Re: Perl jobs in London?
On Wednesday 26 February 2003 22:08, Dave Hodgkinson wrote: Contrary to other answers I'd actually say it's not as bad as it has been. Not according to www.jobstats.co.uk Bottomed? Maybe. given that the stats are just the use of the word 'Perl' in any job add, I'd say the figures are now so low that what you are seeing is statistical noise. They'll be the ones that say 'programmer wanted to port site from Perl to .asp or NT systems administrator, also useful would be unix csh and Perl and even where there is a real job, its difficult to make decent money in a market where people are prepared to undercut each other just to eat. it's dead, it has ceased to be, it has gone orf to meet its maker ... it is a dead parrot. -- Robin Szemeti
Perl Code Optimizer
Hi,
I've been thinking about ways I can make my Perl modules run
faster.
Apart from coming up with faster algorithms .. I've heard that
methods run quicker when they pop parameters off the parameter list using
'shift' and $_[0] etc.
Up until now I've avoided doing this in the interests of code
maintenance and readability - so all methods have a 'signature':
sub doSearch {
my ($this, $query, $ipaddress, $browser) = @_;
}
I'm thinking of writing an optimizer that substitutes $variable
names for parameter list locations $_[0] and strips out the signature?
Something like:
perl optimize_for_production.pl readable.pl faster_but_less_readable.pl
Any other ideas for automatically trimming down Perl source code
so the perl interpreter/compiler can do its job quicker?
Nige
--
Nigel Hamilton
Turbo10 Metasearch Engine
email: [EMAIL PROTECTED]
tel:+44 (0) 207 987 5460
fax:+44 (0) 207 987 5468
http://turbo10.com Search Deeper. Browse Faster.
Re: Perl Code Optimizer
Nigel Hamilton sent the following bits through the ether: I've been thinking about ways I can make my Perl modules run faster. It's hard to guess where your code is slow. Microoptimising isn't really going to make that much difference. Changing algorithms is much more likely. To find out where your code really _is_ slow, you should benchmark it with Devel::DProf. Trying to optimise anything which is taking less that 1% of your total time is probably not worth it. Why not try this on your code and report back the results? Leon -- Leon Brocard.http://www.astray.com/ scribot.http://www.scribot.com/ ... Bother, said Pooh as the brakes went out!
Re: Perl Code Optimizer
Nigel Hamilton wrote:
Hi,
I've been thinking about ways I can make my Perl modules run
faster.
Funny, I was also thinking that. I know, I thought, I'll use the perl
profiler.
Several core dumps later, I've sort of abandoned the idea.
The profiler was never very robust, but in perl 5.8.0 it seems even less
so. Anyone else find this?
Anyway, as for your optimiser, I'd be amazed if the way you handle the
argument stack makes that much overall difference. Also, having two
versions of functionally identical code strikes me as maintenance
unfriendly. That said I'd be interested to see what speed improvements
you do get. Personally, I find that almost all code can be accelerated
via low level caching. Every time you compute something ask yourself
Can this be cached so the next similar request has no computation
overhead? The wonderful or-cache (or Orcish manoeuvre) is your friend
here. Instead of:
$result = compute($argument); # calls compute() function every time
use
$cache{$argument} ||= compute($argument);
$result = $cache{$argument};
And so on. I have a hard time getting my Java developers to do this.
--
Jonathan Peterson
Technical Manager, Unified Ltd, +44 (0)20 7383 6092
[EMAIL PROTECTED]
Re: Perl Code Optimizer
On Thu, Feb 27, 2003 at 10:42:19AM +, Jonathan Peterson wrote:
Nigel Hamilton wrote:
Hi,
I've been thinking about ways I can make my Perl modules run
faster.
Funny, I was also thinking that. I know, I thought, I'll use the perl
profiler.
Several core dumps later, I've sort of abandoned the idea.
The profiler was never very robust, but in perl 5.8.0 it seems even less
so. Anyone else find this?
