1 files changed, 692 insertions, 0 deletions
diff --git a/nxcomp/DecodeBuffer.cpp b/nxcomp/DecodeBuffer.cpp
new file mode 100644
index 000000000..077bfdfc0
--- /dev/null
+++ b/nxcomp/DecodeBuffer.cpp
@@ -0,0 +1,692 @@
+/**************************************************************************/
+/*                                                                        */
+/* Copyright (c) 2001, 2010 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 Medialogic S.p.A.                   */
+/*                                                                        */
+/* All rights reserved.                                                   */
+/*                                                                        */
+/**************************************************************************/
+
+#include "Misc.h"
+#include "Control.h"
+
+#include "DecodeBuffer.h"
+
+//
+// Set the verbosity level.
+//
+
+#define PANIC
+#define WARNING
+#undef  TEST
+#undef  DEBUG
+#undef  DUMP
+
+DecodeBuffer::DecodeBuffer(const unsigned char *data, unsigned int length)
+
+  : buffer_(data), end_(buffer_ + length), nextSrc_(buffer_), srcMask_(0x80)
+{
+  if (control -> isProtoStep7() == 1)
+  {
+    end_ = buffer_ + length - DECODE_BUFFER_POSTFIX_SIZE;
+  }
+}
+
+int DecodeBuffer::decodeValue(unsigned int &value, unsigned int numBits,
+                                  unsigned int blockSize, int endOkay)
+{
+  #ifdef DUMP
+  *logofs << "DecodeBuffer: Decoding " << numBits
+          << " bits value with block " << blockSize
+          << " and " << (nextSrc_ - buffer_)
+          << " bytes in buffer.\n" << logofs_flush;
+  #endif
+
+  unsigned int result = 0;
+  unsigned int destMask = 0x1;
+  unsigned int bitsRead = 0;
+
+  if (blockSize == 0)
+    blockSize = numBits;
+
+  unsigned char nextSrcChar = *nextSrc_;
+  unsigned int numBlocks = 1;
+
+  do
+  {
+    if (numBlocks == 4)
+    {
+      blockSize = numBits;
+    }
+
+    unsigned int bitsToRead = (blockSize > numBits - bitsRead ?
+                                   numBits - bitsRead : blockSize);
+    unsigned int count = 0;
+    unsigned char lastBit;
+
+    do
+    {
+      if (nextSrc_ >= end_)
+      {
+        if (!endOkay)
+        {
+          #ifdef PANIC
+          *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [A] "
+                  << "in decodeValue() nextSrc_ = " << (nextSrc_ - buffer_)
+                  << " end_ = " << (end_ - buffer_) << ".\n"
+                  << logofs_flush;
+          #endif
+
+          //
+          // Label "context" is just used to identify
+          // the routine which detected the problem in
+          // present source file.
