[Boost-users] Using iostreams to serialize into and from a memory buffer

Subject: [Boost-users] Using iostreams to serialize into and from a memory buffer
From: Ivan Gonzalez (iglpdc_at_[hidden])
Date: 2009-07-03 04:19:29

Dear all,
I have some numerical data in my code that I'm saving to a file. My code
loops thousands of times generating a set of this data in each loop step.
The data is reused within the same step but there is no need to save it to
the next one. Currently I'm using the serialization library to write all the
data to a binary file (using the optimization for contiguous arrays) and
then read it. I thought (maybe naively) I could increase performance keeping
the data in memory instead of write/read to disk. I came across this post
http://lists.boost.org/boost-users/2008/05/36235.php where how to serialize
into/from a memory buffer using boost::iostreams is explained. However I
found that using the solution in the post is way slower than write/read to
disk. In fact modifying the code in the post to use std::ofstream and
std::ifstream open with the std::ios::binary flag makes the code 5 times
faster.

Am I missing something or is it right that the iostream solution is slower ?.
 (I understand that sometimes you don't have the option to write to a file,
but is this the fastest way to use a memory buffer ?)

Thanks in advance,

Ivan