Yes. A coredump causing bug has been identified and fixed. It will be
in 5.8.1, which may even be soon. (a bit like Central Line coming soon
although I *think* that 5.8.1 will be second)
overhead? The wonderful or-cache (or Orcish manoeuvre) is your friend
here. Instead of:
$result = compute($argument); # calls compute() function every time
use
$cache{$argument} ||= compute($argument);
$result = $cache{$argument};
Any reason not to use Memoize on the function compute()?
Not the answer to the question asked, but for ideas on manual speedups,
I feel obliged to plug http://www.ccl4.org/~nick/P/Fast_Enough/
Nicholas Clark
Re: Perl Code Optimizer
On Thu, Feb 27, 2003 at 10:42:19AM +, Jonathan Peterson said:
Can this be cached so the next similar request has no computation
overhead? The wonderful or-cache (or Orcish manoeuvre) is your friend
here. Instead of:
$result = compute($argument); # calls compute() function every time
use
$cache{$argument} ||= compute($argument);
$result = $cache{$argument};
Doesn't Memoize do something like this?
Possibly in a more complicated way so for some cases your way may be
better but ...
--
the test for truth is still quicker than the addition
Re: Perl Code Optimizer
Jonathan Peterson wrote: Nigel Hamilton wrote: Hi, I've been thinking about ways I can make my Perl modules run faster. Funny, I was also thinking that. I know, I thought, I'll use the perl profiler. Several core dumps later, I've sort of abandoned the idea. The profiler was never very robust, but in perl 5.8.0 it seems even less so. Anyone else find this? Hmmm, Yes. I see far more frequent core dumps than I'd like. However, you can always rty Sam Tregar's Devel::Profiler, which is a pure perl solution, so shouldn't (in theory) core dump. Recently, I've also been impressed by DBI::ProfileDumper, which is damned useful if you're doing DBI work. -Dom -- | Semantico: creators of major online resources | | URL: http://www.semantico.com/ | | Tel: +44 (1273) 72 | | Address: 33 Bond St., Brighton, Sussex, BN1 1RD, UK. |
Re: Perl Code Optimizer
On Thu, Feb 27, 2003 at 10:42:19AM +, Jonathan Peterson said:
Can this be cached so the next similar request has no computation
overhead? The wonderful or-cache (or Orcish manoeuvre) is your friend
here. Instead of:
$result = compute($argument); # calls compute() function every time
use
$cache{$argument} ||= compute($argument);
$result = $cache{$argument};
Doesn't Memoize do something like this?
Possibly in a more complicated way so for some cases your way may be
better but ...
Hi,
Thanks for all your suggestions .. unfortunatly last time I used
the profiler it crashed, but I'll take another look.
It seems that there is no real gain to be made by stripping out
the signatures - I suppose if there was, perl would do an equivalent
optimization.
I'll keep an eye out for caching opportunities in the code.
I keep forgetting what Donald Knuth once wrote, premature
optimization is the root of all evil.
NIge
--
Nigel Hamilton
Turbo10 Metasearch Engine
email: [EMAIL PROTECTED]
tel:+44 (0) 207 987 5460
fax:+44 (0) 207 987 5468
http://turbo10.com Search Deeper. Browse Faster.
Re: Perl Code Optimizer
However, you can always rty Sam Tregar's Devel::Profiler, which is a pure perl solution, so shouldn't (in theory) core dump. Yup, that works fine. Yay for profilers. -- Jonathan Peterson Technical Manager, Unified Ltd, +44 (0)20 7383 6092 [EMAIL PROTECTED]
London.pm Aptitude Test
Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? I'm sure I missed a few things, feel free to add some more :) -CT
RE: London.pm Aptitude Test
What is perl ? Ducks!!! -Original Message- From: CyberTiger [mailto:[EMAIL PROTECTED] Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? Anadarko Confidentiality Notice: This electronic transmission and any attached documents or other writings are intended only for the person or entity to which it is addressed and may contain information that is privileged, confidential or otherwise protected from disclosure. If you have received this communication in error, please immediately notify sender by return e-mail and destroy the communication. Any disclosure, copying, distribution or the taking of any action concerning the contents of this communication or any attachments by anyone other than the named recipient is strictly prohibited.