+          //
+
+          cerr << "Error" << ": Failure decoding data in context [A].\n";
+
+          HandleAbort();
+        }
+
+        #ifdef PANIC
+        *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [B] "
+                << "in decodeValue() nextSrc_ = " << (nextSrc_ - buffer_)
+                << " end_ = " << (end_ - buffer_) << ".\n"
+                << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Failure decoding data in context [B].\n";
+
+        HandleAbort();
+      }
+
+      lastBit = (nextSrcChar & srcMask_);
+
+      if (lastBit)
+        result |= destMask;
+
+      srcMask_ >>= 1;
+
+      if (srcMask_ == 0)
+      {
+        srcMask_ = 0x80;
+        nextSrc_++;
+        nextSrcChar = *nextSrc_;
+      }
+
+      destMask <<= 1;
+    }
+    while (bitsToRead > ++count);
+
+    bitsRead += bitsToRead;
+
+    if (bitsRead < numBits)
+    {
+      if (nextSrc_ >= end_)
+      {
+        if (!endOkay)
+        {
+          #ifdef PANIC
+          *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [C] "
+                  << "in decodeValue() nextSrc_ = " << (nextSrc_ - buffer_)
+                  << " end_ = " << (end_ - buffer_) << ".\n"
+                  << logofs_flush;
+          #endif
+
+          cerr << "Error" << ": Failure decoding data in context [C].\n";
+
+          HandleAbort();
+        }
+
+        #ifdef PANIC
+        *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [D] "
+                << "in decodeValue() nextSrc_ = " << (nextSrc_ - buffer_)
+                << " end_ = " << (end_ - buffer_) << ".\n"
+                << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Failure decoding data in context [D].\n";
+
+        HandleAbort();
+      }
+
+      unsigned char moreData = (nextSrcChar & srcMask_);
+
+      srcMask_ >>= 1;
+
+      if (srcMask_ == 0)
+      {
+        srcMask_ = 0x80;
+        nextSrc_++;
+        nextSrcChar = *nextSrc_;
+      }
+
+      if (!moreData)
+      {
+        if (lastBit)
+        {
+          do
+          {
+            result |= destMask;
+            destMask <<= 1;
+          }
+          while (numBits > ++bitsRead);
+        }
+        else
+          bitsRead = numBits;
+      }
+    }
+
+    blockSize >>= 1;
+
+    if (blockSize < 2)
+      blockSize = 2;
+
+    numBlocks++;
+  }
+  while (numBits > bitsRead);
+
+  value = result;
+
+  return 1;
+}
+
+int DecodeBuffer::decodeCachedValue(unsigned int &value, unsigned int numBits,
+                                        IntCache &cache, unsigned int blockSize,
+                                            int endOkay)
+{
+  #ifdef DUMP
+  *logofs << "DecodeBuffer: Decoding " << numBits
+          << " bits cached value with block " << blockSize
+          << " and " << (nextSrc_ - buffer_)
+          << " bytes in buffer.\n" << logofs_flush;
+  #endif
+
+  if (nextSrc_ >= end_)
+  {
+    #ifdef PANIC
+    *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [E] "
+            << "in decodeValue() nextSrc_ = " << (nextSrc_ - buffer_)
+            << " end_ = " << (end_ - buffer_) << ".\n"
+            << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Failure decoding data in context [E].\n";
+
+    HandleAbort();
+  }
+
+  unsigned int index = 0;
+  unsigned char nextSrcChar = *nextSrc_;
+
+  while (!(nextSrcChar & srcMask_))
+  {
+    index++;
+    srcMask_ >>= 1;
+    if (srcMask_ == 0)
+    {
+      srcMask_ = 0x80;
+      nextSrc_++;
+      if (nextSrc_ >= end_)
+      {
+        if (!endOkay)
+        {
+          #ifdef PANIC
+          *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [F] "
+                  << "in decodeCachedValue() nextSrc_ = "
