Re^4: In-place sort with order assignment

On your computer?

No!

#! perl -slw
use strict;

our $N //= 10e6;

my %hash;
my $val = 'AAAAA';

undef $hash{ $val++ } for 1 .. $N;

my $start = time;

open SORT, '| sort > sorted' or die $!;
print SORT $_ while $_ = each %hash;
close SORT;

undef %hash;

open IN, '<', 'sorted' or die $!;
chomp(), $hash{ $_ } = $. while <IN>;
close IN;

my $elapsed = time - $start;

printf "Took %.6f seconds for $N items (%.5f per second)\n",
    $elapsed, $elapsed / $N;


__END__
C:\test>junk41 -N=10e6
Took 225.000000 seconds for 10e6 items (0.00002 per second)
[download]

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Comment on Re^4: In-place sort with order assignment Download Code

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Re^5: In-place sort with order assignment by rowdog (Curate) on Sep 20, 2010 at 22:37 UTC
Not that this seems to help you very much but sort was my first instinct too. My rather dated Debian Squeeze box is an AMD 3800+ (64 bit dual core) with 2 gigs RAM and one 5 year old IDE drive can almost do it. `$ perl 860849.pl Took 131.000000 seconds for 10000000 items (0.00001 per second)` [download] I think I could reach that 108 by putting the sorted file on a separate spindle with a thinner filesystem layer (e.g. no ext3 and LVM2). I'm really pointing this out because it's quite attainable with a reasonably recent hard drive. Maybe even just SATA/PATA would do the trick. SSD surely would.	[reply] [d/l]
Re^6: In-place sort with order assignment by BrowserUk (Patriarch) on Sep 21, 2010 at 00:15 UTC
My next intended purchase is a cheap (sub Ł50), small capacity (32 or 64GB) SSD. {This is the closest Ive seen so far.) An external sort would definitely become a viable option if I could use that for the temporary files.	[reply]


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