NAME
Cache::Cache -- the Cache interface.
DESCRIPTION
The Cache interface is implemented by classes that support the get, set, remove, size, purge, and clear instance methods and their corresponding static methods for persisting data across method calls.
SYNOPSIS
To implement the Cache::Cache interface:
package Cache::MyCache;
use Cache::Cache;
use vars qw( @ISA );
@ISA = qw( Cache::Cache );
sub get
{
my ( $self, $identifier ) = @_;
# implement the get method here
}
sub set
{
my ( $self, $identifier, $data, $expires_in ) = @_;
# implement the set method here
}
# implement the other interface methods hereTo use a Cache implementation, such as Cache::MemoryCache:
use Cache::Cache qw( $EXPIRES_NEVER $EXPIRES_NOW );
use Cache::MemoryCache;
my $options_hash_ref = { 'default_expires_in' => '10 seconds' };
my $cache = new Cache::MemoryCache( $options_hash_ref );
my $expires_in = '10 minutes';
$cache->set( 'Key', 'Value', $expires_in );
# if the next line is called within 10 minutes, then this
# will return the cache value
my $value = $cache->get( 'Key' );CONSTANTS
- $SUCCESS
-
Typically returned from a subroutine, this value is synonymous with 1 and can be used as the typical perl "boolean" for true
- $FAILURE
-
Typically returned from a subroutine, this value is synonymous with 0 and can be used as the typical perl "boolean" for false
- $EXPIRES_NEVER
-
The item being set in the cache will never expire.
- $EXPIRES_NOW
-
The item being set in the cache will expire immediately.
- $EXPIRES_NEVER
-
The item being set in the cache will never expire.
METHODS
- Clear( )
-
Remove all objects from all caches of this type.
- Returns
-
Either $SUCCESS or $FAILURE.
- Purge( )
-
Remove all objects that have expired from all caches of this type.
- Returns
-
Either $SUCCESS or $FAILURE.
- Size( $optional_namespace )
-
Calculate the total size of all objects in all caches of this type.
- Returns
-
The total size of all the objects in all caches of this type.
- new( $options_hash_ref )
-
Construct a new instance of a Cache::Cache
- clear( )
-
Remove all objects from the namespace associated with this cache instance.
- Returns
-
Either $SUCCESS or $FAILURE.
- get( $identifier )
-
Fetch the data specified.
- get_object( $identifier )
-
Fetch the underlying Cache::Object object that is used to store the cached data. This will not trigger a removal of the cached object even if the object has expired.
- set_object( $identifier, $object )
-
Stores the underlying Cache::Object object that is to be cached. Using set_object (as opposed to set) does not trigger an automatic purge.
- purge( )
-
Remove all objects that have expired from the namespace associated with this cache instance.
- Returns
-
Either $SUCCESS or $FAILURE.
- remove( $identifier )
-
Delete the data associated with the $identifier from the cache.
- set( $identifier, $data, $expires_in )
-
Store an item in the cache
- $identifier
-
A string uniquely identifying the data.
- $data
-
A scalar or reference to the object to be stored.
- $expires_in
-
Either the time in seconds until this data should be erased, or the constant $EXPIRES_NOW, or the constant $EXPIRES_NEVER. Defaults to $EXPIRES_NEVER. This variable can also be in the extended format of "[number] [unit]", e.g., "10 minutes". The valid units are s, second, seconds, sec, m, minute, minutes, min, h, hour, hours, w, week, weeks, M, month, months, y, year, and years. Additionally, $EXPIRES_NOW can be represented as "now" and $EXPIRES_NEVER can be represented as "never".
- Returns
-
Either $SUCCESS or $FAILURE.
- size( )
-
Calculate the total size of all objects in the namespace associated with this cache instance.
- Returns
-
The total size of all objects in the namespace associated with this cache instance.
OPTIONS
The options are set by passing in a reference to a hash containing any of the following keys:
- namespace
-
The namespace associated with this cache. Defaults to "Default" if not explicitly set.
- default_expires_in
-
The default expiration time for objects place in the cache. Defaults to $EXPIRES_NEVER if not explicitly set.
- auto_purge_interval
-
Sets the auto purge interval. If this option is set to a particular time ( in the same format as the expires_in ), then the purge( ) routine will be called during the first set after the interval expires. The interval will then be reset.
- auto_purge_on_set
-
If this option is true, then the auto purge interval routine will be checked on every set.
- auto_purge_on_get
-
If this option is true, then the auto purge interval routine will be checked on every get.
PROPERTIES
- (get|set)_namespace( )
-
The namespace of this cache instance
- get_default_expires_in( )
-
The default expiration time for objects placed in this cache instance
- get_identifiers( )
-
The list of identifiers specifying objects in the namespace associated with this cache instance
- (get|set)_auto_purge_interval( )
-
Accesses the auto purge interval. If this option is set to a particular time ( in the same format as the expires_in ), then the purge( ) routine will be called during the first get after the interval expires. The interval will then be reset.
- (get|set)_auto_purge_on_set( )
-
If this property is true, then the auto purge interval routine will be checked on every set.
- (get|set)_auto_purge_on_get( )
-
If this property is true, then the auto purge interval routine will be checked on every get.
SEE ALSO
Cache::Object, Cache::MemoryCache, Cache::FileCache, Cache::SharedMemoryCache, and Cache::SizeAwareFileCache
AUTHOR
Original author: DeWitt Clinton <dewitt@unto.net>
Last author: $Author: dclinton $
Copyright (C) 2001 DeWitt Clinton