Imported nxcomp-3.1.0-4.tar.gznxcomp/3.1.0-4

Summary: Imported nxcomp-3.1.0-4.tar.gz
Keywords:

Imported nxcomp-3.1.0-4.tar.gz
into Git repository

1 files changed, 2344 insertions, 0 deletions

diff --git a/nxcomp/Message.cpp b/nxcomp/Message.cpp
new file mode 100755
index 000000000..1bf074e19
--- /dev/null
+++ b/nxcomp/Message.cpp
@@ -0,0 +1,2344 @@
+/**************************************************************************/
+/*                                                                        */
+/* Copyright (c) 2001, 2007 NoMachine, http://www.nomachine.com/.         */
+/*                                                                        */
+/* NXCOMP, NX protocol compression and NX extensions to this software     */
+/* are copyright of NoMachine. Redistribution and use of the present      */
+/* software is allowed according to terms specified in the file LICENSE   */
+/* which comes in the source distribution.                                */
+/*                                                                        */
+/* Check http://www.nomachine.com/licensing.html for applicability.       */
+/*                                                                        */
+/* NX and NoMachine are trademarks of NoMachine S.r.l.                    */
+/*                                                                        */
+/* All rights reserved.                                                   */
+/*                                                                        */
+/**************************************************************************/
+
+#include <stdio.h>
+#include <fstream.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <algorithm>
+
+//
+// We need channel's cache data.
+//
+
+#include "Message.h"
+
+#include "EncodeBuffer.h"
+#include "DecodeBuffer.h"
+
+//
+// Set the verbosity level. You also
+// need to define DUMP in Misc.cpp
+// if DUMP is defined here.
+//
+
+#define PANIC
+#define WARNING
+#undef  TEST
+#undef  DEBUG
+#undef  DUMP
+
+//
+// Define this to log when messages
+// are allocated and deallocated.
+//
+
+#undef  REFERENCES
+
+//
+// Keep track of how many bytes are
+// occupied by cache.
+//
+
+int MessageStore::totalLocalStorageSize_  = 0;
+int MessageStore::totalRemoteStorageSize_ = 0;
+
+//
+// These are used for reference count.
+//
+
+#ifdef REFERENCES
+
+int Message::references_        = 0;
+int MessageStore::references_   = 0;
+
+#endif
+
+//
+// Here are the methods to handle cached messages.
+//
+
+MessageStore::MessageStore(StaticCompressor *compressor)
+
+  : compressor_(compressor)
+{
+  //
+  // Public members.
+  //
+
+  enableCache    = MESSAGE_ENABLE_CACHE;
+  enableData     = MESSAGE_ENABLE_DATA;
+  enableSplit    = MESSAGE_ENABLE_SPLIT;
+  enableCompress = MESSAGE_ENABLE_COMPRESS;
+
+  dataLimit  = MESSAGE_DATA_LIMIT;
+  dataOffset = MESSAGE_DATA_OFFSET;
+
+  cacheSlots          = MESSAGE_CACHE_SLOTS;
+  cacheThreshold      = MESSAGE_CACHE_THRESHOLD;
+  cacheLowerThreshold = MESSAGE_CACHE_LOWER_THRESHOLD;
+
+  #ifdef TEST
+  *logofs << "MessageStore: Static compressor is at "
+          << compressor_ << ".\n" << logofs_flush;
+  #endif
+
+  md5_state_ = new md5_state_t();
+
+  #ifdef DEBUG
+  *logofs << "MessageStore: Created MD5 state for object at " 
+          << this << ".\n" << logofs_flush;
+  #endif
+
+  lastAdded   = cacheSlots;
+  lastHit     = 0;
+  lastRemoved = 0;
+  lastRated   = nothing;
+  lastAction  = is_discarded;
+
+  //
+  // This is used only for compatibility
+  // with older proxies.
+  //
+
+  if (control -> isProtoStep7() == 1)
+  {
+    lastResize = -1;
+  }
+  else
+  {
+    lastResize = 0;
+  }
+
+  //
+  // Private members.
+  //
+
+  localStorageSize_  = 0;
+  remoteStorageSize_ = 0;
+
+  #ifdef TEST
+  *logofs << "MessageStore: Size of total cache is " 
+          << totalLocalStorageSize_ << " bytes at local side and " 
+          << totalRemoteStorageSize_ << " bytes at remote side.\n" 
+          << logofs_flush;
+  #endif
+
+  messages_  = new T_messages();
+  checksums_ = new T_checksums();
+
+  temporary_ = NULL;
+
+  #ifdef REFERENCES
+
+  references_++;
+
+  *logofs << "MessageStore: Created new store at " 
+          << this << "out of " << references_
+          << " allocated stores.\n" << logofs_flush;
+
+  #endif
+}
+
+MessageStore::~MessageStore()
+{
+  //
+  // The virtual destructor of specialized class
+  // must get rid of both messages in container
+  // and temporary.
+  //
+
+  #ifdef DEBUG
+  *logofs << "MessageStore: Deleting MD5 state for object at "
+          << this << ".\n" << logofs_flush;
+  #endif
+
+  delete md5_state_;
+
+  delete messages_;
+  delete checksums_;
+
+  //
+  // Update the static members tracking
+  // size of total memory allocated for
+  // all stores.
+  //
+
+  totalLocalStorageSize_  -= localStorageSize_;
+  totalRemoteStorageSize_ -= remoteStorageSize_;
+
+  #ifdef TEST
+  *logofs << "MessageStore: Size of total cache is " 
+          << totalLocalStorageSize_ << " bytes at local side and " 
+          << totalRemoteStorageSize_ << " bytes at remote side.\n" 
+          << logofs_flush;
+  #endif
+
+  #ifdef REFERENCES
+
+  references_--;
+
+  *logofs << "MessageStore: Deleted store at " 
+          << this << " out of " << references_
+          << " allocated stores.\n" << logofs_flush;
+
+  #endif
+}
+
+//
+// Here are the methods to parse and cache
+// messages in the message stores.
+//
+
+int MessageStore::parse(Message *message, int split, const unsigned char *buffer,
+                            unsigned int size, T_checksum_action checksumAction,
+                                T_data_action dataAction, int bigEndian)
+{
+  //
+  // Save the message size as received on the link.
+  // This information will be used to create an ap-
+  // propriate buffer at the time the message will
+  // be unparsed.
+  //
+
+  message -> size_   = size;
+  message -> i_size_ = identitySize(buffer, size);
+  message -> c_size_ = 0;
+
+  validateSize(size);
+
+  if (checksumAction == use_checksum)
+  {
+    beginChecksum(message);
+
+    parseIdentity(message, buffer, size, bigEndian);
+
+    identityChecksum(message, buffer, size, bigEndian);
+
+    parseData(message, split, buffer, size, checksumAction, dataAction, bigEndian);
+
+    endChecksum(message);
+  }
+  else
+  {
+    parseIdentity(message, buffer, size, bigEndian);
+
+    parseData(message, split, buffer, size, checksumAction, dataAction, bigEndian);
+  }
+
+  return 1;
+}
+
+int MessageStore::parse(Message *message, const unsigned char *buffer,
+                            unsigned int size, const unsigned char *compressedData,
+                                const unsigned int compressedDataSize,
+                                    T_checksum_action checksumAction,
+                                        T_data_action dataAction, int bigEndian)
+{
+  int offset = identitySize(buffer, size);
+
+  message -> size_   = size;
+  message -> i_size_ = offset;
+  message -> c_size_ = compressedDataSize + offset;
+
+  validateSize(message -> size_ - offset, compressedDataSize);
+
+  if (checksumAction == use_checksum)
+  {
+    beginChecksum(message);
+
+    parseIdentity(message, buffer, size, bigEndian);
+
+    identityChecksum(message, buffer, size, bigEndian);
+
+    parseData(message, buffer, size, compressedData, compressedDataSize,
+                  checksumAction, dataAction, bigEndian);
+
+    endChecksum(message);
+  }
+  else
+  {
+    parseIdentity(message, buffer, size, bigEndian);
+
+    parseData(message, buffer, size, compressedData, compressedDataSize,
+                  checksumAction, dataAction, bigEndian);
+  }
+
+  return 1;
+}
+
+int MessageStore::parseData(Message *message, int split, const unsigned char *buffer,
+                                unsigned int size, T_checksum_action checksumAction,
+                                    T_data_action dataAction, int bigEndian)
+{
+  if ((int) size > message -> i_size_)
+  {
+    unsigned int dataSize = size - message -> i_size_;
+
+    if (checksumAction == use_checksum)
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Calculating checksum of object at "
+              << message << " with data size " << dataSize
+              << ".\n" << logofs_flush;
+      #endif
+
+      dataChecksum(message, buffer, size, bigEndian);
+    }
+
+    if (dataAction == discard_data)
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Discarded " << dataSize
+              << " bytes of plain data. Real size is "
+              << message -> size_ << " compressed size is "
+              << message -> c_size_ << ".\n" << logofs_flush;
+      #endif
+
+      return 1;
+    }
+
+    //
+    // Accept anyway data beyond the
+    // expected limit.
