Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation
 
PerlMonks  

Re^5: Daily Counters

by BrowserUk (Pope)
on May 06, 2013 at 22:05 UTC ( #1032408=note: print w/ replies, xml ) Need Help??


in reply to Re^4: Daily Counters
in thread Daily Counters

Depends upon your filing system, but 2 x 2-digits means a max of 100 in the lower levels and 10,000 in the top. 2 x 3-digit, gives 1000 in teh lower levels and 100 in the top. Every filesystem I am aware of will handle those numbers with ease.

The latter probably works better for performance, but you'd have to do a few tests to be sure.

On my system it is much of a muchness at around 3 milliseconds per lookup/increment either way:

#! perl -slw use strict; use Time::HiRes qw[ time ]; mkdir 'myroot'; for my $l1 ( '00' .. '09' ) { mkdir "myroot/$l1"; for my $l2 ( '00' .. '09' ) { mkdir "myroot/$l1/$l2"; mkdir "myroot/$l1/$l2/$l1$l2$_" for '000' .. '999'; mkdir "myroot/$l1/$l2/$l1$l2$_/1" for '000' .. '999'; } } my $start = time; for( 1 .. 1000 ) { my $id = sprintf "%02u%02u%03u", int( rand 10 ), int( rand 10 ), in +t( rand 1000 ); my( $l1, $l2 ) = unpack 'a2a2', $id; opendir D, "myroot/$l1/$l2/$id/"; readdir D; readdir D; ## get rid of '.' & '..' my $count = readdir D; rename "myroot/$l1/$l2/$id/" . $count, "myroot/$l1/$l2/$id/" . ++$c +ount or warn "$! : $id : $count"; closedir D; } printf "2x2x7 took %f secs/lookup&increment\n", ( time() - $start ) / +1000; system "rd /q /s myroot"; mkdir 'myroot'; for my $l1 ( '000' .. '009' ) { mkdir "myroot/$l1"; for my $l2 ( '000' .. '009' ) { mkdir "myroot/$l1/$l2"; mkdir "myroot/$l1/$l2/$l1$l2$_" for '0' .. '9'; mkdir "myroot/$l1/$l2/$l1$l2$_/1" for '0' .. '9'; } } $start = time; for( 1 .. 1000 ) { my $id = sprintf "%03u%03u%01u", int( rand 10 ), int( rand 10 ), in +t( rand 10 ); my( $l1, $l2 ) = unpack 'a3a3', $id; opendir D, "myroot/$l1/$l2/$id/" or warn "$! : myroot/$l1/$l2/$id/" +; readdir D; readdir D; ## get rid of '.' & '..' my $count = readdir D; rename "myroot/$l1/$l2/$id/" . $count, "myroot/$l1/$l2/$id/" . ++$c +ount or warn "$! : $id : $count"; closedir D; } printf "3x3x7 took %f secs/lookup&increment\n", ( time() - $start ) / +1000; system "rd /q /s myroot"; __END__ C:\test>1032393 2x2x7 took 0.002671 secs/lookup&increment 3x3x7 took 0.002761 secs/lookup&increment C:\test>1032393 2x2x7 took 0.002628 secs/lookup&increment 3x3x7 took 0.003111 secs/lookup&increment

BTW: Please note the additional readdir D; readdir D; ## get rid of '.' & '..' which I forgot above.


With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
.


Comment on Re^5: Daily Counters
Select or Download Code

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1032408]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others chilling in the Monastery: (13)
As of 2014-10-01 17:34 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    What is your favourite meta-syntactic variable name?














    Results (31 votes), past polls