rdr

18 files changed, 1579 insertions, 0 deletions

diff --git a/rdr/Exception.h b/rdr/Exception.h
new file mode 100644
index 0000000..49c59d9
--- /dev/null
+++ b/rdr/Exception.h
@@ -0,0 +1,71 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#ifndef __RDR_EXCEPTION_H__
+#define __RDR_EXCEPTION_H__
+
+#include <stdio.h>
+#include <string.h>
+
+namespace rdr {
+
+  struct Exception {
+    enum { len = 256 };
+    char str_[len];
+    Exception(const char* s=0, const char* e="rdr::Exception") {
+      str_[0] = 0;
+      strncat(str_, e, len-1);
+      if (s) {
+        strncat(str_, ": ", len-1-strlen(str_));
+        strncat(str_, s, len-1-strlen(str_));
+      }
+    }
+    virtual const char* str() const { return str_; }
+  };
+
+  struct SystemException : public Exception {
+    int err;
+    SystemException(const char* s, int err_) : err(err_) {
+      str_[0] = 0;
+      strncat(str_, "rdr::SystemException: ", len-1);
+      strncat(str_, s, len-1-strlen(str_));
+      strncat(str_, ": ", len-1-strlen(str_));
+      strncat(str_, strerror(err), len-1-strlen(str_));
+      strncat(str_, " (", len-1-strlen(str_));
+      char buf[20];
+      sprintf(buf,"%d",err);
+      strncat(str_, buf, len-1-strlen(str_));
+      strncat(str_, ")", len-1-strlen(str_));
+    }
+  }; 
+
+  struct TimedOut : public Exception {
+    TimedOut(const char* s=0) : Exception(s,"rdr::TimedOut") {}
+  };
+ 
+  struct EndOfStream : public Exception {
+    EndOfStream(const char* s=0) : Exception(s,"rdr::EndOfStream") {}
+  };
+
+  struct FrameException : public Exception {
+    FrameException(const char* s=0) : Exception(s,"rdr::FrameException") {}
+  };
+
+}
+
+#endif
diff --git a/rdr/FdInStream.cxx b/rdr/FdInStream.cxx
new file mode 100644
index 0000000..b5c4984
--- /dev/null
+++ b/rdr/FdInStream.cxx
@@ -0,0 +1,247 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#ifdef _WIN32
+#include <winsock.h>
+#include <sys/timeb.h>
+#define read(s,b,l) recv(s,(char*)b,l,0)
+#undef errno
+#define errno WSAGetLastError()
+#else
+#include <unistd.h>
+#include <sys/time.h>
+#endif
+
+// XXX should use autoconf HAVE_SYS_SELECT_H
+#ifdef _AIX
+#include <sys/select.h>
+#endif
+
+#include <rdr/FdInStream.h>
+#include <rdr/Exception.h>
+
+using namespace rdr;
+
+enum { DEFAULT_BUF_SIZE = 8192,
+       MIN_BULK_SIZE = 1024 };
+
+FdInStream::FdInStream(int fd_, int timeout_, int bufSize_)
+  : fd(fd_), timeout(timeout_), blockCallback(0), blockCallbackArg(0),
+    timing(false), timeWaitedIn100us(5), timedKbits(0),
+    bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0)
+{
+  ptr = end = start = new U8[bufSize];
+}
+
+FdInStream::FdInStream(int fd_, void (*blockCallback_)(void*),
+                       void* blockCallbackArg_, int bufSize_)
+  : fd(fd_), timeout(0), blockCallback(blockCallback_),
+    blockCallbackArg(blockCallbackArg_),
+    timing(false), timeWaitedIn100us(5), timedKbits(0),
+    bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0)
+{
+  ptr = end = start = new U8[bufSize];
+}
+
+FdInStream::~FdInStream()
+{
+  delete [] start;
+}
+
+
+int FdInStream::pos()
+{
+  return offset + ptr - start;
+}
+
+void FdInStream::readBytes(void* data, int length)
+{
+  if (length < MIN_BULK_SIZE) {
+    InStream::readBytes(data, length);
+    return;
+  }
+
+  U8* dataPtr = (U8*)data;
+
+  int n = end - ptr;
+  if (n > length) n = length;
+
+  memcpy(dataPtr, ptr, n);
+  dataPtr += n;
+  length -= n;
+  ptr += n;
+
+  while (length > 0) {
+    n = readWithTimeoutOrCallback(dataPtr, length);
+    dataPtr += n;
+    length -= n;
+    offset += n;
+  }
+}
+
+
+int FdInStream::overrun(int itemSize, int nItems)
+{
+  if (itemSize > bufSize)
+    throw Exception("FdInStream overrun: max itemSize exceeded");
+
+  if (end - ptr != 0)
+    memmove(start, ptr, end - ptr);
+
