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

Subject: Re: [Boost-users] Fastest way of serializing a huge vector of ints into a human readable string
From: Jens Weller (JensWeller_at_[hidden])
Date: 2009-02-27 12:57:54

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 <int,string> 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 <rbock_at_[hidden]>
> An: boost-users_at_[hidden]
> 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_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users

-- 
Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger01