Re: [boost] [serialization] de-serialization performance issue

Subject: Re: [boost] [serialization] de-serialization performance issue
From: Brad Higgins (bhiggins_at_[hidden])
Date: 2011-01-20 15:39:34

If I roll my own, I would not call reset_object_address(), and it would work much faster.  The issue is that, for each element in the vector, the default deserialization code is calling reset_object_address().  Due to the deserialization of the large multi-index, reset_object_address() iterates through a list that is very large.

I'll spend more time reading the code, but is there a way to avoid the big hit in reset_object_address(), or avoid the call to it all together?

Thanks,
Brad

On Jan 20, 2011, at 1:34 AM, Robert Ramey wrote:

> Brad Higgins wrote:
>> I have encountered a performance issue with serialization, when used
>> with multi-index followed by a vector<size_t>.  I have a reduced
>> program below, which reproduces the issue (using boost 1.44.0).
>> 
>> I basically have a class with a multi-index member, and a
>> vector<size_t> member.  It serializes OK, but deserialization's
>> performance appears to be O(n^2).  It seems to be getting bogged down
>> in basic_iarchive_impl::reset_object_address(), when deserializing
>> the vector.  Any thoughts?
> 
>>       /**
>>        * Boost serialization hook
>>        */
>>       friend class boost::serialization::access;
>>       template<class Archive>
>>           void serialize(Archive & ar, const unsigned int version)
>>           {
>>               std::cout << "SERIALIZE db_\n";
>>               ar & boost::serialization::make_nvp("db", db_);
>>               std::cout << "SERIALIZE vector_ints_\n";
>> //                ar & boost::serialization::make_nvp("vector_ints",
>> //            vector_ints_); //  <- THIS IS SLOW DURING INPUT }
>                FOREACH(size_t x, vector_ints)
>                    ar & x
>> };
>> 
> what happens if you make the change above?  That is, if you substitute 
> you're
> own loop for the boost::serialization implemenation?
> 
> Robert Ramey
> 
> 
> 
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