+    //
+
+    #ifdef TEST
+
+    if (dataSize > (unsigned int) dataLimit)
+    {
+      *logofs << name() << ": WARNING! Data is " << dataSize
+              << " bytes. Ignoring the established limit.\n"
+              << logofs_flush;
+    }
+
+    #endif
+
+    if (dataSize != message -> data_.size())
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Data will be resized from "
+              << message -> data_.size() << " to hold a plain buffer of "
+              << dataSize << " bytes.\n" << logofs_flush;
+      #endif
+
+      message -> data_.clear();
+
+      message -> data_.resize(dataSize);
+    }
+
+    if (split == 0)
+    {
+      memcpy(message -> data_.begin(), buffer + message -> i_size_, dataSize);
+    }
+    #ifdef TEST
+    else
+    {
+      *logofs << name() << ": Not copied " << dataSize
+              << " bytes of fake data for the split message.\n"
+              << logofs_flush;
+    }
+    #endif
+
+    #ifdef DEBUG
+    *logofs << name() << ": Parsed " << dataSize
+            << " bytes of plain data. Real size is "
+            << message -> size_ << " compressed size is "
+            << message -> c_size_ << ".\n" << logofs_flush;
+    #endif
+  }
+
+  return 1;
+}
+
+//
+// Store the data part in compressed format.
+//
+
+int MessageStore::parseData(Message *message, const unsigned char *buffer,
+                                unsigned int size, const unsigned char *compressedData,
+                                    const unsigned int compressedDataSize,
+                                        T_checksum_action checksumAction,
+                                             T_data_action dataAction, int bigEndian)
+{
+  if ((int) size > message -> i_size_)
+  {
+    unsigned int dataSize = size - message -> i_size_;
+
+    if (checksumAction == use_checksum)
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Calculating checksum of object at "
+              << message << " with data size " << dataSize
+              << ".\n" << logofs_flush;
+      #endif
+
+      dataChecksum(message, buffer, size, bigEndian);
+    }
+
+    if (dataAction == discard_data)
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Discarded " << dataSize
+              << " bytes of compressed data. Real size is "
+              << message -> size_ << " compressed size is "
+              << message -> c_size_ << ".\n" << logofs_flush;
+      #endif
+
+      return 1;
+    }
+
+    #ifdef WARNING
+    if (dataSize > (unsigned int) dataLimit)
+    {
+      *logofs << name() << ": WARNING! Data is " << dataSize
+              << " bytes. Ignoring the established limit!\n"
+              << logofs_flush;
+    }
+    #endif
+
+    dataSize = compressedDataSize;
+
+    if (dataSize != message -> data_.size())
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Data will be resized from "
+              << message -> data_.size() << " to hold a compressed buffer of "
+              << dataSize << " bytes.\n" << logofs_flush;
+      #endif
+
+      message -> data_.clear();
+
+      message -> data_.resize(compressedDataSize);
+    }
+
+    memcpy(message -> data_.begin(), compressedData, compressedDataSize);
+
+    #ifdef DEBUG
+    *logofs << name() << ": Parsed " << dataSize
+            << " bytes of compressed data. Real size is "
+            << message -> size_ << " compressed size is "
+            << message -> c_size_ << ".\n" << logofs_flush;
+    #endif
+  }
+
+  return 1;
+}
+
+int MessageStore::unparseData(const Message *message, unsigned char *buffer,
+                                  unsigned int size, int bigEndian)
+{
+  //
+  // Copy data, if any, to the buffer.
+  //
+
+  if ((int) size > message -> i_size_)
+  {
+    //
+    // Check if message has been stored
+    // in compressed format.
+    //
+
+    if (message -> c_size_ == 0)
+    {
+      memcpy(buffer + message -> i_size_, message -> data_.begin(), size - message -> i_size_);
+
+      #ifdef DEBUG
+      *logofs << name() << ": Unparsed " << message -> size_ - message -> i_size_
+              << " bytes of data to a buffer of " << message -> size_ - message -> i_size_
+              << ".\n" << logofs_flush;
+      #endif
+    }
+    else
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Using static compressor at " << (void *) compressor_
+              << ".\n" << logofs_flush;
+      #endif
+
+      if (compressor_ ->
+              decompressBuffer(buffer + message -> i_size_,
+                                   size - message -> i_size_,
+                                       message -> data_.begin(),
+                                           message -> c_size_ - message -> i_size_) < 0)
+      {
+        #ifdef PANIC
+        *logofs << name() << ": PANIC! Data decompression failed.\n"
+                << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Data decompression failed.\n";
+
+        return -1;
+      }
+
+      #ifdef DEBUG
+      *logofs << name() << ": Unparsed " << message -> c_size_ - message -> i_size_
+              << " bytes of compressed data to a buffer of "
+              << message -> size_ - message -> i_size_ << ".\n" << logofs_flush;
+      #endif
+    }
+  }
+
+  //
+  // We could write size to the buffer but this
+  // is something the channel class is doing by
+  // itself.
+  //
+  // PutUINT(size >> 2, buffer + 2, bigEndian);
+  //
+
+  return 1;
+}
+
+void MessageStore::dumpData(const Message *message) const
+{
+  #ifdef DUMP
+
+  *logofs << name() << ": Dumping enumerated data:\n" << logofs_flush; 
+
+  DumpData(message -> data_.begin(), message -> data_.size());
+
+  #endif
+
+  #ifdef DUMP
+
+  *logofs << name() << ": Dumping checksum data:\n" << logofs_flush; 
+
+  DumpData(message -> md5_digest_, MD5_LENGTH);
+
+  #endif
+}
+
+T_checksum MessageStore::getChecksum(const unsigned char *buffer,
+                                         unsigned int size, int bigEndian)
+{
+  Message *message = getTemporary();
+
+  message -> size_   = size;
+  message -> i_size_ = identitySize(buffer, size);
+  message -> c_size_ = 0;
+
+  validateSize(size);
+
+  beginChecksum(message);
+
+  //
+  // We don't need to extract the identity
+  // data from the buffer.
+  //
+  // parseIdentity(message, buffer, size, bigEndian);
+  //
+
+  identityChecksum(message, buffer, size, bigEndian);
+
+  parseData(message, 0, buffer, size, use_checksum, discard_data, bigEndian);
+
+  endChecksum(message);
+
+  //
+  // The caller will have to explicitly
+  // deallocated the memory after use.
