Waiting " << remaining << " Ms "
            << "for a new message on  FD#" << fd_
            << ".\n" << logofs_flush;
    #endif

    readable = transport_ -> wait(remaining);

    if (readable > 0)
    {
      #ifdef TEST
      *logofs << "handleWait: WARNING! Encoding more data "
              << "for FD#" << fd_ << " at " << strMsTimestamp()
              << ".\n" << logofs_flush;
      #endif

      if (proxy -> handleAsyncRead(fd_) < 0)
      {
        return -1;
      }

      return 1;
    }
    else if (readable == -1)
    {
      return -1;
    }

    nowTs = getNewTimestamp();
  }
}

int Channel::handleDrain(int limit, int timeout)
{
  #ifdef TEST
  *logofs << "handleDrain: Going to drain FD#" << fd_
          << " with a limit of " << limit << " bytes "
          << "at " << strMsTimestamp() << ".\n"
          << logofs_flush;
  #endif

  T_timestamp startTs = getNewTimestamp();

  T_timestamp nowTs = startTs;

  int drained;
  int remaining;

  int result;

  for (;;)
  {
    remaining = timeout - diffTimestamp(startTs, nowTs);

    if (remaining <= 0)
    {
      #ifdef TEST
      *logofs << "handleDrain: Timeout raised while draining "
              << "FD#" << fd_ << " at " << strMsTimestamp()
              << ".\n" << logofs_flush;
      #endif

      result = 0;

      goto ChannelDrainEnd;
    }

    #ifdef TEST
    *logofs << "handleDrain: Trying to write to FD#"
            << fd_ << " with " << remaining << " Ms "
            << "remaining.\n" << logofs_flush;
    #endif

    drained = transport_ -> drain(limit, remaining);

    if (drained == 1)
    {
      #ifdef TEST
      *logofs << "handleDrain: Transport for FD#" << fd_
              << " drained to " << transport_ -> length()
              << " bytes at " << strMsTimestamp() << ".\n"
              << logofs_flush;
      #endif

      result = 1;

      goto ChannelDrainEnd;
    }
    else if (drained == 0 && transport_ -> readable() > 0)
    {
      #ifdef TEST
      *logofs << "handleDrain: WARNING! Encoding more data "
              << "for FD#" << fd_ << " at " << strMsTimestamp()
              << ".\n" << logofs_flush;
      #endif

      if (proxy -> handleAsyncRead(fd_) < 0)
      {
        goto ChannelDrainError;
      }
    }
    else if (drained == -1)
    {
      goto ChannelDrainError;
    }

    nowTs = getNewTimestamp();

    if (diffTimestamp(startTs, nowTs) >= control -> ChannelTimeout)
    {
      int seconds = (remaining + control -> LatencyTimeout * 10) / 1000;

      #ifdef WARNING
      *logofs << "handleDrain: WARNING! Could not drain FD#"
              << fd_ << " within " << seconds << " seconds.\n"
              << logofs_flush;
      #endif

      cerr << "Warning" << ": Can't write to connection on FD#"
           << fd_ << " since " << seconds << " seconds.\n";

      if (alert_ == 0)
      {
        if (control -> ProxyMode == proxy_client)
        {
          alert_ = CLOSE_DEAD_X_CONNECTION_CLIENT_ALERT;
        }
        else
        {
          alert_ = CLOSE_DEAD_X_CONNECTION_SERVER_ALERT;
        }

        HandleAlert(alert_, 1);
      }
    }
  }

ChannelDrainEnd:

  //
  // Maybe we drained the channel and are
  // now out of the congestion state.
  //

  handleCongestion();

  return result;

