[Boost-users] [serialization][portable-binary archive] Data not byte-swapped across architectures

11 Jul 2008

      Hello:

I am attempting to use the boost serialization portable-binary archive.

The 2 architectures I am working on are:
1. Intel on MS-Windows/Mac OS X
2. PowerPC on Mac OS X

The version of portable-binary that I am using is from the Trunk.

The attached sample code shows that an integer I serialize on PPC and 
then unserialize on Intel is not byte-swapped. And similarly, an integer 
I serialize on Intel is not byte-swapped on PPC.

It does not appear to be a OS issue, because the data is unserialized 
properly from a MS-Windows Intel system to a Mac OS X Intel system, and 
vise versa.

Another manifestation of this occurs when I serialize a large container, 
 like a vector for example. The code has an exception because the size 
of the container is not byte-swapper. I can provide example code for 
this as well.

This experience leads me to believe either:
1. The portable binary is not functioning properly with Mac OS X PPC
or
2. I am not using the portable-binary archive properly, either 
configuration or code.

It is not clear if I need to archive in a specific endian-ness and then 
manually detect the architecture and byte-swap if necessary. Or if all 
of that is handled automatically by the portable-binary archive.

Advise on this issue would be greatly appreciated.

Best regards, Jon Kroll
Ann Arbor Michigan

=========================================================================
BUILD:
Windows: MS-Visual Studio 2005
Mac OS X:
g++ test_portable_binary.cpp portable_binary_iarchive.cpp 
portable_binary_oarchive.cpp -o test_portable_binary
-I/Volumes/..../boost_1_35_0/
-L/Volumes/..../boost_1_35_0/stage/lib/
-lboost_serialization-mt-1_35

CODE:
========================================================

#include "boost/archive/portable_binary_oarchive.hpp"
#include "boost/archive/portable_binary_iarchive.hpp"

#include <vector>
#include <sstream>
#include <fstream>
#include <iostream>
#include <string>

namespace
{
bool isIntelArch()
{
   char endianTest[2] = { 1, 0 };
   return (*(short *) endianTest == 1);
}
bool isPPCArch()
{
   return !isIntelArch();
}
}

int main(int argc, char* argv[])
{
   if (false) // generate test file
   {
      std::string fileName;
      if (isPPCArch())
         fileName = "PPC_portableBinaryLargeInt.ser";
      else if (isIntelArch())
         fileName = "Intel_portableBinaryLargeInt.ser";

      int val = 16000; // 0x3E80

      std::ofstream os(fileName.c_str(), std::ios::binary);
      portable_binary_oarchive oa(os);
      oa & val;

      return 0;
   }

   int unserializedVal = 0;
   {
      std::string fileName;
      if (isPPCArch())
         fileName = "Intel_portableBinaryLargeInt.ser";
      else if (isIntelArch())
         fileName = "PPC_portableBinaryLargeInt.ser";

      std::ifstream is(fileName.c_str(), std::ios::binary);
      portable_binary_iarchive ia(is);

      ia & unserializedVal;
   }

   if (0x3E80 == unserializedVal)
   {
      return 0; // This is the correct result!
   }
   if (0x803E == unserializedVal)
   {
      return -1; // This is an error, the value is not byte-swapped
   }
   if (0 == unserializedVal)
   {
      return -1; // This is an error, nothing got unserialized
   }
   return 0;
}

[Boost-users] [serialization][portable-binary archive] Data not byte-swapped across architectures

Jon C. Kroll