+                  << (nextSrc_ - buffer_) << " end_ = "
+                  << (end_ - buffer_) << ".\n" << logofs_flush;
+          #endif
+
+          cerr << "Error" << ": Failure decoding data in context [F].\n";
+
+          HandleAbort();
+        }
+
+        #ifdef PANIC
+        *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [G] "
+                << "in decodeValue() nextSrc_ = " << (nextSrc_ - buffer_)
+                << " end_ = " << (end_ - buffer_) << ".\n"
+                << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Failure decoding data in context [G].\n";
+
+        HandleAbort();
+      }
+
+      nextSrcChar = *nextSrc_;
+    }
+  }
+
+  srcMask_ >>= 1;
+
+  if (srcMask_ == 0)
+  {
+    srcMask_ = 0x80;
+    nextSrc_++;
+  }
+
+  if (index == 2)
+  {
+    if (control -> isProtoStep8() == 1)
+    {
+      blockSize = cache.getBlockSize(blockSize);
+
+      if (decodeValue(value, numBits, blockSize, endOkay))
+      {
+        cache.insert(value, IntMask[numBits]);
+
+        return 1;
+      }
+
+      #ifdef PANIC
+      *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [H] "
+              << "in decodeCacheValue() with no value found.\n"
+              << logofs_flush;
+      #endif
+
+      cerr << "Error" << ": Failure decoding data in context [H].\n";
+
+      HandleAbort();
+    }
+    else
+    {
+      unsigned int sameDiff;
+
+      decodeBoolValue(sameDiff);
+
+      if (sameDiff)
+      {
+        value = cache.getLastDiff(IntMask[numBits]);
+
+        cache.insert(value, IntMask[numBits]);
+
+        return 1;
+      }
+      else
+      {
+        blockSize = cache.getBlockSize(blockSize);
+
+        if (decodeValue(value, numBits, blockSize, endOkay))
+        {
+          cache.insert(value, IntMask[numBits]);
+
+          return 1;
+        }
+
+        #ifdef PANIC
+        *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [H] "
+                << "in decodeCacheValue() with no value found.\n"
+                << logofs_flush;
+        #endif
+
+        cerr << "Error" << ": Failure decoding data in context [H].\n";
+
+        HandleAbort();
+      }
+    }
+  }
+  else
+  {
+    if (index > 2)
+    {
+      index--;
+    }
+
+    if (index > cache.getSize())
+    {
+      #ifdef PANIC
+      *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [I] "
+              << "in decodeCachedValue() index = " << index
+              << " cache size = " << cache.getSize() << ".\n"
+              << logofs_flush;
+      #endif
+
+      cerr << "Error" << ": Failure decoding data in context [I].\n";
+
+      HandleAbort();
+    }
+
+    value = cache.get(index);
+
+    return 1;
+  }
+}
+
+int DecodeBuffer::decodeCachedValue(unsigned char &value, unsigned int numBits,
+                                        CharCache &cache, unsigned int blockSize,
+                                            int endOkay)
+{
+  #ifdef DUMP
+  *logofs << "DecodeBuffer: Decoding " << numBits
+          << " bits char cached value with block " << blockSize
+          << " and " << nextSrc_ - buffer_ << " bytes read out of "
+          << end_ - buffer_ << ".\n" << logofs_flush;
+  #endif
+
+  if (nextSrc_ >= end_)
+  {
+    #ifdef TEST
+    *logofs << "DecodeBuffer: End of buffer reached in context [J] with "
+            << nextSrc_ - buffer_ << " bytes read out of "
+            << end_ - buffer_ << ".\n" << logofs_flush;
+    #endif
+
+    return 0;
+  }
+
+  unsigned int index = 0;
+  unsigned char nextSrcChar = *nextSrc_;
+
+  while (!(nextSrcChar & srcMask_))
+  {
+    index++;
+    srcMask_ >>= 1;
+
+    if (srcMask_ == 0)
+    {
