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Date: Mon, 9 Nov 2015 21:04:49 +0000
From: Bob McElrath <bob_bitcoin@mcelrath.org>
To: Peter Tschipper <peter.tschipper@gmail.com>
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Cc: Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] request BIP number for: "Support for Datastream
Compression"
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I would expect that since a block contains mostly hashes and crypto signatures,
it would be almost totally incompressible. I just calculated compression ratios:
zlib -15% (file is LARGER)
gzip 28%
bzip2 25%
So zlib compression is right out. How much is ~25% bandwidth savings worth to
people? This seems not worth it to me. :-/
Peter Tschipper via bitcoin-dev [bitcoin-dev@lists.linuxfoundation.org] wrote:
> This is my first time through this process so please bear with me.
>
> I opened a PR #6973 this morning for Zlib Block Compression for block
> relay and at the request of @sipa this should have a BIP associated
> with it. The idea is simple, to compress the datastream before
> sending, initially for blocks only but it could theoretically be done
> for transactions as well. Initial results show an average of 20% block
> compression and taking 90 milliseconds for a full block (on a very slow
> laptop) to compress. The savings will be mostly in terms of less
> bandwidth used, but I would expect there to be a small performance gain
> during the transmission of the blocks particularly where network latency
> is higher.
>
> I think the BIP title, if accepted should be the more generic, "Support
> for Datastream Compression" rather than the PR title of "Zlib
> Compression for block relay" since it could also be used for
> transactions as well at a later time.
>
> Thanks for your time...
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>
> !DSPAM:5640ff47206804314022622!
--
Cheers, Bob McElrath
"For every complex problem, there is a solution that is simple, neat, and wrong."
-- H. L. Mencken
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