+  offset += ptr - start;
+  end -= ptr - start;
+  ptr = start;
+
+  while (end < start + itemSize) {
+    int n = readWithTimeoutOrCallback((U8*)end, start + bufSize - end);
+    end += n;
+  }
+
+  if (itemSize * nItems > end - ptr)
+    nItems = (end - ptr) / itemSize;
+
+  return nItems;
+}
+
+int FdInStream::checkReadable(int fd, int timeout)
+{
+  while (true) {
+    fd_set rfds;
+    struct timeval tv;
+    
+    tv.tv_sec = timeout / 1000;
+    tv.tv_usec = (timeout % 1000) * 1000;
+
+    FD_ZERO(&rfds);
+    FD_SET(fd, &rfds);
+    int n = select(fd+1, &rfds, 0, 0, &tv);
+    if (n != -1 || errno != EINTR)
+      return n;
+    fprintf(stderr,"select returned EINTR\n");
+  }
+}
+
+#ifdef _WIN32
+static void gettimeofday(struct timeval* tv, void*)
+{
+  LARGE_INTEGER counts, countsPerSec;
+  static double usecPerCount = 0.0;
+
+  if (QueryPerformanceCounter(&counts)) {
+    if (usecPerCount == 0.0) {
+      QueryPerformanceFrequency(&countsPerSec);
+      usecPerCount = 1000000.0 / countsPerSec.QuadPart;
+    }
+
+    LONGLONG usecs = (LONGLONG)(counts.QuadPart * usecPerCount);
+    tv->tv_usec = (long)(usecs % 1000000);
+    tv->tv_sec = (long)(usecs / 1000000);
+
+  } else {
+    struct timeb tb;
+    ftime(&tb);
+    tv->tv_sec = tb.time;
+    tv->tv_usec = tb.millitm * 1000;
+  }
+}
+#endif
+
+int FdInStream::readWithTimeoutOrCallback(void* buf, int len)
+{
+  struct timeval before, after;
+  if (timing)
+    gettimeofday(&before, 0);
+
+  int n = checkReadable(fd, timeout);
+
+  if (n < 0) throw SystemException("select",errno);
+
+  if (n == 0) {
+    if (timeout) throw TimedOut();
+    if (blockCallback) (*blockCallback)(blockCallbackArg);
+  }
+
+  while (true) {
+    n = ::read(fd, buf, len);
+    if (n != -1 || errno != EINTR)
+      break;
+    fprintf(stderr,"read returned EINTR\n");
+  }
+
+  if (n < 0) throw SystemException("read",errno);
+  if (n == 0) throw EndOfStream();
+
+  if (timing) {
+    gettimeofday(&after, 0);
+//      fprintf(stderr,"%d.%06d\n",(after.tv_sec - before.tv_sec),
+//              (after.tv_usec - before.tv_usec));
+    int newTimeWaited = ((after.tv_sec - before.tv_sec) * 10000 +
+                         (after.tv_usec - before.tv_usec) / 100);
+    int newKbits = n * 8 / 1000;
+
+//      if (newTimeWaited == 0) {
+//        fprintf(stderr,"new kbps infinite t %d k %d\n",
+//                newTimeWaited, newKbits);
+//      } else {
+//        fprintf(stderr,"new kbps %d t %d k %d\n",
+//                newKbits * 10000 / newTimeWaited, newTimeWaited, newKbits);
+//      }
+
+    // limit rate to between 10kbit/s and 40Mbit/s
+
+    if (newTimeWaited > newKbits*1000) newTimeWaited = newKbits*1000;
+    if (newTimeWaited < newKbits/4)    newTimeWaited = newKbits/4;
+
+    timeWaitedIn100us += newTimeWaited;
+    timedKbits += newKbits;
+  }
+
+  return n;
+}
+
+void FdInStream::startTiming()
+{
+  timing = true;
+
+  // Carry over up to 1s worth of previous rate for smoothing.
+
+  if (timeWaitedIn100us > 10000) {
+    timedKbits = timedKbits * 10000 / timeWaitedIn100us;
+    timeWaitedIn100us = 10000;
+  }
+}
+
+void FdInStream::stopTiming()
+{
+  timing = false; 
+  if (timeWaitedIn100us < timedKbits/2)
+    timeWaitedIn100us = timedKbits/2; // upper limit 20Mbit/s
+}
+
+unsigned int FdInStream::kbitsPerSecond()
+{
+  // The following calculation will overflow 32-bit arithmetic if we have
+  // received more than about 50Mbytes (400Mbits) since we started timing, so
+  // it should be OK for a single RFB update.
+
+  return timedKbits * 10000 / timeWaitedIn100us;
+}
diff --git a/rdr/FdInStream.h b/rdr/FdInStream.h
new file mode 100644
index 0000000..5a1ed43
--- /dev/null
+++ b/rdr/FdInStream.h
@@ -0,0 +1,72 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+//
+// FdInStream streams from a file descriptor.
