your input loop has a problem!! you test for eof() then attempt a read and do NOT test the results of the read! two fixes given below At Saturday 2004-06-05 18:30, you wrote:

I'm using boost::serializer between two programs: the first creates the data then serializes it, the second loads that data in and analyzes it.

When I had just 420 data samples it all worked fine: I create a vector<Sample> in memory, serialized it and loaded it in the other side. When I moved to 7000 data samples the first program, the creator, sucked all the memory from the machine and then some.

So I moved to serializing each data sample as it was created. To read it back in I changed my code from this:

std::ifstream input_file(fname,std::ios::binary); boost::archive::binary_iarchive archive(input_file); std::vector<Sample> samples; archive>>samples; input_file.close();

Into this:

std::ifstream input_file(fname,std::ios::binary); boost::archive::binary_iarchive archive(input_file);

std::vector<Sample> samples; samples.reserve(8000);

while(!input_file.eof()){ Sample s; archive>>s;

replace the above line with: if(archive>>s)

samples.push_back(s); }

or rewrite the loop: Sample s; while(archive >> s) samples.push_back(s); if it's important that s be destructed at loop end, simply enclose the above two lines in { }

input_file.close();

But every time it fails with an assert [1]. This seems to be when it has reached end of file. I cannot know in advance how many data samples I'll write to disk, so it seems I have three options: A: Make a special "zero" version of Sample to mark end of file B: At end of program 1 write the number of samples to a special file, and read that in before starting the above loop, so I know when to stop. C: Alter the serializer class to throw exception instead of an assert; I can then catch it and carry on.

What is the best way? Is adding a terminator byte to boost::serializer an option (i.e. so I don't have to make a terminator version of each data structure I want to serialize).

Incidentally my above loop does a copy of each sample as it adds it to the vector. Is the above code going to be common enough to make it worth including into boost::serializer as a helper function, which could then be optimized with in-place construction or something clever like that? (And then it could handle the termination handling itself as well.)

Darren

[1]: /usr/local/src/boost_1_31_0/boost/archive/basic_binary_iprimitive.hpp:119: void boost::archive::basic_binary_iprimitive<Archive, IStream>::load_binary(void*, unsigned int) [with Archive = boost::archive::binary_iarchive, IStream = std::basic_istream<char, std::char_traits<char> >]: Assertion `count == static_cast<size_t>(is.gcount())' failed. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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