+  //
+
+  T_checksum checksum = new md5_byte_t[MD5_LENGTH];
+
+  memcpy(checksum, message -> md5_digest_, MD5_LENGTH);
+
+  return checksum;
+}
+
+int MessageStore::clean(T_checksum_action checksumAction)
+{
+  int position = lastRemoved + 1;
+
+  if (position >= cacheSlots)
+  {
+    position = 0;
+  }
+
+  #ifdef DEBUG
+  *logofs << name() << ": Searching a message to remove "
+          << "starting at position " << position
+          << " with " << checksums_ -> size()
+          << " elements in cache.\n"
+          << logofs_flush;
+  #endif
+
+  while (position != lastRemoved)
+  {
+    #ifdef DEBUG
+    *logofs << name() << ": Examining position "
+            << position << ".\n" << logofs_flush;
+    #endif
+
+    if ((*messages_)[position] != NULL)
+    {
+      if (getRating((*messages_)[position], rating_for_clean) == 0)
+      {
+        break;
+      }
+      else
+      {
+        untouch((*messages_)[position]);
+      }
+    }
+
+    if (++position == cacheSlots)
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Rolled position at "
+              << strMsTimestamp() << ".\n"
+              << logofs_flush;
+      #endif
+
+      position = 0;
+    }
+  }
+
+  //
+  // If no message is a good candidate,
+  // then try the object at the next slot
+  // in respect to last element removed.
+  //
+
+  if (position == lastRemoved)
+  {
+    position = lastRemoved + 1;
+
+    if (position >= cacheSlots)
+    {
+      position = 0;
+    }
+
+    if ((*messages_)[position] == NULL ||
+            (*messages_)[position] -> locks_ != 0)
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": WARNING! No message found "
+            << "to be actually removed.\n"
+            << logofs_flush;
+      #endif
+
+      return nothing;
+    }
+
+    #ifdef DEBUG
+    *logofs << name() << ": WARNING! Assuming object "
+            << "at position " << position << ".\n"
+            << logofs_flush;
+    #endif
+  }
+
+  return position;
+}
+
+//
+// This is the insertion method used at local side 
+// side. Cache at remote side side will be kept in
+// sync by telling the to other party where to 
+// store the message. 
+//
+
+int MessageStore::findOrAdd(Message *message, T_checksum_action checksumAction,
+                                T_data_action dataAction, int &added, int &locked)
+{
+  if (checksumAction != use_checksum)
+  {
+    #ifdef PANIC
+    *logofs << name() << ": PANIC! Internal error in context [A]. "
+            << "Cannot find or add message to repository "
+            << "without using checksum.\n" << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Internal error in context [A]. "
+         << "Cannot find or add message to repository "
+         << "without using checksum.\n";
+
+    HandleAbort();
+  }
+
+  //
+  // Set added to true only if message
+  // is inserted in cache.
+  //
+
+  added  = 0;
+  locked = 0;
+
+  //
+  // First of all figure out where to
+  // store this object.
+  //
+
+  #ifdef DEBUG
+  *logofs << name() << ": Searching an empty slot "
+          << "with last rated " << lastRated << " and "
+          << "last added " << lastAdded << ".\n"
+          << logofs_flush;
+  #endif
+
+  int position = lastRated;
+
+  if (position == nothing)
+  {
+    position = lastAdded + 1;
+
+    if (position >= cacheSlots)
+    {
+      position = 0;
+    }
+
+    #ifdef DEBUG
+    *logofs << name() << ": Searching an empty slot "
+            << "starting at position " << position
+            << " with " << checksums_ -> size()
+            << " elements in cache.\n"
+            << logofs_flush;
+    #endif
+
+    while (position != lastAdded)
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": Examining position "
+              << position << ".\n" << logofs_flush;
+      #endif
+
+      if ((*messages_)[position] == NULL)
+      {
+        break;
+      }
+      else if (getRating((*messages_)[position], rating_for_insert) == 0)
+      {
+        break;
+      }
+      else
+      {
+        untouch((*messages_)[position]);
+      }
+
+      if (++position == cacheSlots)
+      {
+        #ifdef DEBUG
+        *logofs << name() << ": Rolled position at "
+                << strMsTimestamp() << ".\n"
+                << logofs_flush;
+        #endif
+
+        position = 0;
+      }
+    }
+  }
+  #ifdef DEBUG
+  else
+  {
+    *logofs << name() << ": Using last rated position "
+            << position << ".\n" << logofs_flush;
+  }
+  #endif
+
+  //
+  // If we made an extensive check but did not
+  // find neither a free slot or a message to
+  // replace, assume slot at next position in
+  // respect to last added. This can happen if
+  // all objects in repository have got an hit
+  // recently.
+  //
+
+  if (position == lastAdded)
+  {
+    position = lastAdded + 1;
+
+    if (position >= cacheSlots)
+    {
+      position = 0;
+    }
+
+    #ifdef DEBUG
+    *logofs << name() << ": WARNING! Assuming slot "
+            << "at position " << position << ".\n"
+            << logofs_flush;
+    #endif
+  }
+  #ifdef DEBUG
+  else
+  {
+    *logofs << name() << ": Found candidate slot "
+            << "at position " << position << ".\n"
+            << logofs_flush;
+  }
+  #endif
+
+  //
+  // Save the search result so if the message
+  // is found in cache, we can use the slot
+  // at next run.
+  //
+
+  lastRated = position;
+
+  if ((*messages_)[position] != NULL &&
+          (*messages_)[position] -> locks_ != 0)
+  {
+    #ifdef WARNING
+    *logofs << name() << ": WARNING! Insertion at position "
+            << position << " would replace a locked message. "
+            << "Forcing channel to discard the message.\n"
+            << logofs_flush;
+    #endif
+
+    #ifdef TEST
+    *logofs << name() << ": Invalidating rating of object "
+            << "at position " << position << ".\n"
+            << logofs_flush;
+    #endif
+
+    return (lastRated = nothing);
+  }
+
+  if (checksumAction == use_checksum)
+  {
+    T_checksum checksum = getChecksum(message);
+
+    #ifdef TEST
+    *logofs << name() << ": Searching checksum ["
+            << DumpChecksum(checksum) << "] in repository.\n"
+            << logofs_flush;
+
+    #endif
+
+    pair<T_checksums::iterator, bool> result;
+
+    result = checksums_ -> insert(T_checksums::value_type(checksum, position));
+
+    //
+    // Message was found in cache or
+    // insertion couldn't take place.
+    //
+
+    if (result.second == 0)
+    {
+      if (result.first == checksums_ -> end())
+      {
+        #ifdef PANIC
+        *logofs << name() << ": PANIC! Failed to insert object "
+                << "in the cache.\n" << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Failed to insert object of type "
+             << name() << " in the cache.\n";
+
+        return nothing;
+      }
+
+      //
+      // Message is in cache.
+      //
+
+      #ifdef TEST
+      *logofs << name() << ": Object is already in cache "
+              << "at position " << (result.first) -> second
+              << ".\n" << logofs_flush;
+      #endif
+
+      #ifdef DEBUG
+
+      printStorageSize();
+
+      #endif
+
+      //
+      // Message is locked, probably because
+      // it has not completely recomposed at
+      // remote side after a split.
+      //
+
+      if ((*messages_)[(result.first) -> second] -> locks_ != 0)
+      {
+        #ifdef TEST
+        *logofs << name() << ": WARNING! Object at position "
+                << (result.first) -> second << " is locked.\n"
+                << logofs_flush;
+        #endif
+
+        locked = 1;
+      }
+
+      //
+      // Object got a hit, so prevent
+      // its removal.