+//
+
+#ifndef __RDR_FDINSTREAM_H__
+#define __RDR_FDINSTREAM_H__
+
+#include <rdr/InStream.h>
+
+namespace rdr {
+
+  class FdInStream : public InStream {
+
+  public:
+
+    FdInStream(int fd, int timeout=0, int bufSize=0);
+    FdInStream(int fd, void (*blockCallback)(void*), void* blockCallbackArg=0,
+		  int bufSize=0);
+    virtual ~FdInStream();
+
+    int getFd() { return fd; }
+    int pos();
+    void readBytes(void* data, int length);
+    int bytesInBuf() { return end - ptr; }
+
+    void startTiming();
+    void stopTiming();
+    unsigned int kbitsPerSecond();
+    unsigned int timeWaited() { return timeWaitedIn100us; }
+
+  protected:
+    int overrun(int itemSize, int nItems);
+
+  private:
+    int checkReadable(int fd, int timeout);
+    int readWithTimeoutOrCallback(void* buf, int len);
+
+    int fd;
+    int timeout;
+    void (*blockCallback)(void*);
+    void* blockCallbackArg;
+
+    bool timing;
+    unsigned int timeWaitedIn100us;
+    unsigned int timedKbits;
+
+    int bufSize;
+    int offset;
+    U8* start;
+  };
+
+} // end of namespace rdr
+
+#endif
diff --git a/rdr/FdOutStream.cxx b/rdr/FdOutStream.cxx
new file mode 100644
index 0000000..40e7ac0
--- /dev/null
+++ b/rdr/FdOutStream.cxx
@@ -0,0 +1,113 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#ifdef _WIN32
+#include <winsock.h>
+#define write(s,b,l) send(s,(const char*)b,l,0)
+#undef errno
+#define errno WSAGetLastError()
+#else
+#include <unistd.h>
+#include <sys/time.h>
+#endif
+
+#include <rdr/FdOutStream.h>
+#include <rdr/Exception.h>
+
+
+using namespace rdr;
+
+enum { DEFAULT_BUF_SIZE = 16384,
+       MIN_BULK_SIZE = 1024 };
+
+FdOutStream::FdOutStream(int fd_, int bufSize_)
+  : fd(fd_), bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0)
+{
+  ptr = start = new U8[bufSize];
+  end = start + bufSize;
+}
+
+FdOutStream::~FdOutStream()
+{
+  try {
+    flush();
+  } catch (Exception&) {
+  }
+  delete [] start;
+}
+
+
+void FdOutStream::writeBytes(const void* data, int length)
+{
+  if (length < MIN_BULK_SIZE) {
+    OutStream::writeBytes(data, length);
+    return;
+  }
+
+  const U8* dataPtr = (const U8*)data;
+
+  flush();
+
+  while (length > 0) {
+    int n = write(fd, dataPtr, length);
+
+    if (n < 0) throw SystemException("write",errno);
+
+    length -= n;
+    dataPtr += n;
+    offset += n;
+  }
+}
+
+int FdOutStream::length()
+{
+  return offset + ptr - start;
+}
+
+void FdOutStream::flush()
+{
+  U8* sentUpTo = start;
+  while (sentUpTo < ptr) {
+    int n = write(fd, (const void*) sentUpTo, ptr - sentUpTo);
+
+    if (n < 0) throw SystemException("write",errno);
+
+    sentUpTo += n;
+    offset += n;
+  }
+
+  ptr = start;
+}
+
+
+int FdOutStream::overrun(int itemSize, int nItems)
+{
+  if (itemSize > bufSize)
+    throw Exception("FdOutStream overrun: max itemSize exceeded");
+
+  flush();
+
+  if (itemSize * nItems > end - ptr)
+    nItems = (end - ptr) / itemSize;
+
+  return nItems;
+}
diff --git a/rdr/FdOutStream.h b/rdr/FdOutStream.h
new file mode 100644
index 0000000..e338852
--- /dev/null
+++ b/rdr/FdOutStream.h
@@ -0,0 +1,53 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+//
+// FdOutStream streams to a file descriptor.
+//
+
+#ifndef __RDR_FDOUTSTREAM_H__
+#define __RDR_FDOUTSTREAM_H__
+
+#include <rdr/OutStream.h>
+
+namespace rdr {
+
+  class FdOutStream : public OutStream {
+
+  public:
+
+    FdOutStream(int fd, int bufSize=0);
+    virtual ~FdOutStream();
+
+    int getFd() { return fd; }
+
+    void flush();
+    int length();
+    void writeBytes(const void* data, int length);
+
+  private:
+    int overrun(int itemSize, int nItems);
+    int fd;
+    int bufSize;
+    int offset;
+    U8* start;
+  };
+
+}
+
+#endif
diff --git a/rdr/FixedMemOutStream.h b/rdr/FixedMemOutStream.h
new file mode 100644
index 0000000..5503505
--- /dev/null
+++ b/rdr/FixedMemOutStream.h
@@ -0,0 +1,52 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+//
+// A FixedMemOutStream writes to a buffer of a fixed length.
