Making a gpg library

[Michael Still]

On Mon, 23 Oct 2000, tftp wrote:

> $ time ./gpgrun 1000
> 5.70user 1.89system 1:32.86elapsed 8%CPU (0avgtext+0avgdata 0maxresident)k
> 0inputs+0outputs (356255major+91062minor)pagefaults 0swaps

My case is for nine million documents. Sure I might not get this all done
in any 24 hour period, but time really starts to matter.

> #!/usr/bin/perl
> for ($n=0; $n < $ARGV[0]; ++$n) {
>         system("gpg --version > /dev/null");
> }
> 
> The perl overhead will be somewhat visible on low pass counts but
> should be irrelevant on longer tests.
> 
> Runs       Time, s.    Time increase   Pass cost, s.
> 1          0:00.26          1            0.26
> 10         0:00.89          3            0.09
> 100        0:09.52         36            0.09
> 1000       1:32.86        358            0.09
> 
> As we see, numerous invocations of gpg (as a new process)
> cost 90 ms. per invocation on AMD Athlon 450 MHz, Linux 2.2.17.
> The first pass has a lot more cost because Perl and gpg aren't
> cached yet. This test does not involve actual crypto work; if
> that is included then cost of loading gpg becomes even smaller.

A system call is perl is as inefficient (if not more) than the shell
option you showed above. A system call has to: fork, exec the shell, and
_then_ exec gpg.

The problem is we have no timing for a dynamic load of a library and then
the call of a routine. The best I can come up with on short notice is
10,000 (plus a few for setup) calls of a PDF generation routine on a PII
300 laptop...

8.56user 0.27system 0:09.32elapsed 94%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (102major+3257minor)pagefaults 0swaps

The function called does some pretty ugly linked list traversal, so that
should be taken into account.

If we take your gpg --version example in perl for 1,000 and times by ten,
my ugly library timing is still faster -- even though it is running on a
slower machine.

Anyway, perhaps my needs are non-standard and therefore should not be
supported. My point is more that the design of gpg makes my task harder,
for no reason that I can fathom...

Mikal


-- 

Michael Still (mikal at stillhq.com)
 - Panda PDF Generation Library (http://www.stillhq.com/panda/)
 - GPG Public Key at http://www.stillhq.com/mikal.asc