Re: [Boost-users] Serialization of C dynamic data

From: Robert Ramey (ramey_at_[hidden])
Date: 2007-10-31 19:35:09

You don't have to use a default contstructor.
see load/save_construct data.

Robert Ramey

BTW - you might also look at binary_object
for a fast saving a a long char array

RR

Lorenzo Cavallaro wrote:
> Hi,
>
>   I'm trying to serialize the following piece of code (a data
>   structure whose object size is dynamically allocated and it should
>   use the correct size/len which has been serialized).
>
>      typedef struct data {
>         char *payload;
>         size_t len;
>      } data_t;
>
>      vector<data_t *> v;
>
>   So I added the corresponding serialize function to the structure
> definition
>
>      void
>      serialize(Archive & ar, const unsigned int file_version) {
>
>         ar & len;
>         for (int i = 0; i < len; i++)
>            ar & payload[i];
>      }
>
>   Moreover, I added a default constructor which is invoked by the
>   serialization library whenever the object has to be unserialized
>
>      data::data() {
>         /* no error checking */
>         payload = (char *)calloc(1, X);
>         len = X;
>      }
>
>   Now, of course X is fixed. I'd like to reuse the serialized 'size'
>   (ar & size) as argument to the calloc to be able to create an
>   object with the right size instead of having to approximate
>   (exceeding, of course) its real dimension.
>
>   Do you have any idea how to get it work the way I'd like to,
>   please? -- if it's possible, of course.
>
>   Nevertheless to say that with a right X everything works fine. I was
>   thinking to iterate over all the elements, after the
>   unserialization step is over, to reallocate payload using the right
> len... but it sucks :-)
>
> TIA, bye
> Lorenzo