Re: Perl object memory overhead

in reply to Perl object memory overhead

If you have 3 million hashes, then you need to be able to refer to them, so, you've probably got them, or rather, references to them, stored in an Array (an @AoH):

@AoH = map{ a=>1, b=>2, c=>3 }, 1 .. 3e6;;
say total_size( \@AoH );;
936000209
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To turn a hashref into an object, you need to bless it. The effect on memory is:

bless $_, 'OO' for @AoH;;
say total_size( \@AoH );;
936000209
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Zilch!

However, then you need to manipulate the contents of those 'objects'.

Manipulate those 3e6 objects via the inconvenience of object notation and accessors:

sub OO::a{ $_[0]->{a}=$_[1] if defined $_[1]; $_[0]->{a} };;
$t = time; 
$_->a( $_->a() +1 ) for @AoH; 
say time - $t;;;
4.60931897163391
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Now perform that same manipulation on those very same "objects" the easy way:

$t = time; 
++$_->{a} for @AoH; 
say time() - $t;;
0.931627988815308
[download]

Of course, that wasn't 'proper OO' above because my methods manipulated the object properties directly, so let's fix that:

sub OO::get_a{ $_[0]->{a} }; sub OO::set_a{ $_[0]->{a} = $_[1] };;
sub OO::get_b{ $_[0]->{b} }; sub OO::set_b{ $_[0]->{b} = $_[1] };;
sub OO::get_c{ $_[0]->{c} }; sub OO::set_c{ $_[0]->{c} = $_[1] };;
sub OO::adjust_a{ $_[0]->set_a( $_[0]->get_a() + 1 ) };;

$t = time; 
$_->adjust_a() for @AoH; 
say time() - $t;;
4.95501685142517
[download]

But you're still not 'doing it properly' because you didn't name your arguments:

sub OO::get_a{ my( $o ) = @_; $o->{a} }; sub OO::set_a{ my( $o, $v ) =
+ @_; $o->{a} = $v };;
sub OO::get_b{ my( $o ) = @_; $o->{b} }; sub OO::set_b{ my( $o, $v ) =
+ @_; $o->{b} = $v };;
sub OO::get_c{ my( $o ) = @_; $o->{c} }; sub OO::set_c{ my( $o, $v ) =
+ @_; $o->{c} = $v };;
sub OO::adjust_a{ my( $o ) = @_; $o->set_a( $o->get_a() + 1 ) };;

$t = time; 
$_->adjust_a() for @AoH; 
say time() - $t;;
6.20793199539185
[download]

Still wrong! I didn't check my arguments:

sub OO::get_a{ my( $o ) = @_; die unless ref( $o ) eq 'OO'; $o->{a} };
+ 
sub OO::set_a{ my( $o, $v ) = @_; die unless ref( $o ) eq 'OO'; die un
+less looks_like_number( $v ); $o->{a} = $v };;
sub OO::get_b{ my( $o ) = @_; die unless ref( $o ) eq 'OO'; $o->{b} };
+ 
sub OO::set_b{ my( $o, $v ) = @_; die unless ref( $o ) eq 'OO'; die un
+less looks_like_number( $v ); $o->{b} = $v };;
sub OO::get_c{ my( $o ) = @_; die unless ref( $o ) eq 'OO'; $o->{c} };
+ 
sub OO::set_c{ my( $o, $v ) = @_; die unless ref( $o ) eq 'OO'; die un
+less looks_like_number( $v ); $o->{c} = $v };;

$t = time; 
$_->adjust_a() for @AoH; 
say time() - $t;;
8.23622608184814
[download]

Of course, writing all those setters and getters manually is just so 'Legacy Perl'; there are packages that'll do that for me:

use Moose;

...
[download]

Best we don't look. The price of modern convenience!

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: Perl object memory overhead Select or Download Code

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Re^2: Perl object memory overhead by tobyink (Canon) on Mar 31, 2014 at 11:44 UTC
Indeed; writing all those getters and setters manually is inconvenient. Read more... (2 kB) `Rate OO MOOSE OO 3.47/s -- -47% MOOSE 6.56/s 89% --` [download] `use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name`	[reply] [d/l] [select]
Re^3: Perl object memory overhead (Benchmark special case?) by BrowserUk (Patriarch) on Mar 31, 2014 at 13:44 UTC
Ooh! Do I spy a benchmark special case like the ones that compiler makers used to add to get good scores? :) `isa => 'Int', traits => ['Counter'], handles => { adjust_a => 'inc' },` [download] What if you changed the increment to +33? Also, it would be really useful to see the timing of adjust_a() run on the 3e6 objects, along with memory consumption? 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.	[reply] [d/l]
Re^4: Perl object memory overhead (Benchmark special case?) by tobyink (Canon) on Mar 31, 2014 at 16:54 UTC
There's this: `handles => { adjust_a => [ 'inc', 33 ] },` [download] It's not as fast because the arrayref in `handles` results in a curried coderef, but not unacceptably slow either. `use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name`	[reply] [d/l] [select]

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