+//
+
+#ifndef __RDR_FIXEDMEMOUTSTREAM_H__
+#define __RDR_FIXEDMEMOUTSTREAM_H__
+
+#include <rdr/OutStream.h>
+#include <rdr/Exception.h>
+
+namespace rdr {
+
+  class FixedMemOutStream : public OutStream {
+
+  public:
+
+    FixedMemOutStream(void* buf, int len) {
+      ptr = start = (U8*)buf;
+      end = start + len;
+    }
+
+    int length() { return ptr - start; }
+    void reposition(int pos) { ptr = start + pos; }
+    const void* data() { return (const void*)start; }
+
+  private:
+
+    int overrun(int itemSize, int nItems) { throw EndOfStream(); }
+    U8* start;
+  };
+
+}
+
+#endif
diff --git a/rdr/InStream.cxx b/rdr/InStream.cxx
new file mode 100644
index 0000000..b5bf509
--- /dev/null
+++ b/rdr/InStream.cxx
@@ -0,0 +1,35 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#include <rdr/InStream.h>
+#include <rdr/Exception.h>
+
+using namespace rdr;
+
+U32 InStream::maxStringLength = 65535;
+
+char* InStream::readString()
+{
+  U32 len = readU32();
+  if (len > maxStringLength)
+    throw Exception("InStream max string length exceeded");
+  char* str = new char[len+1];
+  readBytes(str, len);
+  str[len] = 0;
+  return str;
+}
diff --git a/rdr/InStream.h b/rdr/InStream.h
new file mode 100644
index 0000000..2e2159e
--- /dev/null
+++ b/rdr/InStream.h
@@ -0,0 +1,143 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+//
+// rdr::InStream marshalls data from a buffer stored in RDR (RFB Data
+// Representation).
+//
+
+#ifndef __RDR_INSTREAM_H__
+#define __RDR_INSTREAM_H__
+
+#include <rdr/types.h>
+#include <string.h> // for memcpy
+
+namespace rdr {
+
+  class InStream {
+
+  public:
+
+    virtual ~InStream() {}
+
+    // check() ensures there is buffer data for at least one item of size
+    // itemSize bytes.  Returns the number of items in the buffer (up to a
+    // maximum of nItems).
+
+    inline int check(int itemSize, int nItems=1)
+    {
+      if (ptr + itemSize * nItems > end) {
+        if (ptr + itemSize > end)
+          return overrun(itemSize, nItems);
+
+        nItems = (end - ptr) / itemSize;
+      }
+      return nItems;
+    }
+
+    // readU/SN() methods read unsigned and signed N-bit integers.
+
+    inline U8  readU8()  { check(1); return *ptr++; }
+    inline U16 readU16() { check(2); int b0 = *ptr++; int b1 = *ptr++;
+                           return b0 << 8 | b1; }
+    inline U32 readU32() { check(4); int b0 = *ptr++; int b1 = *ptr++;
+                                     int b2 = *ptr++; int b3 = *ptr++;
+                           return b0 << 24 | b1 << 16 | b2 << 8 | b3; }
+
+    inline S8  readS8()  { return (S8) readU8();  }
+    inline S16 readS16() { return (S16)readU16(); }
+    inline S32 readS32() { return (S32)readU32(); }
+
+    // readString() reads a string - a U32 length followed by the data.
+    // Returns a null-terminated string - the caller should delete[] it
+    // afterwards.
+
+    char* readString();
+
+    // maxStringLength protects against allocating a huge buffer.  Set it
+    // higher if you need longer strings.
+
+    static U32 maxStringLength;
+
+    inline void skip(int bytes) {
+      while (bytes > 0) {
+        int n = check(1, bytes);
+        ptr += n;
+        bytes -= n;
+      }
+    }
+
+    // readBytes() reads an exact number of bytes.
+
+    virtual void readBytes(void* data, int length) {
+      U8* dataPtr = (U8*)data;
+      U8* dataEnd = dataPtr + length;
+      while (dataPtr < dataEnd) {
+        int n = check(1, dataEnd - dataPtr);
+        memcpy(dataPtr, ptr, n);
+        ptr += n;
+        dataPtr += n;
+      }
+    }
+
+    // readOpaqueN() reads a quantity without byte-swapping.
+
+    inline U8  readOpaque8()  { return readU8(); }
+    inline U16 readOpaque16() { check(2); U16 r; ((U8*)&r)[0] = *ptr++;
+                                ((U8*)&r)[1] = *ptr++; return r; }
+    inline U32 readOpaque32() { check(4); U32 r; ((U8*)&r)[0] = *ptr++;
+                                ((U8*)&r)[1] = *ptr++; ((U8*)&r)[2] = *ptr++;
+                                ((U8*)&r)[3] = *ptr++; return r; }
+    inline U32 readOpaque24A() { check(3); U32 r=0; ((U8*)&r)[0] = *ptr++;
+                                 ((U8*)&r)[1] = *ptr++; ((U8*)&r)[2] = *ptr++;
+                                 return r; }
+    inline U32 readOpaque24B() { check(3); U32 r=0; ((U8*)&r)[1] = *ptr++;
+                                 ((U8*)&r)[2] = *ptr++; ((U8*)&r)[3] = *ptr++;
+                                 return r; }
+
+    // pos() returns the position in the stream.
+
+    virtual int pos() = 0;
+
+    // getptr(), getend() and setptr() are "dirty" methods which allow you to
+    // manipulate the buffer directly.  This is useful for a stream which is a
+    // wrapper around an underlying stream.
