Re: [Boost-users] boost::iostreams zlib compression

From: j.c. (jolix_at_[hidden])
Date: 2008-03-04 05:32:49

It's p2p, so lost of connections, packets, etc..

Could I get an updated copy? That would be most helpful.

Again, thanks so  much.
On Mar 3, 2008, at 9:43 PM, KSpam wrote:

> JC,
>
>> Do you think the speed is OK for data transmission over udp sockets?
>
> Unfortunately, this is a difficult question to answer, so I will  
> resort to the
> standard engineering response ... it depends :-)  There are many  
> parameters
> that can play into the answer, and they all depend on the nature of  
> the
> application.  For instance:
>
> What frequency are messages being sent?
> What is the average message size?
> What is the speed and reliability of the network connection?
>
> There will obviously be some overhead required in compressing the  
> messages.
> If the network connection is unreliable or slow, then the overhead  
> may be
> worthwhile.  If the network is reliable and fast (or if your sending  
> or
> receiving processor is slow), the compression overhead may not be  
> worthwhile.
> Of course, the beauty of Boost.Iostreams is that adding, removing, or
> changing the compression type is very easy to do.  When you  
> prototype your
> application, you can perform throughput analysis to determine the  
> optimal
> setup.
>
> I modified the example I sent to add a bzip2 compression test (ALGO  
> 4) and a
> no compression test (ALGO 3).  Here are the results from running a  
> debug
> Linux build on my machine:
>
> ALGO 0 : 10000 cycles took 1.261 seconds!
> ALGO 1 : 10000 cycles took 1.2 seconds!
> ALGO 1 : Improvement 4.83743 %
> ALGO 2 : 10000 cycles took 0.652 seconds!
> ALGO 2 : Improvement 48.295 %
> ALGO 3 : 10000 cycles took 0.218 seconds!
> ALGO 3 : Improvement 82.7121 %
> ALGO 4 : 10000 cycles took 0.928 seconds!
> ALGO 4 : Improvement 26.4076 %
>
> For grins, here are the release build results:
>
> ALGO 0 : 10000 cycles took 0.927 seconds!
> ALGO 1 : 10000 cycles took 0.88 seconds!
> ALGO 1 : Improvement 5.07012 %
> ALGO 2 : 10000 cycles took 0.345 seconds!
> ALGO 2 : Improvement 62.7832 %
> ALGO 3 : 10000 cycles took 0.028 seconds!
> ALGO 3 : Improvement 96.9795 %
> ALGO 4 : 10000 cycles took 0.597 seconds!
> ALGO 4 : Improvement 35.5987 %
>
> As you can see, the no compression case (ALGO 3) is significantly  
> faster.  In
> this case, zlib compression (ALGO 2) is faster than bzip2  
> compression (ALGO
> 4).  Bzip2 compression generally compresses the data better than zlib
> compression though.  There's always a tradeoff :-)
>
> Hope This Helps,
> Justin
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