Bio::EnsEMBL::DBSQL::Support::LruIdCache Class Reference

Inheritance diagram for Bio::EnsEMBL::DBSQL::Support::LruIdCache:

Public Member Functions
public Bio::EnsEMBL::DBSQL::Support::BaseCache	new ()
public Int	lru_size ()
public Bio::EnsEMBL::Utils::Cache	build_cache ()
public Scalar	get ()
public ArrayRef	get_by_list ()
Public Member Functions inherited from Bio::EnsEMBL::DBSQL::Support::BaseCache
public Bio::EnsEMBL::DBSQL::Support::BaseCache	new ()
public Bio::EnsEMBL::DBSQL::BaseAdaptor	adaptor ()
public Hash	cache ()
public void	delete_cache ()
public Scalar	get ()
public ArrayRef	get_by_list ()
public ArrayRef	get_by_sql ()
public Scalar	put ()
public Scalar	remove ()
public void	clear_cache ()
public List	cache_keys ()
public List	cached_values ()
public Int	size ()
public Hash	build_cache ()

Detailed Description

Synopsis

my $cache = Bio::EnsEMBL::DBSQL::Support::LruIdCache->new($adaptor, 2);
my $obj = $cache->put(1, 'a');
my $obj = $cache->put(2, 'b');
my $obj = $cache->put(3, 'c');
 
is_deeply([$cache->cache_keys()], ['b','c']); #ID 1 was ejected under LRU rules

Description

An implementation of caching which uses the oldest accessed key as the 
value to be ejected from the cache when the maximum size has been hit. See
the following page for more information about this algorithm

http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used

Definition at line 27 of file LruIdCache.pm.

Member Function Documentation

build_cache()

public Bio::EnsEMBL::Utils::Cache Bio::EnsEMBL::DBSQL::Support::LruIdCache::build_cache

(

)

  Description: Returns an instance of Bio::EnsEMBL::Utils::Cache and sized
               according to the return value in lru_cache()
  Returntype : Bio::EnsEMBL::Utils::Cache
  Exceptions : none
  Caller     : BaseAdaptors
  Status     : Beta

Code:

get()

public Scalar Bio::EnsEMBL::DBSQL::Support::LruIdCache::get

(

)

  Arg [1]    : String key to retrieve
  Example    :

$is($cache->get(1), 'a');

  Description: Retrieves the value held in the cache. If the value is not in
               the cache we will retrieve the value from 
               _uncached_fetch_by_dbID and then store that value
  Returntype : Scalar value held in the cache or nothing if the ID was not present
  Exceptions : If key was undefined
  Caller     : BaseAdaptors
  Status     : Beta

Code:

get_by_list()

public ArrayRef Bio::EnsEMBL::DBSQL::Support::LruIdCache::get_by_list

(

)

  Arg [1]    : ArrayRef keys to retrieve
  Arg [2]    : Bio::EnsEMBL::Slice optional attribute for 
               _uncached_fetch_all_by_dbID_list() delegation
  Example    :

is($cache->get_by_list([1,2]), ['a','b']);

  Description: Attempts to retrieve all values currently available in the cache,
               fetches any remaining values and stores these in the cache.
  Returntype : ArrayRef of found values
  Exceptions : None
  Caller     : BaseAdaptors
  Status     : Beta

Code:

lru_size()

public Int Bio::EnsEMBL::DBSQL::Support::LruIdCache::lru_size

(

)

  Arg [1]    : Int size of the cache
  Example    :

$cache->lru_size(10);

  Description: Resets the size of the cache and forces a rebuild of the cache 
               object to apply this new sizing. Also functions as a getter
  Returntype : Int
  Exceptions : none
  Caller     : BaseAdaptors
  Status     : Beta

Code:

new()

public Bio::EnsEMBL::DBSQL::Support::BaseCache Bio::EnsEMBL::DBSQL::Support::LruIdCache::new

(

)

  Arg [1]    : Bio::EnsEMBL::DBSQL::BaseAdaptor $db_adaptor
  Arg [2]    : Int size of the cache. Defaults to 1000
  Example    :

my $cache = Bio::EnsEMBL::DBSQL::Support::LruIdCache->new($db_adaptor, 10);

  Description: Creates a new cache class instance
  Returntype : Bio::EnsEMBL::DBSQL::Support::BaseCache
  Exceptions : none
  Caller     : BaseAdaptors
  Status     : Beta

Code:

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The documentation for this class was generated from the following file:

• ensembl/modules/Bio/EnsEMBL/DBSQL/Support/LruIdCache.pm