+
+    inline const U8* getptr() const { return ptr; }
+    inline const U8* getend() const { return end; }
+    inline void setptr(const U8* p) { ptr = p; }
+
+  private:
+
+    // overrun() is implemented by a derived class to cope with buffer overrun.
+    // It ensures there are at least itemSize bytes of buffer data.  Returns
+    // the number of items in the buffer (up to a maximum of nItems).  itemSize
+    // is supposed to be "small" (a few bytes).
+
+    virtual int overrun(int itemSize, int nItems) = 0;
+
+  protected:
+
+    InStream() {}
+    const U8* ptr;
+    const U8* end;
+  };
+
+}
+
+#endif
diff --git a/rdr/MemInStream.h b/rdr/MemInStream.h
new file mode 100644
index 0000000..0167949
--- /dev/null
+++ b/rdr/MemInStream.h
@@ -0,0 +1,47 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#ifndef __RDR_MEMINSTREAM_H__
+#define __RDR_MEMINSTREAM_H__
+
+#include <rdr/InStream.h>
+#include <rdr/Exception.h>
+
+namespace rdr {
+
+  class MemInStream : public InStream {
+
+  public:
+
+    MemInStream(const void* data, int len) {
+      ptr = start = (const U8*)data;
+      end = start + len;
+    }
+
+    int pos() { return ptr - start; }
+    void reposition(int pos) { ptr = start + pos; }
+
+  private:
+
+    int overrun(int itemSize, int nItems) { throw EndOfStream(); }
+    const U8* start;
+  };
+
+}
+
+#endif
diff --git a/rdr/MemOutStream.h b/rdr/MemOutStream.h
new file mode 100644
index 0000000..0031388
--- /dev/null
+++ b/rdr/MemOutStream.h
@@ -0,0 +1,82 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+//
+// A MemOutStream grows as needed when data is written to it.
+//
+
+#ifndef __RDR_MEMOUTSTREAM_H__
+#define __RDR_MEMOUTSTREAM_H__
+
+#include <rdr/OutStream.h>
+
+namespace rdr {
+
+  class MemOutStream : public OutStream {
+
+  public:
+
+    MemOutStream(int len=1024) {
+      start = ptr = new U8[len];
+      end = start + len;
+    }
+
+    virtual ~MemOutStream() {
+      delete [] start;
+    }
+
+    void writeBytes(const void* data, int length) {
+      check(length);
+      memcpy(ptr, data, length);
+      ptr += length;
+    }
+
+    int length() { return ptr - start; }
+    void clear() { ptr = start; };
+    void reposition(int pos) { ptr = start + pos; }
+
+    // data() returns a pointer to the buffer.
+
+    const void* data() { return (const void*)start; }
+
+  private:
+
+    // overrun() either doubles the buffer or adds enough space for nItems of
+    // size itemSize bytes.
+
+    int overrun(int itemSize, int nItems) {
+      int len = ptr - start + itemSize * nItems;
+      if (len < (end - start) * 2)
+        len = (end - start) * 2;
+
+      U8* newStart = new U8[len];
+      memcpy(newStart, start, ptr - start);
+      ptr = newStart + (ptr - start);
+      delete [] start;
+      start = newStart;
+      end = newStart + len;
+
+      return nItems;
+    }
+
+    U8* start;
+  };
+
+}
+
+#endif
diff --git a/rdr/NullOutStream.cxx b/rdr/NullOutStream.cxx
new file mode 100644
index 0000000..aae999d
--- /dev/null
+++ b/rdr/NullOutStream.cxx
@@ -0,0 +1,60 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#include <rdr/NullOutStream.h>
+#include <rdr/Exception.h>
+
+using namespace rdr;
+
+static const int bufferSize = 1024;
+
+NullOutStream::NullOutStream()
+  : offset(0)
+{
+  start = ptr = new U8[bufferSize];
+  end = start + bufferSize;
+}
+
+NullOutStream::~NullOutStream()
+{
+  delete [] start;
+}
+
+int NullOutStream::length()
+{
+  return offset + ptr - start;
+}
+
+void NullOutStream::writeBytes(const void* data, int length)
+{
+  offset += length;
+}
+
+int NullOutStream::overrun(int itemSize, int nItems)
+{
+  if (itemSize > bufferSize)
+    throw Exception("NullOutStream overrun: max itemSize exceeded");
+
+  offset += ptr - start;
+  ptr = start;
+
+  if (itemSize * nItems > end - ptr)
+    nItems = (end - ptr) / itemSize;
+
+  return nItems;
+}
diff --git a/rdr/NullOutStream.h b/rdr/NullOutStream.h
new file mode 100644
index 0000000..15c588b
--- /dev/null
+++ b/rdr/NullOutStream.h
@@ -0,0 +1,42 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#ifndef __RDR_NULLOUTSTREAM_H__
+#define __RDR_NULLOUTSTREAM_H__
+
+#include <rdr/OutStream.h>
+
+namespace rdr {
+
+  class NullOutStream : public OutStream {
+
+  public:
+    NullOutStream();
+    virtual ~NullOutStream();
+    int length();
+    void writeBytes(const void* data, int length);
+
+  private:
+    int overrun(int itemSize, int nItems);
+    int offset;
+    U8* start;
+  };
+
+}
+
+#endif
diff --git a/rdr/OutStream.h b/rdr/OutStream.h
new file mode 100644
index 0000000..9aae80c
--- /dev/null
+++ b/rdr/OutStream.h
@@ -0,0 +1,152 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+//
+// rdr::OutStream marshalls data into a buffer stored in RDR (RFB Data
+// Representation).