+      //
+
+      if (lastRated == (result.first) -> second)
+      {
+        #ifdef TEST
+        *logofs << name() << ": Resetting rating of object "
+                << "at position " << (result.first) -> second
+                << ".\n" << logofs_flush;
+        #endif
+
+        lastRated = nothing;
+      }
+
+      return (result.first) -> second;
+    }
+
+    #ifdef DEBUG
+    *logofs << name() << ": Could not find message in cache.\n"
+            << logofs_flush;
+    #endif
+  }
+
+  //
+  // Message not found in hash table (or insertion
+  // of checksum in hash table was not requested).
+  // Message was added to cache.
+  //
+
+  added = 1;
+
+  //
+  // Log data about the missed message.
+  //
+
+  #ifdef TEST
+
+  if (opcode() == X_PutImage || opcode() == X_NXPutPackedImage)
+  {
+    #ifdef WARNING
+    *logofs << name() << ": WARNING! Dumping identity of "
+            << "missed image object of type " << name()
+            << ".\n" << logofs_flush;
+    #endif
+
+    dumpIdentity(message);
+  }
+
+  #endif
+
+  if ((*messages_)[position] != NULL)
+  {
+    #ifdef DEBUG
+    *logofs << name() << ": The message replaces "
+            << "the old one at position " << position
+            << ".\n" << logofs_flush;
+    #endif
+
+    remove(position, checksumAction, dataAction);
+  }
+
+  (*messages_)[position] = message;
+
+  //
+  // We used the slot. Perform a new
+  // search at next run.
+  //
+
+  lastRated = nothing;
+
+  #ifdef TEST
+  *logofs << name() << ": Stored message object of size "
+          << plainSize(position) << " (" << message -> size_
+          << "/" << message -> c_size_ << ") at position "
+          << position << ".\n" << logofs_flush;
+  #endif
+
+  unsigned int localSize;
+  unsigned int remoteSize;
+
+  storageSize(message, localSize, remoteSize);
+
+  localStorageSize_  += localSize;
+  remoteStorageSize_ += remoteSize;
+
+  totalLocalStorageSize_  += localSize;
+  totalRemoteStorageSize_ += remoteSize;
+
+  #ifdef DEBUG
+
+  printStorageSize();
+
+  #endif
+
+  //
+  // Set hits and timestamp at insertion in cache.
+  //
+
+  message -> hits_ = control -> StoreHitsAddBonus;
+  message -> last_ = (getTimestamp()).tv_sec;
+
+  message -> locks_ = 0;
+
+  #ifdef DEBUG
+  *logofs << name() << ": Set last hit of object at " 
+          << strMsTimestamp() << " with a bonus of "
+          << message -> hits_ << ".\n" << logofs_flush;
+  #endif
+
+  return position;
+}
+
+//
+// Add a parsed message to repository. It is normally used
+// at decoding side or at encoding side when we load store
+// from disk. To handle messages coming from network, the
+// encoding side uses the optimized method findOrAdd().
+//
+
+int MessageStore::add(Message *message, const int position,
+                          T_checksum_action checksumAction, T_data_action dataAction)
+{
+  if (position < 0 || position >= cacheSlots)
+  {
+    #ifdef PANIC
+    *logofs << name() << ": PANIC! Cannot add a message "
+            << "at non existing position " << position
+            << ".\n" << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Cannot add a message "
+         << "at non existing position " << position
+         << ".\n";
+
+    HandleAbort();
+  }
+
+  if ((*messages_)[position] != NULL)
+  {
+    #ifdef DEBUG
+    *logofs << name() << ": The message will replace "
+            << "the old one at position " << position
+            << ".\n" << logofs_flush;
+    #endif
+
+    remove(position, checksumAction, dataAction);
+  }
+
+  #ifdef DEBUG
+  *logofs << name() << ": Inserting object in repository at position "
+          << position << ".\n" << logofs_flush;
+  #endif
+
+  (*messages_)[position] = message;
+
+  //
+  // Get the object's checksum value
+  // and insert it in the table.
+  //
+
+  if (checksumAction == use_checksum)
+  {
+    #ifdef DEBUG
+    *logofs << name() << ": Inserting object's checksum in repository.\n";
+    #endif
+
+    T_checksum checksum = getChecksum(message);
+
+    checksums_ -> insert(T_checksums::value_type(checksum, position));
+  }
+
+  #ifdef DEBUG
+  *logofs << name() << ": Stored message object of size "
+          << plainSize(position) << " (" << message -> size_ 
+          << "/" << message -> c_size_ << ") at position "
+          << position << ".\n" << logofs_flush;
+  #endif
+
+  unsigned int localSize;
+  unsigned int remoteSize;
+
+  storageSize(message, localSize, remoteSize);
+
+  localStorageSize_  += localSize;
+  remoteStorageSize_ += remoteSize;
+
+  totalLocalStorageSize_  += localSize;
+  totalRemoteStorageSize_ += remoteSize;
+
+  #ifdef DEBUG
+
+  printStorageSize();
+
+  #endif
+
+  //
+  // Set hits and timestamp at insertion in cache.
+  //
+
+  message -> hits_ = control -> StoreHitsAddBonus;
+  message -> last_ = (getTimestamp()).tv_sec;
+
+  message -> locks_ = 0;
+
+  #ifdef DEBUG
+  *logofs << name() << ": Set last hit of object at " 
+          << strMsTimestamp() << " with a bonus of "
+          << message -> hits_ << ".\n" << logofs_flush;
+  #endif
+
+  return position;
+}
+
+//
+// The following functions don't modify data,
+// so they are supposed to be called only at
+// the encoding side.
+//
+
+void MessageStore::updateData(const int position, unsigned int dataSize,
+                                  unsigned int compressedDataSize)
+{
+  Message *message = (*messages_)[position];
+
+  validateSize(dataSize, compressedDataSize);
+
+  if (compressedDataSize != 0)
+  {
+    unsigned int localSize;
+    unsigned int remoteSize;
+
+    storageSize(message, localSize, remoteSize);
+
+    localStorageSize_  -= localSize;
+    remoteStorageSize_ -= remoteSize;
+
+    totalLocalStorageSize_  -= localSize;
+    totalRemoteStorageSize_ -= remoteSize;
+
+    message -> c_size_ = compressedDataSize + message -> i_size_;
+
+    #ifdef TEST
+
+    if (message -> size_ != (int) (dataSize + message -> i_size_))
+    {
+      #ifdef PANIC
+      *logofs << name() << ": PANIC! Size of object looks "
+              << message -> size_ << " bytes while it "
+              << "should be " << dataSize + message -> i_size_
+              << ".\n" << logofs_flush;
+      #endif
+
+      cerr << "Error" << ": Size of object looks "
+           << message -> size_ << " bytes while it "
+           << "should be " << dataSize + message -> i_size_
+           << ".\n";
+
+      HandleAbort();
+    }
+
+    #endif
+
+    storageSize(message, localSize, remoteSize);
+
+    localStorageSize_  += localSize;
+    remoteStorageSize_ += remoteSize;
+
+    totalLocalStorageSize_  += localSize;
+    totalRemoteStorageSize_ += remoteSize;
+
+    #ifdef DEBUG
+
+    printStorageSize();
+
+    #endif
+  }
+}
+
+void MessageStore::updateData(const T_checksum checksum, unsigned int compressedDataSize)
+{
+  #ifdef TEST
+  *logofs << name() << ": Searching checksum ["
+          << DumpChecksum(checksum) << "] in repository.\n"
+          << logofs_flush;
+  #endif
+
+  T_checksums::iterator found = checksums_ -> find(checksum);
+
+  if (found != checksums_ -> end())
+  {
+    Message *message = (*messages_)[found -> second];
+
+    #ifdef TEST
+    *logofs << name() << ": Message found in cache at "
+            << "position " << found -> second << " with size "
+            << message -> size_ << " and compressed size "
+            << message -> c_size_ << ".\n" << logofs_flush;
+    #endif
+
+    updateData(found -> second, message -> size_ -
+                   message -> i_size_, compressedDataSize);
+  }
+  #ifdef TEST
+  else if (checksums_ -> size() > 0)
+  {
+    *logofs << name() << ": WARNING! Can't locate the "
+            << "checksum [" << DumpChecksum(checksum)
+            << "] for the update.\n" << logofs_flush;
+  }
+  #endif
+}
+
+//
+// This function replaces the data part of the message
+// and updates the information about its size. Split
+// messages are advertised to the decoding side with
+// their uncompressed size, data is then compressed
+// before sending the first chunk. This function is
+// called by the decoding side after the split message
+// is fully recomposed to replace the dummy data and
+// set the real size.