ChannelDrainError:

  finish_ = 1;

  return -1;
}

int Channel::handleCongestion()
{
  //
  // Send a begin congestion control code
  // if the local end of the channel does
  // not consume its data.
  //

  if (isCongested() == 1)
  {
    if (congestion_ == 0)
    {
      #if defined(TEST) || defined(INFO)
      *logofs << "handleCongestion: Sending congestion for FD#"
              << fd_ << " with length " << transport_ -> length()
              << " at " << strMsTimestamp() << ".\n"
              << logofs_flush;
      #endif

      congestion_ = 1;

      //
      // Use the callback to send the control
      // code immediately.
      //

      if (proxy -> handleAsyncCongestion(fd_) < 0)
      {
        finish_ = 1;

        return -1;
      }
    }
  }
  else
  {
    //
    // If the channel was in congestion state
    // send an end congestion control code.
    //

    if (congestion_ == 1)
    {
      #if defined(TEST) || defined(INFO)
      *logofs << "handleCongestion: Sending decongestion for FD#"
              << fd_ << " with length " << transport_ -> length()
              << " at " << strMsTimestamp() << ".\n"
              << logofs_flush;
      #endif

      congestion_ = 0;

      if (proxy -> handleAsyncDecongestion(fd_) < 0)
      {
        finish_ = 1;

        return -1;
      }
    }

    //
    // Remove the "channel unresponsive"
    // dialog.
    //

    if (alert_ != 0)
    {
      #if defined(TEST) || defined(INFO)
      *logofs << "handleCongestion: Displacing the dialog "
              << "for FD#" << fd_ << ".\n" << logofs_flush;
      #endif

      HandleAlert(DISPLACE_MESSAGE_ALERT, 1);
    }
  }

  return 1;
}

int Channel::handleFlush(T_flush type, int bufferLength, int scratchLength)
{
  if (finish_ == 1)
  {
    #ifdef TEST
    *logofs << "handleFlush: Not flushing data for "
            << "finishing channel for FD#" << fd_
            << ".\n" << logofs_flush;
    #endif

    writeBuffer_.fullReset();

    return -1;
  }

  #ifdef TEST
  *logofs << "handleFlush: Flushing " << bufferLength
          << " + " << scratchLength << " bytes "
          << "to FD#" << fd_ << ".\n"
          << logofs_flush;
  #endif

  //
  // Check if the channel has data available.
  // Recent Linux kernels are very picky.
  // They require that we read often or they
  // assume that the process is non-interact-
  // ive.
  //

  int result = 0;

  if (handleAsyncEvents() < 0)
  {
    goto ChannelFlushError;
  }

  //
  // Write the data in the main buffer first,
  // followed by the data in the scratch buffer.
  //

  if (bufferLength > 0)
  {
    result = transport_ -> write(write_immediate,
                                     writeBuffer_.getData(), bufferLength);
  }

  if (result >= 0 && scratchLength > 0)
  {
    result = transport_ -> write(write_immediate,
                                     writeBuffer_.getScratchData(), scratchLength);
  }

  if (type == flush_if_any)
  {
    writeBuffer_.fullReset();
  }
  else
  {
    writeBuffer_.partialReset();
  }

  //
  // If we failed to write to the X connection then
  // set the finish flag. The caller should continue
  // to handle all the remaining messages or it will
  // corrupt the decode buffer. At the real end, an
  // error will be propagated to the upper layers
  // which will perform any needed cleanup.
  //

  if (result < 0)
  {
    goto ChannelFlushError;
  }

  //
  // Reset transport buffers.
  //

  transport_ -> partialReset();

  //
  // Check if the X server has generated
  // any event in response to our data.
  //

  if (handleAsyncEvents() < 0)
  {
    goto ChannelFlushError;
  }

  //
  // Check if the channel has entered in
  // congestion state and, in this case,
  // send an immediate congestion control
  // code to the remote.
  //

  handleCongestion();

  //
  // We could optionally drain the output
  // buffer if this is X11 channel.
  //
  // if (isCongested() == 1 && isReliable() == 1)
  // {
  //   if (handleDrain(0, control -> ChannelTimeout) < 0)
  //   {
  //     goto ChannelFlushError;
  //   }
  // }
  //

  return 1;