+//
+
+#ifndef __RDR_OUTSTREAM_H__
+#define __RDR_OUTSTREAM_H__
+
+#include <rdr/types.h>
+#include <string.h> // for memcpy
+
+namespace rdr {
+
+  class OutStream {
+
+  protected:
+
+    OutStream() {}
+
+  public:
+
+    virtual ~OutStream() {}
+
+    // check() ensures there is buffer space for at least one item of size
+    // itemSize bytes.  Returns the number of items which fit (up to a maximum
+    // of nItems).
+
+    inline int check(int itemSize, int nItems=1)
+    {
+      if (ptr + itemSize * nItems > end) {
+        if (ptr + itemSize > end)
+          return overrun(itemSize, nItems);
+
+        nItems = (end - ptr) / itemSize;
+      }
+      return nItems;
+    }
+
+    // writeU/SN() methods write unsigned and signed N-bit integers.
+
+    inline void writeU8( U8  u) { check(1); *ptr++ = u; }
+    inline void writeU16(U16 u) { check(2); *ptr++ = u >> 8; *ptr++ = (U8)u; }
+    inline void writeU32(U32 u) { check(4); *ptr++ = u >> 24; *ptr++ = u >> 16;
+                                            *ptr++ = u >> 8; *ptr++ = u; }
+
+    inline void writeS8( S8  s) { writeU8((U8)s); }
+    inline void writeS16(S16 s) { writeU16((U16)s); }
+    inline void writeS32(S32 s) { writeU32((U32)s); }
+
+    // writeString() writes a string - a U32 length followed by the data.  The
+    // given string should be null-terminated (but the terminating null is not
+    // written to the stream).
+
+    inline void writeString(const char* str) {
+      U32 len = strlen(str);
+      writeU32(len);
+      writeBytes(str, len);
+    }
+
+    inline void pad(int bytes) {
+      while (bytes-- > 0) writeU8(0);
+    }
+
+    inline void skip(int bytes) {
+      while (bytes > 0) {
+        int n = check(1, bytes);
+        ptr += n;
+        bytes -= n;
+      }
+    }
+
+    // writeBytes() writes an exact number of bytes.
+
+    virtual void writeBytes(const void* data, int length) {
+      const U8* dataPtr = (const U8*)data;
+      const U8* dataEnd = dataPtr + length;
+      while (dataPtr < dataEnd) {
+        int n = check(1, dataEnd - dataPtr);
+        memcpy(ptr, dataPtr, n);
+        ptr += n;
+        dataPtr += n;
+      }
+    }
+
+    // writeOpaqueN() writes a quantity without byte-swapping.
+
+    inline void writeOpaque8( U8  u) { writeU8(u); }
+    inline void writeOpaque16(U16 u) { check(2); *ptr++ = ((U8*)&u)[0];
+                                       *ptr++ = ((U8*)&u)[1]; }
+    inline void writeOpaque32(U32 u) { check(4); *ptr++ = ((U8*)&u)[0];
+                                       *ptr++ = ((U8*)&u)[1];
+                                       *ptr++ = ((U8*)&u)[2];
+                                       *ptr++ = ((U8*)&u)[3]; }
+    inline void writeOpaque24A(U32 u) { check(3); *ptr++ = ((U8*)&u)[0];
+                                        *ptr++ = ((U8*)&u)[1];
+                                        *ptr++ = ((U8*)&u)[2]; }
+    inline void writeOpaque24B(U32 u) { check(3); *ptr++ = ((U8*)&u)[1];
+                                        *ptr++ = ((U8*)&u)[2];
+                                        *ptr++ = ((U8*)&u)[3]; }
+
+    // length() returns the length of the stream.
+
+    virtual int length() = 0;
+
+    // flush() requests that the stream be flushed.
+
+    virtual void flush() {}
+
+    // getptr(), getend() and setptr() are "dirty" methods which allow you to
+    // manipulate the buffer directly.  This is useful for a stream which is a
+    // wrapper around an underlying stream.
+
+    inline U8* getptr() { return ptr; }
+    inline U8* getend() { return end; }
+    inline void setptr(U8* p) { ptr = p; }
+
+  private:
+
+    // overrun() is implemented by a derived class to cope with buffer overrun.
+    // It ensures there are at least itemSize bytes of buffer space.  Returns
+    // the number of items which fit (up to a maximum of nItems).  itemSize is
+    // supposed to be "small" (a few bytes).