Re: London.pm Aptitude Test
From: CyberTiger [EMAIL PROTECTED] Date: 2/27/03 2:25:14 PM Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? Hmmm. 2 out of 4. That's not very good. I'm sure I'm more than 50% suited to be in london.pm. Your test must be broken. Dave... -- http://www.dave.org.uk Let me see you make decisions, without your television - Depeche Mode (Stripped)
Re: London.pm Aptitude Test
On Thu, 27 Feb 2003, Dave Cross wrote: Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? Hmmm. 2 out of 4. That's not very good. I'm sure I'm more than 50% suited to be in london.pm. Your test must be broken. Depends how many of the 4 you need... Sam -- Flattery: If You Want to Get to the Top, Prepare to Kiss a Lot of the Bottom.
Re: London.pm Aptitude Test
On Thu, Feb 27, 2003 at 06:47:41AM -0800, Dave Cross wrote: From: CyberTiger [EMAIL PROTECTED] Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? Hmmm. 2 out of 4. That's not very good. I'm sure I'm more than 50% suited to be in london.pm. Your test must be broken. Perhaps he should use Test::FlavourOfTheMonth. -- David Cantrell | Looking for work | http://www.cantrell.org.uk/david/cv It would be reasonable to judge cannabis less of a threat to health than alcohol or tobacco ... this should be borne in mind by social legislators who, disapproving of other people's indulgences, seek to make them illegal. -- The Lancet, Volume 352, Number 9140, 14 November 1998
Re: London.pm Aptitude Test
On 27 Feb 2003 at 14:25, CyberTiger wrote: Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? I'm sure I missed a few things, feel free to add some more :) Do you like ponys? Cheers, philip -- Philip Newton [EMAIL PROTECTED]
[OT] PIE! (was:London.pm Aptitude Test)
Do you like pie ? Talking of pie (one of my very favorite subjects), has anyone had the pie at Gordon's (http://london.travelape.com/nightlife/gordons-wine-bar/)? One of the nicest pie's i've ever had (i think it has rabbit n pork). hmm pie, al Do you like kittens ? Do you like Buffy ? Do you like beer ? I'm sure I missed a few things, feel free to add some more :) Do you like ponys? Cheers, philip -- Philip Newton [EMAIL PROTECTED]
Re: London.pm Aptitude Test
* Dave Cross ([EMAIL PROTECTED]) wrote: From: CyberTiger [EMAIL PROTECTED] Date: 2/27/03 2:25:14 PM Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? Hmmm. 2 out of 4. That's not very good. I'm sure I'm more than 50% suited to be in london.pm. Your test must be broken. which two of the 4 do you not like? i note that choosing not to indulge in something doesnt mean you don't like it. -- *** *** *** Email address has changed to [EMAIL PROTECTED] . Please *** *** update your email address book. *** *** *** Greg McCarroll http://www.mccarroll.org.uk/~gem/ jabber://[EMAIL PROTECTED]
RE: London.pm Aptitude Test
On Thu, 27 Feb 2003, Richard Clyne topquoted thus: -Original Message- From: CyberTiger [mailto:[EMAIL PROTECTED] Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? What is perl ? Ducks!!! Do you like ducks? Funny, I don't remember that one ever coming up before... depends, usually, indifferent to tv shows, yes, 4/5's of a gem That I'm on a different continent, but nobody's perfect... -- Chris Devers[EMAIL PROTECTED] quack quack quack
Re: London.pm Aptitude Test
On Thu, Feb 27, 2003 at 04:27:59PM +0100, Philip Newton wrote: On 27 Feb 2003 at 14:25, CyberTiger wrote: Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? I'm sure I missed a few things, feel free to add some more :) Do you like ponys? Do you prefer Willow? -- David Cantrell | Looking for work | http://www.cantrell.org.uk/david/cv Wow, my first sigquoting! I feel so special now! -- Dan Sugalski
RE: London.pm Aptitude Test
-Original Message- From: CyberTiger [mailto:[EMAIL PROTECTED] Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? What is perl ? Ducks!!! Do you like ducks? Funny, I don't remember that one ever coming up before... delurk_cos_bit_drunk Ducks are edible and rather delicious. Therefore infinitely preferable to kittens, which are a bit scrawny. dave yum yum /delurk_cos_bit_drunk