+      srcMask_ = 0x80;
+      nextSrc_++;
+
+      if (nextSrc_ >= end_)
+      {
+        if (!endOkay)
+        {
+          #ifdef PANIC
+          *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [K] "
+                  << "in decodeCachedValue() nextSrc_ "
+                  << (nextSrc_ - buffer_) << " end_ " << (end_ - buffer_)
+                  << ".\n" << logofs_flush;
+          #endif
+
+          cerr << "Error" << ": Failure decoding data in context [K].\n";
+
+          HandleAbort();
+        }
+
+        #ifdef TEST
+        *logofs << "DecodeBuffer: End of buffer reached in context [L] with "
+                << nextSrc_ - buffer_ << " bytes read out of "
+                << end_ - buffer_ << ".\n" << logofs_flush;
+        #endif
+
+        return 0;
+      }
+
+      nextSrcChar = *nextSrc_;
+    }
+  }
+
+  srcMask_ >>= 1;
+
+  if (srcMask_ == 0)
+  {
+    srcMask_ = 0x80;
+    nextSrc_++;
+  }
+
+  if (index == 2)
+  {
+    unsigned int temp;
+
+    if (decodeValue(temp, numBits, blockSize, endOkay))
+    {
+      value = (unsigned char) temp;
+
+      cache.insert(value);
+    }
+    else
+    {
+      #ifdef PANIC
+      *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [M] "
+              << "in decodeValue() with index = 2.\n"
+              << logofs_flush;
+      #endif
+
+      cerr << "Error" << ": Failure decoding data in context [M].\n";
+
+      HandleAbort();
+    }
+  }
+  else
+  {
+    if (index > 2)
+    {
+      index--;
+    }
+
+    if (index > cache.getSize())
+    {
+      #ifdef PANIC
+      *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [N] "
+              << "in decodeCachedValue() " << "index = " << index
+              << " cache size = " << cache.getSize() << ".\n"
+              << logofs_flush;
+      #endif
+
+      cerr << "Error" << ": Failure decoding data in context [N].\n";
+
+      HandleAbort();
+    }
+
+    value = cache.get(index);
+  }
+
+  return 1;
+}
+
+//
+// Simply returns a pointer to the correct spot in
+// the internal buffer. If the caller needs this
+// data to last beyond the lifetime of the internal
+// buffer, it must copy the data in its own memory.
+//
+
+const unsigned char *DecodeBuffer::decodeMemory(unsigned int numBytes)
+{
+  #ifdef DUMP
+  *logofs << "DecodeBuffer: Decoding " << numBytes
+          << " bytes of memory with " << (nextSrc_ - buffer_)
+          << " bytes in buffer.\n" << logofs_flush;
+  #endif
+
+  const unsigned char *result;     
+
+  //
+  // Force ourselves to a byte boundary.
+  // Is up to application to ensure data
+  // is word alligned when needed.
+  //
+
+  if (srcMask_ != 0x80)
+  {
+    srcMask_ = 0x80;
+    nextSrc_++;
+  }
+
+  result = nextSrc_;
+
+  if (numBytes > DECODE_BUFFER_OVERFLOW_SIZE)
+  {
+    #ifdef PANIC
+    *logofs << "DecodeBuffer: PANIC! Can't decode a buffer of "
+            << numBytes << " bytes with limit set to "
+            << DECODE_BUFFER_OVERFLOW_SIZE << ".\n"
+            << logofs_flush;
+
+    *logofs << "DecodeBuffer: PANIC! Assuming failure decoding "
+            << "data in context [O].\n" << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Should never decode buffer of size "
+         << "greater than " << DECODE_BUFFER_OVERFLOW_SIZE
+         << " bytes.\n";
+
+    cerr << "Error" << ": Assuming failure decoding data in "
+         << "context [O].\n";
+
+    HandleAbort();
+  }
+  else if (end_ - nextSrc_ < (int) numBytes)
+  {
+    #ifdef PANIC
+    *logofs << "DecodeBuffer: PANIC! Assertion failed. Error [P] "
+            << "in decodeMemory() " << "with length " << numBytes
+            << " and " << (end_ - nextSrc_)