+
+    virtual int overrun(int itemSize, int nItems) = 0;
+
+  protected:
+
+    U8* ptr;
+    U8* end;
+  };
+
+}
+
+#endif
diff --git a/rdr/ZlibInStream.cxx b/rdr/ZlibInStream.cxx
new file mode 100644
index 0000000..d4d1f1f
--- /dev/null
+++ b/rdr/ZlibInStream.cxx
@@ -0,0 +1,121 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#include <rdr/ZlibInStream.h>
+#include <rdr/Exception.h>
+#include <zlib.h>
+
+using namespace rdr;
+
+enum { DEFAULT_BUF_SIZE = 16384 };
+
+ZlibInStream::ZlibInStream(int bufSize_)
+  : underlying(0), bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0),
+    bytesIn(0)
+{
+  zs = new z_stream;
+  zs->zalloc    = Z_NULL;
+  zs->zfree     = Z_NULL;
+  zs->opaque    = Z_NULL;
+  zs->next_in   = Z_NULL;
+  zs->avail_in  = 0;
+  if (inflateInit(zs) != Z_OK) {
+    delete zs;
+    throw Exception("ZlibInStream: inflateInit failed");
+  }
+  ptr = end = start = new U8[bufSize];
+}
+
+ZlibInStream::~ZlibInStream()
+{
+  delete [] start;
+  inflateEnd(zs);
+  delete zs;
+}
+
+void ZlibInStream::setUnderlying(InStream* is, int bytesIn_)
+{
+  underlying = is;
+  bytesIn = bytesIn_;
+  ptr = end = start;
+}
+
+int ZlibInStream::pos()
+{
+  return offset + ptr - start;
+}
+
+void ZlibInStream::reset()
+{
+  ptr = end = start;
+  if (!underlying) return;
+
+  while (bytesIn > 0) {
+    decompress();
+    end = start; // throw away any data
+  }
+  underlying = 0;
+}
+
+int ZlibInStream::overrun(int itemSize, int nItems)
+{
+  if (itemSize > bufSize)
+    throw Exception("ZlibInStream overrun: max itemSize exceeded");
+  if (!underlying)
+    throw Exception("ZlibInStream overrun: no underlying stream");
+
+  if (end - ptr != 0)
+    memmove(start, ptr, end - ptr);
+
+  offset += ptr - start;
+  end -= ptr - start;
+  ptr = start;
+
+  while (end - ptr < itemSize) {
+    decompress();
+  }
+
+  if (itemSize * nItems > end - ptr)
+    nItems = (end - ptr) / itemSize;
+
+  return nItems;
+}
+
+// decompress() calls the decompressor once.  Note that this won't necessarily
+// generate any output data - it may just consume some input data.
+
+void ZlibInStream::decompress()
+{
+  zs->next_out = (U8*)end;
+  zs->avail_out = start + bufSize - end;
+
+  underlying->check(1);
+  zs->next_in = (U8*)underlying->getptr();
+  zs->avail_in = underlying->getend() - underlying->getptr();
+  if ((int)zs->avail_in > bytesIn)
+    zs->avail_in = bytesIn;
+
+  int rc = inflate(zs, Z_SYNC_FLUSH);
+  if (rc != Z_OK) {
+    throw Exception("ZlibInStream: inflate failed");
+  }
+
+  bytesIn -= zs->next_in - underlying->getptr();
+  end = zs->next_out;
+  underlying->setptr(zs->next_in);
+}
diff --git a/rdr/ZlibInStream.h b/rdr/ZlibInStream.h
new file mode 100644
index 0000000..14ad6f0
--- /dev/null
+++ b/rdr/ZlibInStream.h
@@ -0,0 +1,59 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+//
+// ZlibInStream streams from a compressed data stream ("underlying"),
+// decompressing with zlib on the fly.
+//
+
+#ifndef __RDR_ZLIBINSTREAM_H__
+#define __RDR_ZLIBINSTREAM_H__
+
+#include <rdr/InStream.h>
+
+struct z_stream_s;
+
+namespace rdr {
+
+  class ZlibInStream : public InStream {
+
+  public:
+
+    ZlibInStream(int bufSize=0);
+    virtual ~ZlibInStream();
+
+    void setUnderlying(InStream* is, int bytesIn);
+    void reset();
+    int pos();
+
+  private:
+
+    int overrun(int itemSize, int nItems);
+    void decompress();
+
+    InStream* underlying;
+    int bufSize;
+    int offset;
+    z_stream_s* zs;
+    int bytesIn;
+    U8* start;
+  };
+
+} // end of namespace rdr
+
+#endif
diff --git a/rdr/ZlibOutStream.cxx b/rdr/ZlibOutStream.cxx
new file mode 100644
index 0000000..c3a0ca2
--- /dev/null
+++ b/rdr/ZlibOutStream.cxx
@@ -0,0 +1,140 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#include <rdr/ZlibOutStream.h>
+#include <rdr/Exception.h>
+#include <zlib.h>
+
+using namespace rdr;
+
+enum { DEFAULT_BUF_SIZE = 16384 };
+
+ZlibOutStream::ZlibOutStream(OutStream* os, int bufSize_)
+  : underlying(os), bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0)
+{
+  zs = new z_stream;
+  zs->zalloc    = Z_NULL;
+  zs->zfree     = Z_NULL;
+  zs->opaque    = Z_NULL;
+  if (deflateInit(zs, Z_DEFAULT_COMPRESSION) != Z_OK) {
