Re: [boost] [serialization] fast array serialization (10x speedup)

From: Tom Widmer (tom_usenet_at_[hidden])
Date: 2005-11-25 05:43:07

Peter Dimov wrote:
> Matthias Troyer wrote:

>>What if the number n is infinite (e.g. all possible structs
>>consisting only of fundamental types), which is what Robert calls
>>"bitwise serializable"?
> 
> 
> Structs aren't bitwise serializable in general because of 
> padding/packing/alignment. Archives that do not have a documented external 
> format and just fwrite whatever happens to be in memory at the time aren't 
> really archives, they are a very specific subset with limited uses 
> (interprocess communication on the same machine, the same compiler and the 
> same version) that should not shape the design. ("Archive" implies 
> persistency, and relying on a specific memory layout is not a way to achieve 
> it.)

However, that is a common use case of any serialization library, and it 
is one that benefits greatly from fast array serialization. If the 
serialization library does not support it, those doing IPC may discard 
boost serialization entirely, to avoid implementing two different 
mechanisms in their programs. Some operating systems rely extremely 
heavily on message passing between processes (QNX is an example), and it 
would be nice if boost.serialization would be useful there.

Tom