/ 
Util-Medley-0.061
River stage one • 4 direct dependents • 4 total dependents
/ Util::Medley::Cache

NAME

Util::Medley::Cache - Simple caching mechanism.

VERSION

version 0.060

SYNOPSIS

my $cache = Util::Medley::Cache->new; # see ATTRIBUTES for options 

#
# positional
#
$cache->set('unittest', 'test1', {foo => bar});
my $data = $cache->get('test', 'unittest');
my @keys = $cache->getKeys('unittest');
$cache->delete('unittest', 'test1');
              
# 
# named pair 
#
$cache->set(ns   => 'unittest', 
            key  => 'test1', 
            data => { foo => 'bar' });

my $data = $cache->get(ns  => 'unittest', 
                       key => 'test1');

my @keys = $cache->getKeys(ns => 'unittest');

$cache->delete(ns  => 'unittest', 
              key => 'test1');

DESCRIPTION

This class provides a thin wrapper around CHI. The caching has 2 levels:

  • level 1 (memory)

  • level 2 (disk)

When fetching from the cache, level 1 (L1) is always checked first. If the requested object is not found, it searches the level 2 (L2) cache.

The cached data can be an object, reference, or string.

All methods confess on error.

ATTRIBUTES

rootDir (optional)

Location of the L2 file cache.

default

$HOME/.util-medley/cache

enabled (optional)

Toggles caching on or off.

default

1

expireSecs (optional)

Sets the cache expiration.

default

0 (never)

ns (optional)

Sets the cache namespace.

l1Enabled (optional)

Toggles the L1 cache on or off.

default

1

env var

To disable L1 cache, set MEDLEY_CACHE_L1_DISABLED=1.

l2Enabled (optional)

Toggles the L2 cache on or off.

default

1

env var

To disable L2 cache, set MEDLEY_CACHE_L2_DISABLED=1.

METHODS

clear

Clears all cache for a given namespace.

usage:
clear([$ns])

clear([ns => $ns])
args:
ns [Str]

The cache namespace.

delete

Deletes a cache object.

usage:
delete($key, [$ns])

delete(key => $key, [ns => $ns])
args:
key [Str]

Unique identifier of the cache object.

ns [Str]

The cache namespace.

destroy

Deletes L1 cache and removes L2 from disk completely.

usage:
destroy([$ns])
 
destroy([ns => $ns])
args:
ns [Str]

The cache namespace.

get

Gets a unique cache object. Returns undef if not found.

usage:
get($key, [$ns])

get(key => $key, [ns => $ns])
args:
key [Str]

Unique identifier of the cache object.

ns [Str]

The cache namespace.

getExpiresAt

Returns the expiration epoch for a given key.

usage:
getExpiresAt($key, [$ns])

getExpiresAt(key => $key, [ns => $ns])
args:
key [Str]

Unique identifier of the cache object.

ns [Str]

The cache namespace.

getKeys

Returns a list of cache keys.

usage:
getKeys([$ns])

getKeys([ns => $ns])
args:
ns [Str]

The cache namespace.

getNamespaceDir

Gets the L2 cache dir.

usage:
getNamespaceDir([$ns])

getNamespaceDir([ns => $ns])
args:
ns [Str]

The cache namespace.

getNamespaces

Gets a list of namespaces.

usage:
getNamespaces()

set

Commits the data object to the cache.

usage:
set($key, $data, [$ns], [$expire_epoch])

set(key => $key, 
    data => $data, 
    [ns => $ns], 
    [expire_epoch => $expire_epoch]
);
args:
key [Str]

Unique identifier of the cache object.

data [Object|Ref|Str]

An object, reference, or string.

ns [Str]

The cache namespace.

expire_epoch [Int]

The epoch to expire the cache item at. This overrides the expireSecs attribute.