+    delete zs;
+    throw Exception("ZlibOutStream: deflateInit failed");
+  }
+  ptr = start = new U8[bufSize];
+  end = start + bufSize;
+}
+
+ZlibOutStream::~ZlibOutStream()
+{
+  try {
+    flush();
+  } catch (Exception&) {
+  }
+  delete [] start;
+  deflateEnd(zs);
+  delete zs;
+}
+
+void ZlibOutStream::setUnderlying(OutStream* os)
+{
+  underlying = os;
+}
+
+int ZlibOutStream::length()
+{
+  return offset + ptr - start;
+}
+
+void ZlibOutStream::flush()
+{
+  zs->next_in = start;
+  zs->avail_in = ptr - start;
+
+//    fprintf(stderr,"zos flush: avail_in %d\n",zs->avail_in);
+
+  while (zs->avail_in != 0) {
+
+    do {
+      underlying->check(1);
+      zs->next_out = underlying->getptr();
+      zs->avail_out = underlying->getend() - underlying->getptr();
+
+//        fprintf(stderr,"zos flush: calling deflate, avail_in %d, avail_out %d\n",
+//                zs->avail_in,zs->avail_out);
+      int rc = deflate(zs, Z_SYNC_FLUSH);
+      if (rc != Z_OK) throw Exception("ZlibOutStream: deflate failed");
+
+//        fprintf(stderr,"zos flush: after deflate: %d bytes\n",
+//                zs->next_out-underlying->getptr());
+
+      underlying->setptr(zs->next_out);
+    } while (zs->avail_out == 0);
+  }
+
+  offset += ptr - start;
+  ptr = start;
+}
+
+int ZlibOutStream::overrun(int itemSize, int nItems)
+{
+//    fprintf(stderr,"ZlibOutStream overrun\n");
+
+  if (itemSize > bufSize)
+    throw Exception("ZlibOutStream overrun: max itemSize exceeded");
+
+  while (end - ptr < itemSize) {
+    zs->next_in = start;
+    zs->avail_in = ptr - start;
+
+    do {
+      underlying->check(1);
+      zs->next_out = underlying->getptr();
+      zs->avail_out = underlying->getend() - underlying->getptr();
+
+//        fprintf(stderr,"zos overrun: calling deflate, avail_in %d, avail_out %d\n",
+//                zs->avail_in,zs->avail_out);
+
+      int rc = deflate(zs, 0);
+      if (rc != Z_OK) throw Exception("ZlibOutStream: deflate failed");
+
+//        fprintf(stderr,"zos overrun: after deflate: %d bytes\n",
+//                zs->next_out-underlying->getptr());
+
+      underlying->setptr(zs->next_out);
+    } while (zs->avail_out == 0);
+
+    // output buffer not full
+
+    if (zs->avail_in == 0) {
+      offset += ptr - start;
+      ptr = start;
+    } else {
+      // but didn't consume all the data?  try shifting what's left to the
+      // start of the buffer.
+      fprintf(stderr,"z out buf not full, but in data not consumed\n");
+      memmove(start, zs->next_in, ptr - zs->next_in);
+      offset += zs->next_in - start;
+      ptr -= zs->next_in - start;
+    }
+  }
+
+  if (itemSize * nItems > end - ptr)
+    nItems = (end - ptr) / itemSize;
+
+  return nItems;
+}
diff --git a/rdr/ZlibOutStream.h b/rdr/ZlibOutStream.h
new file mode 100644
index 0000000..72f5239
--- /dev/null
+++ b/rdr/ZlibOutStream.h
@@ -0,0 +1,57 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+//
+// ZlibOutStream streams to a compressed data stream (underlying), compressing
+// with zlib on the fly.
+//
+
+#ifndef __RDR_ZLIBOUTSTREAM_H__
+#define __RDR_ZLIBOUTSTREAM_H__
+
+#include <rdr/OutStream.h>
+
+struct z_stream_s;
+
+namespace rdr {
+
+  class ZlibOutStream : public OutStream {
+
+  public:
+
+    ZlibOutStream(OutStream* os=0, int bufSize=0);
+    virtual ~ZlibOutStream();
+
+    void setUnderlying(OutStream* os);
+    void flush();
+    int length();
+
+  private:
+
+    int overrun(int itemSize, int nItems);
+
+    OutStream* underlying;
+    int bufSize;
+    int offset;
+    z_stream_s* zs;
+    U8* start;
+  };
+
+} // end of namespace rdr
+
+#endif
diff --git a/rdr/types.h b/rdr/types.h
new file mode 100644
index 0000000..00b5c40
--- /dev/null
+++ b/rdr/types.h
@@ -0,0 +1,33 @@
+//
+// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this software; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+// USA.
+
+#ifndef __RDR_TYPES_H__
+#define __RDR_TYPES_H__
+
+namespace rdr {
+
+  typedef unsigned char U8;
+  typedef unsigned short U16;
+  typedef unsigned int U32;
+  typedef signed char S8;
+  typedef signed short S16;
+  typedef signed int S32;
+
+} // end of namespace rdr
+
+#endif