[Monotone-devel] Re: results of mercurial user survey

[Bruce Stephens]

Richard Levitte - VMS Whacker <address@hidden> writes:

> In message <address@hidden> on Fri, 28 Apr 2006 19:19:01 +0100, Bruce 
> Stephens <address@hidden> said:
>
> monotone> OK, here's some back of the envelope costs.  "openssl speed"
> monotone> says it can do 632761 64 byte SHA1's per second, 194433 1K
> monotone> per second.  The current repository contains 6084 revisions,
> monotone> so double that (for a revision and a roster) and call it
> monotone> 20000.
> [...]
> monotone> RSA verification also seems not too bad: openssl says it can
> monotone> do about 7000 verifies of 1024 bit keys per second, so for
> monotone> 25000 certs that's less than 10s.  Maybe more (maybe the
> monotone> openssl speed test uses just one key or something, which
> monotone> might end up in a cache), but it doesn't seem worth worrying
> monotone> about, IMHO.
>
> OpenSSL is quite fast in those areas (not necessarely the fastest,
> but previous tests have shown that it's up there).  Out of
> curiosity, have to done similar tests with the Botan libraries,
> which is what monotone uses?

No, I haven't, and I realise that OpenSSL's pretty fast (and it's a
pretty fast PC).

I was just doing a quick estimate, and I think it's likely that the
SHA1 and RSA cost for checking everything in the current venge.net
repository is a minute or two rather than an hour or two.

If monotone were to give up verification, then it would have to be
because that would avoid some other aspects of work: reconstructing
files, reversing deltas, or whatever.

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