+//
+
+void MessageStore::updateData(const int position, const unsigned char *newData,
+                                  unsigned int dataSize, unsigned int compressedDataSize)
+{
+  Message *message = (*messages_)[position];
+
+  validateSize(dataSize, compressedDataSize);
+
+  #ifdef TEST
+
+  if (message -> size_ != (int) (dataSize + message -> i_size_))
+  {
+    #ifdef PANIC
+    *logofs << name() << ": PANIC! Data of object looks "
+            << dataSize << " bytes while it " << "should be "
+            << message -> size_ - message -> i_size_
+            << ".\n" << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Data of object looks "
+         << dataSize << " bytes while it " << "should be "
+         << message -> size_ - message -> i_size_
+         << ".\n";
+
+    HandleAbort();
+  }
+
+  #endif
+
+  //
+  // A compressed data size of 0 means that
+  // message's data was not compressed.
+  //
+
+  if (compressedDataSize != 0)
+  {
+    unsigned int localSize;
+    unsigned int remoteSize;
+
+    storageSize(message, localSize, remoteSize);
+
+    localStorageSize_  -= localSize;
+    remoteStorageSize_ -= remoteSize;
+
+    totalLocalStorageSize_  -= localSize;
+    totalRemoteStorageSize_ -= remoteSize;
+
+    if (message -> c_size_ != (int) compressedDataSize +
+            message -> i_size_)
+    {
+      #ifdef TEST
+      *logofs << name() << ": Resizing data of message at "
+              << "position " << position << " from " << message ->
+                  c_size_ << " to " << compressedDataSize +
+                  message -> i_size_ << " bytes.\n"
+              << logofs_flush;
+      #endif
+
+      message -> data_.clear();
+
+      message -> data_.resize(compressedDataSize);
+    }
+
+    memcpy(message -> data_.begin(), newData, compressedDataSize);
+
+    #ifdef TEST
+    *logofs << name() << ": Data of message at position "
+            << position << " has size " << message -> data_.size()
+            << " and capacity " << message -> data_.capacity()
+            << ".\n" << logofs_flush;
+    #endif
+
+    message -> c_size_ = compressedDataSize + message -> i_size_;
+
+    storageSize(message, localSize, remoteSize);
+
+    localStorageSize_  += localSize;
+    remoteStorageSize_ += remoteSize;
+
+    totalLocalStorageSize_  += localSize;
+    totalRemoteStorageSize_ += remoteSize;
+
+    #ifdef DEBUG
+
+    printStorageSize();
+
+    #endif
+  }
+  else
+  {
+    #ifdef TEST
+    *logofs << name() << ": No changes to data size for message "
+            << "at position " << position << ".\n" << logofs_flush;
+    #endif
+
+    memcpy(message -> data_.begin(), newData, dataSize);
+  }
+}
+
+int MessageStore::remove(const int position, T_checksum_action checksumAction,
+                             T_data_action dataAction)
+{
+  Message *message;
+
+  if (position < 0 || position >= cacheSlots ||
+          (message = (*messages_)[position]) == NULL)
+  {
+    #ifdef PANIC
+    *logofs << name() << ": PANIC! Cannot remove "
+            << "a non existing message at position "
+            << position << ".\n" << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Cannot remove "
+         << "a non existing message at position "
+         << position << ".\n";
+
+    HandleAbort();
+  }
+
+  #if defined(TEST) || defined(INFO)
+
+  if (opcode() == X_PutImage || opcode() == X_NXPutPackedImage)
+  {
+    #ifdef WARNING
+    *logofs << name() << ": WARNING! Discarding image object "
+            << "of type " << name() << " at position "
+            << position << ".\n" << logofs_flush;
+    #endif
+  }
+
+  #endif
+
+  //
+  // The checksum is only stored at the encoding
+  // side.
+  //
+
+  if (checksumAction == use_checksum)
+  {
+    #ifdef DEBUG
+    *logofs << name() << ": Removing checksum for object at "
+            << "position " << position << ".\n" << logofs_flush;
+    #endif
+
+    //
+    // TODO: If we had stored the iterator and
+    // not the pointer to the message, we could
+    // have removed the message without having
+    // to look up the checksum.
+    //
+
+    T_checksum checksum = getChecksum(message);
+
+    #ifdef TEST
+    *logofs << name() << ": Searching checksum ["
+            << DumpChecksum(checksum) << "] in repository.\n"
+            << logofs_flush;
+    #endif
+
+    T_checksums::iterator found = checksums_ -> find(checksum);
+
+    if (found == checksums_ -> end())
+    {
+      #ifdef PANIC
+      *logofs << name() << ": PANIC! No checksum found for "
+              << "object at position " << position << ".\n"
+              << logofs_flush;
+      #endif
+
+      cerr << "Error" << ": No checksum found for "
+           << "object at position " << position << ".\n";
+
+      HandleAbort();
+    }
+
+    #ifdef TEST
+
+    else if (position != found -> second)
+    {
+      #ifdef PANIC
+      *logofs << name() << ": PANIC! Value of position for object "
+              << "doesn't match position " << position << ".\n"
+              << logofs_flush;
+      #endif
+
+      cerr << "Error" << ": Value of position for object "
+           << "doesn't match position " << position << ".\n";
+
+      HandleAbort();
+    }
+
+    #endif
+
+    checksums_ -> erase(found);
+  }
+
+  #ifdef DEBUG
+  *logofs << name() << ": Removing message at position "
+          << position << " of size " << plainSize(position)
+          << " (" << message -> size_ << "/" << message -> c_size_
+          << ").\n" << logofs_flush;
+  #endif
+
+  unsigned int localSize;
+  unsigned int remoteSize;
+
+  storageSize(message, localSize, remoteSize);
+
+  localStorageSize_  -= localSize;
+  remoteStorageSize_ -= remoteSize;
+
+  totalLocalStorageSize_  -= localSize;
+  totalRemoteStorageSize_ -= remoteSize;
+
+  recycle(message);
+
+  (*messages_)[position] = NULL;
+
+  #ifdef DEBUG
+
+  printStorageSize();
+
+  #endif
+
+  return position;
+}
+
+//
+// This should only be called at encoding side.
+// The decoding side can't rely on the counter
+// as it is decremented by the encoding side
+// every time the repository is searched for a
+// message to be removed.
+//
+
+int MessageStore::getRating(Message *message, T_rating type) const
+{
+  if (message -> locks_ != 0)
+  {
+    #ifdef TEST
+    *logofs << name() << ": Rate set to -1 as locks of object are "
+            << (int) message -> locks_ << ".\n"
+            << logofs_flush;
+    #endif
+
+    return -1;
+  }
+  else if ((type == rating_for_clean ||
+                (int) checksums_ -> size() == cacheSlots) &&
+                    message -> hits_ <= control -> StoreHitsLoadBonus)
+  {
+    //
+    // We don't have any free slot or we exceeded the
+    // available storage size. This is likely to happen
+    // after having loaded objects from persistent cache.
