[Nsclspectcl-cvscommits] SpecTcl/Filter CXdrInputStream.cpp,NONE,1.1 CXdrInputStream.h,NONE,1.1

[<ro...@us...>]

Update of /cvsroot/nsclspectcl/SpecTcl/Filter
In directory sc8-pr-cvs1:/tmp/cvs-serv2756

Added Files:
	CXdrInputStream.cpp CXdrInputStream.h 
Log Message:
CXdrInputStream provides a class capable of decoding files and buffers of files produced by
CXdrOutputStream.  This class is used to produce the FilterBufferDecoder class.


--- NEW FILE: CXdrInputStream.cpp ---
/*
		    GNU GENERAL PUBLIC LICENSE
		       Version 2, June 1991

 Copyright (C) 1989, 1991 Free Software Foundation, Inc.
                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

			    Preamble

  The licenses for most software are designed to take away your
freedom to share and change it.  By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users.  This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it.  (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.)  You can apply it to
your programs, too.

  When we speak of free software, we are referring to freedom, not
price.  Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it
in new free programs; and that you know you can do these things.

  To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.

  For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have.  You must make sure that they, too, receive or can get the
source code.  And you must show them these terms so they know their
rights.

  We protect your rights with two steps: (1) copyright the software, and
(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.

  Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software.  If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.

  Finally, any free program is threatened constantly by software
patents.  We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary.  To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.

  The precise terms and conditions for copying, distribution and
modification follow.

		    GNU GENERAL PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License.  The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language.  (Hereinafter, translation is included without limitation in
the term "modification".)  Each licensee is addressed as "you".

Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope.  The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.

  1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.

You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.

  2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:

    a) You must cause the modified files to carry prominent notices
    stating that you changed the files and the date of any change.

    b) You must cause any work that you distribute or publish, that in
    whole or in part contains or is derived from the Program or any
    part thereof, to be licensed as a whole at no charge to all third
    parties under the terms of this License.

    c) If the modified program normally reads commands interactively
    when run, you must cause it, when started running for such
    interactive use in the most ordinary way, to print or display an
    announcement including an appropriate copyright notice and a
    notice that there is no warranty (or else, saying that you provide
    a warranty) and that users may redistribute the program under
    these conditions, and telling the user how to view a copy of this
    License.  (Exception: if the Program itself is interactive but
    does not normally print such an announcement, your work based on
    the Program is not required to print an announcement.)

These requirements apply to the modified work as a whole.  If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works.  But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.

Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Program.

In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.

  3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms of
Sections 1 and 2 above provided that you also do one of the following:

    a) Accompany it with the complete corresponding machine-readable
    source code, which must be distributed under the terms of Sections
    1 and 2 above on a medium customarily used for software interchange; or,

    b) Accompany it with a written offer, valid for at least three
    years, to give any third party, for a charge no more than your
    cost of physically performing source distribution, a complete
    machine-readable copy of the corresponding source code, to be
    distributed under the terms of Sections 1 and 2 above on a medium
    customarily used for software interchange; or,

    c) Accompany it with the information you received as to the offer
    to distribute corresponding source code.  (This alternative is
    allowed only for noncommercial distribution and only if you
    received the program in object code or executable form with such
    an offer, in accord with Subsection b above.)

The source code for a work means the preferred form of the work for
making modifications to it.  For an executable work, complete source
code means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
control compilation and installation of the executable.  However, as a
special exception, the source code distributed need not include
anything that is normally distributed (in either source or binary
form) with the major components (compiler, kernel, and so on) of the
operating system on which the executable runs, unless that component
itself accompanies the executable.

If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.

  4. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License.  Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this License.
However, parties who have received copies, or rights, from you under
this License will not have their licenses terminated so long as such
parties remain in full compliance.

  5. You are not required to accept this License, since you have not
signed it.  However, nothing else grants you permission to modify or
distribute the Program or its derivative works.  These actions are
prohibited by law if you do not accept this License.  Therefore, by
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Program or works based on it.

  6. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
original licensor to copy, distribute or modify the Program subject to
these terms and conditions.  You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties to
this License.

  7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License.  If you cannot
distribute so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you
may not distribute the Program at all.  For example, if a patent
license would not permit royalty-free redistribution of the Program by
all those who receive copies directly or indirectly through you, then
the only way you could satisfy both it and this License would be to
refrain entirely from distribution of the Program.

If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply and the section as a whole is intended to apply in other
circumstances.

It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system, which is
implemented by public license practices.  Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is willing
to distribute software through any other system and a licensee cannot
impose that choice.

This section is intended to make thoroughly clear what is believed to
be a consequence of the rest of this License.

