Re: [Boost-users] Fastest way of serializing a huge vector of ints into a human readable string

Hm, maybe boost::spirit::karma could do you a favor here, but I think it will not gain much perfomance, if at all. Maybe you could think about a functor which does it on your own. Do the numbers repeat often, then you could also build a table to only convert once to string. Also parellizing with boost Thread would be an option. mfg. Jens Weller -------- Original-Nachricht --------

Datum: Fri, 27 Feb 2009 18:46:07 +0100 Von: Roland Bock An: boost-users@lists.boost.org Betreff: [Boost-users] Fastest way of serializing a huge vector of ints into a human readable string

Hi,

I have a program which produces a vector of integers (several million entries). I need to write that into a human-readable string of space separated numbers.

I wonder, what would be the fastest way?

My first attempt was

stringstream resultStream; copy(integers.begin(), integers.end(), ostream_iterator<int>(resultStream, " ")); string result = resultStream.str();

But that requires copying the string.

Thus I was wondering if I could use boost to write to the target string directly?

boost::iostreams allow me to do the following:

string result; boost::iostreams::filtering_ostream out(boost::iostreams::back_inserter(result)); copy(integers.begin(), integers.end(), ostream_iterator<uint64>(out, " "));

This is faster by almost a factor of 2.

Any ideas how to increase speed even more?

Thanks in advance,

Roland _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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