+    // It's not a bad idea to discard some messages that
+    // were restored but never referenced.
+    //
+
+    #ifdef TEST
+
+    if (type == rating_for_clean)
+    {
+      *logofs << name() << ": Rate set to 0 with hits "
+              << message -> hits_ << " as maximum storage size "
+              << "was exceeded.\n" << logofs_flush;
+    }
+    else
+    {
+      *logofs << name() << ": Rate set to 0 with hits "
+              << message -> hits_ << " as there are no available "
+              << "slots in store.\n" << logofs_flush;
+    }
+
+    #endif
+
+    return 0;
+  }
+  else if (type == rating_for_clean &&
+               (getTimestamp()).tv_sec - message -> last_ >=
+                   control -> StoreTimeLimit)
+  {
+    #ifdef TEST
+    *logofs << name() << ": Rate set to 0 as last hit of object was "
+            << (getTimestamp()).tv_sec - message -> last_
+            << " seconds ago with limit set to " << control ->
+               StoreTimeLimit << ".\n" << logofs_flush;
+    #endif
+
+    return 0;
+  }
+  else
+  {
+    #ifdef TEST
+    if (message -> hits_ < 0)
+    {
+      *logofs << name() << ": PANIC! Rate of object shouldn't be "
+              << message -> hits_ << ".\n" << logofs_flush;
+
+      cerr << "Error" << ": Rate of object of type " << name()
+           << " shouldn't be " << message -> hits_ << ".\n";
+
+      HandleAbort();
+    }
+    #endif
+
+    #ifdef TEST
+    *logofs << name() << ": Rate of object is " << message -> hits_
+            << " with last hit " << (getTimestamp()).tv_sec -
+               message -> last_ << " seconds ago.\n"
+            << logofs_flush;
+    #endif
+
+    return message -> hits_;
+  }
+}
+
+int MessageStore::touch(Message *message) const
+{
+  message -> last_ = (getTimestamp()).tv_sec;
+
+  message -> hits_ += control -> StoreHitsTouch;
+
+  if (message -> hits_ > control -> StoreHitsLimit)
+  {
+    message -> hits_ = control -> StoreHitsLimit;
+  }
+
+  #ifdef TEST
+  *logofs << name() << ": Increased hits of object to "
+          << message -> hits_ << " at " << strMsTimestamp()
+          << ".\n" << logofs_flush;
+  #endif
+
+  return message -> hits_;
+}
+
+int MessageStore::untouch(Message *message) const
+{
+  message -> hits_ -= control -> StoreHitsUntouch;
+
+  if (message -> hits_ < 0)
+  {
+    message -> hits_ = 0;
+  }
+
+  #ifdef TEST
+  *logofs << name() << ": Decreased hits of object to " 
+          << message -> hits_ << ".\n"
+          << logofs_flush;
+  #endif
+
+  return message -> hits_;
+}
+
+int MessageStore::lock(const int position) const
+{
+  Message *message = (*messages_)[position];
+
+  if (message == NULL)
+  {
+    #ifdef PANIC
+    *logofs << name() << ": PANIC! Can't lock the null "
+            << "object at position " << position
+            << ".\n" << logofs_flush;
+    #endif
+
+    return -1;
+  }
+
+  #ifdef DEBUG
+  *logofs << name() << ": Increasing locks of object to " 
+          << (int) message -> locks_ + 1 << ".\n"
+          << logofs_flush;
+  #endif
+
+  return ++(message -> locks_);
+}
+
+int MessageStore::unlock(const int position) const
+{
+  Message *message = (*messages_)[position];
+
+  if (message == NULL)
+  {
+    #ifdef PANIC
+    *logofs << name() << ": PANIC! Can't unlock the null "
+            << "object at position " << position
+            << ".\n" << logofs_flush;
+    #endif
+
+    return -1;
+  }
+
+  #ifdef DEBUG
+  *logofs << name() << ": Decreasing locks of object to " 
+          << (int) message -> locks_ - 1 << ".\n"
+          << logofs_flush;
+  #endif
+
+  return --(message -> locks_);
+}
+
+int MessageStore::saveStore(ostream *cachefs, md5_state_t *md5StateStream,
+                                md5_state_t *md5StateClient, T_checksum_action checksumAction,
+                                    T_data_action dataAction, int bigEndian)
+{
+  Message *message;
+
+  #ifdef TEST
+  *logofs << name() << ": Opcode of this store is "
+          << (unsigned int) opcode() << " default size of "
+          << "identity is " << dataOffset << ".\n"
+          << logofs_flush;
+  #endif
+
+  unsigned char *identityBuffer = new unsigned char[dataOffset];
+  unsigned char *sizeBuffer     = new unsigned char[4 * 2];
+  unsigned char *positionBuffer = new unsigned char[4];
+  unsigned char *opcodeBuffer   = new unsigned char[4];
+
+  #ifdef DUMP
+
+  char *md5ClientDump = new char[dataOffset * 2 + 128];
+
+  #endif
+
+  unsigned char value;
+
+  int offset;
+
+  int failed = 0;
+
+  for (int position = 0; position < cacheSlots; position++)
+  {
+    message = (*messages_)[position];
+
+    //
+    // Don't save split messages.
+    //
+
+    if (message != NULL && message -> locks_ == 0)
+    {
+      //
+      // Use the total size if offset is
+      // beyond the real end of message.
+      //
+
+      offset = dataOffset;
+
+      if (offset > message -> size_)
+      {
+        offset = message -> size_;
+      }
+        
+      #ifdef TEST
+      *logofs << name() << ": Going to save message at position "
+              << position << ".\n" << logofs_flush;
+      #endif
+
+      value = 1;
+
+      PutULONG(position, positionBuffer, bigEndian);
+      PutULONG(opcode(), opcodeBuffer, bigEndian);
+
+      md5_append(md5StateClient, positionBuffer, 4);
+      md5_append(md5StateClient, opcodeBuffer, 4);
+
+      #ifdef DUMP
+
+      *logofs << "Name=" << name() << logofs_flush;
+
+      sprintf(md5ClientDump," Pos=%d Op=%d\n", position, opcode());
+
+      *logofs << md5ClientDump << logofs_flush;
+
+      #endif
+
+      if (PutData(cachefs, &value, 1) < 0)
+      {
+        #ifdef DEBUG
+        *logofs << name() << ": PANIC! Failure writing " << 1
+                << " bytes.\n" << logofs_flush;
+        #endif
+
+        failed = 1;
+
+        break;
+      }
+
+      md5_append(md5StateStream, &value, 1);
+
+      PutULONG(message -> size_, sizeBuffer, bigEndian);
+      PutULONG(message -> c_size_, sizeBuffer + 4, bigEndian);
+
+      //
+      // Note that the identity size is not saved with
+      // the message and will be determined from the
+      // data read when restoring the identity.
+      //
+
+      if (PutData(cachefs, sizeBuffer, 4 * 2) < 0)
+      {
+        #ifdef DEBUG
+        *logofs << name() << ": PANIC! Failure writing " << 4 * 2
+                << " bytes.\n" << logofs_flush;
+        #endif
+
+        failed = 1;
+
+        break;
+      }
+
+      md5_append(md5StateStream, sizeBuffer, 4 * 2);
+      md5_append(md5StateClient, sizeBuffer, 4 * 2);
+
+      #ifdef DUMP
+
+      sprintf(md5ClientDump, "size = %d c_size = %d\n",
+                  message -> size_, message -> c_size_);
+
+      *logofs << md5ClientDump << logofs_flush;
+
+      #endif
+
+      //
+      // Prepare a clean buffer for unparse.
