[Boost-users] [iostreams] Re: gzip_compressor cannot be flushed and closed properly7

From: eg (egoots_at_[hidden])
Date: 2008-02-18 18:35:47

Mengda Wu wrote:
> Hi,
> 
>    I have a code block trying to output a series of gzip files. I wish 
> to have all the files flushed after the block.
> But the files can only be flushed after exiting the whole program.
> The files still have zero size after I try to close them. I am using 
> std::vector to store all the pointers to boost filtering_ostream.
> Can you help?
> 
>   //Open iostreams
>  
>   char filename[20];
>   std::vector<boost::iostreams::filtering_ostream *> os_vector;
>   for(i=0; i<4; i++)
>   {
>      sprintf(filename, "file_%d.gz", i );
>      std::ofstream *of = new std::ofstream(filename, std::ios_base::binary);
>      boost::iostreams::filtering_ostream* os = new 
> boost::iostreams::filtering_ostream;
>      os->push(boost::iostreams::gzip_compressor());
>      os->push(*of);
>      os_vector->push_back(os);
>   }
> 
>   //Output something
>   for(i=0; i<4; i++)
>   {
>      boost::iostreams::filtering_ostream* os = os_vector[i];
>      os<<"Output something here" << std::endl;
>   }
> 
>   //Close streams
>   for(i=0; i<4; i++)
>   {
>     boost::iostreams::filtering_ostream* os = os_vector[i];
>     os->strict_sync();
>     os->pop();
>     os->reset();
>   }
> 

I haven't tried out your sample...
but I am not sure if gzip filters are flushable?