  8. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces, the
original copyright holder who places the Program under this License
may add an explicit geographical distribution limitation excluding
those countries, so that distribution is permitted only in or among
countries not thus excluded.  In such case, this License incorporates
the limitation as if written in the body of this License.

  9. The Free Software Foundation may publish revised and/or new versions of the General Public License from time to time.  Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.

Each version is given a distinguishing version number.  If the Program
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and conditions 
either of that version or of any later version published by the Free Software 
Foundation.  If the Program does not specify a version number of this License,
 you may choose any version ever published by the Free Software Foundation.

  10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the author to 
ask for permission.  For software which is copyrighted by the Free Software 
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			    NO WARRANTY

  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR
THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN 
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE 
THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, 
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND 
PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, 
YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO 
LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR 
THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 
DAMAGES.

		     END OF TERMS AND CONDITIONS
*/

#include "CXdrInputStream.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>

/*!
   Construct a default xdr input stream.  This input stream
   is unconnected to any source.  All we do is:
   - Set the buffersize as per the parameter.
   - Create a buffer for the data.
   - Set the isOpen flag to false.

   \param nBuffersize (int in default = 8192)
      The buffer size for the stream.
*/
CXdrInputStream::CXdrInputStream(int nBuffersize) :
  m_nBuffersize(nBuffersize),
  m_pBuffer(new char[nBuffersize]),
  m_fIsOpen(false),
  m_nFid(-1)
{
  
}
/*!
   Construct an Xdr data source with a connection identifier.
   Note that the source must later be opened via a call to the
   Open() member function.  Open cannot be called now because
   it is virtual and virtuality does not work in constructors.

   Therefore, the only difference between this call and the
   other constructor is that m_sConnectionId is set.

 */
CXdrInputStream::CXdrInputStream(const string& connection,
				 int nBuffersize) :
  m_nBuffersize(nBuffersize),
  m_pBuffer(new char[nBuffersize]),
  m_sConnectionId(connection),
  m_fIsOpen(false),
  m_nFid(-1)
{
}
/*!
   Destructor for input stream:
   - Delete the buffer.
*/
CXdrInputStream::~CXdrInputStream()
{
  delete m_pBuffer;
}

/*!
   Connect the stream to a connection id.
   The default connection is to a file named by the
   connection id.  This function:
   - opens the file for read.
   - Sets m_nFid from the open.
   - Sets m_fIsOpen true.
   - Reads the first buffer from the connection.

   \throw string 
      Description of any errors that were discovered.
      In the event of the throw, none of the state variables
      will have been changed..

    \note
      It is an error to open a file with an empty name.
*/
void
CXdrInputStream::Connect() 
  throw (string)
{
  if(m_sConnectionId == string("")) {
    throw string("Empty filename in CXdrInputStream::Connect");
  }
  int fd = open(m_sConnectionId.c_str(), O_RDONLY);
  if(fd < 0) {
    string msg(strerror(errno));
    throw msg;
  }

  // At this time, everything worked. We set up the member
  // data:

  m_fIsOpen = true;
  m_nFid    = fd;

  // Read the first buffer;

  DoRead();
  
}
/*!
   Fetch an item from the stream.
   \param item (void* [out]):
     Pointer to the item to fetch.  Note that for a string,
     you will need to pass a pointer to a pointer.
   \param cvt (xdrproc_t [in]):
     Pointer to the converstion function e.g. xdr_int

   If the last item is read, then the Read member is called to
   read the next buffer.

   Reading from a disconnected stream results in a string
   exception.
*/
void
CXdrInputStream::Get(void* item, xdrproc_t cvt) throw (string)
{
  if(!m_fIsOpen) {
    throw string("Stream is not open at CXdrInputStream::Get");
  }
  (*cvt)(&m_Xdr, item);

  // See if we need to read another buffer:

  ConditionalRead();



}
/*!
   Read the next buffer from the file.
   \param pBuffer (void* [out]):
     points to the buffer to read.  m_nBuffersize bytes are read.
   \return int
    - Number of bytes read if success
    - 0 if end of file.
    - -1 if error with errno containing the reason.
*/
int
CXdrInputStream::Read(void* pBuffer) 
{
  return read(m_nFid, pBuffer, m_nBuffersize);
}
/*!
   Disconnect a stream from the input file.
*/
void
CXdrInputStream::Disconnect() throw (string)
{
  if(!m_fIsOpen) {
    throw 
      string("File already closed in CXdrInputStream::Disconnect");
  }
  int stat = close(m_nFid);
  m_fIsOpen = false;
  if(stat < 0) {
    string msg(" Close failed in CXdrInputStream::Disconnect ");
    msg += strerror(errno);
    throw msg;
  }
}
/*!
   Do a read and all the associated book-keeping and error checking:
   # The Read member function is called
   # The following conditional action is taken:
   -  If the read completed in error, an string exception is thrown.
   -  If the read completed in end of file, Disconnect is called.
   -  If the read completed normally, the Xdr translator is created,
      and the number of used words is read into m_nSize.
   
   \throw string
     In the event the Read member returns an error.
*/
void
CXdrInputStream::DoRead() throw (string)
{
  int nRead = Read(m_pBuffer);
  if(nRead < 0) {
    string msg(strerror(errno));
    throw msg;
  }
  if(nRead == 0) {
    Disconnect();
  }
  xdrmem_create(&m_Xdr, m_pBuffer, m_nBuffersize, XDR_DECODE);
  xdr_int(&m_Xdr, &m_nSize);
} 
/*!
   Checks the current position within the data buffer.
   If we are at the end of the buffer:
   - The m_Xdr object is destroyed,
   - DoRead is called to setup the next buffer for decoding.

   \throw string
      The DoRead function can throw a string that passes right
      through us/
*/
void
CXdrInputStream::ConditionalRead() throw (string)
{
  int pos = xdr_getpos(&m_Xdr);
  if(pos >= m_nSize) {
    xdr_destroy(&m_Xdr);
    DoRead();
  } 
}
/*!
   Stream operator to extract an integer from the xdr input stream.
   \param n (int& [out])
      The integer will be extracted into this value.
   \return CXdrOutputStream&
   *this to support get chaining.

*/
CXdrInputStream&
CXdrInputStream::operator>>(int& n)
{
  Get(&n, (xdrproc_t)xdr_int);
  return *this;
}
/*!
   Stream operator to extract a float from the xdr input stream.
   \param n (float& [out]):
      The float to extract.
   \return CXdrInputStream&
   *this to support get chaining.

*/
CXdrInputStream&
CXdrInputStream::operator>>(float& n)
{
  Get(&n, (xdrproc_t)xdr_float);
  return *this;
}
/*!
   Stream operator to extract a double from the xdr input stream.
   \param n (double& [out])
      The double to extract.
   \return CXdrInputStream&
   *this to supprot get chaining.
*/
CXdrInputStream&
CXdrInputStream::operator>>(double& n)
{
  Get(&n, (xdrproc_t)xdr_double);
  return *this;
}
/*!
   Stream operator to extract a character from the xdr input
   stream. Note that successive characters are not packed so 
   You may not use this to extract a character at a time from a 
   string.  Either extract into an array (char*) or a string.

   \param c (char& [out])
      The character to extract.
   \return CXdrInputStream&
   *this to supprot get chaining.
*/
CXdrInputStream&
CXdrInputStream::operator>>(char& c)
{
  Get(&c, (xdrproc_t)xdr_char);
  return *this;
}
/*!
   Get character string into a character array.

   \param c (char* [out]):]
     Pointer to the storage for the string.  It is the
     caller's responsibility to allocate a large enough buffer
     for this string.
   \return CXdrInputStream&
   *this to supprot get chaining.

*/
CXdrInputStream&
CXdrInputStream::operator>>(char* c)
{
  Get(&c, (xdrproc_t)xdr_wrapstring);
  return *this;
}
/*!
  Get a character string into an stl string.
  As with all items, the string is assumed not to 
  span buffer boundaries.. fixing it's maximum length
  at m_nBuffersize or so.

  \param s (string& [out]):
    String to get into.
   \return CXdrInputStream&
   *this to support get chaining.

*/
CXdrInputStream&
CXdrInputStream::operator>>(string& s) 
{
  char strbuf[m_nBuffersize];
  (*this) >> strbuf;
  s = strbuf;
  return *this;

}  
/*!
   Get a bool from the xdr input stream buffer.
   \param b (bool & [out]):
     Bool to get into.
   \return CXdrInputStream&
   *this to support get chaining
*/
CXdrInputStream&
CXdrInputStream::operator>>(bool& b)
{
  Get(&b, (xdrproc_t)xdr_bool);
  return *this;
}

--- NEW FILE: CXdrInputStream.h ---
/*
		    GNU GENERAL PUBLIC LICENSE
		       Version 2, June 1991

 Copyright (C) 1989, 1991 Free Software Foundation, Inc.
                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

			    Preamble

  The licenses for most software are designed to take away your
freedom to share and change it.  By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users.  This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it.  (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.)  You can apply it to
your programs, too.

  When we speak of free software, we are referring to freedom, not
price.  Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it
in new free programs; and that you know you can do these things.

  To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.

  For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have.  You must make sure that they, too, receive or can get the
source code.  And you must show them these terms so they know their
rights.

  We protect your rights with two steps: (1) copyright the software, and
(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.

  Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software.  If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.

  Finally, any free program is threatened constantly by software
patents.  We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary.  To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.