+      //
+
+      CleanData(identityBuffer, offset);
+
+      unparseIdentity(message, identityBuffer, offset, bigEndian);
+
+      if (PutData(cachefs, identityBuffer, offset) < 0)
+      {
+        #ifdef DEBUG
+        *logofs << name() << ": PANIC! Failure writing " << offset
+                << " bytes.\n" << logofs_flush;
+        #endif
+
+        failed = 1;
+
+        break;
+      }
+
+      md5_append(md5StateStream, identityBuffer, offset);
+      md5_append(md5StateClient, identityBuffer, offset);
+
+      #ifdef DUMP
+
+      for (int i = 0; i < offset; i++)
+      {
+        sprintf(md5ClientDump + (i * 2), "%02X", identityBuffer[i]);
+      }
+
+      *logofs << "Identity = " << md5ClientDump << "\n" << logofs_flush;
+
+      #endif
+
+      //
+      // Set the real identity size before
+      // saving the data.
+      //
+
+      offset = message -> i_size_;
+
+      if (offset > message -> size_)
+      {
+        offset = message -> size_;
+      }
+
+      if (checksumAction == use_checksum)
+      {
+        if (PutData(cachefs, message -> md5_digest_, MD5_LENGTH) < 0)
+        {
+          #ifdef DEBUG
+          *logofs << name() << ": PANIC! Failure writing " << MD5_LENGTH
+                  << " bytes.\n" << logofs_flush;
+          #endif
+
+          failed = 1;
+
+          break;
+        }
+
+        md5_append(md5StateStream, message -> md5_digest_, MD5_LENGTH);
+      }
+      else if (dataAction == use_data)
+      {
+        int dataSize = (message -> c_size_ == 0 ?
+                             message -> size_ - offset :
+                                 message -> c_size_ - offset);
+        if (dataSize > 0)
+        {
+          if (PutData(cachefs, message -> data_.begin(), dataSize) < 0)
+          {
+            #ifdef DEBUG
+            *logofs << name() << ": PANIC! Failure writing " << dataSize
+                    << " bytes.\n" << logofs_flush;
+            #endif
+
+            failed = 1;
+
+            break;
+          }
+
+          md5_append(md5StateStream, message -> data_.begin(), dataSize);
+        }
+      }
+    }
+    else
+    {
+      #ifdef TEST
+      *logofs << name() << ": Not saving message at position "
+              << position << ".\n" << logofs_flush;
+      #endif
+
+      value = 0;
+
+      if (PutData(cachefs, &value, 1) < 0)
+      {
+        #ifdef DEBUG
+        *logofs << name() << ": PANIC! Failure writing " << 1
+                << " bytes.\n" << logofs_flush;
+        #endif
+
+        failed = 1;
+
+        break;
+      }
+
+      md5_append(md5StateStream, &value, 1);
+    }
+  }
+
+  if (failed == 1)
+  {
+    #ifdef PANIC
+    *logofs << name() << ": PANIC! Write to persistent cache file failed.\n"
+            << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Write to persistent cache file failed.\n";
+  }
+
+  delete [] identityBuffer;
+  delete [] sizeBuffer;
+  delete [] positionBuffer;
+  delete [] opcodeBuffer;
+
+  #ifdef DUMP
+
+  delete [] md5ClientDump;
+
+  #endif
+
+  return (failed == 0 ? 1 : -1);
+}
+
+int MessageStore::loadStore(istream *cachefs, md5_state_t *md5StateStream,
+                                T_checksum_action checksumAction, T_data_action dataAction,
+                                    int bigEndian)
+{
+  Message *message;
+
+  #ifdef TEST
+  *logofs << name() << ": Opcode of this store is "
+          << (unsigned int) opcode() << " default size of "
+          << "identity is " << dataOffset << " slots are "
+          << cacheSlots << ".\n" << logofs_flush;
+  #endif
+
+  //
+  // If packed images or the render extension has been
+  // disabled we don't need to restore these messages
+  // in the cache. Encoding of RENDER in 1.4.0 is also
+  // changed so we want to skip messages saved using
+  // the old format. We want to restore all the other
+  // messages so we'll need to skip these one by one.
+  //
+
+  int skip = 0;
+
+  if ((opcode() == X_NXPutPackedImage &&
+          control -> PersistentCacheLoadPacked == 0) ||
+              (opcode() == X_NXInternalRenderExtension &&
+                  control -> PersistentCacheLoadRender == 0))
+  {
+    #ifdef TEST
+    *logofs << name() << ": All messages for OPCODE#"
+            << (unsigned int) opcode() << " will be discarded.\n"
+            << logofs_flush;
+    #endif
+
+    skip = 1;
+  }
+
+  unsigned char *identityBuffer = new unsigned char[dataOffset];
+  unsigned char *sizeBuffer     = new unsigned char[4 * 2];
+
+  unsigned char value;
+
+  int offset;
+
+  int failed = 0;
+
+  for (int position = 0; position < cacheSlots; position++)
+  {
+    if (GetData(cachefs, &value, 1) < 0)
+    {
+      #ifdef DEBUG
+      *logofs << name() << ": PANIC! Failure reading " << 1
+              << " bytes.\n" << logofs_flush;
+      #endif
+
+      failed = 1;
+
+      break;
+    }
+
+    md5_append(md5StateStream, &value, 1);
+
+    if (value == 1)
+    {
+      #ifdef TEST
+      *logofs << name() << ": Going to load message at position "
+              << position << ".\n" << logofs_flush;
+      #endif
+
+      if (GetData(cachefs, sizeBuffer, 4 * 2) < 0)
+      {
+        #ifdef DEBUG
+        *logofs << name() << ": PANIC! Failure reading " << 4 * 2
+                << " bytes.\n" << logofs_flush;
+        #endif
+
+        failed = 1;
+
+        break;
+      }
+
+      md5_append(md5StateStream, sizeBuffer, 4 * 2);
+
+      message = getTemporary();
+
+      if (message == NULL)
+      {
+        #ifdef PANIC
+        *logofs << name() << ": PANIC! Can't access temporary storage "
+                << "for message in context [B].\n" << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Can't access temporary storage "
+             << "for message in context [B].\n";
+
+        failed = 1;
+
+        break;
+      }
+
+      message -> size_   = GetULONG(sizeBuffer, bigEndian);
+      message -> c_size_ = GetULONG(sizeBuffer + 4, bigEndian);
+
+      #ifdef DEBUG
+      *logofs << name() << ": Size is " << message -> size_
+              << " compressed size is " << message -> c_size_
+              << ".\n" << logofs_flush;
+      #endif
+
+      //
+      // Use the total size if offset is
+      // beyond the real end of message.
+      //
+
+      offset = dataOffset;
+
+      if (offset > message -> size_)
+      {
+        offset = message -> size_;
+      }
+
+      if (GetData(cachefs, identityBuffer, offset) < 0)
+      {
+        #ifdef DEBUG
+        *logofs << name() << ": PANIC! Failure reading " << offset
+                << " bytes.\n" << logofs_flush;
+        #endif
+
+        failed = 1;
+
+        break;
+      }
+
+      md5_append(md5StateStream, identityBuffer, offset);
+
+      //
+      // Get the real identity size based on the value
+      // reported by the message store. The dataOffset
+      // value is guaranteed to be greater or equal to
+      // the maximum identity size of the messages in
+      // the major store.
+      //
+
+      offset = identitySize(identityBuffer, offset);
+
+      if (offset > message -> size_)
+      {
+        offset = message -> size_;
+      }
+
+      message -> i_size_ = offset;
+
+      //
+      // Get identity of message from the buffer we just
+      // created. Don't calculate neither checksum nor
+      // data, restore them from stream. Don't pass the
+      // message's size but the default size of identity.