ChannelFlushError:

  finish_ = 1;

  return -1;
}

int Channel::handleFlush()
{
  #ifdef TEST
  *logofs << "handleFlush: Flushing "
          << transport_ -> length() << " bytes to FD#"
          << fd_ << " with descriptor writable.\n"
          << logofs_flush;
  #endif

  //
  // Check if there is anything to read
  // before anf after having written to
  // the socket.
  //

  if (handleAsyncEvents() < 0)
  {
    goto ChannelFlushError;
  }

  if (transport_ -> flush() < 0)
  {
    #ifdef TEST
    *logofs << "handleFlush: Failure detected "
            << "flushing data to FD#" << fd_
            << ".\n" << logofs_flush;
    #endif

    goto ChannelFlushError;
  }

  if (handleAsyncEvents() < 0)
  {
    goto ChannelFlushError;
  }

  //
  // Reset channel's transport buffers.
  //

  transport_ -> partialReset();

  //
  // Check if the channel went out of the
  // congestion state.
  //

  handleCongestion();

  return 1;

ChannelFlushError:

  finish_ = 1;

  return -1;
}

void Channel::handleResetAlert()
{
  if (alert_ != 0)
  {
    #ifdef TEST
    *logofs << "handleResetAlert: The channel alert '"
            << alert_ << "' was displaced.\n"
            << logofs_flush;
    #endif

    alert_ = 0;
  }
}

int Channel::handleCompress(EncodeBuffer &encodeBuffer, const unsigned char opcode,
                                const unsigned int offset, const unsigned char *buffer,
                                    const unsigned int size, unsigned char *&compressedData,
                                        unsigned int &compressedDataSize)
{
  if (size <= offset)
  {
    #ifdef DEBUG
    *logofs << "handleCompress: Not compressing data for FD#" << fd_
            << " as offset is " << offset << " with data size "
            << size << ".\n" << logofs_flush;
    #endif

    return 0;
  }

  #ifdef DEBUG
  *logofs << "handleCompress: Compressing data for FD#" << fd_
          << " with data size " << size << " and offset "
          << offset << ".\n" << logofs_flush;
  #endif

  //
  // It is responsibility of the compressor to
  // mark the buffer as such if the compression
  // couldn't take place.
  //

  if (compressor_ -> compressBuffer(buffer + offset, size - offset, compressedData,
                                        compressedDataSize, encodeBuffer) <= 0)
  {
    #ifdef DEBUG
    *logofs << "handleCompress: Sent " << size - offset
            << " bytes of plain data for FD#" << fd_
            << ".\n" << logofs_flush;
    #endif

    return 0;
  }
  else
  {
    #ifdef DEBUG
    *logofs << "handleCompress: Sent " << compressedDataSize
            << " bytes of compressed data for FD#"
            << fd_ << ".\n" << logofs_flush;
    #endif

    return 1;
  }
}

int Channel::handleDecompress(DecodeBuffer &decodeBuffer, const unsigned char opcode,
                                  const unsigned int offset, unsigned char *buffer,
                                      const unsigned int size, const unsigned char *&compressedData,
                                          unsigned int &compressedDataSize)
{
  if (size <= offset)
  {
    return 0;
  }

  int result = compressor_ -> decompressBuffer(buffer + offset, size - offset,
                                                   compressedData, compressedDataSize,
                                                       decodeBuffer);
  if (result < 0)
  {
    #ifdef PANIC
    *logofs << "handleDecompress: PANIC! Failed to decompress "
            << size - offset << " bytes of data for FD#" << fd_
            << " with OPCODE#" << (unsigned int) opcode << ".\n"
            << logofs_flush;
    #endif

    cerr << "Error" << ": Data decompression failed for OPCODE#"
         << (unsigned int) opcode << ".\n";