Re: London.pm Aptitude Test
From: Greg McCarroll [EMAIL PROTECTED] Date: 2/27/03 3:45:36 PM * Dave Cross ([EMAIL PROTECTED]) wrote: From: CyberTiger [EMAIL PROTECTED] Date: 2/27/03 2:25:14 PM Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? Hmmm. 2 out of 4. That's not very good. I'm sure I'm more than 50% suited to be in london.pm. Your test must be broken. which two of the 4 do you not like? i note that choosing not to indulge in something doesnt mean you don't like it. Fair point. Tho' continuing to not indulge in something whilst feeling no urges to start indulging again must demonstrate that it didn't mean as much to me as I thought it did. I scored points for kittens and Buffy (the show, not the character). Dave... -- http://www.dave.org.uk Let me see you make decisions, without your television - Depeche Mode (Stripped)
RE: London.pm Aptitude Test
On Thu, 27 Feb 2003, Chris Devers wrote: Ducks!!! Do you like ducks? Funny, I don't remember that one ever coming up before... In a pancake with spring onions, cucumber and hoi sin sauce. Yum! Jason -- UKFSN.ORG Finance Free Software while you surf the 'net http://www.ukfsn.org/ Get the T-Shirt Now
RE: London.pm Aptitude Test
On Thu, 27 Feb 2003, David Wright wrote: Ducks are edible and rather delicious. Therefore infinitely preferable to kittens, which are a bit scrawny. I suspect kitten may have about as much edible meat as duck. I regularly cook duck and it's bloody hard to get them with a decent amount of eating meat on them. I'm thinking of complaining to the local council about the ones in the local pond ;) Jason Clifford -- UKFSN.ORG Finance Free Software while you surf the 'net http://www.ukfsn.org/ Get the T-Shirt Now
Re: London.pm Aptitude Test
On Thu, Feb 27, 2003 at 03:57:14PM +, David Wright wrote: delurk_cos_bit_drunk Ducks are edible and rather delicious. Therefore infinitely preferable to kittens, which are a bit scrawny. I'd say that neither was particularly delicious, but I'm a veggie. /delurk_cos_bit_drunk Spoilsport. MBM -- Lusercop.net - LARTing Lusers everywhere since 2002
Re: London.pm Aptitude Test
On 27 Feb 2003 at 15:58, David Cantrell wrote: Do you prefer Willow? Good one. Cheers, Philip -- Philip Newton [EMAIL PROTECTED]
Re: London.pm Aptitude Test
On Thu, 27 Feb 2003, David Cantrell wrote: On Thu, Feb 27, 2003 at 04:27:59PM +0100, Philip Newton wrote: On 27 Feb 2003 at 14:25, CyberTiger wrote: Do you like pie ? Do you like kittens ? Do you like Buffy ? Do you like beer ? I'm sure I missed a few things, feel free to add some more :) Do you like ponys? Do you prefer Willow? I suppose, but Howard the Duck was in hindsight more memorable... -- Chris Devers[EMAIL PROTECTED]
Re: Perl jobs in London?
On Tue, Feb 25, 2003 at 10:35:38AM +, Nigel Hamilton wrote: Unfortunately some agents do a naive acronym match, between job spec and your CV. Because they often can't discriminate between the important acronyms and the less important ... they often wait until they find a CV that is fully 'acronym compliant.' Which is also, scarily, how their CV databases do information retrieval - and unfortunately the acronym count helps the order in which CVs are displayed. I hope that their CV databases weed out CV's that contain acronym 'payloads' hidden in whitespace, headers and footers. For example, snip Don't laugh. One agency told me my CV wasn't acecptable, and that I needed to send it back with more buzzwords in it. The agent then listed off a long list of them as examples to be spread throughout. -Toby -- Turning and turning in the widening gyre The falcon cannot hear the falconer; Things fall apart, the centre cannot hold; Mere anarchy is loosed upon the world.
Re: Perl jobs in London?
