Data::Lock - makes variables (im)?mutable
use Data::Lock qw/dlock dunlock/;
dlock my $sv = $initial_value;
dlock my $ar = [@values];
dlock my $hr = { key => value, key => value, ... };
dunlock $sv;
dunlock $ar; dunlock \@av;
dunlock $hr; dunlock \%hv;
dlock makes the specified variable immutable like Readonly.
Unlike Readonly which implements immutability via tie, dlock
makes use of the internal flag of perl SV so it imposes almost no
penalty.
Like Readonly, dlock locks not only the variable itself but also
elements therein.
As of verion 0.03, you can dlock objects as well. Below is an
example constructor that returns an immutable object:
sub new {
my $pkg = shift;
my $self = { @_ };
bless $self, $pkg;
dlock($self);
$self;
}
Or consider using Moose.
Like List::Util and Scalar::Util, functions are exported only
explicitly. This module comes with dlock and dunlock.
use Data::Lock; # nothing imported;
use Data::Lock qw/dlock dunlock/; # imports dlock() and dunlock()
dlock($scalar);
Locks $scalar and if $scalar is a reference, recursively locks referents.
Does the opposite of dlock.
Here I have benchmarked like this.
1. Create an immutable variable.
2. try to change it and see if it raises exception
3. make sure the value stored remains unchanged.
See t/benchmark.pl for details.
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Simple scalar
Rate Readonly Attribute glob dlock Readonly 11987/s -- -98% -98% -98% Attribute 484562/s 3943% -- -1% -4% glob 487239/s 3965% 1% -- -3% dlock 504247/s 4107% 4% 3% -- -
Array with 1000 entries
Rate Readonly dlock Attribute Readonly 12396/s -- -97% -97% dlock 444703/s 3488% -- -6% Attribute 475557/s 3736% 7% -- -
Hash with 1000 key/value pairs
Rate Readonly dlock Attribute Readonly 10855/s -- -97% -97% dlock 358867/s 3206% -- -5% Attribute 377087/s 3374% 5% --
Dan Kogai, <dankogai at cpan.org>
Please report any bugs or feature requests to bug-data-lock at rt.cpan.org, or through the web interface at
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Data-Lock. I will
be notified, and then you'll automatically be notified of progress on
your bug as I make changes.
You can find documentation for this module with the perldoc command.
perldoc Data::Lock
You can also look for information at:
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RT: CPAN's request tracker
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AnnoCPAN: Annotated CPAN documentation
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CPAN Ratings
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Copyright 2008-2020 Dan Kogai, all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.