    return -1;
  }
  else if (result == 0)
  {
    #ifdef DEBUG
    *logofs << "handleDecompress: Received " << size - offset
            << " bytes of plain data for FD#" << fd_
            << ".\n" << logofs_flush;
    #endif

    return 0;
  }
  else
  {
    #ifdef DEBUG
    *logofs << "handleDecompress: Received " << compressedDataSize
            << " bytes of compressed data for FD#" << fd_
            << ".\n" << logofs_flush;
    #endif

    return 1;
  }
}

int Channel::handleCleanAndNullRequest(unsigned char &opcode, unsigned char *&buffer,
                                           unsigned int &size)
{
  #ifdef TEST
  *logofs << "handleCleanAndNullRequest: Removing the previous data "
          << "and sending an X_NoOperation " << "for FD#" << fd_
          << " due to OPCODE#" << (unsigned int) opcode << " ("
          << DumpOpcode(opcode) << ").\n" << logofs_flush;
  #endif

  writeBuffer_.removeMessage(size - 4);

  size   = 4;
  opcode = X_NoOperation;

  return 1;
}

int Channel::handleNullRequest(unsigned char &opcode, unsigned char *&buffer,
                                   unsigned int &size)
{
  #ifdef TEST
  *logofs << "handleNullRequest: Sending an X_NoOperation for FD#"
          << fd_ << " due to OPCODE#" << (unsigned int) opcode
          << " (" << DumpOpcode(opcode) << ").\n"
          << logofs_flush;
  #endif

  size   = 4;
  buffer = writeBuffer_.addMessage(size);
  opcode = X_NoOperation;

  return 1;
}

void Channel::handleSplitStoreError(int resource)
{
  if (resource < 0 || resource >= CONNECTIONS_LIMIT)
  {
    #ifdef PANIC
    *logofs << "handleSplitStoreError: PANIC! Resource "
            << resource << " is out of range with limit "
            << "set to " << CONNECTIONS_LIMIT << ".\n"
            << logofs_flush;
    #endif

    cerr << "Error" << ": Resource " << resource
         << " is out of range with limit set to "
         << CONNECTIONS_LIMIT << ".\n";

    HandleCleanup();
  }
  else
  {
    #ifdef PANIC
    *logofs << "handleSplitStoreError: PANIC! Cannot "
            << "allocate the split store for resource "
            << resource << ".\n" << logofs_flush;
    #endif

    cerr << "Error" << ": Cannot allocate the "
         << "split store for resource " << resource
         << ".\n";

    HandleCleanup();
  }
}

void Channel::handleSplitStoreAlloc(List *list, int resource)
{
  if (resource < 0 || resource >= CONNECTIONS_LIMIT)
  {
    handleSplitStoreError(resource);
  }

  if (clientStore_ -> getSplitStore(resource) == NULL)
  {
    #if defined(TEST) || defined(SPLIT)
    *logofs << "handleSplitStoreAlloc: Allocating a new "
            << "split store for resource " << resource
            << ".\n" << logofs_flush;
    #endif

    SplitStore *splitStore = clientStore_ -> createSplitStore(resource);

    if (splitStore == NULL)
    {
      handleSplitStoreError(resource);
    }

    list -> add(resource);
  }
  #if defined(TEST) || defined(SPLIT)
  else
  {
    //
    // Old proxy versions only use a single
    // split store.
    //

    if (resource != 0)
    {
      *logofs << "handleSplitStoreAlloc: WARNING! A split "
              << "store for resource " << resource
              << " already exists.\n" << logofs_flush;
    }
  }
  #endif
}

void Channel::handleSplitStoreRemove(List *list, int resource)
{
  if (resource < 0 || resource >= CONNECTIONS_LIMIT)
  {
    handleSplitStoreError(resource);
  }