On Tue, Feb 25, 2003 at 10:33:25AM +, Ian Brayshaw wrote: On Tue, 2003-02-25 at 10:14, Simon Wistow wrote: I think that's your problem right there. 50 agencies is too many I think it's been discussed before that it's better just to find one or two good agents and stick with them. Agreed. But when you need a job you apply for all the jobs you can find. Those 50 agencies represent over 50 jobs that I feel I have the skills for and would like to do. It's more a measure of how flooded the market is with applications when most recruiters don't read most CVs that come through to them. My experience of about 5 months of hunting for C/C++/UNIX/Perl jobs is that job agencies are useless. I've had several interviews in the past few months, but every one of them has come thru an alternative channel.. Either a friend, or a technical-group-mailing-list (such as this one). All job agencies have done is waste my time and my (phone bill) money. I've found that some agents are definately more clueful than others.. I think it helps to try and identify yourself in some way to them, so that *if* a job comes thru that you fit, that they will actually think of you and call you. I get the feeling that random people calling up about jobs just get transfered into a limbo part of their brain. When I have had job interviews, I've found that the interviewers have thought highly of me.. but there's just a lot of other good people out there, and some are both better and cheaper than me. I'm still looking for work currently, but luckily I am semi-employed at the moment, finally. Still, it's a temporary IT position, and if you extrapolate the wage out to a yearly amount, it's about £15k/annum before tax. But one takes what one can get, and one is happy for it. Toby -- Turning and turning in the widening gyre The falcon cannot hear the falconer; Things fall apart, the centre cannot hold; Mere anarchy is loosed upon the world.
Re: Perl jobs in London?
On Thu, Feb 27, 2003 at 01:52:19PM -0800, Toby|Wintrmute wrote: On Tue, Feb 25, 2003 at 10:33:25AM +, Ian Brayshaw wrote: On Tue, 2003-02-25 at 10:14, Simon Wistow wrote: I think that's your problem right there. 50 agencies is too many I think it's been discussed before that it's better just to find one or two good agents and stick with them. Agreed. But when you need a job you apply for all the jobs you can find for some reason, this email came back to me containing none of my reply.. wierd. I'll repost below: My experience of about 5 months of hunting for C/C++/UNIX/Perl jobs is that job agencies are useless. I've had several interviews in the past few months, but every one of them has come thru an alternative channel.. Either a friend, or a technical-group-mailing-list (such as this one). All job agencies have done is waste my time and my (phone bill) money. I've found that some agents are definately more clueful than others.. I think it helps to try and identify yourself in some way to them, so that *if* a job comes thru that you fit, that they will actually think of you and call you. I get the feeling that random people calling up about jobs just get transfered into a limbo part of their brain. When I have had job interviews, I've found that the interviewers have thought highly of me.. but there's just a lot of other good people out there, and some are both better and cheaper than me. I'm still looking for work currently, but luckily I am semi-employed at the moment, finally. Still, it's a temporary IT position, and if you extrapolate the wage out to a yearly amount, it's about £15k/annum before tax. But one takes what one can get, and one is happy for it. -Toby -- Turning and turning in the widening gyre The falcon cannot hear the falconer; Things fall apart, the centre cannot hold; Mere anarchy is loosed upon the world.
alternative work
Just chatting to a friend, turns out both he and his partner have changed their profession. One was an Oracle DBA, and his lovely partner was an NT sysadmin. He was still employed, but position looking shaky, and she had already lost her job a while ago. He is now working as a carpenter, and she is a property manager. Apparently there's a lot of work for a good carpenter, you get flexible hours, your own business, and good pay. So, add that to the anecdotal statistics of IT people moving into other trades.. tjc -- Turning and turning in the widening gyre The falcon cannot hear the falconer; Things fall apart, the centre cannot hold; Mere anarchy is loosed upon the world.