  The precise terms and conditions for copying, distribution and
modification follow.

		    GNU GENERAL PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License.  The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language.  (Hereinafter, translation is included without limitation in
the term "modification".)  Each licensee is addressed as "you".

Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope.  The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.

  1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.

You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.

  2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:

    a) You must cause the modified files to carry prominent notices
    stating that you changed the files and the date of any change.

    b) You must cause any work that you distribute or publish, that in
    whole or in part contains or is derived from the Program or any
    part thereof, to be licensed as a whole at no charge to all third
    parties under the terms of this License.

    c) If the modified program normally reads commands interactively
    when run, you must cause it, when started running for such
    interactive use in the most ordinary way, to print or display an
    announcement including an appropriate copyright notice and a
    notice that there is no warranty (or else, saying that you provide
    a warranty) and that users may redistribute the program under
    these conditions, and telling the user how to view a copy of this
    License.  (Exception: if the Program itself is interactive but
    does not normally print such an announcement, your work based on
    the Program is not required to print an announcement.)

These requirements apply to the modified work as a whole.  If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works.  But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.

Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Program.

In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.

  3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms of
Sections 1 and 2 above provided that you also do one of the following:

    a) Accompany it with the complete corresponding machine-readable
    source code, which must be distributed under the terms of Sections
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		     END OF TERMS AND CONDITIONS
*/

#ifndef __CXDRINPUTSTREAM_H
#define __CXDRINPUTSTREAM_H

#ifndef __STL_STRING
#include <string>
#define __STL_STRING
#endif

#ifndef __RPC_XDR_H
#include <rpc/xdr.h>
#define __RPC_XDR_H
#endif


/*!
   This class reads a buffered output stream in XDR format.  The user
   must know the order and type of each data item in the stream,
   however this class will do buffer management as well as XDR decoding
   of individual data items on behalf of the user.

   The format of the file is assumed to be a list of fixed length 
   buffers.  Each buffer has a one int header.  The int contains
   the offset at the end of the buffer (result from xdr_getpos when
   the buffer was flushed).

   The remainder of the data is whatever the writer stuck into the
   stream.

   The stream is written in a way that an arbitrary source of
   buffers can be used.
*/
class CXdrInputStream {
  // Private member data:
private:
  int    m_nBuffersize;		//!< Read Unit size.
  char  *m_pBuffer;		//!< The actual buffer.
  XDR    m_Xdr;			//!< XDR conversion data structs.
  string m_sConnectionId;	//!< Identifies data source.
  bool   m_fIsOpen;		//!< True when input stream open.
  int    m_nFid;		//!< Base class is a file!!.
  int    m_nSize;		//!< # bytes used in buffer.
public:
  // Constructors and other canonical functions:

  CXdrInputStream(int nBuffersize = 8192);
  CXdrInputStream(const string& connection, 
		  int nBuffersize = 8192);
  ~CXdrInputStream();
private:
  CXdrInputStream(const CXdrInputStream& rhs);
  CXdrInputStream& operator=(const CXdrInputStream& rhs);
  int operator==(const CXdrInputStream& rhs);
  int operator!=(const CXdrInputStream& rhs);
public:

  // Selectors
  
  int getBufferSize() const {
    return m_nBuffersize;
  }
  void* getBuffer() {
    return (void*)m_pBuffer;
  }
  bool isOpen() const {
    return m_fIsOpen;
  }
  string getConnectionId() const {
    return m_sConnectionId;
  }
  /*! Get file id: note this may be meaningless in derived classes */
  int getFid() const {
    return m_nFid;
  }


  // class operations


   //!  Give name and connect.

  void Connect(const string& rName) throw (string) {
    m_sConnectionId = rName;
    Connect();
  }

  //! Get an arbitrarily typed item from the buffer:

  void Get(void* item, xdrproc_t cvt) throw (string);

  //  Stream-like operations:

  CXdrInputStream& operator>>(int& n);	//!< Get int.
  CXdrInputStream& operator>>(float& n); //!< Get float.
  CXdrInputStream& operator>>(double& n); //!< Get double.
  CXdrInputStream& operator>>(char& c); //!< Get single char.
  CXdrInputStream& operator>>(char* c); //!< Get czstring
  CXdrInputStream& operator>>(string& s); //!< Get stl string
  CXdrInputStream& operator>>(bool& b); //!< Get a bool.


  // overrides:

  virtual void Connect() throw (string);
  virtual void Disconnect() throw(string);

protected:
  virtual int  Read(void* pBuffer);


protected:
  // Utility functions.

  void DoRead() throw(string);	//!< Drive a read and all book-keeping
  void ConditionalRead() throw (string); //!< Read if buffer done.

};
   

#endif