+      //
+
+      parseIdentity(message, identityBuffer, offset, bigEndian);
+
+      if (checksumAction == use_checksum)
+      {
+        if (message -> md5_digest_ == NULL)
+        {
+          message -> md5_digest_ = new md5_byte_t[MD5_LENGTH];
+        }
+
+        if (GetData(cachefs, message -> md5_digest_, MD5_LENGTH) < 0)
+        {
+          #ifdef DEBUG
+          *logofs << name() << ": PANIC! Failure reading " << MD5_LENGTH
+                  << " bytes.\n" << logofs_flush;
+          #endif
+
+          failed = 1;
+
+          break;
+        }
+
+        //
+        // Add message's checksum to checksum that will
+        // be saved together with this cache. Checksum
+        // will be verified when cache file is restored
+        // to ensure file is not corrupted.
+        //
+
+        md5_append(md5StateStream, message -> md5_digest_, MD5_LENGTH);
+
+        if (skip == 1)
+        {
+          #ifdef TEST
+          *logofs << name() << ": Discarding message for OPCODE#"
+                  << (unsigned int) opcode() << ".\n"
+                  << logofs_flush;
+          #endif
+          
+          continue;
+        }
+      }
+      else if (dataAction == use_data)
+      {
+        //
+        // Restore the data part.
+        //
+
+        int dataSize = (message -> c_size_ == 0 ?
+                             message -> size_ - offset :
+                                 message -> c_size_ - offset);
+
+        if (dataSize < 0 || dataSize > control -> MaximumMessageSize)
+        {
+          #ifdef PANIC
+          *logofs << name() << ": PANIC! Bad data size "
+                  << dataSize << " loading persistent cache.\n"
+                  << logofs_flush;
+          #endif
+
+          cerr << "Error" << ": Bad data size " << dataSize
+               << " loading persistent cache.\n";
+
+          failed = 1;
+
+          break;
+        }
+        else if (dataSize > 0)
+        {
+          //
+          // If need to skip the message let anyway
+          // it to be part of the calculated MD5.
+          //
+
+          if (skip == 1)
+          {
+            unsigned char *dummy = new unsigned char[dataSize];
+
+            if (dummy == NULL)
+            {
+              #ifdef PANIC
+              *logofs << name() << ": PANIC! Can't allocate dummy buffer "
+                      << "of size " << dataSize << " loading cache.\n"
+                      << logofs_flush;
+              #endif
+
+              cerr << "Error" << ": Can't allocate dummy buffer "
+                   << "of size " << dataSize << " loading cache.\n";
+
+              failed = 1;
+
+              break;
+            }
+
+            if (GetData(cachefs, dummy, dataSize) < 0)
+            {
+              #ifdef DEBUG
+              *logofs << name() << ": PANIC! Failure reading " << dataSize
+                      << " bytes.\n" << logofs_flush;
+              #endif
+
+              failed = 1;
+
+              break;
+            }
+
+            md5_append(md5StateStream, dummy, dataSize);
+
+            delete [] dummy;
+
+            #ifdef TEST
+            *logofs << name() << ": Discarding message for OPCODE#"
+                    << (unsigned int) opcode() << ".\n"
+                    << logofs_flush;
+            #endif
+
+            continue;
+          }
+          else
+          {
+            message -> data_.clear();
+
+            message -> data_.resize(dataSize);
+
+            if (GetData(cachefs, message -> data_.begin(), dataSize) < 0)
+            {
+              #ifdef DEBUG
+              *logofs << name() << ": PANIC! Failure reading " << dataSize
+                      << " bytes.\n" << logofs_flush;
+              #endif
+
+              failed = 1;
+
+              break;
+            }
+
+            //
+            // Add message's data to cache checksum.
+            //
+
+            md5_append(md5StateStream, message -> data_.begin(), dataSize);
+          }
+        }
+        else
+        {
+          //
+          // We are here if data part is zero.
+          //
+
+          if (skip == 1)
+          {
+            #ifdef TEST
+            *logofs << name() << ": Discarding message for OPCODE#"
+                    << (unsigned int) opcode() << ".\n"
+                    << logofs_flush;
+            #endif
+
+            continue;
+          }
+        }
+      }
+
+      int added;
+
+      added = add(message, position, checksumAction, dataAction);
+
+      if (added != position)
+      {
+        #ifdef PANIC
+        *logofs << name() << ": PANIC! Can't store message "
+                << "in the cache at position " << position
+                << ".\n" << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Can't store message "
+             << "in the cache at position " << position
+             << ".\n";
+
+        failed = 1;
+
+        break;
+      }
+      else
+      {
+        //
+        // Replace default value of hits set by add
+        // function. Messages read from cache start
+        // with a lower bonus than fresh messages
+        // inserted.
+        //
+
+        message -> hits_ = control -> StoreHitsLoadBonus;
+
+        #ifdef DEBUG
+        *logofs << name() << ": Updated last hit of object at " 
+                << strMsTimestamp() << " with a bonus of "
+                << message -> hits_ << ".\n" << logofs_flush;
+        #endif
+
+        resetTemporary();
+      }
+    }
+    else if ((*messages_)[position] != NULL)
+    {
+      #ifdef TEST
+      *logofs << name() << ": Going to remove message at position "
+              << position << ".\n" << logofs_flush;
+      #endif
+
+      int removed;
+
+      removed = remove(position, checksumAction, dataAction);
+
+      if (removed != position)
+      {
+        #ifdef PANIC
+        *logofs << name() << ": PANIC! Can't remove message from cache "
+                << "at position " << position << ".\n"
+                << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Can't remove message from cache "
+             << "at position " << position << ".\n";
+
+        failed = 1;
+
+        break;
+      }
+    }
+    #ifdef TEST
+    else
+    {
+      *logofs << name() << ": Not loading message at position "
+              << position << ".\n" << logofs_flush;
+    }
+    #endif
+  }
+
+  #ifdef WARNING
+
+  if (failed == 1)
+  {
+    *logofs << name() << ": WARNING! Read from persistent cache file failed.\n"
+            << logofs_flush;
+  }
+
+  #endif
+
+  delete [] identityBuffer;
+  delete [] sizeBuffer;
+
+  return (failed == 0 ? 1 : -1);
+}
+
+void MessageStore::storageSize(const Message *message, unsigned int &local,
+                                   unsigned int &remote) const
+{
+  local = remote = storage();
+
+  //
+  // Encoding side includes 48 bytes for
+  // the map of checksums and 24 bytes
+  // of adjustment for total overhead.
+  //
+
+  local += MD5_LENGTH + 48 + 24;
+
+  //
+  // At decoding side we include size of
+  // data part and 24 bytes of adjustment
+  // for total overhead.
+  //
+
+  if (message -> c_size_ == 0)
+  {
+    remote += message -> size_ + 24;
+  }
+  else
+  {
+    remote += message -> c_size_ + 24;
+  }
+
+  //
+  // Check if we are the encoding or the
+  // decoding side and, if needed, swap
+  // the values.
+  //
+
+  if (message -> md5_digest_ == NULL)
+  {
+    unsigned int t = local;
+
+    local = remote;
+
+    remote = t;
+  }
+}
+
+void MessageStore::printStorageSize()
+{
+  #ifdef TEST
+
+  *logofs << name() << ": There are "
+          << checksums_ -> size() << " checksums in this store "
+          << "out of " << cacheSlots << " slots.\n"
+          << logofs_flush;
+
+  *logofs << name() << ": Size of this store is "
+          << localStorageSize_ << " bytes at local side and "
+          << remoteStorageSize_ << " bytes at remote side.\n"
+          << logofs_flush;
+
+  *logofs << name() << ": Size of total cache is "
+          << totalLocalStorageSize_ << " bytes at local side and "
+          << totalRemoteStorageSize_ << " bytes at remote side.\n"
+          << logofs_flush;
+
+  #endif
+}