  SplitStore *splitStore = clientStore_ -> getSplitStore(resource);

  if (splitStore != NULL)
  {
    #if defined(TEST) || defined(SPLIT)
    *logofs << "handleSplitStoreRemove: Deleting the "
            << "split store for resource " << resource
            << ".\n" << logofs_flush;
    #endif

    clientStore_ -> destroySplitStore(resource);

    #if defined(TEST) || defined(SPLIT)
    *logofs << "handleSplitStoreRemove: Deleting resource "
            << resource << " from the list " << ".\n"
            << logofs_flush;
    #endif

    list -> remove(resource);
  }
  #if defined(TEST) || defined(SPLIT)
  else
  {
    *logofs << "handleSplitStoreRemove: WARNING! A split "
            << "store for resource " << resource
            << " does not exist.\n" << logofs_flush;
  }
  #endif
}

Split *Channel::handleSplitCommitRemove(int request, int resource, int position)
{
  #if defined(TEST) || defined(SPLIT)
  *logofs << "handleSplitCommitRemove: SPLIT! Checking split "
          << "commit with resource " << resource << " request "
          << request << " and position " << position
          << ".\n" << logofs_flush;
  #endif

  //
  // Remove the split from the split queue.
  //

  CommitStore *commitStore = clientStore_ -> getCommitStore();

  Split *split = commitStore -> pop();

  if (split == NULL)
  {
    #ifdef PANIC
    *logofs << "handleSplitCommitRemove: PANIC! Can't "
            << "find the split in the commit queue.\n"
            << logofs_flush;
    #endif

    cerr << "Error" << ": Can't find the "
         << "split in the commit queue.\n";

    HandleCleanup();
  }

  #if defined(TEST) || defined(SPLIT)
  *logofs << "handleSplitCommitRemove: SPLIT! Element from "
          << "the queue has resource " << split -> getResource()
          << " request " << split -> getRequest() << " and "
          << "position " << split -> getPosition()
          << ".\n" << logofs_flush;
  #endif

1952 1953 1954 1955
  // Since ProtoStep7 (#issue 108)
  if (resource != split -> getResource() ||
           request != split -> getRequest() ||
               position != split -> getPosition())
1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
  {
    #ifdef PANIC
    *logofs << "handleSplitCommitRemove: PANIC! The data in "
            << "the split doesn't match the commit request.\n"
            << logofs_flush;
    #endif

    cerr << "Error" << ": The data in the split doesn't "
         << "match the commit request.\n";

    return NULL;
  }

  #if defined(TEST) || defined(SPLIT)

  commitStore -> dump();

  #endif

  return split;
}

int Channel::setReferences()
{
  #ifdef TEST
  *logofs << "Channel: Initializing the static "
          << "members for the base class.\n"
          << logofs_flush;
  #endif

  firstClient_ = -1;

  fontPort_ = -1;

  #ifdef REFERENCES

  references_ = 0;

  #endif

  return 1;
}

int Channel::setOpcodes(OpcodeStore *opcodeStore)
{
  opcodeStore_ = opcodeStore;

  #ifdef TEST
  *logofs << "setOpcodes: Propagated opcodes store to channel "
          << "for FD#" << fd_ << ".\n" << logofs_flush;
  #endif

  return 1;
}

int Channel::setStores(ClientStore *clientStore, ServerStore *serverStore)
{
  clientStore_ = clientStore;
  serverStore_ = serverStore;

  #ifdef TEST
  *logofs << "setStores: Propagated message stores to channel "
          << "for FD#" << fd_ << ".\n" << logofs_flush;
  #endif

  return 1;
}

int Channel::setCaches(ClientCache *clientCache, ServerCache *serverCache)
{
  clientCache_ = clientCache;
  serverCache_ = serverCache;

  #ifdef TEST
  *logofs << "setCaches: Propagated encode caches to channel "
          << "for FD#" << fd_ << ".\n" << logofs_flush;
  #endif

  return 1;
}