Re: alternative work
On Thu, 27 Feb 2003, Toby|Wintrmute wrote: He is now working as a carpenter, and she is a property manager. Apparently there's a lot of work for a good carpenter, you get flexible hours, your own business, and good pay. there is a lot of well paid work for skilled people within the building industry. chippies earn a lot of money but sparkies earn about the same but don't have to get as dirty. plumbers arn't badly paid aswell. there is in fact a shortage of skilled people in the building industry. especially given the push to build more homes in the south-east or so I'm led to believe. although coming from a long line of builders ( I even have the crack to prove it) I'm certainly happier in the IT industry. building is to much like manual labour, unless you are a sparky. -- Bob Walker http://www.randomness.org.uk/ Help! Mutated Tigers from the Antartic are invading Outer Mongolia. Send the Mashed Bunnies of Perpignan to defeat them.
Wierd file problem (perl)
I have a script that allows a user to upload images to the filesystem as part of
the backend to a CGI shopping cart system has been working fine. I then added
another section allowing the user to upload images for a different part of the
site but this doesn't work. The code used to process the uploads is the same
[0] for both upload sections and continues to work for the first upload function.
This is the code that processes the uploads for the two image upload sections:
-
my $buffer= ;
my $buffer_size = 16384;
#print Content-type: text/plain\n\n;
open (OUTPUT, $filename) or die Could not open file $filename for writing: $!;
while (read($file, $buffer, $buffer_size)) {
print OUTPUT $buffer;
}
close OUTPUT or die Could not close file $filename : $!;
#exit;
-
$filename is a correct filename and $file is the filehandle returned from CGI.pm
which parses the form input. All the ownerships and permissions on the
directories that are being uploaded to are the same and I am trying to upload
the same files.
I have noticed that if I include the two commented lines in the above script
(the print.. and exit lines, uncommented of course) then it does successfully
write the correct file. If they are commented out then the file is not written
and no errors are trapped by die.
Any ideas what is goin on here? I assume that there is a problem somewhere else
in the script, but the two sections calling this subroutine seem to be pretty
much the same. What should I be looking for, and why does it only work with
those two lines uncommented for one upload section, but works always for the
other one?
Many thanks
Will
[0] actually the same code, in a subroutine.
Re: Domain reseller survey
We use Tucows OpenSRS at my company, The Cyber Design Factory (http://www.cyberdesignfactory.com). The test is quite easy to pass and the service is pretty good I would say. It's good that you can do a wide range of domains through the same API, including *.uk, though it probably is cheaper to go directly through Nominet for those. Rob. On Sat, Feb 22, 2003 at 11:05:31PM +, Paul Makepeace wrote: Is anyone else reselling domain names? (Or even ICANN accredited?!) I recently become a value added service provider for BulkRegister and am poking about with their API. (You can either contact them via HTTPS POSTs or send XML at a socket. It's nice if only to check domain availability, and have a programmatic way to change nameservers en masse.) Who else provides these kinds of services? In particular BR don't offer *.uk registrations. Paul
Re: London.pm Aptitude Test
On Thu, 27 Feb 2003, CyberTiger wrote: Do you like pie ? Yes. Do you like kittens ? With orange sauce. Do you like Buffy ? I like Willow more but yes she'll do. Do you like beer ? Is that a question? I'm sure I missed a few things, feel free to add some more :) Do you use perl? Jason -- UKFSN.ORG Finance Free Software while you surf the 'net http://www.ukfsn.org/ Get the T-Shirt Now
Wierd file problem (perl)
Ignore the post from this address (hellacool.co.uk), I have sent it from the correct email address this time. Sorry for any inconvenience. Bloody mozilla mail. Will
Microptomisation games
I did quite a bit of microopomisation during early work on the PPI module.
sub foo {
my ($this, $that, $theother) = @_;
print $this, $that, $theother;
}
is slower than
sub foo {
my $this = shift;
my $that = shift;
my $theother = shift;
print $this, $that, $theother;
}
is slower than
sub foo {
print $_[0], $_[1], $_[2];
}
I use the second form these days in most of my coding.
The real question is when does it become significant.
In my experience the sort of optomisation you see above become valuable
at about 100,000 - 1,000,000 function invocations.
Any function that get's called a million times deserves to be either
micro-optomised, or even better inlined. ( inlining saves more than any
of the above steps ).
I managed to double the speed of PPI by doing that sort of
micro-optimisation.
If a function is getting executed less than 100,000 times, the point
becomes largely moot and becomes a style choice.
Adam
