Re: [Boost-users] Serialization newbie needs help

From: Frank Birbacher (bloodymir.crap_at_[hidden])
Date: 2007-08-22 07:50:29

Hi!

Robert Ramey schrieb:
> The real easy way is just to use a binary_object which saves/loads a 
> specified number of bytes.
> so the above would look like:
> 
> void write_to_cbuffer(char* buf_p, size_t* buf_sz_p) { // note only one *
>     std::ostringstream oss;
>     boost::archive::text_oarchive oa(oss);
>     oa << binary_object(bf_sz_p,  mc);
> }
> void read_from_cbuffer(const char* buf, const size_t buf_sz) {
>     std::istringstream iss(buf_str);
>     boost::archive::text_iarchive ia(iss);
>     ia >> binary_object(buf_sz, buf)
> }

You got this one mixed up. The char array is not something to serailize
but it is the storage to searialize to. The "read_from_cbuffer" function
does *read* the cbuffer and construct a my_class instance out of it by
using serialization. The "write_to_cbuffer" serializes a my_class
instance an stores the result in the cbuffer.

I can think of using the old strstream class to read from the buffer or
take something from Boost.IOStreams. And writing could be faster if you
use a std::deque wrapped with IOStreams and later on std::copy this into
a char array (instead of memcpy). A deque has usually better performance
on push_back than a vector or string, I guess. But then I don't know the
internals of a stringstream.

Frank