# NAME Hash::Compact - A hash-based object implementation with key alias and default value support # SYNOPSIS package My::Memcached; use strict; use warnings; use parent qw(Cache::Memcached::Fast); use JSON; use Hash::Compact; my $OPTIONS = { foo => { alias_for => 'f', }, bar => { alias_for => 'b', default => 'bar', }, }; sub get { my ($self, $key) = @_; my $value = $self->SUPER::get($key); Hash::Compact->new(decode_json $value, $OPTIONS); } sub set { my ($self, $key, $value, $expire) = @_; my $hash = Hash::Compact->new($value, $OPTIONS); $self->SUPER::set($key, encode_json $hash->to_hash, $expire); } package main; use strict; use warnings; use Test::More; my $key = 'key'; my $value = { foo => 'foo' }; my $memd = My::Memcached->new({servers => [qw(localhost:11211)]}); $memd->set($key, $value); my $cached_value = $memd->get($key); is $cached_value->param('foo'), 'foo'; is $cached_value->param('bar'), 'bar'; is_deeply $cached_value->to_hash, +{ f => 'foo' }; $cached_value->param(bar => 'baz'); $memd->set($key, $cached_value->to_hash); $cached_value = $memd->get($key); is $cached_value->param('foo'), 'foo'; is $cached_value->param('bar'), 'baz'; is_deeply $cached_value->to_hash, +{ f => 'foo', b => 'baz' }; done_testing; # DESCRIPTION When we store some structured value into a column of a relational database or some key/value storage, redundancy of long key names can be a problem for storage space. This module is yet another hash-based object implementation which aims to be aware of both space efficiency and easiness to use for us. # METHODS ## new (I<\%hash> I<[, \%options]>) my $hash = Hash::Compact->new({ foo => 'foo', }, { foo => { alias_for => 'f', }, bar => { alias_for => 'b', default => 'bar', }, }, ); Creates and returns a new Hash::Compact object. If `\%options` not passed, Hash::Compact object `$hash` will be just a plain hash-based object. `\%options` is a hash-ref which key/value pairs are associated with ones of `\%hash`. It may contain the fields below: - * alias_for Alias to an actual key. If it's passed, `\%hash` will be compacted into another hash which has aliased key. The original key of `\%hash` will be just an alias to an actual key. - * default If this exists and the value associated with the key of `\%hash` is undefined, Hash::Compact object `$hash` returns just the value. It's for space efficiency; `$hash` doesn't need to have key/value pair when the value isn't defined or it's same as default value. ## param (I<$key> I<[, $value]>) $hash->param('foo'); #=> 'foo' $hash->param('bar'); #=> 'bar' (returns the default value) $hash->param(bar => 'baz'); $hash->param('bar'); #=> 'baz' Setter/getter method. ## to_hash () my $compact_hash_ref = $hash->to_hash; #=> { f => 'foo', b => 'baz' } (returns a compacted hash) Returns a compacted hash according to `\%options` passed into the constructor above; # AUTHOR Kentaro Kuribayashi # SEE ALSO # LICENSE Copyright (C) Kentaro Kuribayashi This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.