Re: [boost] [serialization] performance comparison

From: brass goowy (brass_at_[hidden])
Date: 2007-02-15 13:37:44

Robert Ramey writes: 
>brass goowy wrote: 
>> B"H 
>> Robert Ramey writes: 
>>> Our experiments with 1.3 revealed that the single biggest time 
>>> consumer with the binary archive was with the stream i/o. version 
>>> 1.34 - is re-implemented in terms of std::streambuf rather than 
>>> stream i/o. It is significantly faster because of this. 
>> 
>> I hope to test with 1.34 and report what I find. 

>I'll be curious how much difference still exists. 
 
I ran this 
cvs -z3 -d:pserver:anonymous_at_[hidden]:/cvsroot/boost checkout boost
and I think I got the development version of 1.35.  I've done a little bit of testing with it.
I've returned to Linux and compared saving a list<int>  using release versions of the 
libraries (I forgot to mention that with the Windows tests.)  The lists had 20000 ints.
I'm using 4.0.3 of the gnu compiler and -O3 on all of these tests.  


1.33.1  // I pass an ofstream to binary_oarchive
takes ~5200 microseconds
 
1.35     // I pass a filebuf to the binary_oarchive here
takes ~3900 microseconds
 
Ebenezer Enterprises
takes ~1200 microseconds
 
The stripped 1.35 executable is ~22,600 bytes  and the stripped EE version 
is ~8,200 bytes.
 
  [...]
 
 
>>Does the 1.34 binary_oarchive take a streambuf 
>> instead of an ofstream? Is this documented somewhere? 

>It can take a stream buf or or an ofstream. If passed a stream, the stream 
>buf is used directly. This preserves the common archive interface while 
>gaining benefits of avoiding stream i/o operators. 

>I double checked the CVS using the browser interface. 1.34 indeed includes 
>updated documention and code which supports the streambuffer interface. It 
>doesn't say much, because whether binary archives were implemented in terms 
>of stream operators or streambuf calls was considered an implementation 
>detail. The only difference from a user stand point is that one can create 
>and use a streambuf without having to create a stream itself. 

>In our tests we found avoid the stream io and using streambuf calls directly 
>decreased the time required for vectos and arrays of primitives by a factor 
>of 4 (if I remember correctly) - when used with a large buffer. 


I haven't tested with vectors yet.  But with list<int> I didn't see a factor of
4.  It wasn't quite a factor of 2 between 1.33.1 and 1.35.  I know 1.35 could
be in the middle of changes so I didn't want to do a bunch of tests on it.
I'm not sure how to get a version of 1.34.  I just ran that command above and 
built it and the libraries have 1_35 in the names...  How do I get 1.34?

 [  ...]

>> These may not be the most common application, but the 
>> C++ middleware/serialization frameworks that I'm familiar with support 
>> container classes. From my perspective the tests I chose are basic 
>> things you have to have in order to support more complicated things. 

>I took a cursory look at the www.ebenezer.net and the documentation. If you 
>want I can include a pointer to it in the introduction to the serialization 
>library - as I have with other libraries which have been brought to my 
>attention. 
 
That is up to you.  But the address above is incorrect.  The correct address 
is below.
 
Shalom
Brian Wood
www.webEbenezer.net
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