+            << " bytes remaining.\n" << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Failure decoding data in context [P].\n";
+
+    HandleAbort();
+  }
+
+  nextSrc_ += numBytes;
+
+  return result;
+}
+
+void DecodeBuffer::decodeActionValue(unsigned char &value, unsigned short &position,
+                                         ActionCache &cache)
+{
+  unsigned int t;
+
+  decodeCachedValue(t, 15, *(cache.base_[cache.slot_]));
+
+  cache.last_ += t;
+  cache.last_ &= 0x7fff;
+
+  value = cache.last_ >> 13;
+
+  position = cache.last_ & 0x1fff;
+
+  #ifdef DEBUG
+  *logofs << "DecodeBuffer: Decoded value "
+          << (unsigned) value << " and position "
+          << position << " with base " << cache.slot_
+          << ".\n" << logofs_flush;
+  #endif
+
+  #ifdef DEBUG
+  *logofs << "DecodeBuffer: Action block prediction is "
+          << (*(cache.base_[cache.slot_])).getBlockSize(15)
+          << ".\n" << logofs_flush;
+  #endif
+
+  cache.slot_ = (cache.last_ & 0xff);
+}
+
+void DecodeBuffer::decodeNewXidValue(unsigned int &value, unsigned int &lastId,
+                                         IntCache &lastIdCache, IntCache &cache,
+                                             FreeCache &freeCache)
+{
+  decodeCachedValue(value, 29, lastIdCache);
+
+  lastId += (value + 1);
+  lastId &= 0x1fffffff;
+
+  value = lastId;
+
+  cache.push(value, 0x1fffffff);
+
+  freeCache.push(value, 0x1fffffff);
+}
+
+void DecodeBuffer::decodeNewXidValue(unsigned int &value, unsigned int &lastId,
+                                         IntCache &lastIdCache, XidCache &cache,
+                                             FreeCache &freeCache)
+{
+  decodeCachedValue(value, 29, lastIdCache);
+
+  #ifdef DEBUG
+  *logofs << "DecodeBuffer: Decoded new Xid difference "
+          << value << ".\n" << logofs_flush;
+  #endif
+
+  lastId += (value + 1);
+  lastId &= 0x1fffffff;
+
+  value = lastId;
+
+  unsigned int t = (value - cache.last_);
+
+  cache.last_ = value;
+
+  #ifdef DEBUG
+  *logofs << "DecodeBuffer: Decoded new Xid " << value
+          << " with base " << cache.slot_ << ".\n"
+          << logofs_flush;
+  #endif
+
+  cache.slot_ = (value & 0xff);
+
+  cache.base_[cache.slot_] -> push(t, 0x1fffffff);
+
+  freeCache.push(value, 0x1fffffff);
+}
+
+void DecodeBuffer::decodeXidValue(unsigned int &value, XidCache &cache)
+{
+  unsigned int t;
+
+  decodeCachedValue(t, 29, *(cache.base_[cache.slot_]));
+
+  cache.last_ += t;
+  cache.last_ &= 0x1fffffff;
+
+  value = cache.last_;
+
+  #ifdef DEBUG
+  *logofs << "DecodeBuffer: Decoded Xid " << value
+          << " with base " << cache.slot_ << ".\n"
+          << logofs_flush;
+  #endif
+
+  cache.slot_ = (value & 0xff);
+
+  #ifdef DEBUG
+  *logofs << "DecodeBuffer: Xid block prediction is "
+          << (*(cache.base_[cache.slot_])).getBlockSize(29)
+          << ".\n" << logofs_flush;
+  #endif
+}
+
+void DecodeBuffer::decodeFreeXidValue(unsigned int &value, FreeCache &cache)
+{
+  decodeCachedValue(value, 29, cache);
+}
+
+void DecodeBuffer::decodePositionValueCompat(short int &value, PositionCacheCompat &cache)
+{
+  unsigned int t;
+
+  decodeCachedValue(t, 13, *(cache.base_[cache.slot_]));
+
+  cache.last_ += t;
+  cache.last_ &= 0x1fff;
+
+  value = cache.last_;
+
+  #ifdef DEBUG
+  *logofs << "DecodeBuffer: Decoded position "
+          << value << " with base " << cache.slot_
+          << ".\n" << logofs_flush;
+  #endif
+
+  #ifdef DEBUG
+  *logofs << "DecodeBuffer: Position block prediction is "
+          << (*(cache.base_[cache.slot_])).getBlockSize(13)
+          << ".\n" << logofs_flush;
+  #endif
+
+  cache.slot_ = (value & 0x1f);
+}